Google Git
Sign in
nest-open-source / nest-learning-thermostat / 5.10 / linux-imx-4.1.15 / refs/heads/master / . / Documentation / DocBook / media / v4l / controls.xml
blob: 4e9462f1ab4cc04ea68fd9c89bccb7b2e11c01b8 [file] [log] [blame]
Nest DevInfra778ffd22018-07-20 17:16:31 -0700[diff] [blame]1 <section id="control">
2 <title>User Controls</title>
3
4 <para>Devices typically have a number of user-settable controls
5such as brightness, saturation and so on, which would be presented to
6the user on a graphical user interface. But, different devices
7will have different controls available, and furthermore, the range of
8possible values, and the default value will vary from device to
9device. The control ioctls provide the information and a mechanism to
10create a nice user interface for these controls that will work
11correctly with any device.</para>
12
13 <para>All controls are accessed using an ID value. V4L2 defines
14several IDs for specific purposes. Drivers can also implement their
15own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant>
16<footnote><para>The use of <constant>V4L2_CID_PRIVATE_BASE</constant>
17is problematic because different drivers may use the same
18<constant>V4L2_CID_PRIVATE_BASE</constant> ID for different controls.
19This makes it hard to programatically set such controls since the meaning
20of the control with that ID is driver dependent. In order to resolve this
21drivers use unique IDs and the <constant>V4L2_CID_PRIVATE_BASE</constant>
22IDs are mapped to those unique IDs by the kernel. Consider these
23<constant>V4L2_CID_PRIVATE_BASE</constant> IDs as aliases to the real
24IDs.</para>
25<para>Many applications today still use the <constant>V4L2_CID_PRIVATE_BASE</constant>
26IDs instead of using &VIDIOC-QUERYCTRL; with the <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>
27flag to enumerate all IDs, so support for <constant>V4L2_CID_PRIVATE_BASE</constant>
28is still around.</para></footnote>
29and higher values. The pre-defined control IDs have the prefix
30<constant>V4L2_CID_</constant>, and are listed in <xref
31linkend="control-id" />. The ID is used when querying the attributes of
32a control, and when getting or setting the current value.</para>
33
34 <para>Generally applications should present controls to the user
35without assumptions about their purpose. Each control comes with a
36name string the user is supposed to understand. When the purpose is
37non-intuitive the driver writer should provide a user manual, a user
38interface plug-in or a driver specific panel application. Predefined
39IDs were introduced to change a few controls programmatically, for
40example to mute a device during a channel switch.</para>
41
42 <para>Drivers may enumerate different controls after switching
43the current video input or output, tuner or modulator, or audio input
44or output. Different in the sense of other bounds, another default and
45current value, step size or other menu items. A control with a certain
46<emphasis>custom</emphasis> ID can also change name and
47type.</para>
48
49 <para>If a control is not applicable to the current configuration
50of the device (for example, it doesn't apply to the current video input)
51drivers set the <constant>V4L2_CTRL_FLAG_INACTIVE</constant> flag.</para>
52
53 <para>Control values are stored globally, they do not
54change when switching except to stay within the reported bounds. They
55also do not change &eg; when the device is opened or closed, when the
56tuner radio frequency is changed or generally never without
57application request.</para>
58
59 <para>V4L2 specifies an event mechanism to notify applications
60when controls change value (see &VIDIOC-SUBSCRIBE-EVENT;, event
61<constant>V4L2_EVENT_CTRL</constant>), panel applications might want to make
62use of that in order to always reflect the correct control value.</para>
63
64 <para>
65 All controls use machine endianness.
66 </para>
67
68 <table pgwide="1" frame="none" id="control-id">
69 <title>Control IDs</title>
70 <tgroup cols="3">
71 &cs-def;
72 <thead>
73 <row>
74 <entry>ID</entry>
75 <entry>Type</entry>
76 <entry>Description</entry>
77 </row>
78 </thead>
79 <tbody valign="top">
80 <row>
81 <entry><constant>V4L2_CID_BASE</constant></entry>
82 <entry></entry>
83 <entry>First predefined ID, equal to
84<constant>V4L2_CID_BRIGHTNESS</constant>.</entry>
85 </row>
86 <row>
87 <entry><constant>V4L2_CID_USER_BASE</constant></entry>
88 <entry></entry>
89 <entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry>
90 </row>
91 <row>
92 <entry><constant>V4L2_CID_BRIGHTNESS</constant></entry>
93 <entry>integer</entry>
94 <entry>Picture brightness, or more precisely, the black
95level.</entry>
96 </row>
97 <row>
98 <entry><constant>V4L2_CID_CONTRAST</constant></entry>
99 <entry>integer</entry>
100 <entry>Picture contrast or luma gain.</entry>
101 </row>
102 <row>
103 <entry><constant>V4L2_CID_SATURATION</constant></entry>
104 <entry>integer</entry>
105 <entry>Picture color saturation or chroma gain.</entry>
106 </row>
107 <row>
108 <entry><constant>V4L2_CID_HUE</constant></entry>
109 <entry>integer</entry>
110 <entry>Hue or color balance.</entry>
111 </row>
112 <row>
113 <entry><constant>V4L2_CID_AUDIO_VOLUME</constant></entry>
114 <entry>integer</entry>
115 <entry>Overall audio volume. Note some drivers also
116provide an OSS or ALSA mixer interface.</entry>
117 </row>
118 <row>
119 <entry><constant>V4L2_CID_AUDIO_BALANCE</constant></entry>
120 <entry>integer</entry>
121 <entry>Audio stereo balance. Minimum corresponds to all
122the way left, maximum to right.</entry>
123 </row>
124 <row>
125 <entry><constant>V4L2_CID_AUDIO_BASS</constant></entry>
126 <entry>integer</entry>
127 <entry>Audio bass adjustment.</entry>
128 </row>
129 <row>
130 <entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry>
131 <entry>integer</entry>
132 <entry>Audio treble adjustment.</entry>
133 </row>
134 <row>
135 <entry><constant>V4L2_CID_AUDIO_MUTE</constant></entry>
136 <entry>boolean</entry>
137 <entry>Mute audio, &ie; set the volume to zero, however
138without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like
139ALSA drivers, V4L2 drivers must mute at load time to avoid excessive
140noise. Actually the entire device should be reset to a low power
141consumption state.</entry>
142 </row>
143 <row>
144 <entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry>
145 <entry>boolean</entry>
146 <entry>Loudness mode (bass boost).</entry>
147 </row>
148 <row>
149 <entry><constant>V4L2_CID_BLACK_LEVEL</constant></entry>
150 <entry>integer</entry>
151 <entry>Another name for brightness (not a synonym of
152<constant>V4L2_CID_BRIGHTNESS</constant>). This control is deprecated
153and should not be used in new drivers and applications.</entry>
154 </row>
155 <row>
156 <entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry>
157 <entry>boolean</entry>
158 <entry>Automatic white balance (cameras).</entry>
159 </row>
160 <row>
161 <entry><constant>V4L2_CID_DO_WHITE_BALANCE</constant></entry>
162 <entry>button</entry>
163 <entry>This is an action control. When set (the value is
164ignored), the device will do a white balance and then hold the current
165setting. Contrast this with the boolean
166<constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when
167activated, keeps adjusting the white balance.</entry>
168 </row>
169 <row>
170 <entry><constant>V4L2_CID_RED_BALANCE</constant></entry>
171 <entry>integer</entry>
172 <entry>Red chroma balance.</entry>
173 </row>
174 <row>
175 <entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry>
176 <entry>integer</entry>
177 <entry>Blue chroma balance.</entry>
178 </row>
179 <row>
180 <entry><constant>V4L2_CID_GAMMA</constant></entry>
181 <entry>integer</entry>
182 <entry>Gamma adjust.</entry>
183 </row>
184 <row>
185 <entry><constant>V4L2_CID_WHITENESS</constant></entry>
186 <entry>integer</entry>
187 <entry>Whiteness for grey-scale devices. This is a synonym
188for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated
189and should not be used in new drivers and applications.</entry>
190 </row>
191 <row>
192 <entry><constant>V4L2_CID_EXPOSURE</constant></entry>
193 <entry>integer</entry>
194 <entry>Exposure (cameras). [Unit?]</entry>
195 </row>
196 <row>
197 <entry><constant>V4L2_CID_AUTOGAIN</constant></entry>
198 <entry>boolean</entry>
199 <entry>Automatic gain/exposure control.</entry>
200 </row>
201 <row>
202 <entry><constant>V4L2_CID_GAIN</constant></entry>
203 <entry>integer</entry>
204 <entry>Gain control.</entry>
205 </row>
206 <row>
207 <entry><constant>V4L2_CID_HFLIP</constant></entry>
208 <entry>boolean</entry>
209 <entry>Mirror the picture horizontally.</entry>
210 </row>
211 <row>
212 <entry><constant>V4L2_CID_VFLIP</constant></entry>
213 <entry>boolean</entry>
214 <entry>Mirror the picture vertically.</entry>
215 </row>
216 <row id="v4l2-power-line-frequency">
217 <entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></entry>
218 <entry>enum</entry>
219 <entry>Enables a power line frequency filter to avoid
220flicker. Possible values for <constant>enum v4l2_power_line_frequency</constant> are:
221<constant>V4L2_CID_POWER_LINE_FREQUENCY_DISABLED</constant> (0),
222<constant>V4L2_CID_POWER_LINE_FREQUENCY_50HZ</constant> (1),
223<constant>V4L2_CID_POWER_LINE_FREQUENCY_60HZ</constant> (2) and
224<constant>V4L2_CID_POWER_LINE_FREQUENCY_AUTO</constant> (3).</entry>
225 </row>
226 <row>
227 <entry><constant>V4L2_CID_HUE_AUTO</constant></entry>
228 <entry>boolean</entry>
229 <entry>Enables automatic hue control by the device. The
230effect of setting <constant>V4L2_CID_HUE</constant> while automatic
231hue control is enabled is undefined, drivers should ignore such
232request.</entry>
233 </row>
234 <row>
235 <entry><constant>V4L2_CID_WHITE_BALANCE_TEMPERATURE</constant></entry>
236 <entry>integer</entry>
237 <entry>This control specifies the white balance settings
238as a color temperature in Kelvin. A driver should have a minimum of
2392800 (incandescent) to 6500 (daylight). For more information about
240color temperature see <ulink
241url="http://en.wikipedia.org/wiki/Color_temperature">Wikipedia</ulink>.</entry>
242 </row>
243 <row>
244 <entry><constant>V4L2_CID_SHARPNESS</constant></entry>
245 <entry>integer</entry>
246 <entry>Adjusts the sharpness filters in a camera. The
247minimum value disables the filters, higher values give a sharper
248picture.</entry>
249 </row>
250 <row>
251 <entry><constant>V4L2_CID_BACKLIGHT_COMPENSATION</constant></entry>
252 <entry>integer</entry>
253 <entry>Adjusts the backlight compensation in a camera. The
254minimum value disables backlight compensation.</entry>
255 </row>
256 <row>
257 <entry><constant>V4L2_CID_CHROMA_AGC</constant></entry>
258 <entry>boolean</entry>
259 <entry>Chroma automatic gain control.</entry>
260 </row>
261 <row>
262 <entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry>
263 <entry>integer</entry>
264 <entry>Adjusts the Chroma gain control (for use when chroma AGC
265 is disabled).</entry>
266 </row>
267 <row>
268 <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
269 <entry>boolean</entry>
270 <entry>Enable the color killer (&ie; force a black &amp; white image in case of a weak video signal).</entry>
271 </row>
272 <row id="v4l2-colorfx">
273 <entry><constant>V4L2_CID_COLORFX</constant></entry>
274 <entry>enum</entry>
275 <entry>Selects a color effect. The following values are defined:
276 </entry>
277 </row><row>
278 <entry></entry>
279 <entry></entry>
280 <entrytbl spanname="descr" cols="2">
281 <tbody valign="top">
282 <row>
283 <entry><constant>V4L2_COLORFX_NONE</constant>&nbsp;</entry>
284 <entry>Color effect is disabled.</entry>
285 </row>
286 <row>
287 <entry><constant>V4L2_COLORFX_ANTIQUE</constant>&nbsp;</entry>
288 <entry>An aging (old photo) effect.</entry>
289 </row>
290 <row>
291 <entry><constant>V4L2_COLORFX_ART_FREEZE</constant>&nbsp;</entry>
292 <entry>Frost color effect.</entry>
293 </row>
294 <row>
295 <entry><constant>V4L2_COLORFX_AQUA</constant>&nbsp;</entry>
296 <entry>Water color, cool tone.</entry>
297 </row>
298 <row>
299 <entry><constant>V4L2_COLORFX_BW</constant>&nbsp;</entry>
300 <entry>Black and white.</entry>
301 </row>
302 <row>
303 <entry><constant>V4L2_COLORFX_EMBOSS</constant>&nbsp;</entry>
304 <entry>Emboss, the highlights and shadows replace light/dark boundaries
305 and low contrast areas are set to a gray background.</entry>
306 </row>
307 <row>
308 <entry><constant>V4L2_COLORFX_GRASS_GREEN</constant>&nbsp;</entry>
309 <entry>Grass green.</entry>
310 </row>
311 <row>
312 <entry><constant>V4L2_COLORFX_NEGATIVE</constant>&nbsp;</entry>
313 <entry>Negative.</entry>
314 </row>
315 <row>
316 <entry><constant>V4L2_COLORFX_SEPIA</constant>&nbsp;</entry>
317 <entry>Sepia tone.</entry>
318 </row>
319 <row>
320 <entry><constant>V4L2_COLORFX_SKETCH</constant>&nbsp;</entry>
321 <entry>Sketch.</entry>
322 </row>
323 <row>
324 <entry><constant>V4L2_COLORFX_SKIN_WHITEN</constant>&nbsp;</entry>
325 <entry>Skin whiten.</entry>
326 </row>
327 <row>
328 <entry><constant>V4L2_COLORFX_SKY_BLUE</constant>&nbsp;</entry>
329 <entry>Sky blue.</entry>
330 </row>
331 <row>
332 <entry><constant>V4L2_COLORFX_SOLARIZATION</constant>&nbsp;</entry>
333 <entry>Solarization, the image is partially reversed in tone,
334 only color values above or below a certain threshold are inverted.
335 </entry>
336 </row>
337 <row>
338 <entry><constant>V4L2_COLORFX_SILHOUETTE</constant>&nbsp;</entry>
339 <entry>Silhouette (outline).</entry>
340 </row>
341 <row>
342 <entry><constant>V4L2_COLORFX_VIVID</constant>&nbsp;</entry>
343 <entry>Vivid colors.</entry>
344 </row>
345 <row>
346 <entry><constant>V4L2_COLORFX_SET_CBCR</constant>&nbsp;</entry>
347 <entry>The Cb and Cr chroma components are replaced by fixed
348 coefficients determined by <constant>V4L2_CID_COLORFX_CBCR</constant>
349 control.</entry>
350 </row>
351 </tbody>
352 </entrytbl>
353 </row>
354 <row>
355 <entry><constant>V4L2_CID_COLORFX_CBCR</constant></entry>
356 <entry>integer</entry>
357 <entry>Determines the Cb and Cr coefficients for <constant>V4L2_COLORFX_SET_CBCR</constant>
358 color effect. Bits [7:0] of the supplied 32 bit value are interpreted as
359 Cr component, bits [15:8] as Cb component and bits [31:16] must be zero.
360 </entry>
361 </row>
362 <row>
363 <entry><constant>V4L2_CID_AUTOBRIGHTNESS</constant></entry>
364 <entry>boolean</entry>
365 <entry>Enable Automatic Brightness.</entry>
366 </row>
367 <row>
368 <entry><constant>V4L2_CID_ROTATE</constant></entry>
369 <entry>integer</entry>
370 <entry>Rotates the image by specified angle. Common angles are 90,
371 270 and 180. Rotating the image to 90 and 270 will reverse the height
372 and width of the display window. It is necessary to set the new height and
373 width of the picture using the &VIDIOC-S-FMT; ioctl according to
374 the rotation angle selected.</entry>
375 </row>
376 <row>
377 <entry><constant>V4L2_CID_BG_COLOR</constant></entry>
378 <entry>integer</entry>
379 <entry>Sets the background color on the current output device.
380 Background color needs to be specified in the RGB24 format. The
381 supplied 32 bit value is interpreted as bits 0-7 Red color information,
382 bits 8-15 Green color information, bits 16-23 Blue color
383 information and bits 24-31 must be zero.</entry>
384 </row>
385 <row>
386 <entry><constant>V4L2_CID_ILLUMINATORS_1</constant>
387 <constant>V4L2_CID_ILLUMINATORS_2</constant></entry>
388 <entry>boolean</entry>
389 <entry>Switch on or off the illuminator 1 or 2 of the device
390 (usually a microscope).</entry>
391 </row>
392 <row>
393 <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_CAPTURE</constant></entry>
394 <entry>integer</entry>
395 <entry>This is a read-only control that can be read by the application
396and used as a hint to determine the number of CAPTURE buffers to pass to REQBUFS.
397The value is the minimum number of CAPTURE buffers that is necessary for hardware
398to work.</entry>
399 </row>
400 <row>
401 <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_OUTPUT</constant></entry>
402 <entry>integer</entry>
403 <entry>This is a read-only control that can be read by the application
404and used as a hint to determine the number of OUTPUT buffers to pass to REQBUFS.
405The value is the minimum number of OUTPUT buffers that is necessary for hardware
406to work.</entry>
407 </row>
408 <row id="v4l2-alpha-component">
409 <entry><constant>V4L2_CID_ALPHA_COMPONENT</constant></entry>
410 <entry>integer</entry>
411 <entry>Sets the alpha color component. When a capture device (or
412 capture queue of a mem-to-mem device) produces a frame format that
413 includes an alpha component
414 (e.g. <link linkend="rgb-formats">packed RGB image formats</link>)
415 and the alpha value is not defined by the device or the mem-to-mem
416 input data this control lets you select the alpha component value of
417 all pixels. When an output device (or output queue of a mem-to-mem
418 device) consumes a frame format that doesn't include an alpha
419 component and the device supports alpha channel processing this
420 control lets you set the alpha component value of all pixels for
421 further processing in the device.
422 </entry>
423 </row>
424 <row>
425 <entry><constant>V4L2_CID_LASTP1</constant></entry>
426 <entry></entry>
427 <entry>End of the predefined control IDs (currently
428 <constant>V4L2_CID_ALPHA_COMPONENT</constant> + 1).</entry>
429 </row>
430 <row>
431 <entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
432 <entry></entry>
433 <entry>ID of the first custom (driver specific) control.
434Applications depending on particular custom controls should check the
435driver name and version, see <xref linkend="querycap" />.</entry>
436 </row>
437 </tbody>
438 </tgroup>
439 </table>
440
441 <para>Applications can enumerate the available controls with the
442&VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a
443control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls.
444Drivers must implement <constant>VIDIOC_QUERYCTRL</constant>,
445<constant>VIDIOC_G_CTRL</constant> and
446<constant>VIDIOC_S_CTRL</constant> when the device has one or more
447controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or
448more menu type controls.</para>
449
450 <example id="enum_all_controls">
451 <title>Enumerating all user controls</title>
452
453 <programlisting>
454&v4l2-queryctrl; queryctrl;
455&v4l2-querymenu; querymenu;
456
457static void enumerate_menu(void)
458{
459 printf(" Menu items:\n");
460
461 memset(&amp;querymenu, 0, sizeof(querymenu));
462 querymenu.id = queryctrl.id;
463
464 for (querymenu.index = queryctrl.minimum;
465 querymenu.index &lt;= queryctrl.maximum;
466 querymenu.index++) {
467 if (0 == ioctl(fd, &VIDIOC-QUERYMENU;, &amp;querymenu)) {
468 printf(" %s\n", querymenu.name);
469 }
470 }
471}
472
473memset(&amp;queryctrl, 0, sizeof(queryctrl));
474
475for (queryctrl.id = V4L2_CID_BASE;
476 queryctrl.id &lt; V4L2_CID_LASTP1;
477 queryctrl.id++) {
478 if (0 == ioctl(fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
479 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
480 continue;
481
482 printf("Control %s\n", queryctrl.name);
483
484 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
485 enumerate_menu();
486 } else {
487 if (errno == EINVAL)
488 continue;
489
490 perror("VIDIOC_QUERYCTRL");
491 exit(EXIT_FAILURE);
492 }
493}
494
495for (queryctrl.id = V4L2_CID_PRIVATE_BASE;;
496 queryctrl.id++) {
497 if (0 == ioctl(fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
498 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
499 continue;
500
501 printf("Control %s\n", queryctrl.name);
502
503 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
504 enumerate_menu();
505 } else {
506 if (errno == EINVAL)
507 break;
508
509 perror("VIDIOC_QUERYCTRL");
510 exit(EXIT_FAILURE);
511 }
512}
513</programlisting>
514 </example>
515
516 <example>
517 <title>Enumerating all user controls (alternative)</title>
518 <programlisting>
519memset(&amp;queryctrl, 0, sizeof(queryctrl));
520
521queryctrl.id = V4L2_CTRL_CLASS_USER | V4L2_CTRL_FLAG_NEXT_CTRL;
522while (0 == ioctl(fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
523 if (V4L2_CTRL_ID2CLASS(queryctrl.id) != V4L2_CTRL_CLASS_USER)
524 break;
525 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
526 continue;
527
528 printf("Control %s\n", queryctrl.name);
529
530 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
531 enumerate_menu();
532
533 queryctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
534}
535if (errno != EINVAL) {
536 perror("VIDIOC_QUERYCTRL");
537 exit(EXIT_FAILURE);
538}
539</programlisting>
540 </example>
541
542 <example>
543 <title>Changing controls</title>
544
545 <programlisting>
546&v4l2-queryctrl; queryctrl;
547&v4l2-control; control;
548
549memset(&amp;queryctrl, 0, sizeof(queryctrl));
550queryctrl.id = V4L2_CID_BRIGHTNESS;
551
552if (-1 == ioctl(fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
553 if (errno != EINVAL) {
554 perror("VIDIOC_QUERYCTRL");
555 exit(EXIT_FAILURE);
556 } else {
557 printf("V4L2_CID_BRIGHTNESS is not supported\n");
558 }
559} else if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED) {
560 printf("V4L2_CID_BRIGHTNESS is not supported\n");
561} else {
562 memset(&amp;control, 0, sizeof (control));
563 control.id = V4L2_CID_BRIGHTNESS;
564 control.value = queryctrl.default_value;
565
566 if (-1 == ioctl(fd, &VIDIOC-S-CTRL;, &amp;control)) {
567 perror("VIDIOC_S_CTRL");
568 exit(EXIT_FAILURE);
569 }
570}
571
572memset(&amp;control, 0, sizeof(control));
573control.id = V4L2_CID_CONTRAST;
574
575if (0 == ioctl(fd, &VIDIOC-G-CTRL;, &amp;control)) {
576 control.value += 1;
577
578 /* The driver may clamp the value or return ERANGE, ignored here */
579
580 if (-1 == ioctl(fd, &VIDIOC-S-CTRL;, &amp;control)
581 &amp;&amp; errno != ERANGE) {
582 perror("VIDIOC_S_CTRL");
583 exit(EXIT_FAILURE);
584 }
585/* Ignore if V4L2_CID_CONTRAST is unsupported */
586} else if (errno != EINVAL) {
587 perror("VIDIOC_G_CTRL");
588 exit(EXIT_FAILURE);
589}
590
591control.id = V4L2_CID_AUDIO_MUTE;
592control.value = 1; /* silence */
593
594/* Errors ignored */
595ioctl(fd, VIDIOC_S_CTRL, &amp;control);
596</programlisting>
597 </example>
598 </section>
599
600 <section id="extended-controls">
601 <title>Extended Controls</title>
602
603 <section>
604 <title>Introduction</title>
605
606 <para>The control mechanism as originally designed was meant
607to be used for user settings (brightness, saturation, etc). However,
608it turned out to be a very useful model for implementing more
609complicated driver APIs where each driver implements only a subset of
610a larger API.</para>
611
612 <para>The MPEG encoding API was the driving force behind
613designing and implementing this extended control mechanism: the MPEG
614standard is quite large and the currently supported hardware MPEG
615encoders each only implement a subset of this standard. Further more,
616many parameters relating to how the video is encoded into an MPEG
617stream are specific to the MPEG encoding chip since the MPEG standard
618only defines the format of the resulting MPEG stream, not how the
619video is actually encoded into that format.</para>
620
621 <para>Unfortunately, the original control API lacked some
622features needed for these new uses and so it was extended into the
623(not terribly originally named) extended control API.</para>
624
625 <para>Even though the MPEG encoding API was the first effort
626to use the Extended Control API, nowadays there are also other classes
627of Extended Controls, such as Camera Controls and FM Transmitter Controls.
628The Extended Controls API as well as all Extended Controls classes are
629described in the following text.</para>
630 </section>
631
632 <section>
633 <title>The Extended Control API</title>
634
635 <para>Three new ioctls are available: &VIDIOC-G-EXT-CTRLS;,
636&VIDIOC-S-EXT-CTRLS; and &VIDIOC-TRY-EXT-CTRLS;. These ioctls act on
637arrays of controls (as opposed to the &VIDIOC-G-CTRL; and
638&VIDIOC-S-CTRL; ioctls that act on a single control). This is needed
639since it is often required to atomically change several controls at
640once.</para>
641
642 <para>Each of the new ioctls expects a pointer to a
643&v4l2-ext-controls;. This structure contains a pointer to the control
644array, a count of the number of controls in that array and a control
645class. Control classes are used to group similar controls into a
646single class. For example, control class
647<constant>V4L2_CTRL_CLASS_USER</constant> contains all user controls
648(&ie; all controls that can also be set using the old
649<constant>VIDIOC_S_CTRL</constant> ioctl). Control class
650<constant>V4L2_CTRL_CLASS_MPEG</constant> contains all controls
651relating to MPEG encoding, etc.</para>
652
653 <para>All controls in the control array must belong to the
654specified control class. An error is returned if this is not the
655case.</para>
656
657 <para>It is also possible to use an empty control array (count
658== 0) to check whether the specified control class is
659supported.</para>
660
661 <para>The control array is a &v4l2-ext-control; array. The
662<structname>v4l2_ext_control</structname> structure is very similar to
663&v4l2-control;, except for the fact that it also allows for 64-bit
664values and pointers to be passed.</para>
665
666 <para>Since the &v4l2-ext-control; supports pointers it is now
667also possible to have controls with compound types such as N-dimensional arrays
668and/or structures. You need to specify the <constant>V4L2_CTRL_FLAG_NEXT_COMPOUND</constant>
669when enumerating controls to actually be able to see such compound controls.
670In other words, these controls with compound types should only be used
671programmatically.</para>
672
673 <para>Since such compound controls need to expose more information
674about themselves than is possible with &VIDIOC-QUERYCTRL; the
675&VIDIOC-QUERY-EXT-CTRL; ioctl was added. In particular, this ioctl gives
676the dimensions of the N-dimensional array if this control consists of more than
677one element.</para>
678
679 <para>It is important to realize that due to the flexibility of
680controls it is necessary to check whether the control you want to set
681actually is supported in the driver and what the valid range of values
682is. So use the &VIDIOC-QUERYCTRL; (or &VIDIOC-QUERY-EXT-CTRL;) and
683&VIDIOC-QUERYMENU; ioctls to check this. Also note that it is possible
684that some of the menu indices in a control of type
685<constant>V4L2_CTRL_TYPE_MENU</constant> may not be supported
686(<constant>VIDIOC_QUERYMENU</constant> will return an error). A good
687example is the list of supported MPEG audio bitrates. Some drivers only
688support one or two bitrates, others support a wider range.</para>
689
690 <para>
691 All controls use machine endianness.
692 </para>
693 </section>
694
695 <section>
696 <title>Enumerating Extended Controls</title>
697
698 <para>The recommended way to enumerate over the extended
699controls is by using &VIDIOC-QUERYCTRL; in combination with the
700<constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag:</para>
701
702 <informalexample>
703 <programlisting>
704&v4l2-queryctrl; qctrl;
705
706qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
707while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
708 /* ... */
709 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
710}
711</programlisting>
712 </informalexample>
713
714 <para>The initial control ID is set to 0 ORed with the
715<constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag. The
716<constant>VIDIOC_QUERYCTRL</constant> ioctl will return the first
717control with a higher ID than the specified one. When no such controls
718are found an error is returned.</para>
719
720 <para>If you want to get all controls within a specific control
721class, then you can set the initial
722<structfield>qctrl.id</structfield> value to the control class and add
723an extra check to break out of the loop when a control of another
724control class is found:</para>
725
726 <informalexample>
727 <programlisting>
728qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL;
729while (0 == ioctl(fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
730 if (V4L2_CTRL_ID2CLASS(qctrl.id) != V4L2_CTRL_CLASS_MPEG)
731 break;
732 /* ... */
733 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
734}
735</programlisting>
736 </informalexample>
737
738 <para>The 32-bit <structfield>qctrl.id</structfield> value is
739subdivided into three bit ranges: the top 4 bits are reserved for
740flags (&eg; <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>) and are not
741actually part of the ID. The remaining 28 bits form the control ID, of
742which the most significant 12 bits define the control class and the
743least significant 16 bits identify the control within the control
744class. It is guaranteed that these last 16 bits are always non-zero
745for controls. The range of 0x1000 and up are reserved for
746driver-specific controls. The macro
747<constant>V4L2_CTRL_ID2CLASS(id)</constant> returns the control class
748ID based on a control ID.</para>
749
750 <para>If the driver does not support extended controls, then
751<constant>VIDIOC_QUERYCTRL</constant> will fail when used in
752combination with <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>. In
753that case the old method of enumerating control should be used (see
754<xref linkend="enum_all_controls" />). But if it is supported, then it is guaranteed to enumerate over
755all controls, including driver-private controls.</para>
756 </section>
757
758 <section>
759 <title>Creating Control Panels</title>
760
761 <para>It is possible to create control panels for a graphical
762user interface where the user can select the various controls.
763Basically you will have to iterate over all controls using the method
764described above. Each control class starts with a control of type
765<constant>V4L2_CTRL_TYPE_CTRL_CLASS</constant>.
766<constant>VIDIOC_QUERYCTRL</constant> will return the name of this
767control class which can be used as the title of a tab page within a
768control panel.</para>
769
770 <para>The flags field of &v4l2-queryctrl; also contains hints on
771the behavior of the control. See the &VIDIOC-QUERYCTRL; documentation
772for more details.</para>
773 </section>
774
775 <section id="mpeg-controls">
776 <title>Codec Control Reference</title>
777
778 <para>Below all controls within the Codec control class are
779described. First the generic controls, then controls specific for
780certain hardware.</para>
781
782 <para>Note: These controls are applicable to all codecs and
783not just MPEG. The defines are prefixed with V4L2_CID_MPEG/V4L2_MPEG
784as the controls were originally made for MPEG codecs and later
785extended to cover all encoding formats.</para>
786
787 <section>
788 <title>Generic Codec Controls</title>
789
790 <table pgwide="1" frame="none" id="mpeg-control-id">
791 <title>Codec Control IDs</title>
792 <tgroup cols="4">
793 <colspec colname="c1" colwidth="1*" />
794 <colspec colname="c2" colwidth="6*" />
795 <colspec colname="c3" colwidth="2*" />
796 <colspec colname="c4" colwidth="6*" />
797 <spanspec namest="c1" nameend="c2" spanname="id" />
798 <spanspec namest="c2" nameend="c4" spanname="descr" />
799 <thead>
800 <row>
801 <entry spanname="id" align="left">ID</entry>
802 <entry align="left">Type</entry>
803 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
804 </row>
805 </thead>
806 <tbody valign="top">
807 <row><entry></entry></row>
808 <row>
809 <entry spanname="id"><constant>V4L2_CID_MPEG_CLASS</constant>&nbsp;</entry>
810 <entry>class</entry>
811 </row><row><entry spanname="descr">The Codec class
812descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
813description of this control class. This description can be used as the
814caption of a Tab page in a GUI, for example.</entry>
815 </row>
816 <row><entry></entry></row>
817 <row id="v4l2-mpeg-stream-type">
818 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_TYPE</constant>&nbsp;</entry>
819 <entry>enum&nbsp;v4l2_mpeg_stream_type</entry>
820 </row><row><entry spanname="descr">The MPEG-1, -2 or -4
821output stream type. One cannot assume anything here. Each hardware
822MPEG encoder tends to support different subsets of the available MPEG
823stream types. This control is specific to multiplexed MPEG streams.
824The currently defined stream types are:</entry>
825 </row>
826 <row>
827 <entrytbl spanname="descr" cols="2">
828 <tbody valign="top">
829 <row>
830 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_PS</constant>&nbsp;</entry>
831 <entry>MPEG-2 program stream</entry>
832 </row>
833 <row>
834 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_TS</constant>&nbsp;</entry>
835 <entry>MPEG-2 transport stream</entry>
836 </row>
837 <row>
838 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_SS</constant>&nbsp;</entry>
839 <entry>MPEG-1 system stream</entry>
840 </row>
841 <row>
842 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_DVD</constant>&nbsp;</entry>
843 <entry>MPEG-2 DVD-compatible stream</entry>
844 </row>
845 <row>
846 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_VCD</constant>&nbsp;</entry>
847 <entry>MPEG-1 VCD-compatible stream</entry>
848 </row>
849 <row>
850 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD</constant>&nbsp;</entry>
851 <entry>MPEG-2 SVCD-compatible stream</entry>
852 </row>
853 </tbody>
854 </entrytbl>
855 </row>
856 <row><entry></entry></row>
857 <row>
858 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PMT</constant>&nbsp;</entry>
859 <entry>integer</entry>
860 </row><row><entry spanname="descr">Program Map Table
861Packet ID for the MPEG transport stream (default 16)</entry>
862 </row>
863 <row><entry></entry></row>
864 <row>
865 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_AUDIO</constant>&nbsp;</entry>
866 <entry>integer</entry>
867 </row><row><entry spanname="descr">Audio Packet ID for
868the MPEG transport stream (default 256)</entry>
869 </row>
870 <row><entry></entry></row>
871 <row>
872 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_VIDEO</constant>&nbsp;</entry>
873 <entry>integer</entry>
874 </row><row><entry spanname="descr">Video Packet ID for
875the MPEG transport stream (default 260)</entry>
876 </row>
877 <row><entry></entry></row>
878 <row>
879 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PCR</constant>&nbsp;</entry>
880 <entry>integer</entry>
881 </row><row><entry spanname="descr">Packet ID for the
882MPEG transport stream carrying PCR fields (default 259)</entry>
883 </row>
884 <row><entry></entry></row>
885 <row>
886 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_AUDIO</constant>&nbsp;</entry>
887 <entry>integer</entry>
888 </row><row><entry spanname="descr">Audio ID for MPEG
889PES</entry>
890 </row>
891 <row><entry></entry></row>
892 <row>
893 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_VIDEO</constant>&nbsp;</entry>
894 <entry>integer</entry>
895 </row><row><entry spanname="descr">Video ID for MPEG
896PES</entry>
897 </row>
898 <row><entry></entry></row>
899 <row id="v4l2-mpeg-stream-vbi-fmt">
900 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_VBI_FMT</constant>&nbsp;</entry>
901 <entry>enum&nbsp;v4l2_mpeg_stream_vbi_fmt</entry>
902 </row><row><entry spanname="descr">Some cards can embed
903VBI data (&eg; Closed Caption, Teletext) into the MPEG stream. This
904control selects whether VBI data should be embedded, and if so, what
905embedding method should be used. The list of possible VBI formats
906depends on the driver. The currently defined VBI format types
907are:</entry>
908 </row>
909 <row>
910 <entrytbl spanname="descr" cols="2">
911 <tbody valign="top">
912 <row>
913 <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_NONE</constant>&nbsp;</entry>
914 <entry>No VBI in the MPEG stream</entry>
915 </row>
916 <row>
917 <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_IVTV</constant>&nbsp;</entry>
918 <entry>VBI in private packets, IVTV format (documented
919in the kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.vbi</filename>)</entry>
920 </row>
921 </tbody>
922 </entrytbl>
923 </row>
924 <row><entry></entry></row>
925 <row id="v4l2-mpeg-audio-sampling-freq">
926 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ</constant>&nbsp;</entry>
927 <entry>enum&nbsp;v4l2_mpeg_audio_sampling_freq</entry>
928 </row><row><entry spanname="descr">MPEG Audio sampling
929frequency. Possible values are:</entry>
930 </row>
931 <row>
932 <entrytbl spanname="descr" cols="2">
933 <tbody valign="top">
934 <row>
935 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100</constant>&nbsp;</entry>
936 <entry>44.1 kHz</entry>
937 </row>
938 <row>
939 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000</constant>&nbsp;</entry>
940 <entry>48 kHz</entry>
941 </row>
942 <row>
943 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000</constant>&nbsp;</entry>
944 <entry>32 kHz</entry>
945 </row>
946 </tbody>
947 </entrytbl>
948 </row>
949 <row><entry></entry></row>
950 <row id="v4l2-mpeg-audio-encoding">
951 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_ENCODING</constant>&nbsp;</entry>
952 <entry>enum&nbsp;v4l2_mpeg_audio_encoding</entry>
953 </row><row><entry spanname="descr">MPEG Audio encoding.
954This control is specific to multiplexed MPEG streams.
955Possible values are:</entry>
956 </row>
957 <row>
958 <entrytbl spanname="descr" cols="2">
959 <tbody valign="top">
960 <row>
961 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_1</constant>&nbsp;</entry>
962 <entry>MPEG-1/2 Layer I encoding</entry>
963 </row>
964 <row>
965 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_2</constant>&nbsp;</entry>
966 <entry>MPEG-1/2 Layer II encoding</entry>
967 </row>
968 <row>
969 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_3</constant>&nbsp;</entry>
970 <entry>MPEG-1/2 Layer III encoding</entry>
971 </row>
972 <row>
973 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AAC</constant>&nbsp;</entry>
974 <entry>MPEG-2/4 AAC (Advanced Audio Coding)</entry>
975 </row>
976 <row>
977 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AC3</constant>&nbsp;</entry>
978 <entry>AC-3 aka ATSC A/52 encoding</entry>
979 </row>
980 </tbody>
981 </entrytbl>
982 </row>
983 <row><entry></entry></row>
984 <row id="v4l2-mpeg-audio-l1-bitrate">
985 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L1_BITRATE</constant>&nbsp;</entry>
986 <entry>enum&nbsp;v4l2_mpeg_audio_l1_bitrate</entry>
987 </row><row><entry spanname="descr">MPEG-1/2 Layer I bitrate.
988Possible values are:</entry>
989 </row>
990 <row>
991 <entrytbl spanname="descr" cols="2">
992 <tbody valign="top">
993 <row>
994 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_32K</constant>&nbsp;</entry>
995 <entry>32 kbit/s</entry></row>
996 <row>
997 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_64K</constant>&nbsp;</entry>
998 <entry>64 kbit/s</entry>
999 </row>
1000 <row>
1001 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_96K</constant>&nbsp;</entry>
1002 <entry>96 kbit/s</entry>
1003 </row>
1004 <row>
1005 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_128K</constant>&nbsp;</entry>
1006 <entry>128 kbit/s</entry>
1007 </row>
1008 <row>
1009 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_160K</constant>&nbsp;</entry>
1010 <entry>160 kbit/s</entry>
1011 </row>
1012 <row>
1013 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_192K</constant>&nbsp;</entry>
1014 <entry>192 kbit/s</entry>
1015 </row>
1016 <row>
1017 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_224K</constant>&nbsp;</entry>
1018 <entry>224 kbit/s</entry>
1019 </row>
1020 <row>
1021 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_256K</constant>&nbsp;</entry>
1022 <entry>256 kbit/s</entry>
1023 </row>
1024 <row>
1025 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_288K</constant>&nbsp;</entry>
1026 <entry>288 kbit/s</entry>
1027 </row>
1028 <row>
1029 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_320K</constant>&nbsp;</entry>
1030 <entry>320 kbit/s</entry>
1031 </row>
1032 <row>
1033 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_352K</constant>&nbsp;</entry>
1034 <entry>352 kbit/s</entry>
1035 </row>
1036 <row>
1037 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_384K</constant>&nbsp;</entry>
1038 <entry>384 kbit/s</entry>
1039 </row>
1040 <row>
1041 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_416K</constant>&nbsp;</entry>
1042 <entry>416 kbit/s</entry>
1043 </row>
1044 <row>
1045 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_448K</constant>&nbsp;</entry>
1046 <entry>448 kbit/s</entry>
1047 </row>
1048 </tbody>
1049 </entrytbl>
1050 </row>
1051 <row><entry></entry></row>
1052 <row id="v4l2-mpeg-audio-l2-bitrate">
1053 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L2_BITRATE</constant>&nbsp;</entry>
1054 <entry>enum&nbsp;v4l2_mpeg_audio_l2_bitrate</entry>
1055 </row><row><entry spanname="descr">MPEG-1/2 Layer II bitrate.
1056Possible values are:</entry>
1057 </row>
1058 <row>
1059 <entrytbl spanname="descr" cols="2">
1060 <tbody valign="top">
1061 <row>
1062 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_32K</constant>&nbsp;</entry>
1063 <entry>32 kbit/s</entry>
1064 </row>
1065 <row>
1066 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_48K</constant>&nbsp;</entry>
1067 <entry>48 kbit/s</entry>
1068 </row>
1069 <row>
1070 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_56K</constant>&nbsp;</entry>
1071 <entry>56 kbit/s</entry>
1072 </row>
1073 <row>
1074 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_64K</constant>&nbsp;</entry>
1075 <entry>64 kbit/s</entry>
1076 </row>
1077 <row>
1078 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_80K</constant>&nbsp;</entry>
1079 <entry>80 kbit/s</entry>
1080 </row>
1081 <row>
1082 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_96K</constant>&nbsp;</entry>
1083 <entry>96 kbit/s</entry>
1084 </row>
1085 <row>
1086 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_112K</constant>&nbsp;</entry>
1087 <entry>112 kbit/s</entry>
1088 </row>
1089 <row>
1090 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_128K</constant>&nbsp;</entry>
1091 <entry>128 kbit/s</entry>
1092 </row>
1093 <row>
1094 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_160K</constant>&nbsp;</entry>
1095 <entry>160 kbit/s</entry>
1096 </row>
1097 <row>
1098 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_192K</constant>&nbsp;</entry>
1099 <entry>192 kbit/s</entry>
1100 </row>
1101 <row>
1102 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_224K</constant>&nbsp;</entry>
1103 <entry>224 kbit/s</entry>
1104 </row>
1105 <row>
1106 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_256K</constant>&nbsp;</entry>
1107 <entry>256 kbit/s</entry>
1108 </row>
1109 <row>
1110 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_320K</constant>&nbsp;</entry>
1111 <entry>320 kbit/s</entry>
1112 </row>
1113 <row>
1114 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_384K</constant>&nbsp;</entry>
1115 <entry>384 kbit/s</entry>
1116 </row>
1117 </tbody>
1118 </entrytbl>
1119 </row>
1120 <row><entry></entry></row>
1121 <row id="v4l2-mpeg-audio-l3-bitrate">
1122 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L3_BITRATE</constant>&nbsp;</entry>
1123 <entry>enum&nbsp;v4l2_mpeg_audio_l3_bitrate</entry>
1124 </row><row><entry spanname="descr">MPEG-1/2 Layer III bitrate.
1125Possible values are:</entry>
1126 </row>
1127 <row>
1128 <entrytbl spanname="descr" cols="2">
1129 <tbody valign="top">
1130 <row>
1131 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_32K</constant>&nbsp;</entry>
1132 <entry>32 kbit/s</entry>
1133 </row>
1134 <row>
1135 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_40K</constant>&nbsp;</entry>
1136 <entry>40 kbit/s</entry>
1137 </row>
1138 <row>
1139 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_48K</constant>&nbsp;</entry>
1140 <entry>48 kbit/s</entry>
1141 </row>
1142 <row>
1143 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_56K</constant>&nbsp;</entry>
1144 <entry>56 kbit/s</entry>
1145 </row>
1146 <row>
1147 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_64K</constant>&nbsp;</entry>
1148 <entry>64 kbit/s</entry>
1149 </row>
1150 <row>
1151 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_80K</constant>&nbsp;</entry>
1152 <entry>80 kbit/s</entry>
1153 </row>
1154 <row>
1155 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_96K</constant>&nbsp;</entry>
1156 <entry>96 kbit/s</entry>
1157 </row>
1158 <row>
1159 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_112K</constant>&nbsp;</entry>
1160 <entry>112 kbit/s</entry>
1161 </row>
1162 <row>
1163 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_128K</constant>&nbsp;</entry>
1164 <entry>128 kbit/s</entry>
1165 </row>
1166 <row>
1167 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_160K</constant>&nbsp;</entry>
1168 <entry>160 kbit/s</entry>
1169 </row>
1170 <row>
1171 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_192K</constant>&nbsp;</entry>
1172 <entry>192 kbit/s</entry>
1173 </row>
1174 <row>
1175 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_224K</constant>&nbsp;</entry>
1176 <entry>224 kbit/s</entry>
1177 </row>
1178 <row>
1179 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_256K</constant>&nbsp;</entry>
1180 <entry>256 kbit/s</entry>
1181 </row>
1182 <row>
1183 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_320K</constant>&nbsp;</entry>
1184 <entry>320 kbit/s</entry>
1185 </row>
1186 </tbody>
1187 </entrytbl>
1188 </row>
1189 <row><entry></entry></row>
1190 <row>
1191 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AAC_BITRATE</constant>&nbsp;</entry>
1192 <entry>integer</entry>
1193 </row><row><entry spanname="descr">AAC bitrate in bits per second.</entry>
1194 </row>
1195 <row><entry></entry></row>
1196 <row id="v4l2-mpeg-audio-ac3-bitrate">
1197 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AC3_BITRATE</constant>&nbsp;</entry>
1198 <entry>enum&nbsp;v4l2_mpeg_audio_ac3_bitrate</entry>
1199 </row><row><entry spanname="descr">AC-3 bitrate.
1200Possible values are:</entry>
1201 </row>
1202 <row>
1203 <entrytbl spanname="descr" cols="2">
1204 <tbody valign="top">
1205 <row>
1206 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_32K</constant>&nbsp;</entry>
1207 <entry>32 kbit/s</entry>
1208 </row>
1209 <row>
1210 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_40K</constant>&nbsp;</entry>
1211 <entry>40 kbit/s</entry>
1212 </row>
1213 <row>
1214 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_48K</constant>&nbsp;</entry>
1215 <entry>48 kbit/s</entry>
1216 </row>
1217 <row>
1218 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_56K</constant>&nbsp;</entry>
1219 <entry>56 kbit/s</entry>
1220 </row>
1221 <row>
1222 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_64K</constant>&nbsp;</entry>
1223 <entry>64 kbit/s</entry>
1224 </row>
1225 <row>
1226 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_80K</constant>&nbsp;</entry>
1227 <entry>80 kbit/s</entry>
1228 </row>
1229 <row>
1230 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_96K</constant>&nbsp;</entry>
1231 <entry>96 kbit/s</entry>
1232 </row>
1233 <row>
1234 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_112K</constant>&nbsp;</entry>
1235 <entry>112 kbit/s</entry>
1236 </row>
1237 <row>
1238 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_128K</constant>&nbsp;</entry>
1239 <entry>128 kbit/s</entry>
1240 </row>
1241 <row>
1242 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_160K</constant>&nbsp;</entry>
1243 <entry>160 kbit/s</entry>
1244 </row>
1245 <row>
1246 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_192K</constant>&nbsp;</entry>
1247 <entry>192 kbit/s</entry>
1248 </row>
1249 <row>
1250 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_224K</constant>&nbsp;</entry>
1251 <entry>224 kbit/s</entry>
1252 </row>
1253 <row>
1254 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_256K</constant>&nbsp;</entry>
1255 <entry>256 kbit/s</entry>
1256 </row>
1257 <row>
1258 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_320K</constant>&nbsp;</entry>
1259 <entry>320 kbit/s</entry>
1260 </row>
1261 <row>
1262 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_384K</constant>&nbsp;</entry>
1263 <entry>384 kbit/s</entry>
1264 </row>
1265 <row>
1266 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_448K</constant>&nbsp;</entry>
1267 <entry>448 kbit/s</entry>
1268 </row>
1269 <row>
1270 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_512K</constant>&nbsp;</entry>
1271 <entry>512 kbit/s</entry>
1272 </row>
1273 <row>
1274 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_576K</constant>&nbsp;</entry>
1275 <entry>576 kbit/s</entry>
1276 </row>
1277 <row>
1278 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_640K</constant>&nbsp;</entry>
1279 <entry>640 kbit/s</entry>
1280 </row>
1281 </tbody>
1282 </entrytbl>
1283 </row>
1284 <row><entry></entry></row>
1285 <row id="v4l2-mpeg-audio-mode">
1286 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE</constant>&nbsp;</entry>
1287 <entry>enum&nbsp;v4l2_mpeg_audio_mode</entry>
1288 </row><row><entry spanname="descr">MPEG Audio mode.
1289Possible values are:</entry>
1290 </row>
1291 <row>
1292 <entrytbl spanname="descr" cols="2">
1293 <tbody valign="top">
1294 <row>
1295 <entry><constant>V4L2_MPEG_AUDIO_MODE_STEREO</constant>&nbsp;</entry>
1296 <entry>Stereo</entry>
1297 </row>
1298 <row>
1299 <entry><constant>V4L2_MPEG_AUDIO_MODE_JOINT_STEREO</constant>&nbsp;</entry>
1300 <entry>Joint Stereo</entry>
1301 </row>
1302 <row>
1303 <entry><constant>V4L2_MPEG_AUDIO_MODE_DUAL</constant>&nbsp;</entry>
1304 <entry>Bilingual</entry>
1305 </row>
1306 <row>
1307 <entry><constant>V4L2_MPEG_AUDIO_MODE_MONO</constant>&nbsp;</entry>
1308 <entry>Mono</entry>
1309 </row>
1310 </tbody>
1311 </entrytbl>
1312 </row>
1313 <row><entry></entry></row>
1314 <row id="v4l2-mpeg-audio-mode-extension">
1315 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE_EXTENSION</constant>&nbsp;</entry>
1316 <entry>enum&nbsp;v4l2_mpeg_audio_mode_extension</entry>
1317 </row><row><entry spanname="descr">Joint Stereo
1318audio mode extension. In Layer I and II they indicate which subbands
1319are in intensity stereo. All other subbands are coded in stereo. Layer
1320III is not (yet) supported. Possible values
1321are:</entry>
1322 </row>
1323 <row>
1324 <entrytbl spanname="descr" cols="2">
1325 <tbody valign="top">
1326 <row>
1327 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4</constant>&nbsp;</entry>
1328 <entry>Subbands 4-31 in intensity stereo</entry>
1329 </row>
1330 <row>
1331 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_8</constant>&nbsp;</entry>
1332 <entry>Subbands 8-31 in intensity stereo</entry>
1333 </row>
1334 <row>
1335 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_12</constant>&nbsp;</entry>
1336 <entry>Subbands 12-31 in intensity stereo</entry>
1337 </row>
1338 <row>
1339 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16</constant>&nbsp;</entry>
1340 <entry>Subbands 16-31 in intensity stereo</entry>
1341 </row>
1342 </tbody>
1343 </entrytbl>
1344 </row>
1345 <row><entry></entry></row>
1346 <row id="v4l2-mpeg-audio-emphasis">
1347 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_EMPHASIS</constant>&nbsp;</entry>
1348 <entry>enum&nbsp;v4l2_mpeg_audio_emphasis</entry>
1349 </row><row><entry spanname="descr">Audio Emphasis.
1350Possible values are:</entry>
1351 </row>
1352 <row>
1353 <entrytbl spanname="descr" cols="2">
1354 <tbody valign="top">
1355 <row>
1356 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_NONE</constant>&nbsp;</entry>
1357 <entry>None</entry>
1358 </row>
1359 <row>
1360 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_50_DIV_15_uS</constant>&nbsp;</entry>
1361 <entry>50/15 microsecond emphasis</entry>
1362 </row>
1363 <row>
1364 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17</constant>&nbsp;</entry>
1365 <entry>CCITT J.17</entry>
1366 </row>
1367 </tbody>
1368 </entrytbl>
1369 </row>
1370 <row><entry></entry></row>
1371 <row id="v4l2-mpeg-audio-crc">
1372 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_CRC</constant>&nbsp;</entry>
1373 <entry>enum&nbsp;v4l2_mpeg_audio_crc</entry>
1374 </row><row><entry spanname="descr">CRC method. Possible
1375values are:</entry>
1376 </row>
1377 <row>
1378 <entrytbl spanname="descr" cols="2">
1379 <tbody valign="top">
1380 <row>
1381 <entry><constant>V4L2_MPEG_AUDIO_CRC_NONE</constant>&nbsp;</entry>
1382 <entry>None</entry>
1383 </row>
1384 <row>
1385 <entry><constant>V4L2_MPEG_AUDIO_CRC_CRC16</constant>&nbsp;</entry>
1386 <entry>16 bit parity check</entry>
1387 </row>
1388 </tbody>
1389 </entrytbl>
1390 </row>
1391 <row><entry></entry></row>
1392 <row>
1393 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MUTE</constant>&nbsp;</entry>
1394 <entry>boolean</entry>
1395 </row><row><entry spanname="descr">Mutes the audio when
1396capturing. This is not done by muting audio hardware, which can still
1397produce a slight hiss, but in the encoder itself, guaranteeing a fixed
1398and reproducible audio bitstream. 0 = unmuted, 1 = muted.</entry>
1399 </row>
1400 <row><entry></entry></row>
1401 <row id="v4l2-mpeg-audio-dec-playback">
1402 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_PLAYBACK</constant>&nbsp;</entry>
1403 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1404 </row><row><entry spanname="descr">Determines how monolingual audio should be played back.
1405Possible values are:</entry>
1406 </row>
1407 <row>
1408 <entrytbl spanname="descr" cols="2">
1409 <tbody valign="top">
1410 <row>
1411 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_AUTO</constant>&nbsp;</entry>
1412 <entry>Automatically determines the best playback mode.</entry>
1413 </row>
1414 <row>
1415 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_STEREO</constant>&nbsp;</entry>
1416 <entry>Stereo playback.</entry>
1417 </row>
1418 <row>
1419 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_LEFT</constant>&nbsp;</entry>
1420 <entry>Left channel playback.</entry>
1421 </row>
1422 <row>
1423 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_RIGHT</constant>&nbsp;</entry>
1424 <entry>Right channel playback.</entry>
1425 </row>
1426 <row>
1427 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_MONO</constant>&nbsp;</entry>
1428 <entry>Mono playback.</entry>
1429 </row>
1430 <row>
1431 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_SWAPPED_STEREO</constant>&nbsp;</entry>
1432 <entry>Stereo playback with swapped left and right channels.</entry>
1433 </row>
1434 </tbody>
1435 </entrytbl>
1436 </row>
1437 <row><entry></entry></row>
1438 <row id="v4l2-mpeg-audio-dec-multilingual-playback">
1439 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_MULTILINGUAL_PLAYBACK</constant>&nbsp;</entry>
1440 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1441 </row><row><entry spanname="descr">Determines how multilingual audio should be played back.</entry>
1442 </row>
1443 <row><entry></entry></row>
1444 <row id="v4l2-mpeg-video-encoding">
1445 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ENCODING</constant>&nbsp;</entry>
1446 <entry>enum&nbsp;v4l2_mpeg_video_encoding</entry>
1447 </row><row><entry spanname="descr">MPEG Video encoding
1448method. This control is specific to multiplexed MPEG streams.
1449Possible values are:</entry>
1450 </row>
1451 <row>
1452 <entrytbl spanname="descr" cols="2">
1453 <tbody valign="top">
1454 <row>
1455 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_1</constant>&nbsp;</entry>
1456 <entry>MPEG-1 Video encoding</entry>
1457 </row>
1458 <row>
1459 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_2</constant>&nbsp;</entry>
1460 <entry>MPEG-2 Video encoding</entry>
1461 </row>
1462 <row>
1463 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC</constant>&nbsp;</entry>
1464 <entry>MPEG-4 AVC (H.264) Video encoding</entry>
1465 </row>
1466 </tbody>
1467 </entrytbl>
1468 </row>
1469 <row><entry></entry></row>
1470 <row id="v4l2-mpeg-video-aspect">
1471 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ASPECT</constant>&nbsp;</entry>
1472 <entry>enum&nbsp;v4l2_mpeg_video_aspect</entry>
1473 </row><row><entry spanname="descr">Video aspect.
1474Possible values are:</entry>
1475 </row>
1476 <row>
1477 <entrytbl spanname="descr" cols="2">
1478 <tbody valign="top">
1479 <row>
1480 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_1x1</constant>&nbsp;</entry>
1481 </row>
1482 <row>
1483 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_4x3</constant>&nbsp;</entry>
1484 </row>
1485 <row>
1486 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_16x9</constant>&nbsp;</entry>
1487 </row>
1488 <row>
1489 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_221x100</constant>&nbsp;</entry>
1490 </row>
1491 </tbody>
1492 </entrytbl>
1493 </row>
1494 <row><entry></entry></row>
1495 <row>
1496 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_B_FRAMES</constant>&nbsp;</entry>
1497 <entry>integer</entry>
1498 </row><row><entry spanname="descr">Number of B-Frames
1499(default 2)</entry>
1500 </row>
1501 <row><entry></entry></row>
1502 <row>
1503 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_SIZE</constant>&nbsp;</entry>
1504 <entry>integer</entry>
1505 </row><row><entry spanname="descr">GOP size (default
150612)</entry>
1507 </row>
1508 <row><entry></entry></row>
1509 <row>
1510 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_CLOSURE</constant>&nbsp;</entry>
1511 <entry>boolean</entry>
1512 </row><row><entry spanname="descr">GOP closure (default
15131)</entry>
1514 </row>
1515 <row><entry></entry></row>
1516 <row>
1517 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_PULLDOWN</constant>&nbsp;</entry>
1518 <entry>boolean</entry>
1519 </row><row><entry spanname="descr">Enable 3:2 pulldown
1520(default 0)</entry>
1521 </row>
1522 <row><entry></entry></row>
1523 <row id="v4l2-mpeg-video-bitrate-mode">
1524 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_MODE</constant>&nbsp;</entry>
1525 <entry>enum&nbsp;v4l2_mpeg_video_bitrate_mode</entry>
1526 </row><row><entry spanname="descr">Video bitrate mode.
1527Possible values are:</entry>
1528 </row>
1529 <row>
1530 <entrytbl spanname="descr" cols="2">
1531 <tbody valign="top">
1532 <row>
1533 <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_VBR</constant>&nbsp;</entry>
1534 <entry>Variable bitrate</entry>
1535 </row>
1536 <row>
1537 <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_CBR</constant>&nbsp;</entry>
1538 <entry>Constant bitrate</entry>
1539 </row>
1540 </tbody>
1541 </entrytbl>
1542 </row>
1543 <row><entry></entry></row>
1544 <row>
1545 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE</constant>&nbsp;</entry>
1546 <entry>integer</entry>
1547 </row><row><entry spanname="descr">Video bitrate in bits
1548per second.</entry>
1549 </row>
1550 <row><entry></entry></row>
1551 <row>
1552 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_PEAK</constant>&nbsp;</entry>
1553 <entry>integer</entry>
1554 </row><row><entry spanname="descr">Peak video bitrate in
1555bits per second. Must be larger or equal to the average video bitrate.
1556It is ignored if the video bitrate mode is set to constant
1557bitrate.</entry>
1558 </row>
1559 <row><entry></entry></row>
1560 <row>
1561 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION</constant>&nbsp;</entry>
1562 <entry>integer</entry>
1563 </row><row><entry spanname="descr">For every captured
1564frame, skip this many subsequent frames (default 0).</entry>
1565 </row>
1566 <row><entry></entry></row>
1567 <row>
1568 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE</constant>&nbsp;</entry>
1569 <entry>boolean</entry>
1570 </row>
1571 <row><entry spanname="descr">"Mutes" the video to a
1572fixed color when capturing. This is useful for testing, to produce a
1573fixed video bitstream. 0 = unmuted, 1 = muted.</entry>
1574 </row>
1575 <row><entry></entry></row>
1576 <row>
1577 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE_YUV</constant>&nbsp;</entry>
1578 <entry>integer</entry>
1579 </row><row><entry spanname="descr">Sets the "mute" color
1580of the video. The supplied 32-bit integer is interpreted as follows (bit
15810 = least significant bit):</entry>
1582 </row>
1583 <row>
1584 <entrytbl spanname="descr" cols="2">
1585 <tbody valign="top">
1586 <row>
1587 <entry>Bit 0:7</entry>
1588 <entry>V chrominance information</entry>
1589 </row>
1590 <row>
1591 <entry>Bit 8:15</entry>
1592 <entry>U chrominance information</entry>
1593 </row>
1594 <row>
1595 <entry>Bit 16:23</entry>
1596 <entry>Y luminance information</entry>
1597 </row>
1598 <row>
1599 <entry>Bit 24:31</entry>
1600 <entry>Must be zero.</entry>
1601 </row>
1602 </tbody>
1603 </entrytbl>
1604 </row>
1605 <row><entry></entry></row>
1606 <row id="v4l2-mpeg-video-dec-pts">
1607 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_PTS</constant>&nbsp;</entry>
1608 <entry>integer64</entry>
1609 </row><row><entry spanname="descr">This read-only control returns the
161033-bit video Presentation Time Stamp as defined in ITU T-REC-H.222.0 and ISO/IEC 13818-1 of
1611the currently displayed frame. This is the same PTS as is used in &VIDIOC-DECODER-CMD;.</entry>
1612 </row>
1613 <row><entry></entry></row>
1614 <row id="v4l2-mpeg-video-dec-frame">
1615 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_FRAME</constant>&nbsp;</entry>
1616 <entry>integer64</entry>
1617 </row><row><entry spanname="descr">This read-only control returns the
1618frame counter of the frame that is currently displayed (decoded). This value is reset to 0 whenever
1619the decoder is started.</entry>
1620 </row>
1621
1622 <row><entry></entry></row>
1623 <row>
1624 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_SLICE_INTERFACE</constant>&nbsp;</entry>
1625 <entry>boolean</entry>
1626 </row>
1627 <row><entry spanname="descr">If enabled the decoder expects to receive a single slice per buffer, otherwise
1628the decoder expects a single frame in per buffer. Applicable to the decoder, all codecs.
1629</entry>
1630 </row>
1631
1632 <row><entry></entry></row>
1633 <row>
1634 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_ENABLE</constant>&nbsp;</entry>
1635 <entry>boolean</entry>
1636 </row>
1637 <row><entry spanname="descr">Enable writing sample aspect ratio in the Video Usability Information.
1638Applicable to the H264 encoder.</entry>
1639 </row>
1640
1641 <row><entry></entry></row>
1642 <row id="v4l2-mpeg-video-h264-vui-sar-idc">
1643 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_IDC</constant>&nbsp;</entry>
1644 <entry>enum&nbsp;v4l2_mpeg_video_h264_vui_sar_idc</entry>
1645 </row>
1646 <row><entry spanname="descr">VUI sample aspect ratio indicator for H.264 encoding. The value
1647is defined in the table E-1 in the standard. Applicable to the H264 encoder.</entry>
1648 </row>
1649 <row>
1650 <entrytbl spanname="descr" cols="2">
1651 <tbody valign="top">
1652
1653 <row>
1654 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_UNSPECIFIED</constant>&nbsp;</entry>
1655 <entry>Unspecified</entry>
1656 </row>
1657 <row>
1658 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_1x1</constant>&nbsp;</entry>
1659 <entry>1x1</entry>
1660 </row>
1661 <row>
1662 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_12x11</constant>&nbsp;</entry>
1663 <entry>12x11</entry>
1664 </row>
1665 <row>
1666 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_10x11</constant>&nbsp;</entry>
1667 <entry>10x11</entry>
1668 </row>
1669 <row>
1670 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_16x11</constant>&nbsp;</entry>
1671 <entry>16x11</entry>
1672 </row>
1673 <row>
1674 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_40x33</constant>&nbsp;</entry>
1675 <entry>40x33</entry>
1676 </row>
1677 <row>
1678 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_24x11</constant>&nbsp;</entry>
1679 <entry>24x11</entry>
1680 </row>
1681 <row>
1682 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_20x11</constant>&nbsp;</entry>
1683 <entry>20x11</entry>
1684 </row>
1685 <row>
1686 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_32x11</constant>&nbsp;</entry>
1687 <entry>32x11</entry>
1688 </row>
1689 <row>
1690 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_80x33</constant>&nbsp;</entry>
1691 <entry>80x33</entry>
1692 </row>
1693 <row>
1694 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_18x11</constant>&nbsp;</entry>
1695 <entry>18x11</entry>
1696 </row>
1697 <row>
1698 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_15x11</constant>&nbsp;</entry>
1699 <entry>15x11</entry>
1700 </row>
1701 <row>
1702 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_64x33</constant>&nbsp;</entry>
1703 <entry>64x33</entry>
1704 </row>
1705 <row>
1706 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_160x99</constant>&nbsp;</entry>
1707 <entry>160x99</entry>
1708 </row>
1709 <row>
1710 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_4x3</constant>&nbsp;</entry>
1711 <entry>4x3</entry>
1712 </row>
1713 <row>
1714 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_3x2</constant>&nbsp;</entry>
1715 <entry>3x2</entry>
1716 </row>
1717 <row>
1718 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_2x1</constant>&nbsp;</entry>
1719 <entry>2x1</entry>
1720 </row>
1721 <row>
1722 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_EXTENDED</constant>&nbsp;</entry>
1723 <entry>Extended SAR</entry>
1724 </row>
1725 </tbody>
1726 </entrytbl>
1727 </row>
1728
1729 <row><entry></entry></row>
1730 <row>
1731 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH</constant>&nbsp;</entry>
1732 <entry>integer</entry>
1733 </row>
1734 <row><entry spanname="descr">Extended sample aspect ratio width for H.264 VUI encoding.
1735Applicable to the H264 encoder.</entry>
1736 </row>
1737
1738 <row><entry></entry></row>
1739 <row>
1740 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT</constant>&nbsp;</entry>
1741 <entry>integer</entry>
1742 </row>
1743 <row><entry spanname="descr">Extended sample aspect ratio height for H.264 VUI encoding.
1744Applicable to the H264 encoder.</entry>
1745 </row>
1746
1747 <row><entry></entry></row>
1748 <row id="v4l2-mpeg-video-h264-level">
1749 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LEVEL</constant>&nbsp;</entry>
1750 <entry>enum&nbsp;v4l2_mpeg_video_h264_level</entry>
1751 </row>
1752 <row><entry spanname="descr">The level information for the H264 video elementary stream.
1753Applicable to the H264 encoder.
1754Possible values are:</entry>
1755 </row>
1756 <row>
1757 <entrytbl spanname="descr" cols="2">
1758 <tbody valign="top">
1759 <row>
1760 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_0</constant>&nbsp;</entry>
1761 <entry>Level 1.0</entry>
1762 </row>
1763 <row>
1764 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1B</constant>&nbsp;</entry>
1765 <entry>Level 1B</entry>
1766 </row>
1767 <row>
1768 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_1</constant>&nbsp;</entry>
1769 <entry>Level 1.1</entry>
1770 </row>
1771 <row>
1772 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_2</constant>&nbsp;</entry>
1773 <entry>Level 1.2</entry>
1774 </row>
1775 <row>
1776 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_3</constant>&nbsp;</entry>
1777 <entry>Level 1.3</entry>
1778 </row>
1779 <row>
1780 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_0</constant>&nbsp;</entry>
1781 <entry>Level 2.0</entry>
1782 </row>
1783 <row>
1784 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_1</constant>&nbsp;</entry>
1785 <entry>Level 2.1</entry>
1786 </row>
1787 <row>
1788 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_2</constant>&nbsp;</entry>
1789 <entry>Level 2.2</entry>
1790 </row>
1791 <row>
1792 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_0</constant>&nbsp;</entry>
1793 <entry>Level 3.0</entry>
1794 </row>
1795 <row>
1796 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_1</constant>&nbsp;</entry>
1797 <entry>Level 3.1</entry>
1798 </row>
1799 <row>
1800 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_2</constant>&nbsp;</entry>
1801 <entry>Level 3.2</entry>
1802 </row>
1803 <row>
1804 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_0</constant>&nbsp;</entry>
1805 <entry>Level 4.0</entry>
1806 </row>
1807 <row>
1808 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_1</constant>&nbsp;</entry>
1809 <entry>Level 4.1</entry>
1810 </row>
1811 <row>
1812 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_2</constant>&nbsp;</entry>
1813 <entry>Level 4.2</entry>
1814 </row>
1815 <row>
1816 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_0</constant>&nbsp;</entry>
1817 <entry>Level 5.0</entry>
1818 </row>
1819 <row>
1820 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_1</constant>&nbsp;</entry>
1821 <entry>Level 5.1</entry>
1822 </row>
1823 </tbody>
1824 </entrytbl>
1825 </row>
1826
1827 <row><entry></entry></row>
1828 <row id="v4l2-mpeg-video-mpeg4-level">
1829 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_LEVEL</constant>&nbsp;</entry>
1830 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_level</entry>
1831 </row>
1832 <row><entry spanname="descr">The level information for the MPEG4 elementary stream.
1833Applicable to the MPEG4 encoder.
1834Possible values are:</entry>
1835 </row>
1836 <row>
1837 <entrytbl spanname="descr" cols="2">
1838 <tbody valign="top">
1839 <row>
1840 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0</constant>&nbsp;</entry>
1841 <entry>Level 0</entry>
1842 </row>
1843 <row>
1844 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0B</constant>&nbsp;</entry>
1845 <entry>Level 0b</entry>
1846 </row>
1847 <row>
1848 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_1</constant>&nbsp;</entry>
1849 <entry>Level 1</entry>
1850 </row>
1851 <row>
1852 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_2</constant>&nbsp;</entry>
1853 <entry>Level 2</entry>
1854 </row>
1855 <row>
1856 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3</constant>&nbsp;</entry>
1857 <entry>Level 3</entry>
1858 </row>
1859 <row>
1860 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3B</constant>&nbsp;</entry>
1861 <entry>Level 3b</entry>
1862 </row>
1863 <row>
1864 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_4</constant>&nbsp;</entry>
1865 <entry>Level 4</entry>
1866 </row>
1867 <row>
1868 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_5</constant>&nbsp;</entry>
1869 <entry>Level 5</entry>
1870 </row>
1871 </tbody>
1872 </entrytbl>
1873 </row>
1874
1875 <row><entry></entry></row>
1876 <row id="v4l2-mpeg-video-h264-profile">
1877 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_PROFILE</constant>&nbsp;</entry>
1878 <entry>enum&nbsp;v4l2_mpeg_video_h264_profile</entry>
1879 </row>
1880 <row><entry spanname="descr">The profile information for H264.
1881Applicable to the H264 encoder.
1882Possible values are:</entry>
1883 </row>
1884 <row>
1885 <entrytbl spanname="descr" cols="2">
1886 <tbody valign="top">
1887 <row>
1888 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE</constant>&nbsp;</entry>
1889 <entry>Baseline profile</entry>
1890 </row>
1891 <row>
1892 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE</constant>&nbsp;</entry>
1893 <entry>Constrained Baseline profile</entry>
1894 </row>
1895 <row>
1896 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MAIN</constant>&nbsp;</entry>
1897 <entry>Main profile</entry>
1898 </row>
1899 <row>
1900 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED</constant>&nbsp;</entry>
1901 <entry>Extended profile</entry>
1902 </row>
1903 <row>
1904 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH</constant>&nbsp;</entry>
1905 <entry>High profile</entry>
1906 </row>
1907 <row>
1908 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10</constant>&nbsp;</entry>
1909 <entry>High 10 profile</entry>
1910 </row>
1911 <row>
1912 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422</constant>&nbsp;</entry>
1913 <entry>High 422 profile</entry>
1914 </row>
1915 <row>
1916 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE</constant>&nbsp;</entry>
1917 <entry>High 444 Predictive profile</entry>
1918 </row>
1919 <row>
1920 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA</constant>&nbsp;</entry>
1921 <entry>High 10 Intra profile</entry>
1922 </row>
1923 <row>
1924 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA</constant>&nbsp;</entry>
1925 <entry>High 422 Intra profile</entry>
1926 </row>
1927 <row>
1928 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA</constant>&nbsp;</entry>
1929 <entry>High 444 Intra profile</entry>
1930 </row>
1931 <row>
1932 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA</constant>&nbsp;</entry>
1933 <entry>CAVLC 444 Intra profile</entry>
1934 </row>
1935 <row>
1936 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE</constant>&nbsp;</entry>
1937 <entry>Scalable Baseline profile</entry>
1938 </row>
1939 <row>
1940 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH</constant>&nbsp;</entry>
1941 <entry>Scalable High profile</entry>
1942 </row>
1943 <row>
1944 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA</constant>&nbsp;</entry>
1945 <entry>Scalable High Intra profile</entry>
1946 </row>
1947 <row>
1948 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH</constant>&nbsp;</entry>
1949 <entry>Stereo High profile</entry>
1950 </row>
1951 <row>
1952 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH</constant>&nbsp;</entry>
1953 <entry>Multiview High profile</entry>
1954 </row>
1955
1956 </tbody>
1957 </entrytbl>
1958 </row>
1959
1960 <row><entry></entry></row>
1961 <row id="v4l2-mpeg-video-mpeg4-profile">
1962 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_PROFILE</constant>&nbsp;</entry>
1963 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_profile</entry>
1964 </row>
1965 <row><entry spanname="descr">The profile information for MPEG4.
1966Applicable to the MPEG4 encoder.
1967Possible values are:</entry>
1968 </row>
1969 <row>
1970 <entrytbl spanname="descr" cols="2">
1971 <tbody valign="top">
1972 <row>
1973 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE</constant>&nbsp;</entry>
1974 <entry>Simple profile</entry>
1975 </row>
1976 <row>
1977 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_SIMPLE</constant>&nbsp;</entry>
1978 <entry>Advanced Simple profile</entry>
1979 </row>
1980 <row>
1981 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_CORE</constant>&nbsp;</entry>
1982 <entry>Core profile</entry>
1983 </row>
1984 <row>
1985 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE_SCALABLE</constant>&nbsp;</entry>
1986 <entry>Simple Scalable profile</entry>
1987 </row>
1988 <row>
1989 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_CODING_EFFICIENCY</constant>&nbsp;</entry>
1990 <entry></entry>
1991 </row>
1992 </tbody>
1993 </entrytbl>
1994 </row>
1995
1996 <row><entry></entry></row>
1997 <row>
1998 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MAX_REF_PIC</constant>&nbsp;</entry>
1999 <entry>integer</entry>
2000 </row>
2001 <row><entry spanname="descr">The maximum number of reference pictures used for encoding.
2002Applicable to the encoder.
2003</entry>
2004 </row>
2005
2006 <row><entry></entry></row>
2007 <row id="v4l2-mpeg-video-multi-slice-mode">
2008 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant>&nbsp;</entry>
2009 <entry>enum&nbsp;v4l2_mpeg_video_multi_slice_mode</entry>
2010 </row>
2011 <row><entry spanname="descr">Determines how the encoder should handle division of frame into slices.
2012Applicable to the encoder.
2013Possible values are:</entry>
2014 </row>
2015 <row>
2016 <entrytbl spanname="descr" cols="2">
2017 <tbody valign="top">
2018 <row>
2019 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_SINGLE</constant>&nbsp;</entry>
2020 <entry>Single slice per frame.</entry>
2021 </row>
2022 <row>
2023 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>&nbsp;</entry>
2024 <entry>Multiple slices with set maximum number of macroblocks per slice.</entry>
2025 </row>
2026 <row>
2027 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>&nbsp;</entry>
2028 <entry>Multiple slice with set maximum size in bytes per slice.</entry>
2029 </row>
2030 </tbody>
2031 </entrytbl>
2032 </row>
2033
2034 <row><entry></entry></row>
2035 <row>
2036 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB</constant>&nbsp;</entry>
2037 <entry>integer</entry>
2038 </row>
2039 <row><entry spanname="descr">The maximum number of macroblocks in a slice. Used when
2040<constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>.
2041Applicable to the encoder.</entry>
2042 </row>
2043
2044 <row><entry></entry></row>
2045 <row>
2046 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES</constant>&nbsp;</entry>
2047 <entry>integer</entry>
2048 </row>
2049 <row><entry spanname="descr">The maximum size of a slice in bytes. Used when
2050<constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>.
2051Applicable to the encoder.</entry>
2052 </row>
2053
2054 <row><entry></entry></row>
2055 <row id="v4l2-mpeg-video-h264-loop-filter-mode">
2056 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_MODE</constant>&nbsp;</entry>
2057 <entry>enum&nbsp;v4l2_mpeg_video_h264_loop_filter_mode</entry>
2058 </row>
2059 <row><entry spanname="descr">Loop filter mode for H264 encoder.
2060Possible values are:</entry>
2061 </row>
2062 <row>
2063 <entrytbl spanname="descr" cols="2">
2064 <tbody valign="top">
2065 <row>
2066 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_ENABLED</constant>&nbsp;</entry>
2067 <entry>Loop filter is enabled.</entry>
2068 </row>
2069 <row>
2070 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED</constant>&nbsp;</entry>
2071 <entry>Loop filter is disabled.</entry>
2072 </row>
2073 <row>
2074 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED_AT_SLICE_BOUNDARY</constant>&nbsp;</entry>
2075 <entry>Loop filter is disabled at the slice boundary.</entry>
2076 </row>
2077 </tbody>
2078 </entrytbl>
2079 </row>
2080
2081 <row><entry></entry></row>
2082 <row>
2083 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_ALPHA</constant>&nbsp;</entry>
2084 <entry>integer</entry>
2085 </row>
2086 <row><entry spanname="descr">Loop filter alpha coefficient, defined in the H264 standard.
2087Applicable to the H264 encoder.</entry>
2088 </row>
2089
2090 <row><entry></entry></row>
2091 <row>
2092 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_BETA</constant>&nbsp;</entry>
2093 <entry>integer</entry>
2094 </row>
2095 <row><entry spanname="descr">Loop filter beta coefficient, defined in the H264 standard.
2096Applicable to the H264 encoder.</entry>
2097 </row>
2098
2099 <row><entry></entry></row>
2100 <row id="v4l2-mpeg-video-h264-entropy-mode">
2101 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE</constant>&nbsp;</entry>
2102 <entry>enum&nbsp;v4l2_mpeg_video_h264_entropy_mode</entry>
2103 </row>
2104 <row><entry spanname="descr">Entropy coding mode for H264 - CABAC/CAVALC.
2105Applicable to the H264 encoder.
2106Possible values are:</entry>
2107 </row>
2108 <row>
2109 <entrytbl spanname="descr" cols="2">
2110 <tbody valign="top">
2111 <row>
2112 <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CAVLC</constant>&nbsp;</entry>
2113 <entry>Use CAVLC entropy coding.</entry>
2114 </row>
2115 <row>
2116 <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CABAC</constant>&nbsp;</entry>
2117 <entry>Use CABAC entropy coding.</entry>
2118 </row>
2119 </tbody>
2120 </entrytbl>
2121 </row>
2122
2123 <row><entry></entry></row>
2124 <row>
2125 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_8X8_TRANSFORM</constant>&nbsp;</entry>
2126 <entry>boolean</entry>
2127 </row>
2128 <row><entry spanname="descr">Enable 8X8 transform for H264. Applicable to the H264 encoder.</entry>
2129 </row>
2130
2131 <row><entry></entry></row>
2132 <row>
2133 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB</constant>&nbsp;</entry>
2134 <entry>integer</entry>
2135 </row>
2136 <row><entry spanname="descr">Cyclic intra macroblock refresh. This is the number of continuous macroblocks
2137refreshed every frame. Each frame a successive set of macroblocks is refreshed until the cycle completes and starts from the
2138top of the frame. Applicable to H264, H263 and MPEG4 encoder.</entry>
2139 </row>
2140
2141 <row><entry></entry></row>
2142 <row>
2143 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE</constant>&nbsp;</entry>
2144 <entry>boolean</entry>
2145 </row>
2146 <row><entry spanname="descr">Frame level rate control enable.
2147If this control is disabled then the quantization parameter for each frame type is constant and set with appropriate controls
2148(e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>).
2149If frame rate control is enabled then quantization parameter is adjusted to meet the chosen bitrate. Minimum and maximum value
2150for the quantization parameter can be set with appropriate controls (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>).
2151Applicable to encoders.</entry>
2152 </row>
2153
2154 <row><entry></entry></row>
2155 <row>
2156 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>&nbsp;</entry>
2157 <entry>boolean</entry>
2158 </row>
2159 <row><entry spanname="descr">Macroblock level rate control enable.
2160Applicable to the MPEG4 and H264 encoders.</entry>
2161 </row>
2162
2163 <row><entry></entry></row>
2164 <row>
2165 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_QPEL</constant>&nbsp;</entry>
2166 <entry>boolean</entry>
2167 </row>
2168 <row><entry spanname="descr">Quarter pixel motion estimation for MPEG4. Applicable to the MPEG4 encoder.</entry>
2169 </row>
2170
2171 <row><entry></entry></row>
2172 <row>
2173 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>&nbsp;</entry>
2174 <entry>integer</entry>
2175 </row>
2176 <row><entry spanname="descr">Quantization parameter for an I frame for H263. Valid range: from 1 to 31.</entry>
2177 </row>
2178
2179 <row><entry></entry></row>
2180 <row>
2181 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>&nbsp;</entry>
2182 <entry>integer</entry>
2183 </row>
2184 <row><entry spanname="descr">Minimum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2185 </row>
2186
2187 <row><entry></entry></row>
2188 <row>
2189 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MAX_QP</constant>&nbsp;</entry>
2190 <entry>integer</entry>
2191 </row>
2192 <row><entry spanname="descr">Maximum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2193 </row>
2194
2195 <row><entry></entry></row>
2196 <row>
2197 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_P_FRAME_QP</constant>&nbsp;</entry>
2198 <entry>integer</entry>
2199 </row>
2200 <row><entry spanname="descr">Quantization parameter for an P frame for H263. Valid range: from 1 to 31.</entry>
2201 </row>
2202
2203 <row><entry></entry></row>
2204 <row>
2205 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_B_FRAME_QP</constant>&nbsp;</entry>
2206 <entry>integer</entry>
2207 </row>
2208 <row><entry spanname="descr">Quantization parameter for an B frame for H263. Valid range: from 1 to 31.</entry>
2209 </row>
2210
2211 <row><entry></entry></row>
2212 <row>
2213 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP</constant>&nbsp;</entry>
2214 <entry>integer</entry>
2215 </row>
2216 <row><entry spanname="descr">Quantization parameter for an I frame for H264. Valid range: from 0 to 51.</entry>
2217 </row>
2218
2219 <row><entry></entry></row>
2220 <row>
2221 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MIN_QP</constant>&nbsp;</entry>
2222 <entry>integer</entry>
2223 </row>
2224 <row><entry spanname="descr">Minimum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2225 </row>
2226
2227 <row><entry></entry></row>
2228 <row>
2229 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MAX_QP</constant>&nbsp;</entry>
2230 <entry>integer</entry>
2231 </row>
2232 <row><entry spanname="descr">Maximum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2233 </row>
2234
2235 <row><entry></entry></row>
2236 <row>
2237 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP</constant>&nbsp;</entry>
2238 <entry>integer</entry>
2239 </row>
2240 <row><entry spanname="descr">Quantization parameter for an P frame for H264. Valid range: from 0 to 51.</entry>
2241 </row>
2242
2243 <row><entry></entry></row>
2244 <row>
2245 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP</constant>&nbsp;</entry>
2246 <entry>integer</entry>
2247 </row>
2248 <row><entry spanname="descr">Quantization parameter for an B frame for H264. Valid range: from 0 to 51.</entry>
2249 </row>
2250
2251 <row><entry></entry></row>
2252 <row>
2253 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP</constant>&nbsp;</entry>
2254 <entry>integer</entry>
2255 </row>
2256 <row><entry spanname="descr">Quantization parameter for an I frame for MPEG4. Valid range: from 1 to 31.</entry>
2257 </row>
2258
2259 <row><entry></entry></row>
2260 <row>
2261 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MIN_QP</constant>&nbsp;</entry>
2262 <entry>integer</entry>
2263 </row>
2264 <row><entry spanname="descr">Minimum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2265 </row>
2266
2267 <row><entry></entry></row>
2268 <row>
2269 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MAX_QP</constant>&nbsp;</entry>
2270 <entry>integer</entry>
2271 </row>
2272 <row><entry spanname="descr">Maximum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2273 </row>
2274
2275 <row><entry></entry></row>
2276 <row>
2277 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP</constant>&nbsp;</entry>
2278 <entry>integer</entry>
2279 </row>
2280 <row><entry spanname="descr">Quantization parameter for an P frame for MPEG4. Valid range: from 1 to 31.</entry>
2281 </row>
2282
2283 <row><entry></entry></row>
2284 <row>
2285 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP</constant>&nbsp;</entry>
2286 <entry>integer</entry>
2287 </row>
2288 <row><entry spanname="descr">Quantization parameter for an B frame for MPEG4. Valid range: from 1 to 31.</entry>
2289 </row>
2290
2291 <row><entry></entry></row>
2292 <row>
2293 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_SIZE</constant>&nbsp;</entry>
2294 <entry>integer</entry>
2295 </row>
2296 <row><entry spanname="descr">The Video Buffer Verifier size in kilobytes, it is used as a limitation of frame skip.
2297The VBV is defined in the standard as a mean to verify that the produced stream will be successfully decoded.
2298The standard describes it as "Part of a hypothetical decoder that is conceptually connected to the
2299output of the encoder. Its purpose is to provide a constraint on the variability of the data rate that an
2300encoder or editing process may produce.".
2301Applicable to the MPEG1, MPEG2, MPEG4 encoders.</entry>
2302 </row>
2303
2304 <row><entry></entry></row>
2305 <row id="v4l2-mpeg-video-vbv-delay">
2306 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_DELAY</constant>&nbsp;</entry>
2307 <entry>integer</entry>
2308 </row><row><entry spanname="descr">Sets the initial delay in milliseconds for
2309VBV buffer control.</entry>
2310 </row>
2311
2312 <row><entry></entry></row>
2313 <row id="v4l2-mpeg-video-hor-search-range">
2314 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MV_H_SEARCH_RANGE</constant>&nbsp;</entry>
2315 <entry>integer</entry>
2316 </row>
2317 <row><entry spanname="descr">Horizontal search range defines maximum horizontal search area in pixels
2318to search and match for the present Macroblock (MB) in the reference picture. This V4L2 control macro is used to set
2319horizontal search range for motion estimation module in video encoder.</entry>
2320 </row>
2321
2322 <row><entry></entry></row>
2323 <row id="v4l2-mpeg-video-vert-search-range">
2324 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MV_V_SEARCH_RANGE</constant>&nbsp;</entry>
2325 <entry>integer</entry>
2326 </row>
2327 <row><entry spanname="descr">Vertical search range defines maximum vertical search area in pixels
2328to search and match for the present Macroblock (MB) in the reference picture. This V4L2 control macro is used to set
2329vertical search range for motion estimation module in video encoder.</entry>
2330 </row>
2331
2332 <row><entry></entry></row>
2333 <row>
2334 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE</constant>&nbsp;</entry>
2335 <entry>integer</entry>
2336 </row>
2337 <row><entry spanname="descr">The Coded Picture Buffer size in kilobytes, it is used as a limitation of frame skip.
2338The CPB is defined in the H264 standard as a mean to verify that the produced stream will be successfully decoded.
2339Applicable to the H264 encoder.</entry>
2340 </row>
2341
2342 <row><entry></entry></row>
2343 <row>
2344 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_PERIOD</constant>&nbsp;</entry>
2345 <entry>integer</entry>
2346 </row>
2347 <row><entry spanname="descr">Period between I-frames in the open GOP for H264. In case of an open GOP
2348this is the period between two I-frames. The period between IDR (Instantaneous Decoding Refresh) frames is taken from the GOP_SIZE control.
2349An IDR frame, which stands for Instantaneous Decoding Refresh is an I-frame after which no prior frames are
2350referenced. This means that a stream can be restarted from an IDR frame without the need to store or decode any
2351previous frames. Applicable to the H264 encoder.</entry>
2352 </row>
2353
2354 <row><entry></entry></row>
2355 <row id="v4l2-mpeg-video-header-mode">
2356 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_HEADER_MODE</constant>&nbsp;</entry>
2357 <entry>enum&nbsp;v4l2_mpeg_video_header_mode</entry>
2358 </row>
2359 <row><entry spanname="descr">Determines whether the header is returned as the first buffer or is
2360it returned together with the first frame. Applicable to encoders.
2361Possible values are:</entry>
2362 </row>
2363 <row>
2364 <entrytbl spanname="descr" cols="2">
2365 <tbody valign="top">
2366 <row>
2367 <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_SEPARATE</constant>&nbsp;</entry>
2368 <entry>The stream header is returned separately in the first buffer.</entry>
2369 </row>
2370 <row>
2371 <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_JOINED_WITH_1ST_FRAME</constant>&nbsp;</entry>
2372 <entry>The stream header is returned together with the first encoded frame.</entry>
2373 </row>
2374 </tbody>
2375 </entrytbl>
2376 </row>
2377 <row><entry></entry></row>
2378 <row>
2379 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER</constant>&nbsp;</entry>
2380 <entry>boolean</entry>
2381 </row><row><entry spanname="descr">Repeat the video sequence headers. Repeating these
2382headers makes random access to the video stream easier. Applicable to the MPEG1, 2 and 4 encoder.</entry>
2383 </row>
2384 <row>
2385 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_MPEG4_DEBLOCK_FILTER</constant>&nbsp;</entry>
2386 <entry>boolean</entry>
2387 </row><row><entry spanname="descr">Enabled the deblocking post processing filter for MPEG4 decoder.
2388Applicable to the MPEG4 decoder.</entry>
2389 </row>
2390 <row><entry></entry></row>
2391 <row>
2392 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_RES</constant>&nbsp;</entry>
2393 <entry>integer</entry>
2394 </row><row><entry spanname="descr">vop_time_increment_resolution value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2395 </row>
2396 <row><entry></entry></row>
2397 <row>
2398 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_INC</constant>&nbsp;</entry>
2399 <entry>integer</entry>
2400 </row><row><entry spanname="descr">vop_time_increment value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2401 </row>
2402
2403 <row><entry></entry></row>
2404 <row>
2405 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FRAME_PACKING</constant>&nbsp;</entry>
2406 <entry>boolean</entry>
2407 </row>
2408 <row><entry spanname="descr">Enable generation of frame packing supplemental enhancement information in the encoded bitstream.
2409The frame packing SEI message contains the arrangement of L and R planes for 3D viewing. Applicable to the H264 encoder.</entry>
2410 </row>
2411
2412 <row><entry></entry></row>
2413 <row>
2414 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_CURRENT_FRAME_0</constant>&nbsp;</entry>
2415 <entry>boolean</entry>
2416 </row>
2417 <row><entry spanname="descr">Sets current frame as frame0 in frame packing SEI.
2418Applicable to the H264 encoder.</entry>
2419 </row>
2420
2421 <row><entry></entry></row>
2422 <row id="v4l2-mpeg-video-h264-sei-fp-arrangement-type">
2423 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE</constant>&nbsp;</entry>
2424 <entry>enum&nbsp;v4l2_mpeg_video_h264_sei_fp_arrangement_type</entry>
2425 </row>
2426 <row><entry spanname="descr">Frame packing arrangement type for H264 SEI.
2427Applicable to the H264 encoder.
2428Possible values are:</entry>
2429 </row>
2430 <row>
2431 <entrytbl spanname="descr" cols="2">
2432 <tbody valign="top">
2433 <row>
2434 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_CHEKERBOARD</constant>&nbsp;</entry>
2435 <entry>Pixels are alternatively from L and R.</entry>
2436 </row>
2437 <row>
2438 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_COLUMN</constant>&nbsp;</entry>
2439 <entry>L and R are interlaced by column.</entry>
2440 </row>
2441 <row>
2442 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_ROW</constant>&nbsp;</entry>
2443 <entry>L and R are interlaced by row.</entry>
2444 </row>
2445 <row>
2446 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_SIDE_BY_SIDE</constant>&nbsp;</entry>
2447 <entry>L is on the left, R on the right.</entry>
2448 </row>
2449 <row>
2450 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TOP_BOTTOM</constant>&nbsp;</entry>
2451 <entry>L is on top, R on bottom.</entry>
2452 </row>
2453 <row>
2454 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TEMPORAL</constant>&nbsp;</entry>
2455 <entry>One view per frame.</entry>
2456 </row>
2457 </tbody>
2458 </entrytbl>
2459 </row>
2460
2461 <row><entry></entry></row>
2462 <row>
2463 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO</constant>&nbsp;</entry>
2464 <entry>boolean</entry>
2465 </row>
2466 <row><entry spanname="descr">Enables flexible macroblock ordering in the encoded bitstream. It is a technique
2467used for restructuring the ordering of macroblocks in pictures. Applicable to the H264 encoder.</entry>
2468 </row>
2469
2470 <row><entry></entry></row>
2471 <row id="v4l2-mpeg-video-h264-fmo-map-type">
2472 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_MAP_TYPE</constant>&nbsp;</entry>
2473 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_map_type</entry>
2474 </row>
2475 <row><entry spanname="descr">When using FMO, the map type divides the image in different scan patterns of macroblocks.
2476Applicable to the H264 encoder.
2477Possible values are:</entry>
2478 </row>
2479 <row>
2480 <entrytbl spanname="descr" cols="2">
2481 <tbody valign="top">
2482 <row>
2483 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_INTERLEAVED_SLICES</constant>&nbsp;</entry>
2484 <entry>Slices are interleaved one after other with macroblocks in run length order.</entry>
2485 </row>
2486 <row>
2487 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_SCATTERED_SLICES</constant>&nbsp;</entry>
2488 <entry>Scatters the macroblocks based on a mathematical function known to both encoder and decoder.</entry>
2489 </row>
2490 <row>
2491 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_FOREGROUND_WITH_LEFT_OVER</constant>&nbsp;</entry>
2492 <entry>Macroblocks arranged in rectangular areas or regions of interest.</entry>
2493 </row>
2494 <row>
2495 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_BOX_OUT</constant>&nbsp;</entry>
2496 <entry>Slice groups grow in a cyclic way from centre to outwards.</entry>
2497 </row>
2498 <row>
2499 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_RASTER_SCAN</constant>&nbsp;</entry>
2500 <entry>Slice groups grow in raster scan pattern from left to right.</entry>
2501 </row>
2502 <row>
2503 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_WIPE_SCAN</constant>&nbsp;</entry>
2504 <entry>Slice groups grow in wipe scan pattern from top to bottom.</entry>
2505 </row>
2506 <row>
2507 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_EXPLICIT</constant>&nbsp;</entry>
2508 <entry>User defined map type.</entry>
2509 </row>
2510 </tbody>
2511 </entrytbl>
2512 </row>
2513
2514 <row><entry></entry></row>
2515 <row>
2516 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_SLICE_GROUP</constant>&nbsp;</entry>
2517 <entry>integer</entry>
2518 </row>
2519 <row><entry spanname="descr">Number of slice groups in FMO.
2520Applicable to the H264 encoder.</entry>
2521 </row>
2522
2523 <row><entry></entry></row>
2524 <row id="v4l2-mpeg-video-h264-fmo-change-direction">
2525 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_DIRECTION</constant>&nbsp;</entry>
2526 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_change_dir</entry>
2527 </row>
2528 <row><entry spanname="descr">Specifies a direction of the slice group change for raster and wipe maps.
2529Applicable to the H264 encoder.
2530Possible values are:</entry>
2531 </row>
2532 <row>
2533 <entrytbl spanname="descr" cols="2">
2534 <tbody valign="top">
2535 <row>
2536 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_RIGHT</constant>&nbsp;</entry>
2537 <entry>Raster scan or wipe right.</entry>
2538 </row>
2539 <row>
2540 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_LEFT</constant>&nbsp;</entry>
2541 <entry>Reverse raster scan or wipe left.</entry>
2542 </row>
2543 </tbody>
2544 </entrytbl>
2545 </row>
2546
2547 <row><entry></entry></row>
2548 <row>
2549 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_RATE</constant>&nbsp;</entry>
2550 <entry>integer</entry>
2551 </row>
2552 <row><entry spanname="descr">Specifies the size of the first slice group for raster and wipe map.
2553Applicable to the H264 encoder.</entry>
2554 </row>
2555
2556 <row><entry></entry></row>
2557 <row>
2558 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_RUN_LENGTH</constant>&nbsp;</entry>
2559 <entry>integer</entry>
2560 </row>
2561 <row><entry spanname="descr">Specifies the number of consecutive macroblocks for the interleaved map.
2562Applicable to the H264 encoder.</entry>
2563 </row>
2564
2565 <row><entry></entry></row>
2566 <row>
2567 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO</constant>&nbsp;</entry>
2568 <entry>boolean</entry>
2569 </row>
2570 <row><entry spanname="descr">Enables arbitrary slice ordering in encoded bitstream.
2571Applicable to the H264 encoder.</entry>
2572 </row>
2573
2574 <row><entry></entry></row>
2575 <row>
2576 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO_SLICE_ORDER</constant>&nbsp;</entry>
2577 <entry>integer</entry>
2578 </row><row><entry spanname="descr">Specifies the slice order in ASO. Applicable to the H264 encoder.
2579The supplied 32-bit integer is interpreted as follows (bit
25800 = least significant bit):</entry>
2581 </row>
2582 <row>
2583 <entrytbl spanname="descr" cols="2">
2584 <tbody valign="top">
2585 <row>
2586 <entry>Bit 0:15</entry>
2587 <entry>Slice ID</entry>
2588 </row>
2589 <row>
2590 <entry>Bit 16:32</entry>
2591 <entry>Slice position or order</entry>
2592 </row>
2593 </tbody>
2594 </entrytbl>
2595 </row>
2596
2597 <row><entry></entry></row>
2598 <row>
2599 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING</constant>&nbsp;</entry>
2600 <entry>boolean</entry>
2601 </row>
2602 <row><entry spanname="descr">Enables H264 hierarchical coding.
2603Applicable to the H264 encoder.</entry>
2604 </row>
2605
2606 <row><entry></entry></row>
2607 <row id="v4l2-mpeg-video-h264-hierarchical-coding-type">
2608 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_TYPE</constant>&nbsp;</entry>
2609 <entry>enum&nbsp;v4l2_mpeg_video_h264_hierarchical_coding_type</entry>
2610 </row>
2611 <row><entry spanname="descr">Specifies the hierarchical coding type.
2612Applicable to the H264 encoder.
2613Possible values are:</entry>
2614 </row>
2615 <row>
2616 <entrytbl spanname="descr" cols="2">
2617 <tbody valign="top">
2618 <row>
2619 <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_B</constant>&nbsp;</entry>
2620 <entry>Hierarchical B coding.</entry>
2621 </row>
2622 <row>
2623 <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_P</constant>&nbsp;</entry>
2624 <entry>Hierarchical P coding.</entry>
2625 </row>
2626 </tbody>
2627 </entrytbl>
2628 </row>
2629
2630 <row><entry></entry></row>
2631 <row>
2632 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER</constant>&nbsp;</entry>
2633 <entry>integer</entry>
2634 </row>
2635 <row><entry spanname="descr">Specifies the number of hierarchical coding layers.
2636Applicable to the H264 encoder.</entry>
2637 </row>
2638
2639 <row><entry></entry></row>
2640 <row>
2641 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP</constant>&nbsp;</entry>
2642 <entry>integer</entry>
2643 </row><row><entry spanname="descr">Specifies a user defined QP for each layer. Applicable to the H264 encoder.
2644The supplied 32-bit integer is interpreted as follows (bit
26450 = least significant bit):</entry>
2646 </row>
2647 <row>
2648 <entrytbl spanname="descr" cols="2">
2649 <tbody valign="top">
2650 <row>
2651 <entry>Bit 0:15</entry>
2652 <entry>QP value</entry>
2653 </row>
2654 <row>
2655 <entry>Bit 16:32</entry>
2656 <entry>Layer number</entry>
2657 </row>
2658 </tbody>
2659 </entrytbl>
2660 </row>
2661
2662 </tbody>
2663 </tgroup>
2664 </table>
2665 </section>
2666
2667 <section>
2668 <title>MFC 5.1 MPEG Controls</title>
2669
2670 <para>The following MPEG class controls deal with MPEG
2671decoding and encoding settings that are specific to the Multi Format Codec 5.1 device present
2672in the S5P family of SoCs by Samsung.
2673</para>
2674
2675 <table pgwide="1" frame="none" id="mfc51-control-id">
2676 <title>MFC 5.1 Control IDs</title>
2677 <tgroup cols="4">
2678 <colspec colname="c1" colwidth="1*" />
2679 <colspec colname="c2" colwidth="6*" />
2680 <colspec colname="c3" colwidth="2*" />
2681 <colspec colname="c4" colwidth="6*" />
2682 <spanspec namest="c1" nameend="c2" spanname="id" />
2683 <spanspec namest="c2" nameend="c4" spanname="descr" />
2684 <thead>
2685 <row>
2686 <entry spanname="id" align="left">ID</entry>
2687 <entry align="left">Type</entry>
2688 </row><row><entry spanname="descr" align="left">Description</entry>
2689 </row>
2690 </thead>
2691 <tbody valign="top">
2692 <row><entry></entry></row>
2693 <row>
2694 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY_ENABLE</constant>&nbsp;</entry>
2695 <entry>boolean</entry>
2696 </row><row><entry spanname="descr">If the display delay is enabled then the decoder is forced to return a
2697CAPTURE buffer (decoded frame) after processing a certain number of OUTPUT buffers. The delay can be set through
2698<constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY</constant>. This feature can be used for example
2699for generating thumbnails of videos. Applicable to the H264 decoder.
2700 </entry>
2701 </row>
2702 <row><entry></entry></row>
2703 <row>
2704 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY</constant>&nbsp;</entry>
2705 <entry>integer</entry>
2706 </row><row><entry spanname="descr">Display delay value for H264 decoder.
2707The decoder is forced to return a decoded frame after the set 'display delay' number of frames. If this number is
2708low it may result in frames returned out of dispaly order, in addition the hardware may still be using the returned buffer
2709as a reference picture for subsequent frames.
2710</entry>
2711 </row>
2712 <row><entry></entry></row>
2713 <row>
2714 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_NUM_REF_PIC_FOR_P</constant>&nbsp;</entry>
2715 <entry>integer</entry>
2716 </row><row><entry spanname="descr">The number of reference pictures used for encoding a P picture.
2717Applicable to the H264 encoder.</entry>
2718 </row>
2719 <row><entry></entry></row>
2720 <row>
2721 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING</constant>&nbsp;</entry>
2722 <entry>boolean</entry>
2723 </row><row><entry spanname="descr">Padding enable in the encoder - use a color instead of repeating border pixels.
2724Applicable to encoders.</entry>
2725 </row>
2726 <row><entry></entry></row>
2727 <row>
2728 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING_YUV</constant>&nbsp;</entry>
2729 <entry>integer</entry>
2730 </row><row><entry spanname="descr">Padding color in the encoder. Applicable to encoders. The supplied 32-bit integer is interpreted as follows (bit
27310 = least significant bit):</entry>
2732 </row>
2733 <row>
2734 <entrytbl spanname="descr" cols="2">
2735 <tbody valign="top">
2736 <row>
2737 <entry>Bit 0:7</entry>
2738 <entry>V chrominance information</entry>
2739 </row>
2740 <row>
2741 <entry>Bit 8:15</entry>
2742 <entry>U chrominance information</entry>
2743 </row>
2744 <row>
2745 <entry>Bit 16:23</entry>
2746 <entry>Y luminance information</entry>
2747 </row>
2748 <row>
2749 <entry>Bit 24:31</entry>
2750 <entry>Must be zero.</entry>
2751 </row>
2752 </tbody>
2753 </entrytbl>
2754 </row>
2755 <row><entry></entry></row>
2756 <row>
2757 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_REACTION_COEFF</constant>&nbsp;</entry>
2758 <entry>integer</entry>
2759 </row><row><entry spanname="descr">Reaction coefficient for MFC rate control. Applicable to encoders.
2760<para>Note 1: Valid only when the frame level RC is enabled.</para>
2761<para>Note 2: For tight CBR, this field must be small (ex. 2 ~ 10).
2762For VBR, this field must be large (ex. 100 ~ 1000).</para>
2763<para>Note 3: It is not recommended to use the greater number than FRAME_RATE * (10^9 / BIT_RATE).</para>
2764</entry>
2765 </row>
2766 <row><entry></entry></row>
2767 <row>
2768 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_DARK</constant>&nbsp;</entry>
2769 <entry>boolean</entry>
2770 </row><row><entry spanname="descr">Adaptive rate control for dark region.
2771Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2772Applicable to the H264 encoder.</entry>
2773 </row>
2774 <row><entry></entry></row>
2775 <row>
2776 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_SMOOTH</constant>&nbsp;</entry>
2777 <entry>boolean</entry>
2778 </row><row><entry spanname="descr">Adaptive rate control for smooth region.
2779Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2780Applicable to the H264 encoder.</entry>
2781 </row>
2782 <row><entry></entry></row>
2783 <row>
2784 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_STATIC</constant>&nbsp;</entry>
2785 <entry>boolean</entry>
2786 </row><row><entry spanname="descr">Adaptive rate control for static region.
2787Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2788Applicable to the H264 encoder.</entry>
2789 </row>
2790 <row><entry></entry></row>
2791 <row>
2792 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_ACTIVITY</constant>&nbsp;</entry>
2793 <entry>boolean</entry>
2794 </row><row><entry spanname="descr">Adaptive rate control for activity region.
2795Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2796Applicable to the H264 encoder.</entry>
2797 </row>
2798 <row><entry></entry></row>
2799 <row id="v4l2-mpeg-mfc51-video-frame-skip-mode">
2800 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FRAME_SKIP_MODE</constant>&nbsp;</entry>
2801 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_frame_skip_mode</entry>
2802 </row>
2803 <row><entry spanname="descr">
2804Indicates in what conditions the encoder should skip frames. If encoding a frame would cause the encoded stream to be larger then
2805a chosen data limit then the frame will be skipped.
2806Possible values are:</entry>
2807 </row>
2808 <row>
2809 <entrytbl spanname="descr" cols="2">
2810 <tbody valign="top">
2811 <row>
2812 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_DISABLED</constant>&nbsp;</entry>
2813 <entry>Frame skip mode is disabled.</entry>
2814 </row>
2815 <row>
2816 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_LEVEL_LIMIT</constant>&nbsp;</entry>
2817 <entry>Frame skip mode enabled and buffer limit is set by the chosen level and is defined by the standard.</entry>
2818 </row>
2819 <row>
2820 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_BUF_LIMIT</constant>&nbsp;</entry>
2821 <entry>Frame skip mode enabled and buffer limit is set by the VBV (MPEG1/2/4) or CPB (H264) buffer size control.</entry>
2822 </row>
2823 </tbody>
2824 </entrytbl>
2825 </row>
2826 <row><entry></entry></row>
2827 <row>
2828 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_FIXED_TARGET_BIT</constant>&nbsp;</entry>
2829 <entry>integer</entry>
2830 </row><row><entry spanname="descr">Enable rate-control with fixed target bit.
2831If this setting is enabled, then the rate control logic of the encoder will calculate the average bitrate
2832for a GOP and keep it below or equal the set bitrate target. Otherwise the rate control logic calculates the
2833overall average bitrate for the stream and keeps it below or equal to the set bitrate. In the first case
2834the average bitrate for the whole stream will be smaller then the set bitrate. This is caused because the
2835average is calculated for smaller number of frames, on the other hand enabling this setting will ensure that
2836the stream will meet tight bandwidth contraints. Applicable to encoders.
2837</entry>
2838 </row>
2839 <row><entry></entry></row>
2840 <row id="v4l2-mpeg-mfc51-video-force-frame-type">
2841 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FORCE_FRAME_TYPE</constant>&nbsp;</entry>
2842 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_force_frame_type</entry>
2843 </row>
2844 <row><entry spanname="descr">Force a frame type for the next queued buffer. Applicable to encoders.
2845Possible values are:</entry>
2846 </row>
2847 <row>
2848 <entrytbl spanname="descr" cols="2">
2849 <tbody valign="top">
2850 <row>
2851 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_DISABLED</constant>&nbsp;</entry>
2852 <entry>Forcing a specific frame type disabled.</entry>
2853 </row>
2854 <row>
2855 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_I_FRAME</constant>&nbsp;</entry>
2856 <entry>Force an I-frame.</entry>
2857 </row>
2858 <row>
2859 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_NOT_CODED</constant>&nbsp;</entry>
2860 <entry>Force a non-coded frame.</entry>
2861 </row>
2862 </tbody>
2863 </entrytbl>
2864 </row>
2865 </tbody>
2866 </tgroup>
2867 </table>
2868 </section>
2869
2870 <section>
2871 <title>CX2341x MPEG Controls</title>
2872
2873 <para>The following MPEG class controls deal with MPEG
2874encoding settings that are specific to the Conexant CX23415 and
2875CX23416 MPEG encoding chips.</para>
2876
2877 <table pgwide="1" frame="none" id="cx2341x-control-id">
2878 <title>CX2341x Control IDs</title>
2879 <tgroup cols="4">
2880 <colspec colname="c1" colwidth="1*" />
2881 <colspec colname="c2" colwidth="6*" />
2882 <colspec colname="c3" colwidth="2*" />
2883 <colspec colname="c4" colwidth="6*" />
2884 <spanspec namest="c1" nameend="c2" spanname="id" />
2885 <spanspec namest="c2" nameend="c4" spanname="descr" />
2886 <thead>
2887 <row>
2888 <entry spanname="id" align="left">ID</entry>
2889 <entry align="left">Type</entry>
2890 </row><row><entry spanname="descr" align="left">Description</entry>
2891 </row>
2892 </thead>
2893 <tbody valign="top">
2894 <row><entry></entry></row>
2895 <row id="v4l2-mpeg-cx2341x-video-spatial-filter-mode">
2896 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE</constant>&nbsp;</entry>
2897 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_spatial_filter_mode</entry>
2898 </row><row><entry spanname="descr">Sets the Spatial
2899Filter mode (default <constant>MANUAL</constant>). Possible values
2900are:</entry>
2901 </row>
2902 <row>
2903 <entrytbl spanname="descr" cols="2">
2904 <tbody valign="top">
2905 <row>
2906 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2907 <entry>Choose the filter manually</entry>
2908 </row>
2909 <row>
2910 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2911 <entry>Choose the filter automatically</entry>
2912 </row>
2913 </tbody>
2914 </entrytbl>
2915 </row>
2916 <row><entry></entry></row>
2917 <row>
2918 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER</constant>&nbsp;</entry>
2919 <entry>integer&nbsp;(0-15)</entry>
2920 </row><row><entry spanname="descr">The setting for the
2921Spatial Filter. 0 = off, 15 = maximum. (Default is 0.)</entry>
2922 </row>
2923 <row><entry></entry></row>
2924 <row id="luma-spatial-filter-type">
2925 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2926 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_luma_spatial_filter_type</entry>
2927 </row><row><entry spanname="descr">Select the algorithm
2928to use for the Luma Spatial Filter (default
2929<constant>1D_HOR</constant>). Possible values:</entry>
2930 </row>
2931 <row>
2932 <entrytbl spanname="descr" cols="2">
2933 <tbody valign="top">
2934 <row>
2935 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2936 <entry>No filter</entry>
2937 </row>
2938 <row>
2939 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2940 <entry>One-dimensional horizontal</entry>
2941 </row>
2942 <row>
2943 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_VERT</constant>&nbsp;</entry>
2944 <entry>One-dimensional vertical</entry>
2945 </row>
2946 <row>
2947 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_HV_SEPARABLE</constant>&nbsp;</entry>
2948 <entry>Two-dimensional separable</entry>
2949 </row>
2950 <row>
2951 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_SYM_NON_SEPARABLE</constant>&nbsp;</entry>
2952 <entry>Two-dimensional symmetrical
2953non-separable</entry>
2954 </row>
2955 </tbody>
2956 </entrytbl>
2957 </row>
2958 <row><entry></entry></row>
2959 <row id="chroma-spatial-filter-type">
2960 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2961 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_chroma_spatial_filter_type</entry>
2962 </row><row><entry spanname="descr">Select the algorithm
2963for the Chroma Spatial Filter (default <constant>1D_HOR</constant>).
2964Possible values are:</entry>
2965 </row>
2966 <row>
2967 <entrytbl spanname="descr" cols="2">
2968 <tbody valign="top">
2969 <row>
2970 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2971 <entry>No filter</entry>
2972 </row>
2973 <row>
2974 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2975 <entry>One-dimensional horizontal</entry>
2976 </row>
2977 </tbody>
2978 </entrytbl>
2979 </row>
2980 <row><entry></entry></row>
2981 <row id="v4l2-mpeg-cx2341x-video-temporal-filter-mode">
2982 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE</constant>&nbsp;</entry>
2983 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_temporal_filter_mode</entry>
2984 </row><row><entry spanname="descr">Sets the Temporal
2985Filter mode (default <constant>MANUAL</constant>). Possible values
2986are:</entry>
2987 </row>
2988 <row>
2989 <entrytbl spanname="descr" cols="2">
2990 <tbody valign="top">
2991 <row>
2992 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2993 <entry>Choose the filter manually</entry>
2994 </row>
2995 <row>
2996 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2997 <entry>Choose the filter automatically</entry>
2998 </row>
2999 </tbody>
3000 </entrytbl>
3001 </row>
3002 <row><entry></entry></row>
3003 <row>
3004 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER</constant>&nbsp;</entry>
3005 <entry>integer&nbsp;(0-31)</entry>
3006 </row><row><entry spanname="descr">The setting for the
3007Temporal Filter. 0 = off, 31 = maximum. (Default is 8 for full-scale
3008capturing and 0 for scaled capturing.)</entry>
3009 </row>
3010 <row><entry></entry></row>
3011 <row id="v4l2-mpeg-cx2341x-video-median-filter-type">
3012 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE</constant>&nbsp;</entry>
3013 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_median_filter_type</entry>
3014 </row><row><entry spanname="descr">Median Filter Type
3015(default <constant>OFF</constant>). Possible values are:</entry>
3016 </row>
3017 <row>
3018 <entrytbl spanname="descr" cols="2">
3019 <tbody valign="top">
3020 <row>
3021 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_OFF</constant>&nbsp;</entry>
3022 <entry>No filter</entry>
3023 </row>
3024 <row>
3025 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR</constant>&nbsp;</entry>
3026 <entry>Horizontal filter</entry>
3027 </row>
3028 <row>
3029 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_VERT</constant>&nbsp;</entry>
3030 <entry>Vertical filter</entry>
3031 </row>
3032 <row>
3033 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR_VERT</constant>&nbsp;</entry>
3034 <entry>Horizontal and vertical filter</entry>
3035 </row>
3036 <row>
3037 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_DIAG</constant>&nbsp;</entry>
3038 <entry>Diagonal filter</entry>
3039 </row>
3040 </tbody>
3041 </entrytbl>
3042 </row>
3043 <row><entry></entry></row>
3044 <row>
3045 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
3046 <entry>integer&nbsp;(0-255)</entry>
3047 </row><row><entry spanname="descr">Threshold above which
3048the luminance median filter is enabled (default 0)</entry>
3049 </row>
3050 <row><entry></entry></row>
3051 <row>
3052 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
3053 <entry>integer&nbsp;(0-255)</entry>
3054 </row><row><entry spanname="descr">Threshold below which
3055the luminance median filter is enabled (default 255)</entry>
3056 </row>
3057 <row><entry></entry></row>
3058 <row>
3059 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
3060 <entry>integer&nbsp;(0-255)</entry>
3061 </row><row><entry spanname="descr">Threshold above which
3062the chroma median filter is enabled (default 0)</entry>
3063 </row>
3064 <row><entry></entry></row>
3065 <row>
3066 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
3067 <entry>integer&nbsp;(0-255)</entry>
3068 </row><row><entry spanname="descr">Threshold below which
3069the chroma median filter is enabled (default 255)</entry>
3070 </row>
3071 <row><entry></entry></row>
3072 <row>
3073 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_STREAM_INSERT_NAV_PACKETS</constant>&nbsp;</entry>
3074 <entry>boolean</entry>
3075 </row>
3076 <row><entry spanname="descr">The CX2341X MPEG encoder
3077can insert one empty MPEG-2 PES packet into the stream between every
3078four video frames. The packet size is 2048 bytes, including the
3079packet_start_code_prefix and stream_id fields. The stream_id is 0xBF
3080(private stream 2). The payload consists of 0x00 bytes, to be filled
3081in by the application. 0 = do not insert, 1 = insert packets.</entry>
3082 </row>
3083 </tbody>
3084 </tgroup>
3085 </table>
3086 </section>
3087
3088 <section>
3089 <title>VPX Control Reference</title>
3090
3091 <para>The VPX controls include controls for encoding parameters
3092 of VPx video codec.</para>
3093
3094 <table pgwide="1" frame="none" id="vpx-control-id">
3095 <title>VPX Control IDs</title>
3096
3097 <tgroup cols="4">
3098 <colspec colname="c1" colwidth="1*" />
3099 <colspec colname="c2" colwidth="6*" />
3100 <colspec colname="c3" colwidth="2*" />
3101 <colspec colname="c4" colwidth="6*" />
3102 <spanspec namest="c1" nameend="c2" spanname="id" />
3103 <spanspec namest="c2" nameend="c4" spanname="descr" />
3104 <thead>
3105 <row>
3106 <entry spanname="id" align="left">ID</entry>
3107 <entry align="left">Type</entry>
3108 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3109 </row>
3110 </thead>
3111 <tbody valign="top">
3112 <row><entry></entry></row>
3113
3114 <row><entry></entry></row>
3115 <row id="v4l2-vpx-num-partitions">
3116 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_NUM_PARTITIONS</constant></entry>
3117 <entry>enum v4l2_vp8_num_partitions</entry>
3118 </row>
3119 <row><entry spanname="descr">The number of token partitions to use in VP8 encoder.
3120Possible values are:</entry>
3121 </row>
3122 <row>
3123 <entrytbl spanname="descr" cols="2">
3124 <tbody valign="top">
3125 <row>
3126 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_PARTITION</constant></entry>
3127 <entry>1 coefficient partition</entry>
3128 </row>
3129 <row>
3130 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_2_PARTITIONS</constant></entry>
3131 <entry>2 coefficient partitions</entry>
3132 </row>
3133 <row>
3134 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_4_PARTITIONS</constant></entry>
3135 <entry>4 coefficient partitions</entry>
3136 </row>
3137 <row>
3138 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_8_PARTITIONS</constant></entry>
3139 <entry>8 coefficient partitions</entry>
3140 </row>
3141 </tbody>
3142 </entrytbl>
3143 </row>
3144
3145 <row><entry></entry></row>
3146 <row>
3147 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_IMD_DISABLE_4X4</constant></entry>
3148 <entry>boolean</entry>
3149 </row>
3150 <row><entry spanname="descr">Setting this prevents intra 4x4 mode in the intra mode decision.</entry>
3151 </row>
3152
3153 <row><entry></entry></row>
3154 <row id="v4l2-vpx-num-ref-frames">
3155 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_NUM_REF_FRAMES</constant></entry>
3156 <entry>enum v4l2_vp8_num_ref_frames</entry>
3157 </row>
3158 <row><entry spanname="descr">The number of reference pictures for encoding P frames.
3159Possible values are:</entry>
3160 </row>
3161 <row>
3162 <entrytbl spanname="descr" cols="2">
3163 <tbody valign="top">
3164 <row>
3165 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_REF_FRAME</constant></entry>
3166 <entry>Last encoded frame will be searched</entry>
3167 </row>
3168 <row>
3169 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_2_REF_FRAME</constant></entry>
3170 <entry>Two frames will be searched among the last encoded frame, the golden frame
3171and the alternate reference (altref) frame. The encoder implementation will decide which two are chosen.</entry>
3172 </row>
3173 <row>
3174 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_3_REF_FRAME</constant></entry>
3175 <entry>The last encoded frame, the golden frame and the altref frame will be searched.</entry>
3176 </row>
3177 </tbody>
3178 </entrytbl>
3179 </row>
3180
3181 <row><entry></entry></row>
3182 <row>
3183 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_LEVEL</constant></entry>
3184 <entry>integer</entry>
3185 </row>
3186 <row><entry spanname="descr">Indicates the loop filter level. The adjustment of the loop
3187filter level is done via a delta value against a baseline loop filter value.</entry>
3188 </row>
3189
3190 <row><entry></entry></row>
3191 <row>
3192 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_SHARPNESS</constant></entry>
3193 <entry>integer</entry>
3194 </row>
3195 <row><entry spanname="descr">This parameter affects the loop filter. Anything above
3196zero weakens the deblocking effect on the loop filter.</entry>
3197 </row>
3198
3199 <row><entry></entry></row>
3200 <row>
3201 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD</constant></entry>
3202 <entry>integer</entry>
3203 </row>
3204 <row><entry spanname="descr">Sets the refresh period for the golden frame. The period is defined
3205in number of frames. For a value of 'n', every nth frame starting from the first key frame will be taken as a golden frame.
3206For eg. for encoding sequence of 0, 1, 2, 3, 4, 5, 6, 7 where the golden frame refresh period is set as 4, the frames
32070, 4, 8 etc will be taken as the golden frames as frame 0 is always a key frame.</entry>
3208 </row>
3209
3210 <row><entry></entry></row>
3211 <row id="v4l2-vpx-golden-frame-sel">
3212 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_SEL</constant></entry>
3213 <entry>enum v4l2_vp8_golden_frame_sel</entry>
3214 </row>
3215 <row><entry spanname="descr">Selects the golden frame for encoding.
3216Possible values are:</entry>
3217 </row>
3218 <row>
3219 <entrytbl spanname="descr" cols="2">
3220 <tbody valign="top">
3221 <row>
3222 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_USE_PREV</constant></entry>
3223 <entry>Use the (n-2)th frame as a golden frame, current frame index being 'n'.</entry>
3224 </row>
3225 <row>
3226 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_USE_REF_PERIOD</constant></entry>
3227 <entry>Use the previous specific frame indicated by
3228V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD as a golden frame.</entry>
3229 </row>
3230 </tbody>
3231 </entrytbl>
3232 </row>
3233
3234 <row><entry></entry></row>
3235 <row>
3236 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MIN_QP</constant></entry>
3237 <entry>integer</entry>
3238 </row>
3239 <row><entry spanname="descr">Minimum quantization parameter for VP8.</entry>
3240 </row>
3241
3242 <row><entry></entry></row>
3243 <row>
3244 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MAX_QP</constant></entry>
3245 <entry>integer</entry>
3246 </row>
3247 <row><entry spanname="descr">Maximum quantization parameter for VP8.</entry>
3248 </row>
3249
3250 <row><entry></entry></row>
3251 <row>
3252 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_I_FRAME_QP</constant>&nbsp;</entry>
3253 <entry>integer</entry>
3254 </row>
3255 <row><entry spanname="descr">Quantization parameter for an I frame for VP8.</entry>
3256 </row>
3257
3258 <row><entry></entry></row>
3259 <row>
3260 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_P_FRAME_QP</constant>&nbsp;</entry>
3261 <entry>integer</entry>
3262 </row>
3263 <row><entry spanname="descr">Quantization parameter for a P frame for VP8.</entry>
3264 </row>
3265
3266 <row><entry></entry></row>
3267 <row>
3268 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_PROFILE</constant>&nbsp;</entry>
3269 <entry>integer</entry>
3270 </row>
3271 <row><entry spanname="descr">Select the desired profile for VPx encoder.
3272Acceptable values are 0, 1, 2 and 3 corresponding to encoder profiles 0, 1, 2 and 3.</entry>
3273 </row>
3274
3275 <row><entry></entry></row>
3276 </tbody>
3277 </tgroup>
3278 </table>
3279
3280 </section>
3281 </section>
3282
3283 <section id="camera-controls">
3284 <title>Camera Control Reference</title>
3285
3286 <para>The Camera class includes controls for mechanical (or
3287equivalent digital) features of a device such as controllable lenses
3288or sensors.</para>
3289
3290 <table pgwide="1" frame="none" id="camera-control-id">
3291 <title>Camera Control IDs</title>
3292 <tgroup cols="4">
3293 <colspec colname="c1" colwidth="1*" />
3294 <colspec colname="c2" colwidth="6*" />
3295 <colspec colname="c3" colwidth="2*" />
3296 <colspec colname="c4" colwidth="6*" />
3297 <spanspec namest="c1" nameend="c2" spanname="id" />
3298 <spanspec namest="c2" nameend="c4" spanname="descr" />
3299 <thead>
3300 <row>
3301 <entry spanname="id" align="left">ID</entry>
3302 <entry align="left">Type</entry>
3303 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3304 </row>
3305 </thead>
3306 <tbody valign="top">
3307 <row><entry></entry></row>
3308 <row>
3309 <entry spanname="id"><constant>V4L2_CID_CAMERA_CLASS</constant>&nbsp;</entry>
3310 <entry>class</entry>
3311 </row><row><entry spanname="descr">The Camera class
3312descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3313description of this control class.</entry>
3314 </row>
3315 <row><entry></entry></row>
3316
3317 <row id="v4l2-exposure-auto-type">
3318 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO</constant>&nbsp;</entry>
3319 <entry>enum&nbsp;v4l2_exposure_auto_type</entry>
3320 </row><row><entry spanname="descr">Enables automatic
3321adjustments of the exposure time and/or iris aperture. The effect of
3322manual changes of the exposure time or iris aperture while these
3323features are enabled is undefined, drivers should ignore such
3324requests. Possible values are:</entry>
3325 </row>
3326 <row>
3327 <entrytbl spanname="descr" cols="2">
3328 <tbody valign="top">
3329 <row>
3330 <entry><constant>V4L2_EXPOSURE_AUTO</constant>&nbsp;</entry>
3331 <entry>Automatic exposure time, automatic iris
3332aperture.</entry>
3333 </row>
3334 <row>
3335 <entry><constant>V4L2_EXPOSURE_MANUAL</constant>&nbsp;</entry>
3336 <entry>Manual exposure time, manual iris.</entry>
3337 </row>
3338 <row>
3339 <entry><constant>V4L2_EXPOSURE_SHUTTER_PRIORITY</constant>&nbsp;</entry>
3340 <entry>Manual exposure time, auto iris.</entry>
3341 </row>
3342 <row>
3343 <entry><constant>V4L2_EXPOSURE_APERTURE_PRIORITY</constant>&nbsp;</entry>
3344 <entry>Auto exposure time, manual iris.</entry>
3345 </row>
3346 </tbody>
3347 </entrytbl>
3348 </row>
3349 <row><entry></entry></row>
3350
3351 <row>
3352 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_ABSOLUTE</constant>&nbsp;</entry>
3353 <entry>integer</entry>
3354 </row><row><entry spanname="descr">Determines the exposure
3355time of the camera sensor. The exposure time is limited by the frame
3356interval. Drivers should interpret the values as 100 &micro;s units,
3357where the value 1 stands for 1/10000th of a second, 10000 for 1 second
3358and 100000 for 10 seconds.</entry>
3359 </row>
3360 <row><entry></entry></row>
3361
3362 <row>
3363 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO_PRIORITY</constant>&nbsp;</entry>
3364 <entry>boolean</entry>
3365 </row><row><entry spanname="descr">When
3366<constant>V4L2_CID_EXPOSURE_AUTO</constant> is set to
3367<constant>AUTO</constant> or <constant>APERTURE_PRIORITY</constant>,
3368this control determines if the device may dynamically vary the frame
3369rate. By default this feature is disabled (0) and the frame rate must
3370remain constant.</entry>
3371 </row>
3372 <row><entry></entry></row>
3373
3374 <row>
3375 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_BIAS</constant>&nbsp;</entry>
3376 <entry>integer menu</entry>
3377 </row><row><entry spanname="descr"> Determines the automatic
3378exposure compensation, it is effective only when <constant>V4L2_CID_EXPOSURE_AUTO</constant>
3379control is set to <constant>AUTO</constant>, <constant>SHUTTER_PRIORITY </constant>
3380or <constant>APERTURE_PRIORITY</constant>.
3381It is expressed in terms of EV, drivers should interpret the values as 0.001 EV
3382units, where the value 1000 stands for +1 EV.
3383<para>Increasing the exposure compensation value is equivalent to decreasing
3384the exposure value (EV) and will increase the amount of light at the image
3385sensor. The camera performs the exposure compensation by adjusting absolute
3386exposure time and/or aperture.</para></entry>
3387 </row>
3388 <row><entry></entry></row>
3389
3390 <row id="v4l2-exposure-metering">
3391 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_METERING</constant>&nbsp;</entry>
3392 <entry>enum&nbsp;v4l2_exposure_metering</entry>
3393 </row><row><entry spanname="descr">Determines how the camera measures
3394the amount of light available for the frame exposure. Possible values are:</entry>
3395 </row>
3396 <row>
3397 <entrytbl spanname="descr" cols="2">
3398 <tbody valign="top">
3399 <row>
3400 <entry><constant>V4L2_EXPOSURE_METERING_AVERAGE</constant>&nbsp;</entry>
3401 <entry>Use the light information coming from the entire frame
3402and average giving no weighting to any particular portion of the metered area.
3403 </entry>
3404 </row>
3405 <row>
3406 <entry><constant>V4L2_EXPOSURE_METERING_CENTER_WEIGHTED</constant>&nbsp;</entry>
3407 <entry>Average the light information coming from the entire frame
3408giving priority to the center of the metered area.</entry>
3409 </row>
3410 <row>
3411 <entry><constant>V4L2_EXPOSURE_METERING_SPOT</constant>&nbsp;</entry>
3412 <entry>Measure only very small area at the center of the frame.</entry>
3413 </row>
3414 <row>
3415 <entry><constant>V4L2_EXPOSURE_METERING_MATRIX</constant>&nbsp;</entry>
3416 <entry>A multi-zone metering. The light intensity is measured
3417in several points of the frame and the the results are combined. The
3418algorithm of the zones selection and their significance in calculating the
3419final value is device dependent.</entry>
3420 </row>
3421 </tbody>
3422 </entrytbl>
3423 </row>
3424 <row><entry></entry></row>
3425
3426 <row>
3427 <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant>&nbsp;</entry>
3428 <entry>integer</entry>
3429 </row><row><entry spanname="descr">This control turns the
3430camera horizontally by the specified amount. The unit is undefined. A
3431positive value moves the camera to the right (clockwise when viewed
3432from above), a negative value to the left. A value of zero does not
3433cause motion. This is a write-only control.</entry>
3434 </row>
3435 <row><entry></entry></row>
3436
3437 <row>
3438 <entry spanname="id"><constant>V4L2_CID_TILT_RELATIVE</constant>&nbsp;</entry>
3439 <entry>integer</entry>
3440 </row><row><entry spanname="descr">This control turns the
3441camera vertically by the specified amount. The unit is undefined. A
3442positive value moves the camera up, a negative value down. A value of
3443zero does not cause motion. This is a write-only control.</entry>
3444 </row>
3445 <row><entry></entry></row>
3446
3447 <row>
3448 <entry spanname="id"><constant>V4L2_CID_PAN_RESET</constant>&nbsp;</entry>
3449 <entry>button</entry>
3450 </row><row><entry spanname="descr">When this control is set,
3451the camera moves horizontally to the default position.</entry>
3452 </row>
3453 <row><entry></entry></row>
3454
3455 <row>
3456 <entry spanname="id"><constant>V4L2_CID_TILT_RESET</constant>&nbsp;</entry>
3457 <entry>button</entry>
3458 </row><row><entry spanname="descr">When this control is set,
3459the camera moves vertically to the default position.</entry>
3460 </row>
3461 <row><entry></entry></row>
3462
3463 <row>
3464 <entry spanname="id"><constant>V4L2_CID_PAN_ABSOLUTE</constant>&nbsp;</entry>
3465 <entry>integer</entry>
3466 </row><row><entry spanname="descr">This control
3467turns the camera horizontally to the specified position. Positive
3468values move the camera to the right (clockwise when viewed from above),
3469negative values to the left. Drivers should interpret the values as arc
3470seconds, with valid values between -180 * 3600 and +180 * 3600
3471inclusive.</entry>
3472 </row>
3473 <row><entry></entry></row>
3474
3475 <row>
3476 <entry spanname="id"><constant>V4L2_CID_TILT_ABSOLUTE</constant>&nbsp;</entry>
3477 <entry>integer</entry>
3478 </row><row><entry spanname="descr">This control
3479turns the camera vertically to the specified position. Positive values
3480move the camera up, negative values down. Drivers should interpret the
3481values as arc seconds, with valid values between -180 * 3600 and +180
3482* 3600 inclusive.</entry>
3483 </row>
3484 <row><entry></entry></row>
3485
3486 <row>
3487 <entry spanname="id"><constant>V4L2_CID_FOCUS_ABSOLUTE</constant>&nbsp;</entry>
3488 <entry>integer</entry>
3489 </row><row><entry spanname="descr">This control sets the
3490focal point of the camera to the specified position. The unit is
3491undefined. Positive values set the focus closer to the camera,
3492negative values towards infinity.</entry>
3493 </row>
3494 <row><entry></entry></row>
3495
3496 <row>
3497 <entry spanname="id"><constant>V4L2_CID_FOCUS_RELATIVE</constant>&nbsp;</entry>
3498 <entry>integer</entry>
3499 </row><row><entry spanname="descr">This control moves the
3500focal point of the camera by the specified amount. The unit is
3501undefined. Positive values move the focus closer to the camera,
3502negative values towards infinity. This is a write-only control.</entry>
3503 </row>
3504 <row><entry></entry></row>
3505
3506 <row>
3507 <entry spanname="id"><constant>V4L2_CID_FOCUS_AUTO</constant>&nbsp;</entry>
3508 <entry>boolean</entry>
3509 </row><row><entry spanname="descr">Enables continuous automatic
3510focus adjustments. The effect of manual focus adjustments while this feature
3511is enabled is undefined, drivers should ignore such requests.</entry>
3512 </row>
3513 <row><entry></entry></row>
3514
3515 <row>
3516 <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_START</constant>&nbsp;</entry>
3517 <entry>button</entry>
3518 </row><row><entry spanname="descr">Starts single auto focus process.
3519The effect of setting this control when <constant>V4L2_CID_FOCUS_AUTO</constant>
3520is set to <constant>TRUE</constant> (1) is undefined, drivers should ignore
3521such requests.</entry>
3522 </row>
3523 <row><entry></entry></row>
3524
3525 <row>
3526 <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_STOP</constant>&nbsp;</entry>
3527 <entry>button</entry>
3528 </row><row><entry spanname="descr">Aborts automatic focusing
3529started with <constant>V4L2_CID_AUTO_FOCUS_START</constant> control. It is
3530effective only when the continuous autofocus is disabled, that is when
3531<constant>V4L2_CID_FOCUS_AUTO</constant> control is set to <constant>FALSE
3532</constant> (0).</entry>
3533 </row>
3534 <row><entry></entry></row>
3535
3536 <row id="v4l2-auto-focus-status">
3537 <entry spanname="id">
3538 <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>&nbsp;</entry>
3539 <entry>bitmask</entry>
3540 </row>
3541 <row><entry spanname="descr">The automatic focus status. This is a read-only
3542 control.</entry>
3543 </row>
3544 <row>
3545 <entrytbl spanname="descr" cols="2">
3546 <tbody valign="top">
3547 <row>
3548 <entry><constant>V4L2_AUTO_FOCUS_STATUS_IDLE</constant>&nbsp;</entry>
3549 <entry>Automatic focus is not active.</entry>
3550 </row>
3551 <row>
3552 <entry><constant>V4L2_AUTO_FOCUS_STATUS_BUSY</constant>&nbsp;</entry>
3553 <entry>Automatic focusing is in progress.</entry>
3554 </row>
3555 <row>
3556 <entry><constant>V4L2_AUTO_FOCUS_STATUS_REACHED</constant>&nbsp;</entry>
3557 <entry>Focus has been reached.</entry>
3558 </row>
3559 <row>
3560 <entry><constant>V4L2_AUTO_FOCUS_STATUS_FAILED</constant>&nbsp;</entry>
3561 <entry>Automatic focus has failed, the driver will not
3562 transition from this state until another action is
3563 performed by an application.</entry>
3564 </row>
3565 </tbody>
3566 </entrytbl>
3567 </row>
3568 <row><entry spanname="descr">
3569Setting <constant>V4L2_LOCK_FOCUS</constant> lock bit of the <constant>V4L2_CID_3A_LOCK
3570</constant> control may stop updates of the <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>
3571control value.</entry>
3572 </row>
3573 <row><entry></entry></row>
3574
3575 <row id="v4l2-auto-focus-range">
3576 <entry spanname="id">
3577 <constant>V4L2_CID_AUTO_FOCUS_RANGE</constant>&nbsp;</entry>
3578 <entry>enum&nbsp;v4l2_auto_focus_range</entry>
3579 </row>
3580 <row><entry spanname="descr">Determines auto focus distance range
3581for which lens may be adjusted. </entry>
3582 </row>
3583 <row>
3584 <entrytbl spanname="descr" cols="2">
3585 <tbody valign="top">
3586 <row>
3587 <entry><constant>V4L2_AUTO_FOCUS_RANGE_AUTO</constant>&nbsp;</entry>
3588 <entry>The camera automatically selects the focus range.</entry>
3589 </row>
3590 <row>
3591 <entry><constant>V4L2_AUTO_FOCUS_RANGE_NORMAL</constant>&nbsp;</entry>
3592 <entry>Normal distance range, limited for best automatic focus
3593performance.</entry>
3594 </row>
3595 <row>
3596 <entry><constant>V4L2_AUTO_FOCUS_RANGE_MACRO</constant>&nbsp;</entry>
3597 <entry>Macro (close-up) auto focus. The camera will
3598use its minimum possible distance for auto focus.</entry>
3599 </row>
3600 <row>
3601 <entry><constant>V4L2_AUTO_FOCUS_RANGE_INFINITY</constant>&nbsp;</entry>
3602 <entry>The lens is set to focus on an object at infinite distance.</entry>
3603 </row>
3604 </tbody>
3605 </entrytbl>
3606 </row>
3607 <row><entry></entry></row>
3608
3609 <row>
3610 <entry spanname="id"><constant>V4L2_CID_ZOOM_ABSOLUTE</constant>&nbsp;</entry>
3611 <entry>integer</entry>
3612 </row><row><entry spanname="descr">Specify the objective lens
3613focal length as an absolute value. The zoom unit is driver-specific and its
3614value should be a positive integer.</entry>
3615 </row>
3616 <row><entry></entry></row>
3617
3618 <row>
3619 <entry spanname="id"><constant>V4L2_CID_ZOOM_RELATIVE</constant>&nbsp;</entry>
3620 <entry>integer</entry>
3621 </row><row><entry spanname="descr">Specify the objective lens
3622focal length relatively to the current value. Positive values move the zoom
3623lens group towards the telephoto direction, negative values towards the
3624wide-angle direction. The zoom unit is driver-specific. This is a write-only control.</entry>
3625 </row>
3626 <row><entry></entry></row>
3627
3628 <row>
3629 <entry spanname="id"><constant>V4L2_CID_ZOOM_CONTINUOUS</constant>&nbsp;</entry>
3630 <entry>integer</entry>
3631 </row><row><entry spanname="descr">Move the objective lens group
3632at the specified speed until it reaches physical device limits or until an
3633explicit request to stop the movement. A positive value moves the zoom lens
3634group towards the telephoto direction. A value of zero stops the zoom lens
3635group movement. A negative value moves the zoom lens group towards the
3636wide-angle direction. The zoom speed unit is driver-specific.</entry>
3637 </row>
3638 <row><entry></entry></row>
3639
3640 <row>
3641 <entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant>&nbsp;</entry>
3642 <entry>integer</entry>
3643 </row><row><entry spanname="descr">This control sets the
3644camera's aperture to the specified value. The unit is undefined.
3645Larger values open the iris wider, smaller values close it.</entry>
3646 </row>
3647 <row><entry></entry></row>
3648
3649 <row>
3650 <entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant>&nbsp;</entry>
3651 <entry>integer</entry>
3652 </row><row><entry spanname="descr">This control modifies the
3653camera's aperture by the specified amount. The unit is undefined.
3654Positive values open the iris one step further, negative values close
3655it one step further. This is a write-only control.</entry>
3656 </row>
3657 <row><entry></entry></row>
3658
3659 <row>
3660 <entry spanname="id"><constant>V4L2_CID_PRIVACY</constant>&nbsp;</entry>
3661 <entry>boolean</entry>
3662 </row><row><entry spanname="descr">Prevent video from being acquired
3663by the camera. When this control is set to <constant>TRUE</constant> (1), no
3664image can be captured by the camera. Common means to enforce privacy are
3665mechanical obturation of the sensor and firmware image processing, but the
3666device is not restricted to these methods. Devices that implement the privacy
3667control must support read access and may support write access.</entry>
3668 </row>
3669
3670 <row>
3671 <entry spanname="id"><constant>V4L2_CID_BAND_STOP_FILTER</constant>&nbsp;</entry>
3672 <entry>integer</entry>
3673 </row><row><entry spanname="descr">Switch the band-stop filter of a
3674camera sensor on or off, or specify its strength. Such band-stop filters can
3675be used, for example, to filter out the fluorescent light component.</entry>
3676 </row>
3677 <row><entry></entry></row>
3678
3679 <row id="v4l2-auto-n-preset-white-balance">
3680 <entry spanname="id"><constant>V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE</constant>&nbsp;</entry>
3681 <entry>enum&nbsp;v4l2_auto_n_preset_white_balance</entry>
3682 </row><row><entry spanname="descr">Sets white balance to automatic,
3683manual or a preset. The presets determine color temperature of the light as
3684a hint to the camera for white balance adjustments resulting in most accurate
3685color representation. The following white balance presets are listed in order
3686of increasing color temperature.</entry>
3687 </row>
3688 <row>
3689 <entrytbl spanname="descr" cols="2">
3690 <tbody valign="top">
3691 <row>
3692 <entry><constant>V4L2_WHITE_BALANCE_MANUAL</constant>&nbsp;</entry>
3693 <entry>Manual white balance.</entry>
3694 </row>
3695 <row>
3696 <entry><constant>V4L2_WHITE_BALANCE_AUTO</constant>&nbsp;</entry>
3697 <entry>Automatic white balance adjustments.</entry>
3698 </row>
3699 <row>
3700 <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant>&nbsp;</entry>
3701 <entry>White balance setting for incandescent (tungsten) lighting.
3702It generally cools down the colors and corresponds approximately to 2500...3500 K
3703color temperature range.</entry>
3704 </row>
3705 <row>
3706 <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant>&nbsp;</entry>
3707 <entry>White balance preset for fluorescent lighting.
3708It corresponds approximately to 4000...5000 K color temperature.</entry>
3709 </row>
3710 <row>
3711 <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT_H</constant>&nbsp;</entry>
3712 <entry>With this setting the camera will compensate for
3713fluorescent H lighting.</entry>
3714 </row>
3715 <row>
3716 <entry><constant>V4L2_WHITE_BALANCE_HORIZON</constant>&nbsp;</entry>
3717 <entry>White balance setting for horizon daylight.
3718It corresponds approximately to 5000 K color temperature.</entry>
3719 </row>
3720 <row>
3721 <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant>&nbsp;</entry>
3722 <entry>White balance preset for daylight (with clear sky).
3723It corresponds approximately to 5000...6500 K color temperature.</entry>
3724 </row>
3725 <row>
3726 <entry><constant>V4L2_WHITE_BALANCE_FLASH</constant>&nbsp;</entry>
3727 <entry>With this setting the camera will compensate for the flash
3728light. It slightly warms up the colors and corresponds roughly to 5000...5500 K
3729color temperature.</entry>
3730 </row>
3731 <row>
3732 <entry><constant>V4L2_WHITE_BALANCE_CLOUDY</constant>&nbsp;</entry>
3733 <entry>White balance preset for moderately overcast sky.
3734This option corresponds approximately to 6500...8000 K color temperature
3735range.</entry>
3736 </row>
3737 <row>
3738 <entry><constant>V4L2_WHITE_BALANCE_SHADE</constant>&nbsp;</entry>
3739 <entry>White balance preset for shade or heavily overcast
3740sky. It corresponds approximately to 9000...10000 K color temperature.
3741</entry>
3742 </row>
3743 </tbody>
3744 </entrytbl>
3745 </row>
3746 <row><entry></entry></row>
3747
3748 <row id="v4l2-wide-dynamic-range">
3749 <entry spanname="id"><constant>V4L2_CID_WIDE_DYNAMIC_RANGE</constant></entry>
3750 <entry>boolean</entry>
3751 </row>
3752 <row>
3753 <entry spanname="descr">Enables or disables the camera's wide dynamic
3754range feature. This feature allows to obtain clear images in situations where
3755intensity of the illumination varies significantly throughout the scene, i.e.
3756there are simultaneously very dark and very bright areas. It is most commonly
3757realized in cameras by combining two subsequent frames with different exposure
3758times. <footnote id="ctypeconv"><para> This control may be changed to a menu
3759control in the future, if more options are required.</para></footnote></entry>
3760 </row>
3761 <row><entry></entry></row>
3762
3763 <row id="v4l2-image-stabilization">
3764 <entry spanname="id"><constant>V4L2_CID_IMAGE_STABILIZATION</constant></entry>
3765 <entry>boolean</entry>
3766 </row>
3767 <row>
3768 <entry spanname="descr">Enables or disables image stabilization.
3769 <footnoteref linkend="ctypeconv"/></entry>
3770 </row>
3771 <row><entry></entry></row>
3772
3773 <row>
3774 <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY</constant>&nbsp;</entry>
3775 <entry>integer menu</entry>
3776 </row><row><entry spanname="descr">Determines ISO equivalent of an
3777image sensor indicating the sensor's sensitivity to light. The numbers are
3778expressed in arithmetic scale, as per <xref linkend="iso12232" /> standard,
3779where doubling the sensor sensitivity is represented by doubling the numerical
3780ISO value. Applications should interpret the values as standard ISO values
3781multiplied by 1000, e.g. control value 800 stands for ISO 0.8. Drivers will
3782usually support only a subset of standard ISO values. The effect of setting
3783this control while the <constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>
3784control is set to a value other than <constant>V4L2_CID_ISO_SENSITIVITY_MANUAL
3785</constant> is undefined, drivers should ignore such requests.</entry>
3786 </row>
3787 <row><entry></entry></row>
3788
3789 <row id="v4l2-iso-sensitivity-auto-type">
3790 <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3791 <entry>enum&nbsp;v4l2_iso_sensitivity_type</entry>
3792 </row><row><entry spanname="descr">Enables or disables automatic ISO
3793sensitivity adjustments.</entry>
3794 </row>
3795 <row>
3796 <entrytbl spanname="descr" cols="2">
3797 <tbody valign="top">
3798 <row>
3799 <entry><constant>V4L2_CID_ISO_SENSITIVITY_MANUAL</constant>&nbsp;</entry>
3800 <entry>Manual ISO sensitivity.</entry>
3801 </row>
3802 <row>
3803 <entry><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3804 <entry>Automatic ISO sensitivity adjustments.</entry>
3805 </row>
3806 </tbody>
3807 </entrytbl>
3808 </row>
3809 <row><entry></entry></row>
3810
3811 <row id="v4l2-scene-mode">
3812 <entry spanname="id"><constant>V4L2_CID_SCENE_MODE</constant>&nbsp;</entry>
3813 <entry>enum&nbsp;v4l2_scene_mode</entry>
3814 </row><row><entry spanname="descr">This control allows to select
3815scene programs as the camera automatic modes optimized for common shooting
3816scenes. Within these modes the camera determines best exposure, aperture,
3817focusing, light metering, white balance and equivalent sensitivity. The
3818controls of those parameters are influenced by the scene mode control.
3819An exact behavior in each mode is subject to the camera specification.
3820
3821<para>When the scene mode feature is not used, this control should be set to
3822<constant>V4L2_SCENE_MODE_NONE</constant> to make sure the other possibly
3823related controls are accessible. The following scene programs are defined:
3824</para>
3825</entry>
3826 </row>
3827 <row>
3828 <entrytbl spanname="descr" cols="2">
3829 <tbody valign="top">
3830 <row>
3831 <entry><constant>V4L2_SCENE_MODE_NONE</constant>&nbsp;</entry>
3832 <entry>The scene mode feature is disabled.</entry>
3833 </row>
3834 <row>
3835 <entry><constant>V4L2_SCENE_MODE_BACKLIGHT</constant>&nbsp;</entry>
3836 <entry>Backlight. Compensates for dark shadows when light is
3837 coming from behind a subject, also by automatically turning
3838 on the flash.</entry>
3839 </row>
3840 <row>
3841 <entry><constant>V4L2_SCENE_MODE_BEACH_SNOW</constant>&nbsp;</entry>
3842 <entry>Beach and snow. This mode compensates for all-white or
3843bright scenes, which tend to look gray and low contrast, when camera's automatic
3844exposure is based on an average scene brightness. To compensate, this mode
3845automatically slightly overexposes the frames. The white balance may also be
3846adjusted to compensate for the fact that reflected snow looks bluish rather
3847than white.</entry>
3848 </row>
3849 <row>
3850 <entry><constant>V4L2_SCENE_MODE_CANDLELIGHT</constant>&nbsp;</entry>
3851 <entry>Candle light. The camera generally raises the ISO
3852sensitivity and lowers the shutter speed. This mode compensates for relatively
3853close subject in the scene. The flash is disabled in order to preserve the
3854ambiance of the light.</entry>
3855 </row>
3856 <row>
3857 <entry><constant>V4L2_SCENE_MODE_DAWN_DUSK</constant>&nbsp;</entry>
3858 <entry>Dawn and dusk. Preserves the colors seen in low
3859natural light before dusk and after down. The camera may turn off the flash,
3860and automatically focus at infinity. It will usually boost saturation and
3861lower the shutter speed.</entry>
3862 </row>
3863 <row>
3864 <entry><constant>V4L2_SCENE_MODE_FALL_COLORS</constant>&nbsp;</entry>
3865 <entry>Fall colors. Increases saturation and adjusts white
3866balance for color enhancement. Pictures of autumn leaves get saturated reds
3867and yellows.</entry>
3868 </row>
3869 <row>
3870 <entry><constant>V4L2_SCENE_MODE_FIREWORKS</constant>&nbsp;</entry>
3871 <entry>Fireworks. Long exposure times are used to capture
3872the expanding burst of light from a firework. The camera may invoke image
3873stabilization.</entry>
3874 </row>
3875 <row>
3876 <entry><constant>V4L2_SCENE_MODE_LANDSCAPE</constant>&nbsp;</entry>
3877 <entry>Landscape. The camera may choose a small aperture to
3878provide deep depth of field and long exposure duration to help capture detail
3879in dim light conditions. The focus is fixed at infinity. Suitable for distant
3880and wide scenery.</entry>
3881 </row>
3882 <row>
3883 <entry><constant>V4L2_SCENE_MODE_NIGHT</constant>&nbsp;</entry>
3884 <entry>Night, also known as Night Landscape. Designed for low
3885light conditions, it preserves detail in the dark areas without blowing out bright
3886objects. The camera generally sets itself to a medium-to-high ISO sensitivity,
3887with a relatively long exposure time, and turns flash off. As such, there will be
3888increased image noise and the possibility of blurred image.</entry>
3889 </row>
3890 <row>
3891 <entry><constant>V4L2_SCENE_MODE_PARTY_INDOOR</constant>&nbsp;</entry>
3892 <entry>Party and indoor. Designed to capture indoor scenes
3893that are lit by indoor background lighting as well as the flash. The camera
3894usually increases ISO sensitivity, and adjusts exposure for the low light
3895conditions.</entry>
3896 </row>
3897 <row>
3898 <entry><constant>V4L2_SCENE_MODE_PORTRAIT</constant>&nbsp;</entry>
3899 <entry>Portrait. The camera adjusts the aperture so that the
3900depth of field is reduced, which helps to isolate the subject against a smooth
3901background. Most cameras recognize the presence of faces in the scene and focus
3902on them. The color hue is adjusted to enhance skin tones. The intensity of the
3903flash is often reduced.</entry>
3904 </row>
3905 <row>
3906 <entry><constant>V4L2_SCENE_MODE_SPORTS</constant>&nbsp;</entry>
3907 <entry>Sports. Significantly increases ISO and uses a fast
3908shutter speed to freeze motion of rapidly-moving subjects. Increased image
3909noise may be seen in this mode.</entry>
3910 </row>
3911 <row>
3912 <entry><constant>V4L2_SCENE_MODE_SUNSET</constant>&nbsp;</entry>
3913 <entry>Sunset. Preserves deep hues seen in sunsets and
3914sunrises. It bumps up the saturation.</entry>
3915 </row>
3916 <row>
3917 <entry><constant>V4L2_SCENE_MODE_TEXT</constant>&nbsp;</entry>
3918 <entry>Text. It applies extra contrast and sharpness, it is
3919typically a black-and-white mode optimized for readability. Automatic focus
3920may be switched to close-up mode and this setting may also involve some
3921lens-distortion correction.</entry>
3922 </row>
3923 </tbody>
3924 </entrytbl>
3925 </row>
3926 <row><entry></entry></row>
3927
3928 <row>
3929 <entry spanname="id"><constant>V4L2_CID_3A_LOCK</constant></entry>
3930 <entry>bitmask</entry>
3931 </row>
3932 <row>
3933 <entry spanname="descr">This control locks or unlocks the automatic
3934focus, exposure and white balance. The automatic adjustments can be paused
3935independently by setting the corresponding lock bit to 1. The camera then retains
3936the settings until the lock bit is cleared. The following lock bits are defined:
3937</entry>
3938 </row>
3939 <row>
3940 <entrytbl spanname="descr" cols="2">
3941 <tbody valign="top">
3942 <row>
3943 <entry><constant>V4L2_LOCK_EXPOSURE</constant></entry>
3944 <entry>Automatic exposure adjustments lock.</entry>
3945 </row>
3946 <row>
3947 <entry><constant>V4L2_LOCK_WHITE_BALANCE</constant></entry>
3948 <entry>Automatic white balance adjustments lock.</entry>
3949 </row>
3950 <row>
3951 <entry><constant>V4L2_LOCK_FOCUS</constant></entry>
3952 <entry>Automatic focus lock.</entry>
3953 </row>
3954 </tbody>
3955 </entrytbl>
3956 </row>
3957 <row><entry spanname="descr">
3958When a given algorithm is not enabled, drivers should ignore requests
3959to lock it and should return no error. An example might be an application
3960setting bit <constant>V4L2_LOCK_WHITE_BALANCE</constant> when the
3961<constant>V4L2_CID_AUTO_WHITE_BALANCE</constant> control is set to
3962<constant>FALSE</constant>. The value of this control may be changed
3963by exposure, white balance or focus controls.</entry>
3964 </row>
3965 <row><entry></entry></row>
3966
3967 <row>
3968 <entry spanname="id"><constant>V4L2_CID_PAN_SPEED</constant>&nbsp;</entry>
3969 <entry>integer</entry>
3970 </row><row><entry spanname="descr">This control turns the
3971camera horizontally at the specific speed. The unit is undefined. A
3972positive value moves the camera to the right (clockwise when viewed
3973from above), a negative value to the left. A value of zero stops the motion
3974if one is in progress and has no effect otherwise.</entry>
3975 </row>
3976 <row><entry></entry></row>
3977
3978 <row>
3979 <entry spanname="id"><constant>V4L2_CID_TILT_SPEED</constant>&nbsp;</entry>
3980 <entry>integer</entry>
3981 </row><row><entry spanname="descr">This control turns the
3982camera vertically at the specified speed. The unit is undefined. A
3983positive value moves the camera up, a negative value down. A value of zero
3984stops the motion if one is in progress and has no effect otherwise.</entry>
3985 </row>
3986 <row><entry></entry></row>
3987
3988 </tbody>
3989 </tgroup>
3990 </table>
3991 </section>
3992
3993 <section id="fm-tx-controls">
3994 <title>FM Transmitter Control Reference</title>
3995
3996 <para>The FM Transmitter (FM_TX) class includes controls for common features of
3997FM transmissions capable devices. Currently this class includes parameters for audio
3998compression, pilot tone generation, audio deviation limiter, RDS transmission and
3999tuning power features.</para>
4000
4001 <table pgwide="1" frame="none" id="fm-tx-control-id">
4002 <title>FM_TX Control IDs</title>
4003
4004 <tgroup cols="4">
4005 <colspec colname="c1" colwidth="1*" />
4006 <colspec colname="c2" colwidth="6*" />
4007 <colspec colname="c3" colwidth="2*" />
4008 <colspec colname="c4" colwidth="6*" />
4009 <spanspec namest="c1" nameend="c2" spanname="id" />
4010 <spanspec namest="c2" nameend="c4" spanname="descr" />
4011 <thead>
4012 <row>
4013 <entry spanname="id" align="left">ID</entry>
4014 <entry align="left">Type</entry>
4015 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4016 </row>
4017 </thead>
4018 <tbody valign="top">
4019 <row><entry></entry></row>
4020 <row>
4021 <entry spanname="id"><constant>V4L2_CID_FM_TX_CLASS</constant>&nbsp;</entry>
4022 <entry>class</entry>
4023 </row><row><entry spanname="descr">The FM_TX class
4024descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
4025description of this control class.</entry>
4026 </row>
4027 <row>
4028 <entry spanname="id"><constant>V4L2_CID_RDS_TX_DEVIATION</constant>&nbsp;</entry>
4029 <entry>integer</entry>
4030 </row>
4031 <row><entry spanname="descr">Configures RDS signal frequency deviation level in Hz.
4032The range and step are driver-specific.</entry>
4033 </row>
4034 <row>
4035 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PI</constant>&nbsp;</entry>
4036 <entry>integer</entry>
4037 </row>
4038 <row><entry spanname="descr">Sets the RDS Programme Identification field
4039for transmission.</entry>
4040 </row>
4041 <row>
4042 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PTY</constant>&nbsp;</entry>
4043 <entry>integer</entry>
4044 </row>
4045 <row><entry spanname="descr">Sets the RDS Programme Type field for transmission.
4046This encodes up to 31 pre-defined programme types.</entry>
4047 </row>
4048 <row>
4049 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PS_NAME</constant>&nbsp;</entry>
4050 <entry>string</entry>
4051 </row>
4052 <row><entry spanname="descr">Sets the Programme Service name (PS_NAME) for transmission.
4053It is intended for static display on a receiver. It is the primary aid to listeners in programme service
4054identification and selection. In Annex E of <xref linkend="iec62106" />, the RDS specification,
4055there is a full description of the correct character encoding for Programme Service name strings.
4056Also from RDS specification, PS is usually a single eight character text. However, it is also possible
4057to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured
4058with steps of 8 characters. The result is it must always contain a string with size multiple of 8.</entry>
4059 </row>
4060 <row>
4061 <entry spanname="id"><constant>V4L2_CID_RDS_TX_RADIO_TEXT</constant>&nbsp;</entry>
4062 <entry>string</entry>
4063 </row>
4064 <row><entry spanname="descr">Sets the Radio Text info for transmission. It is a textual description of
4065what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names,
4066programme-related information or any other text. In these cases, RadioText should be used in addition to
4067<constant>V4L2_CID_RDS_TX_PS_NAME</constant>. The encoding for Radio Text strings is also fully described
4068in Annex E of <xref linkend="iec62106" />. The length of Radio Text strings depends on which RDS Block is being
4069used to transmit it, either 32 (2A block) or 64 (2B block). However, it is also possible
4070to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured
4071with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. </entry>
4072 </row>
4073 <row>
4074 <entry spanname="id"><constant>V4L2_CID_RDS_TX_MONO_STEREO</constant>&nbsp;</entry>
4075 <entry>boolean</entry>
4076 </row>
4077 <row><entry spanname="descr">Sets the Mono/Stereo bit of the Decoder Identification code. If set,
4078then the audio was recorded as stereo.</entry>
4079 </row>
4080 <row>
4081 <entry spanname="id"><constant>V4L2_CID_RDS_TX_ARTIFICIAL_HEAD</constant>&nbsp;</entry>
4082 <entry>boolean</entry>
4083 </row>
4084 <row><entry spanname="descr">Sets the
4085<ulink url="http://en.wikipedia.org/wiki/Artificial_head">Artificial Head</ulink> bit of the Decoder
4086Identification code. If set, then the audio was recorded using an artificial head.</entry>
4087 </row>
4088 <row>
4089 <entry spanname="id"><constant>V4L2_CID_RDS_TX_COMPRESSED</constant>&nbsp;</entry>
4090 <entry>boolean</entry>
4091 </row>
4092 <row><entry spanname="descr">Sets the Compressed bit of the Decoder Identification code. If set,
4093then the audio is compressed.</entry>
4094 </row>
4095 <row>
4096 <entry spanname="id"><constant>V4L2_CID_RDS_TX_DYNAMIC_PTY</constant>&nbsp;</entry>
4097 <entry>boolean</entry>
4098 </row>
4099 <row><entry spanname="descr">Sets the Dynamic PTY bit of the Decoder Identification code. If set,
4100then the PTY code is dynamically switched.</entry>
4101 </row>
4102 <row>
4103 <entry spanname="id"><constant>V4L2_CID_RDS_TX_TRAFFIC_ANNOUNCEMENT</constant>&nbsp;</entry>
4104 <entry>boolean</entry>
4105 </row>
4106 <row><entry spanname="descr">If set, then a traffic announcement is in progress.</entry>
4107 </row>
4108 <row>
4109 <entry spanname="id"><constant>V4L2_CID_RDS_TX_TRAFFIC_PROGRAM</constant>&nbsp;</entry>
4110 <entry>boolean</entry>
4111 </row>
4112 <row><entry spanname="descr">If set, then the tuned programme carries traffic announcements.</entry>
4113 </row>
4114 <row>
4115 <entry spanname="id"><constant>V4L2_CID_RDS_TX_MUSIC_SPEECH</constant>&nbsp;</entry>
4116 <entry>boolean</entry>
4117 </row>
4118 <row><entry spanname="descr">If set, then this channel broadcasts music. If cleared, then it
4119broadcasts speech. If the transmitter doesn't make this distinction, then it should be set.</entry>
4120 </row>
4121 <row>
4122 <entry spanname="id"><constant>V4L2_CID_RDS_TX_ALT_FREQS_ENABLE</constant>&nbsp;</entry>
4123 <entry>boolean</entry>
4124 </row>
4125 <row><entry spanname="descr">If set, then transmit alternate frequencies.</entry>
4126 </row>
4127 <row>
4128 <entry spanname="id"><constant>V4L2_CID_RDS_TX_ALT_FREQS</constant>&nbsp;</entry>
4129 <entry>__u32 array</entry>
4130 </row>
4131 <row><entry spanname="descr">The alternate frequencies in kHz units. The RDS standard allows
4132for up to 25 frequencies to be defined. Drivers may support fewer frequencies so check
4133the array size.</entry>
4134 </row>
4135 <row>
4136 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant>&nbsp;</entry>
4137 <entry>boolean</entry>
4138 </row>
4139 <row><entry spanname="descr">Enables or disables the audio deviation limiter feature.
4140The limiter is useful when trying to maximize the audio volume, minimize receiver-generated
4141distortion and prevent overmodulation.
4142</entry>
4143 </row>
4144 <row>
4145 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant>&nbsp;</entry>
4146 <entry>integer</entry>
4147 </row>
4148 <row><entry spanname="descr">Sets the audio deviation limiter feature release time.
4149Unit is in useconds. Step and range are driver-specific.</entry>
4150 </row>
4151 <row>
4152 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant>&nbsp;</entry>
4153 <entry>integer</entry>
4154 </row>
4155 <row><entry spanname="descr">Configures audio frequency deviation level in Hz.
4156The range and step are driver-specific.</entry>
4157 </row>
4158 <row>
4159 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant>&nbsp;</entry>
4160 <entry>boolean</entry>
4161 </row>
4162 <row><entry spanname="descr">Enables or disables the audio compression feature.
4163This feature amplifies signals below the threshold by a fixed gain and compresses audio
4164signals above the threshold by the ratio of Threshold/(Gain + Threshold).</entry>
4165 </row>
4166 <row>
4167 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant>&nbsp;</entry>
4168 <entry>integer</entry>
4169 </row>
4170 <row><entry spanname="descr">Sets the gain for audio compression feature. It is
4171a dB value. The range and step are driver-specific.</entry>
4172 </row>
4173 <row>
4174 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant>&nbsp;</entry>
4175 <entry>integer</entry>
4176 </row>
4177 <row><entry spanname="descr">Sets the threshold level for audio compression freature.
4178It is a dB value. The range and step are driver-specific.</entry>
4179 </row>
4180 <row>
4181 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant>&nbsp;</entry>
4182 <entry>integer</entry>
4183 </row>
4184 <row><entry spanname="descr">Sets the attack time for audio compression feature.
4185It is a useconds value. The range and step are driver-specific.</entry>
4186 </row>
4187 <row>
4188 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant>&nbsp;</entry>
4189 <entry>integer</entry>
4190 </row>
4191 <row><entry spanname="descr">Sets the release time for audio compression feature.
4192It is a useconds value. The range and step are driver-specific.</entry>
4193 </row>
4194 <row>
4195 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant>&nbsp;</entry>
4196 <entry>boolean</entry>
4197 </row>
4198 <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry>
4199 </row>
4200 <row>
4201 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant>&nbsp;</entry>
4202 <entry>integer</entry>
4203 </row>
4204 <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is
4205in Hz. The range and step are driver-specific.</entry>
4206 </row>
4207 <row>
4208 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant>&nbsp;</entry>
4209 <entry>integer</entry>
4210 </row>
4211 <row><entry spanname="descr">Configures pilot tone frequency value. Unit is
4212in Hz. The range and step are driver-specific.</entry>
4213 </row>
4214 <row>
4215 <entry spanname="id"><constant>V4L2_CID_TUNE_PREEMPHASIS</constant>&nbsp;</entry>
4216 <entry>enum v4l2_preemphasis</entry>
4217 </row>
4218 <row id="v4l2-preemphasis"><entry spanname="descr">Configures the pre-emphasis value for broadcasting.
4219A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
4220Depending on the region, a time constant of either 50 or 75 useconds is used. The enum&nbsp;v4l2_preemphasis
4221defines possible values for pre-emphasis. Here they are:</entry>
4222 </row><row>
4223 <entrytbl spanname="descr" cols="2">
4224 <tbody valign="top">
4225 <row>
4226 <entry><constant>V4L2_PREEMPHASIS_DISABLED</constant>&nbsp;</entry>
4227 <entry>No pre-emphasis is applied.</entry>
4228 </row>
4229 <row>
4230 <entry><constant>V4L2_PREEMPHASIS_50_uS</constant>&nbsp;</entry>
4231 <entry>A pre-emphasis of 50 uS is used.</entry>
4232 </row>
4233 <row>
4234 <entry><constant>V4L2_PREEMPHASIS_75_uS</constant>&nbsp;</entry>
4235 <entry>A pre-emphasis of 75 uS is used.</entry>
4236 </row>
4237 </tbody>
4238 </entrytbl>
4239
4240 </row>
4241 <row>
4242 <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant>&nbsp;</entry>
4243 <entry>integer</entry>
4244 </row>
4245 <row><entry spanname="descr">Sets the output power level for signal transmission.
4246Unit is in dBuV. Range and step are driver-specific.</entry>
4247 </row>
4248 <row>
4249 <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant>&nbsp;</entry>
4250 <entry>integer</entry>
4251 </row>
4252 <row><entry spanname="descr">This selects the value of antenna tuning capacitor
4253manually or automatically if set to zero. Unit, range and step are driver-specific.</entry>
4254 </row>
4255 <row><entry></entry></row>
4256 </tbody>
4257 </tgroup>
4258 </table>
4259
4260<para>For more details about RDS specification, refer to
4261<xref linkend="iec62106" /> document, from CENELEC.</para>
4262 </section>
4263
4264 <section id="flash-controls">
4265 <title>Flash Control Reference</title>
4266
4267 <note>
4268 <title>Experimental</title>
4269
4270 <para>This is an <link linkend="experimental">experimental</link>
4271interface and may change in the future.</para>
4272 </note>
4273
4274 <para>
4275 The V4L2 flash controls are intended to provide generic access
4276 to flash controller devices. Flash controller devices are
4277 typically used in digital cameras.
4278 </para>
4279
4280 <para>
4281 The interface can support both LED and xenon flash devices. As
4282 of writing this, there is no xenon flash driver using this
4283 interface.
4284 </para>
4285
4286 <section id="flash-controls-use-cases">
4287 <title>Supported use cases</title>
4288
4289 <section>
4290 <title>Unsynchronised LED flash (software strobe)</title>
4291
4292 <para>
4293 Unsynchronised LED flash is controlled directly by the
4294 host as the sensor. The flash must be enabled by the host
4295 before the exposure of the image starts and disabled once
4296 it ends. The host is fully responsible for the timing of
4297 the flash.
4298 </para>
4299
4300 <para>Example of such device: Nokia N900.</para>
4301 </section>
4302
4303 <section>
4304 <title>Synchronised LED flash (hardware strobe)</title>
4305
4306 <para>
4307 The synchronised LED flash is pre-programmed by the host
4308 (power and timeout) but controlled by the sensor through a
4309 strobe signal from the sensor to the flash.
4310 </para>
4311
4312 <para>
4313 The sensor controls the flash duration and timing. This
4314 information typically must be made available to the
4315 sensor.
4316 </para>
4317
4318 </section>
4319
4320 <section>
4321 <title>LED flash as torch</title>
4322
4323 <para>
4324 LED flash may be used as torch in conjunction with another
4325 use case involving camera or individually.
4326 </para>
4327
4328
4329 <table pgwide="1" frame="none" id="flash-control-id">
4330 <title>Flash Control IDs</title>
4331
4332 <tgroup cols="4">
4333 <colspec colname="c1" colwidth="1*" />
4334 <colspec colname="c2" colwidth="6*" />
4335 <colspec colname="c3" colwidth="2*" />
4336 <colspec colname="c4" colwidth="6*" />
4337 <spanspec namest="c1" nameend="c2" spanname="id" />
4338 <spanspec namest="c2" nameend="c4" spanname="descr" />
4339 <thead>
4340 <row>
4341 <entry spanname="id" align="left">ID</entry>
4342 <entry align="left">Type</entry>
4343 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4344 </row>
4345 </thead>
4346 <tbody valign="top">
4347 <row><entry></entry></row>
4348 <row>
4349 <entry spanname="id"><constant>V4L2_CID_FLASH_CLASS</constant></entry>
4350 <entry>class</entry>
4351 </row>
4352 <row>
4353 <entry spanname="descr">The FLASH class descriptor.</entry>
4354 </row>
4355 <row>
4356 <entry spanname="id"><constant>V4L2_CID_FLASH_LED_MODE</constant></entry>
4357 <entry>menu</entry>
4358 </row>
4359 <row id="v4l2-flash-led-mode">
4360 <entry spanname="descr">Defines the mode of the flash LED,
4361 the high-power white LED attached to the flash controller.
4362 Setting this control may not be possible in presence of
4363 some faults. See V4L2_CID_FLASH_FAULT.</entry>
4364 </row>
4365 <row>
4366 <entrytbl spanname="descr" cols="2">
4367 <tbody valign="top">
4368 <row>
4369 <entry><constant>V4L2_FLASH_LED_MODE_NONE</constant></entry>
4370 <entry>Off.</entry>
4371 </row>
4372 <row>
4373 <entry><constant>V4L2_FLASH_LED_MODE_FLASH</constant></entry>
4374 <entry>Flash mode.</entry>
4375 </row>
4376 <row>
4377 <entry><constant>V4L2_FLASH_LED_MODE_TORCH</constant></entry>
4378 <entry>Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.</entry>
4379 </row>
4380 </tbody>
4381 </entrytbl>
4382 </row>
4383 <row>
4384 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_SOURCE</constant></entry>
4385 <entry>menu</entry>
4386 </row>
4387 <row id="v4l2-flash-strobe-source"><entry
4388 spanname="descr">Defines the source of the flash LED
4389 strobe.</entry>
4390 </row>
4391 <row>
4392 <entrytbl spanname="descr" cols="2">
4393 <tbody valign="top">
4394 <row>
4395 <entry><constant>V4L2_FLASH_STROBE_SOURCE_SOFTWARE</constant></entry>
4396 <entry>The flash strobe is triggered by using
4397 the V4L2_CID_FLASH_STROBE control.</entry>
4398 </row>
4399 <row>
4400 <entry><constant>V4L2_FLASH_STROBE_SOURCE_EXTERNAL</constant></entry>
4401 <entry>The flash strobe is triggered by an
4402 external source. Typically this is a sensor,
4403 which makes it possible to synchronises the
4404 flash strobe start to exposure start.</entry>
4405 </row>
4406 </tbody>
4407 </entrytbl>
4408 </row>
4409 <row>
4410 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE</constant></entry>
4411 <entry>button</entry>
4412 </row>
4413 <row>
4414 <entry spanname="descr">Strobe flash. Valid when
4415 V4L2_CID_FLASH_LED_MODE is set to
4416 V4L2_FLASH_LED_MODE_FLASH and V4L2_CID_FLASH_STROBE_SOURCE
4417 is set to V4L2_FLASH_STROBE_SOURCE_SOFTWARE. Setting this
4418 control may not be possible in presence of some faults.
4419 See V4L2_CID_FLASH_FAULT.</entry>
4420 </row>
4421 <row>
4422 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STOP</constant></entry>
4423 <entry>button</entry>
4424 </row>
4425 <row><entry spanname="descr">Stop flash strobe immediately.</entry>
4426 </row>
4427 <row>
4428 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STATUS</constant></entry>
4429 <entry>boolean</entry>
4430 </row>
4431 <row>
4432 <entry spanname="descr">Strobe status: whether the flash
4433 is strobing at the moment or not. This is a read-only
4434 control.</entry>
4435 </row>
4436 <row>
4437 <entry spanname="id"><constant>V4L2_CID_FLASH_TIMEOUT</constant></entry>
4438 <entry>integer</entry>
4439 </row>
4440 <row>
4441 <entry spanname="descr">Hardware timeout for flash. The
4442 flash strobe is stopped after this period of time has
4443 passed from the start of the strobe.</entry>
4444 </row>
4445 <row>
4446 <entry spanname="id"><constant>V4L2_CID_FLASH_INTENSITY</constant></entry>
4447 <entry>integer</entry>
4448 </row>
4449 <row>
4450 <entry spanname="descr">Intensity of the flash strobe when
4451 the flash LED is in flash mode
4452 (V4L2_FLASH_LED_MODE_FLASH). The unit should be milliamps
4453 (mA) if possible.</entry>
4454 </row>
4455 <row>
4456 <entry spanname="id"><constant>V4L2_CID_FLASH_TORCH_INTENSITY</constant></entry>
4457 <entry>integer</entry>
4458 </row>
4459 <row>
4460 <entry spanname="descr">Intensity of the flash LED in
4461 torch mode (V4L2_FLASH_LED_MODE_TORCH). The unit should be
4462 milliamps (mA) if possible. Setting this control may not
4463 be possible in presence of some faults. See
4464 V4L2_CID_FLASH_FAULT.</entry>
4465 </row>
4466 <row>
4467 <entry spanname="id"><constant>V4L2_CID_FLASH_INDICATOR_INTENSITY</constant></entry>
4468 <entry>integer</entry>
4469 </row>
4470 <row>
4471 <entry spanname="descr">Intensity of the indicator LED.
4472 The indicator LED may be fully independent of the flash
4473 LED. The unit should be microamps (uA) if possible.</entry>
4474 </row>
4475 <row>
4476 <entry spanname="id"><constant>V4L2_CID_FLASH_FAULT</constant></entry>
4477 <entry>bitmask</entry>
4478 </row>
4479 <row>
4480 <entry spanname="descr">Faults related to the flash. The
4481 faults tell about specific problems in the flash chip
4482 itself or the LEDs attached to it. Faults may prevent
4483 further use of some of the flash controls. In particular,
4484 V4L2_CID_FLASH_LED_MODE is set to V4L2_FLASH_LED_MODE_NONE
4485 if the fault affects the flash LED. Exactly which faults
4486 have such an effect is chip dependent. Reading the faults
4487 resets the control and returns the chip to a usable state
4488 if possible.</entry>
4489 </row>
4490 <row>
4491 <entrytbl spanname="descr" cols="2">
4492 <tbody valign="top">
4493 <row>
4494 <entry><constant>V4L2_FLASH_FAULT_OVER_VOLTAGE</constant></entry>
4495 <entry>Flash controller voltage to the flash LED
4496 has exceeded the limit specific to the flash
4497 controller.</entry>
4498 </row>
4499 <row>
4500 <entry><constant>V4L2_FLASH_FAULT_TIMEOUT</constant></entry>
4501 <entry>The flash strobe was still on when
4502 the timeout set by the user ---
4503 V4L2_CID_FLASH_TIMEOUT control --- has expired.
4504 Not all flash controllers may set this in all
4505 such conditions.</entry>
4506 </row>
4507 <row>
4508 <entry><constant>V4L2_FLASH_FAULT_OVER_TEMPERATURE</constant></entry>
4509 <entry>The flash controller has overheated.</entry>
4510 </row>
4511 <row>
4512 <entry><constant>V4L2_FLASH_FAULT_SHORT_CIRCUIT</constant></entry>
4513 <entry>The short circuit protection of the flash
4514 controller has been triggered.</entry>
4515 </row>
4516 <row>
4517 <entry><constant>V4L2_FLASH_FAULT_OVER_CURRENT</constant></entry>
4518 <entry>Current in the LED power supply has exceeded the limit
4519 specific to the flash controller.</entry>
4520 </row>
4521 <row>
4522 <entry><constant>V4L2_FLASH_FAULT_INDICATOR</constant></entry>
4523 <entry>The flash controller has detected a short or open
4524 circuit condition on the indicator LED.</entry>
4525 </row>
4526 <row>
4527 <entry><constant>V4L2_FLASH_FAULT_UNDER_VOLTAGE</constant></entry>
4528 <entry>Flash controller voltage to the flash LED
4529 has been below the minimum limit specific to the flash
4530 controller.</entry>
4531 </row>
4532 <row>
4533 <entry><constant>V4L2_FLASH_FAULT_INPUT_VOLTAGE</constant></entry>
4534 <entry>The input voltage of the flash controller is below
4535 the limit under which strobing the flash at full current
4536 will not be possible.The condition persists until this flag
4537 is no longer set.</entry>
4538 </row>
4539 <row>
4540 <entry><constant>V4L2_FLASH_FAULT_LED_OVER_TEMPERATURE</constant></entry>
4541 <entry>The temperature of the LED has exceeded its
4542 allowed upper limit.</entry>
4543 </row>
4544 </tbody>
4545 </entrytbl>
4546 </row>
4547 <row>
4548 <entry spanname="id"><constant>V4L2_CID_FLASH_CHARGE</constant></entry>
4549 <entry>boolean</entry>
4550 </row>
4551 <row><entry spanname="descr">Enable or disable charging of the xenon
4552 flash capacitor.</entry>
4553 </row>
4554 <row>
4555 <entry spanname="id"><constant>V4L2_CID_FLASH_READY</constant></entry>
4556 <entry>boolean</entry>
4557 </row>
4558 <row>
4559 <entry spanname="descr">Is the flash ready to strobe?
4560 Xenon flashes require their capacitors charged before
4561 strobing. LED flashes often require a cooldown period
4562 after strobe during which another strobe will not be
4563 possible. This is a read-only control.</entry>
4564 </row>
4565 <row><entry></entry></row>
4566 </tbody>
4567 </tgroup>
4568 </table>
4569 </section>
4570 </section>
4571 </section>
4572
4573 <section id="jpeg-controls">
4574 <title>JPEG Control Reference</title>
4575 <para>The JPEG class includes controls for common features of JPEG
4576 encoders and decoders. Currently it includes features for codecs
4577 implementing progressive baseline DCT compression process with
4578 Huffman entrophy coding.</para>
4579 <table pgwide="1" frame="none" id="jpeg-control-id">
4580 <title>JPEG Control IDs</title>
4581
4582 <tgroup cols="4">
4583 <colspec colname="c1" colwidth="1*" />
4584 <colspec colname="c2" colwidth="6*" />
4585 <colspec colname="c3" colwidth="2*" />
4586 <colspec colname="c4" colwidth="6*" />
4587 <spanspec namest="c1" nameend="c2" spanname="id" />
4588 <spanspec namest="c2" nameend="c4" spanname="descr" />
4589 <thead>
4590 <row>
4591 <entry spanname="id" align="left">ID</entry>
4592 <entry align="left">Type</entry>
4593 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4594 </row>
4595 </thead>
4596 <tbody valign="top">
4597 <row><entry></entry></row>
4598 <row>
4599 <entry spanname="id"><constant>V4L2_CID_JPEG_CLASS</constant>&nbsp;</entry>
4600 <entry>class</entry>
4601 </row><row><entry spanname="descr">The JPEG class descriptor. Calling
4602 &VIDIOC-QUERYCTRL; for this control will return a description of this
4603 control class.
4604
4605 </entry>
4606 </row>
4607 <row>
4608 <entry spanname="id"><constant>V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant></entry>
4609 <entry>menu</entry>
4610 </row>
4611 <row id="v4l2-jpeg-chroma-subsampling">
4612 <entry spanname="descr">The chroma subsampling factors describe how
4613 each component of an input image is sampled, in respect to maximum
4614 sample rate in each spatial dimension. See <xref linkend="itu-t81"/>,
4615 clause A.1.1. for more details. The <constant>
4616 V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant> control determines how
4617 Cb and Cr components are downsampled after coverting an input image
4618 from RGB to Y'CbCr color space.
4619 </entry>
4620 </row>
4621 <row>
4622 <entrytbl spanname="descr" cols="2">
4623 <tbody valign="top">
4624 <row>
4625 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_444</constant>
4626 </entry><entry>No chroma subsampling, each pixel has
4627 Y, Cr and Cb values.</entry>
4628 </row>
4629 <row>
4630 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_422</constant>
4631 </entry><entry>Horizontally subsample Cr, Cb components
4632 by a factor of 2.</entry>
4633 </row>
4634 <row>
4635 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_420</constant>
4636 </entry><entry>Subsample Cr, Cb components horizontally
4637 and vertically by 2.</entry>
4638 </row>
4639 <row>
4640 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_411</constant>
4641 </entry><entry>Horizontally subsample Cr, Cb components
4642 by a factor of 4.</entry>
4643 </row>
4644 <row>
4645 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_410</constant>
4646 </entry><entry>Subsample Cr, Cb components horizontally
4647 by 4 and vertically by 2.</entry>
4648 </row>
4649 <row>
4650 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY</constant>
4651 </entry><entry>Use only luminance component.</entry>
4652 </row>
4653 </tbody>
4654 </entrytbl>
4655 </row>
4656 <row>
4657 <entry spanname="id"><constant>V4L2_CID_JPEG_RESTART_INTERVAL</constant>
4658 </entry><entry>integer</entry>
4659 </row>
4660 <row><entry spanname="descr">
4661 The restart interval determines an interval of inserting RSTm
4662 markers (m = 0..7). The purpose of these markers is to additionally
4663 reinitialize the encoder process, in order to process blocks of
4664 an image independently.
4665 For the lossy compression processes the restart interval unit is
4666 MCU (Minimum Coded Unit) and its value is contained in DRI
4667 (Define Restart Interval) marker. If <constant>
4668 V4L2_CID_JPEG_RESTART_INTERVAL</constant> control is set to 0,
4669 DRI and RSTm markers will not be inserted.
4670 </entry>
4671 </row>
4672 <row id="jpeg-quality-control">
4673 <entry spanname="id"><constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant></entry>
4674 <entry>integer</entry>
4675 </row>
4676 <row>
4677 <entry spanname="descr">
4678 <constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control
4679 determines trade-off between image quality and size.
4680 It provides simpler method for applications to control image quality,
4681 without a need for direct reconfiguration of luminance and chrominance
4682 quantization tables.
4683
4684 In cases where a driver uses quantization tables configured directly
4685 by an application, using interfaces defined elsewhere, <constant>
4686 V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control should be set
4687 by driver to 0.
4688
4689 <para>The value range of this control is driver-specific. Only
4690 positive, non-zero values are meaningful. The recommended range
4691 is 1 - 100, where larger values correspond to better image quality.
4692 </para>
4693 </entry>
4694 </row>
4695 <row id="jpeg-active-marker-control">
4696 <entry spanname="id"><constant>V4L2_CID_JPEG_ACTIVE_MARKER</constant></entry>
4697 <entry>bitmask</entry>
4698 </row>
4699 <row>
4700 <entry spanname="descr">Specify which JPEG markers are included
4701 in compressed stream. This control is valid only for encoders.
4702 </entry>
4703 </row>
4704 <row>
4705 <entrytbl spanname="descr" cols="2">
4706 <tbody valign="top">
4707 <row>
4708 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP0</constant></entry>
4709 <entry>Application data segment APP<subscript>0</subscript>.</entry>
4710 </row><row>
4711 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP1</constant></entry>
4712 <entry>Application data segment APP<subscript>1</subscript>.</entry>
4713 </row><row>
4714 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_COM</constant></entry>
4715 <entry>Comment segment.</entry>
4716 </row><row>
4717 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DQT</constant></entry>
4718 <entry>Quantization tables segment.</entry>
4719 </row><row>
4720 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DHT</constant></entry>
4721 <entry>Huffman tables segment.</entry>
4722 </row>
4723 </tbody>
4724 </entrytbl>
4725 </row>
4726 <row><entry></entry></row>
4727 </tbody>
4728 </tgroup>
4729 </table>
4730 <para>For more details about JPEG specification, refer
4731 to <xref linkend="itu-t81"/>, <xref linkend="jfif"/>,
4732 <xref linkend="w3c-jpeg-jfif"/>.</para>
4733 </section>
4734
4735 <section id="image-source-controls">
4736 <title>Image Source Control Reference</title>
4737
4738 <note>
4739 <title>Experimental</title>
4740
4741 <para>This is an <link
4742 linkend="experimental">experimental</link> interface and may
4743 change in the future.</para>
4744 </note>
4745
4746 <para>
4747 The Image Source control class is intended for low-level
4748 control of image source devices such as image sensors. The
4749 devices feature an analogue to digital converter and a bus
4750 transmitter to transmit the image data out of the device.
4751 </para>
4752
4753 <table pgwide="1" frame="none" id="image-source-control-id">
4754 <title>Image Source Control IDs</title>
4755
4756 <tgroup cols="4">
4757 <colspec colname="c1" colwidth="1*" />
4758 <colspec colname="c2" colwidth="6*" />
4759 <colspec colname="c3" colwidth="2*" />
4760 <colspec colname="c4" colwidth="6*" />
4761 <spanspec namest="c1" nameend="c2" spanname="id" />
4762 <spanspec namest="c2" nameend="c4" spanname="descr" />
4763 <thead>
4764 <row>
4765 <entry spanname="id" align="left">ID</entry>
4766 <entry align="left">Type</entry>
4767 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4768 </row>
4769 </thead>
4770 <tbody valign="top">
4771 <row><entry></entry></row>
4772 <row>
4773 <entry spanname="id"><constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant></entry>
4774 <entry>class</entry>
4775 </row>
4776 <row>
4777 <entry spanname="descr">The IMAGE_SOURCE class descriptor.</entry>
4778 </row>
4779 <row>
4780 <entry spanname="id"><constant>V4L2_CID_VBLANK</constant></entry>
4781 <entry>integer</entry>
4782 </row>
4783 <row>
4784 <entry spanname="descr">Vertical blanking. The idle period
4785 after every frame during which no image data is produced.
4786 The unit of vertical blanking is a line. Every line has
4787 length of the image width plus horizontal blanking at the
4788 pixel rate defined by
4789 <constant>V4L2_CID_PIXEL_RATE</constant> control in the
4790 same sub-device.</entry>
4791 </row>
4792 <row>
4793 <entry spanname="id"><constant>V4L2_CID_HBLANK</constant></entry>
4794 <entry>integer</entry>
4795 </row>
4796 <row>
4797 <entry spanname="descr">Horizontal blanking. The idle
4798 period after every line of image data during which no
4799 image data is produced. The unit of horizontal blanking is
4800 pixels.</entry>
4801 </row>
4802 <row>
4803 <entry spanname="id"><constant>V4L2_CID_ANALOGUE_GAIN</constant></entry>
4804 <entry>integer</entry>
4805 </row>
4806 <row>
4807 <entry spanname="descr">Analogue gain is gain affecting
4808 all colour components in the pixel matrix. The gain
4809 operation is performed in the analogue domain before A/D
4810 conversion.
4811 </entry>
4812 </row>
4813 <row>
4814 <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN_RED</constant></entry>
4815 <entry>integer</entry>
4816 </row>
4817 <row>
4818 <entry spanname="descr">Test pattern red colour component.
4819 </entry>
4820 </row>
4821 <row>
4822 <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN_GREENR</constant></entry>
4823 <entry>integer</entry>
4824 </row>
4825 <row>
4826 <entry spanname="descr">Test pattern green (next to red)
4827 colour component.
4828 </entry>
4829 </row>
4830 <row>
4831 <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN_BLUE</constant></entry>
4832 <entry>integer</entry>
4833 </row>
4834 <row>
4835 <entry spanname="descr">Test pattern blue colour component.
4836 </entry>
4837 </row>
4838 <row>
4839 <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN_GREENB</constant></entry>
4840 <entry>integer</entry>
4841 </row>
4842 <row>
4843 <entry spanname="descr">Test pattern green (next to blue)
4844 colour component.
4845 </entry>
4846 </row>
4847 <row><entry></entry></row>
4848 </tbody>
4849 </tgroup>
4850 </table>
4851
4852 </section>
4853
4854 <section id="image-process-controls">
4855 <title>Image Process Control Reference</title>
4856
4857 <note>
4858 <title>Experimental</title>
4859
4860 <para>This is an <link
4861 linkend="experimental">experimental</link> interface and may
4862 change in the future.</para>
4863 </note>
4864
4865 <para>
4866 The Image Source control class is intended for low-level control of
4867 image processing functions. Unlike
4868 <constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant>, the controls in
4869 this class affect processing the image, and do not control capturing
4870 of it.
4871 </para>
4872
4873 <table pgwide="1" frame="none" id="image-process-control-id">
4874 <title>Image Source Control IDs</title>
4875
4876 <tgroup cols="4">
4877 <colspec colname="c1" colwidth="1*" />
4878 <colspec colname="c2" colwidth="6*" />
4879 <colspec colname="c3" colwidth="2*" />
4880 <colspec colname="c4" colwidth="6*" />
4881 <spanspec namest="c1" nameend="c2" spanname="id" />
4882 <spanspec namest="c2" nameend="c4" spanname="descr" />
4883 <thead>
4884 <row>
4885 <entry spanname="id" align="left">ID</entry>
4886 <entry align="left">Type</entry>
4887 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4888 </row>
4889 </thead>
4890 <tbody valign="top">
4891 <row><entry></entry></row>
4892 <row>
4893 <entry spanname="id"><constant>V4L2_CID_IMAGE_PROC_CLASS</constant></entry>
4894 <entry>class</entry>
4895 </row>
4896 <row>
4897 <entry spanname="descr">The IMAGE_PROC class descriptor.</entry>
4898 </row>
4899 <row>
4900 <entry spanname="id"><constant>V4L2_CID_LINK_FREQ</constant></entry>
4901 <entry>integer menu</entry>
4902 </row>
4903 <row>
4904 <entry spanname="descr">Data bus frequency. Together with the
4905 media bus pixel code, bus type (clock cycles per sample), the
4906 data bus frequency defines the pixel rate
4907 (<constant>V4L2_CID_PIXEL_RATE</constant>) in the
4908 pixel array (or possibly elsewhere, if the device is not an
4909 image sensor). The frame rate can be calculated from the pixel
4910 clock, image width and height and horizontal and vertical
4911 blanking. While the pixel rate control may be defined elsewhere
4912 than in the subdev containing the pixel array, the frame rate
4913 cannot be obtained from that information. This is because only
4914 on the pixel array it can be assumed that the vertical and
4915 horizontal blanking information is exact: no other blanking is
4916 allowed in the pixel array. The selection of frame rate is
4917 performed by selecting the desired horizontal and vertical
4918 blanking. The unit of this control is Hz. </entry>
4919 </row>
4920 <row>
4921 <entry spanname="id"><constant>V4L2_CID_PIXEL_RATE</constant></entry>
4922 <entry>64-bit integer</entry>
4923 </row>
4924 <row>
4925 <entry spanname="descr">Pixel rate in the source pads of
4926 the subdev. This control is read-only and its unit is
4927 pixels / second.
4928 </entry>
4929 </row>
4930 <row>
4931 <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN</constant></entry>
4932 <entry>menu</entry>
4933 </row>
4934 <row id="v4l2-test-pattern">
4935 <entry spanname="descr"> Some capture/display/sensor devices have
4936 the capability to generate test pattern images. These hardware
4937 specific test patterns can be used to test if a device is working
4938 properly.</entry>
4939 </row>
4940 <row><entry></entry></row>
4941 </tbody>
4942 </tgroup>
4943 </table>
4944
4945 </section>
4946
4947 <section id="dv-controls">
4948 <title>Digital Video Control Reference</title>
4949
4950 <note>
4951 <title>Experimental</title>
4952
4953 <para>This is an <link
4954 linkend="experimental">experimental</link> interface and may
4955 change in the future.</para>
4956 </note>
4957
4958 <para>
4959 The Digital Video control class is intended to control receivers
4960 and transmitters for <ulink url="http://en.wikipedia.org/wiki/Vga">VGA</ulink>,
4961 <ulink url="http://en.wikipedia.org/wiki/Digital_Visual_Interface">DVI</ulink>
4962 (Digital Visual Interface), HDMI (<xref linkend="hdmi" />) and DisplayPort (<xref linkend="dp" />).
4963 These controls are generally expected to be private to the receiver or transmitter
4964 subdevice that implements them, so they are only exposed on the
4965 <filename>/dev/v4l-subdev*</filename> device node.
4966 </para>
4967
4968 <para>Note that these devices can have multiple input or output pads which are
4969 hooked up to e.g. HDMI connectors. Even though the subdevice will receive or
4970 transmit video from/to only one of those pads, the other pads can still be
4971 active when it comes to EDID (Extended Display Identification Data,
4972 <xref linkend="vesaedid" />) and HDCP (High-bandwidth Digital Content
4973 Protection System, <xref linkend="hdcp" />) processing, allowing the device
4974 to do the fairly slow EDID/HDCP handling in advance. This allows for quick
4975 switching between connectors.</para>
4976
4977 <para>These pads appear in several of the controls in this section as
4978 bitmasks, one bit for each pad. Bit 0 corresponds to pad 0, bit 1 to pad 1,
4979 etc. The maximum value of the control is the set of valid pads.</para>
4980
4981 <table pgwide="1" frame="none" id="dv-control-id">
4982 <title>Digital Video Control IDs</title>
4983
4984 <tgroup cols="4">
4985 <colspec colname="c1" colwidth="1*" />
4986 <colspec colname="c2" colwidth="6*" />
4987 <colspec colname="c3" colwidth="2*" />
4988 <colspec colname="c4" colwidth="6*" />
4989 <spanspec namest="c1" nameend="c2" spanname="id" />
4990 <spanspec namest="c2" nameend="c4" spanname="descr" />
4991 <thead>
4992 <row>
4993 <entry spanname="id" align="left">ID</entry>
4994 <entry align="left">Type</entry>
4995 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4996 </row>
4997 </thead>
4998 <tbody valign="top">
4999 <row><entry></entry></row>
5000 <row>
5001 <entry spanname="id"><constant>V4L2_CID_DV_CLASS</constant></entry>
5002 <entry>class</entry>
5003 </row>
5004 <row>
5005 <entry spanname="descr">The Digital Video class descriptor.</entry>
5006 </row>
5007 <row>
5008 <entry spanname="id"><constant>V4L2_CID_DV_TX_HOTPLUG</constant></entry>
5009 <entry>bitmask</entry>
5010 </row>
5011 <row>
5012 <entry spanname="descr">Many connectors have a hotplug pin which is high
5013 if EDID information is available from the source. This control shows the
5014 state of the hotplug pin as seen by the transmitter.
5015 Each bit corresponds to an output pad on the transmitter. If an output pad
5016 does not have an associated hotplug pin, then the bit for that pad will be 0.
5017 This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
5018 </entry>
5019 </row>
5020 <row>
5021 <entry spanname="id"><constant>V4L2_CID_DV_TX_RXSENSE</constant></entry>
5022 <entry>bitmask</entry>
5023 </row>
5024 <row>
5025 <entry spanname="descr">Rx Sense is the detection of pull-ups on the TMDS
5026 clock lines. This normally means that the sink has left/entered standby (i.e.
5027 the transmitter can sense that the receiver is ready to receive video).
5028 Each bit corresponds to an output pad on the transmitter. If an output pad
5029 does not have an associated Rx Sense, then the bit for that pad will be 0.
5030 This read-only control is applicable to DVI-D and HDMI devices.
5031 </entry>
5032 </row>
5033 <row>
5034 <entry spanname="id"><constant>V4L2_CID_DV_TX_EDID_PRESENT</constant></entry>
5035 <entry>bitmask</entry>
5036 </row>
5037 <row>
5038 <entry spanname="descr">When the transmitter sees the hotplug signal from the
5039 receiver it will attempt to read the EDID. If set, then the transmitter has read
5040 at least the first block (= 128 bytes).
5041 Each bit corresponds to an output pad on the transmitter. If an output pad
5042 does not support EDIDs, then the bit for that pad will be 0.
5043 This read-only control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
5044 </entry>
5045 </row>
5046 <row>
5047 <entry spanname="id"><constant>V4L2_CID_DV_TX_MODE</constant></entry>
5048 <entry id="v4l2-dv-tx-mode">enum v4l2_dv_tx_mode</entry>
5049 </row>
5050 <row>
5051 <entry spanname="descr">HDMI transmitters can transmit in DVI-D mode (just video)
5052 or in HDMI mode (video + audio + auxiliary data). This control selects which mode
5053 to use: V4L2_DV_TX_MODE_DVI_D or V4L2_DV_TX_MODE_HDMI.
5054 This control is applicable to HDMI connectors.
5055 </entry>
5056 </row>
5057 <row>
5058 <entry spanname="id"><constant>V4L2_CID_DV_TX_RGB_RANGE</constant></entry>
5059 <entry id="v4l2-dv-rgb-range">enum v4l2_dv_rgb_range</entry>
5060 </row>
5061 <row>
5062 <entry spanname="descr">Select the quantization range for RGB output. V4L2_DV_RANGE_AUTO
5063 follows the RGB quantization range specified in the standard for the video interface
5064 (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
5065 to be compatible with sinks that have not implemented the standard correctly
5066 (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
5067 used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
5068 where N is the number of bits per component.
5069 This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
5070 </entry>
5071 </row>
5072 <row>
5073 <entry spanname="id"><constant>V4L2_CID_DV_RX_POWER_PRESENT</constant></entry>
5074 <entry>bitmask</entry>
5075 </row>
5076 <row>
5077 <entry spanname="descr">Detects whether the receiver receives power from the source
5078 (e.g. HDMI carries 5V on one of the pins). This is often used to power an eeprom
5079 which contains EDID information, such that the source can read the EDID even if
5080 the sink is in standby/power off.
5081 Each bit corresponds to an input pad on the transmitter. If an input pad
5082 cannot detect whether power is present, then the bit for that pad will be 0.
5083 This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
5084 </entry>
5085 </row>
5086 <row>
5087 <entry spanname="id"><constant>V4L2_CID_DV_RX_RGB_RANGE</constant></entry>
5088 <entry>enum v4l2_dv_rgb_range</entry>
5089 </row>
5090 <row>
5091 <entry spanname="descr">Select the quantization range for RGB input. V4L2_DV_RANGE_AUTO
5092 follows the RGB quantization range specified in the standard for the video interface
5093 (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
5094 to be compatible with sources that have not implemented the standard correctly
5095 (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
5096 used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
5097 where N is the number of bits per component.
5098 This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
5099 </entry>
5100 </row>
5101 <row><entry></entry></row>
5102 </tbody>
5103 </tgroup>
5104 </table>
5105
5106 </section>
5107
5108 <section id="fm-rx-controls">
5109 <title>FM Receiver Control Reference</title>
5110
5111 <para>The FM Receiver (FM_RX) class includes controls for common features of
5112 FM Reception capable devices.</para>
5113
5114 <table pgwide="1" frame="none" id="fm-rx-control-id">
5115 <title>FM_RX Control IDs</title>
5116
5117 <tgroup cols="4">
5118 <colspec colname="c1" colwidth="1*" />
5119 <colspec colname="c2" colwidth="6*" />
5120 <colspec colname="c3" colwidth="2*" />
5121 <colspec colname="c4" colwidth="6*" />
5122 <spanspec namest="c1" nameend="c2" spanname="id" />
5123 <spanspec namest="c2" nameend="c4" spanname="descr" />
5124 <thead>
5125 <row>
5126 <entry spanname="id" align="left">ID</entry>
5127 <entry align="left">Type</entry>
5128 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
5129 </row>
5130 </thead>
5131 <tbody valign="top">
5132 <row><entry></entry></row>
5133 <row>
5134 <entry spanname="id"><constant>V4L2_CID_FM_RX_CLASS</constant>&nbsp;</entry>
5135 <entry>class</entry>
5136 </row><row><entry spanname="descr">The FM_RX class
5137descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
5138description of this control class.</entry>
5139 </row>
5140 <row>
5141 <entry spanname="id"><constant>V4L2_CID_RDS_RECEPTION</constant>&nbsp;</entry>
5142 <entry>boolean</entry>
5143 </row><row><entry spanname="descr">Enables/disables RDS
5144 reception by the radio tuner</entry>
5145 </row>
5146 <row>
5147 <entry spanname="id"><constant>V4L2_CID_RDS_RX_PTY</constant>&nbsp;</entry>
5148 <entry>integer</entry>
5149 </row>
5150 <row><entry spanname="descr">Gets RDS Programme Type field.
5151This encodes up to 31 pre-defined programme types.</entry>
5152 </row>
5153 <row>
5154 <entry spanname="id"><constant>V4L2_CID_RDS_RX_PS_NAME</constant>&nbsp;</entry>
5155 <entry>string</entry>
5156 </row>
5157 <row><entry spanname="descr">Gets the Programme Service name (PS_NAME).
5158It is intended for static display on a receiver. It is the primary aid to listeners in programme service
5159identification and selection. In Annex E of <xref linkend="iec62106" />, the RDS specification,
5160there is a full description of the correct character encoding for Programme Service name strings.
5161Also from RDS specification, PS is usually a single eight character text. However, it is also possible
5162to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured
5163with steps of 8 characters. The result is it must always contain a string with size multiple of 8.</entry>
5164 </row>
5165 <row>
5166 <entry spanname="id"><constant>V4L2_CID_RDS_RX_RADIO_TEXT</constant>&nbsp;</entry>
5167 <entry>string</entry>
5168 </row>
5169 <row><entry spanname="descr">Gets the Radio Text info. It is a textual description of
5170what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names,
5171programme-related information or any other text. In these cases, RadioText can be used in addition to
5172<constant>V4L2_CID_RDS_RX_PS_NAME</constant>. The encoding for Radio Text strings is also fully described
5173in Annex E of <xref linkend="iec62106" />. The length of Radio Text strings depends on which RDS Block is being
5174used to transmit it, either 32 (2A block) or 64 (2B block). However, it is also possible
5175to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured
5176with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. </entry>
5177 </row>
5178 <row>
5179 <entry spanname="id"><constant>V4L2_CID_RDS_RX_TRAFFIC_ANNOUNCEMENT</constant>&nbsp;</entry>
5180 <entry>boolean</entry>
5181 </row>
5182 <row><entry spanname="descr">If set, then a traffic announcement is in progress.</entry>
5183 </row>
5184 <row>
5185 <entry spanname="id"><constant>V4L2_CID_RDS_RX_TRAFFIC_PROGRAM</constant>&nbsp;</entry>
5186 <entry>boolean</entry>
5187 </row>
5188 <row><entry spanname="descr">If set, then the tuned programme carries traffic announcements.</entry>
5189 </row>
5190 <row>
5191 <entry spanname="id"><constant>V4L2_CID_RDS_RX_MUSIC_SPEECH</constant>&nbsp;</entry>
5192 <entry>boolean</entry>
5193 </row>
5194 <row><entry spanname="descr">If set, then this channel broadcasts music. If cleared, then it
5195broadcasts speech. If the transmitter doesn't make this distinction, then it will be set.</entry>
5196 </row>
5197 <row>
5198 <entry spanname="id"><constant>V4L2_CID_TUNE_DEEMPHASIS</constant>&nbsp;</entry>
5199 <entry>enum v4l2_deemphasis</entry>
5200 </row>
5201 <row id="v4l2-deemphasis"><entry spanname="descr">Configures the de-emphasis value for reception.
5202A de-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
5203Depending on the region, a time constant of either 50 or 75 useconds is used. The enum&nbsp;v4l2_deemphasis
5204defines possible values for de-emphasis. Here they are:</entry>
5205 </row><row>
5206 <entrytbl spanname="descr" cols="2">
5207 <tbody valign="top">
5208 <row>
5209 <entry><constant>V4L2_DEEMPHASIS_DISABLED</constant>&nbsp;</entry>
5210 <entry>No de-emphasis is applied.</entry>
5211 </row>
5212 <row>
5213 <entry><constant>V4L2_DEEMPHASIS_50_uS</constant>&nbsp;</entry>
5214 <entry>A de-emphasis of 50 uS is used.</entry>
5215 </row>
5216 <row>
5217 <entry><constant>V4L2_DEEMPHASIS_75_uS</constant>&nbsp;</entry>
5218 <entry>A de-emphasis of 75 uS is used.</entry>
5219 </row>
5220 </tbody>
5221 </entrytbl>
5222
5223 </row>
5224 <row><entry></entry></row>
5225 </tbody>
5226 </tgroup>
5227 </table>
5228 </section>
5229
5230 <section id="detect-controls">
5231 <title>Detect Control Reference</title>
5232
5233 <para>The Detect class includes controls for common features of
5234 various motion or object detection capable devices.</para>
5235
5236 <table pgwide="1" frame="none" id="detect-control-id">
5237 <title>Detect Control IDs</title>
5238
5239 <tgroup cols="4">
5240 <colspec colname="c1" colwidth="1*" />
5241 <colspec colname="c2" colwidth="6*" />
5242 <colspec colname="c3" colwidth="2*" />
5243 <colspec colname="c4" colwidth="6*" />
5244 <spanspec namest="c1" nameend="c2" spanname="id" />
5245 <spanspec namest="c2" nameend="c4" spanname="descr" />
5246 <thead>
5247 <row>
5248 <entry spanname="id" align="left">ID</entry>
5249 <entry align="left">Type</entry>
5250 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
5251 </row>
5252 </thead>
5253 <tbody valign="top">
5254 <row><entry></entry></row>
5255 <row>
5256 <entry spanname="id"><constant>V4L2_CID_DETECT_CLASS</constant>&nbsp;</entry>
5257 <entry>class</entry>
5258 </row><row><entry spanname="descr">The Detect class
5259descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
5260description of this control class.</entry>
5261 </row>
5262 <row>
5263 <entry spanname="id"><constant>V4L2_CID_DETECT_MD_MODE</constant>&nbsp;</entry>
5264 <entry>menu</entry>
5265 </row><row><entry spanname="descr">Sets the motion detection mode.</entry>
5266 </row>
5267 <row>
5268 <entrytbl spanname="descr" cols="2">
5269 <tbody valign="top">
5270 <row>
5271 <entry><constant>V4L2_DETECT_MD_MODE_DISABLED</constant>
5272 </entry><entry>Disable motion detection.</entry>
5273 </row>
5274 <row>
5275 <entry><constant>V4L2_DETECT_MD_MODE_GLOBAL</constant>
5276 </entry><entry>Use a single motion detection threshold.</entry>
5277 </row>
5278 <row>
5279 <entry><constant>V4L2_DETECT_MD_MODE_THRESHOLD_GRID</constant>
5280 </entry><entry>The image is divided into a grid, each cell with its own
5281 motion detection threshold. These thresholds are set through the
5282 <constant>V4L2_CID_DETECT_MD_THRESHOLD_GRID</constant> matrix control.</entry>
5283 </row>
5284 <row>
5285 <entry><constant>V4L2_DETECT_MD_MODE_REGION_GRID</constant>
5286 </entry><entry>The image is divided into a grid, each cell with its own
5287 region value that specifies which per-region motion detection thresholds
5288 should be used. Each region has its own thresholds. How these per-region
5289 thresholds are set up is driver-specific. The region values for the grid are set
5290 through the <constant>V4L2_CID_DETECT_MD_REGION_GRID</constant> matrix
5291 control.</entry>
5292 </row>
5293 </tbody>
5294 </entrytbl>
5295 </row>
5296 <row>
5297 <entry spanname="id"><constant>V4L2_CID_DETECT_MD_GLOBAL_THRESHOLD</constant>&nbsp;</entry>
5298 <entry>integer</entry>
5299 </row>
5300 <row><entry spanname="descr">Sets the global motion detection threshold to be
5301 used with the <constant>V4L2_DETECT_MD_MODE_GLOBAL</constant> motion detection mode.</entry>
5302 </row>
5303 <row>
5304 <entry spanname="id"><constant>V4L2_CID_DETECT_MD_THRESHOLD_GRID</constant>&nbsp;</entry>
5305 <entry>__u16 matrix</entry>
5306 </row>
5307 <row><entry spanname="descr">Sets the motion detection thresholds for each cell in the grid.
5308 To be used with the <constant>V4L2_DETECT_MD_MODE_THRESHOLD_GRID</constant>
5309 motion detection mode. Matrix element (0, 0) represents the cell at the top-left of the
5310 grid.</entry>
5311 </row>
5312 <row>
5313 <entry spanname="id"><constant>V4L2_CID_DETECT_MD_REGION_GRID</constant>&nbsp;</entry>
5314 <entry>__u8 matrix</entry>
5315 </row>
5316 <row><entry spanname="descr">Sets the motion detection region value for each cell in the grid.
5317 To be used with the <constant>V4L2_DETECT_MD_MODE_REGION_GRID</constant>
5318 motion detection mode. Matrix element (0, 0) represents the cell at the top-left of the
5319 grid.</entry>
5320 </row>
5321 </tbody>
5322 </tgroup>
5323 </table>
5324
5325 </section>
5326
5327 <section id="rf-tuner-controls">
5328 <title>RF Tuner Control Reference</title>
5329
5330 <para>
5331The RF Tuner (RF_TUNER) class includes controls for common features of devices
5332having RF tuner.
5333 </para>
5334 <para>
5335In this context, RF tuner is radio receiver circuit between antenna and
5336demodulator. It receives radio frequency (RF) from the antenna and converts that
5337received signal to lower intermediate frequency (IF) or baseband frequency (BB).
5338Tuners that could do baseband output are often called Zero-IF tuners. Older
5339tuners were typically simple PLL tuners inside a metal box, whilst newer ones
5340are highly integrated chips without a metal box "silicon tuners". These controls
5341are mostly applicable for new feature rich silicon tuners, just because older
5342tuners does not have much adjustable features.
5343 </para>
5344 <para>
5345For more information about RF tuners see
5346<ulink url="http://en.wikipedia.org/wiki/Tuner_%28radio%29">Tuner (radio)</ulink>
5347and
5348<ulink url="http://en.wikipedia.org/wiki/RF_front_end">RF front end</ulink>
5349from Wikipedia.
5350 </para>
5351
5352 <table pgwide="1" frame="none" id="rf-tuner-control-id">
5353 <title>RF_TUNER Control IDs</title>
5354
5355 <tgroup cols="4">
5356 <colspec colname="c1" colwidth="1*" />
5357 <colspec colname="c2" colwidth="6*" />
5358 <colspec colname="c3" colwidth="2*" />
5359 <colspec colname="c4" colwidth="6*" />
5360 <spanspec namest="c1" nameend="c2" spanname="id" />
5361 <spanspec namest="c2" nameend="c4" spanname="descr" />
5362 <thead>
5363 <row>
5364 <entry spanname="id" align="left">ID</entry>
5365 <entry align="left">Type</entry>
5366 </row>
5367 <row rowsep="1">
5368 <entry spanname="descr" align="left">Description</entry>
5369 </row>
5370 </thead>
5371 <tbody valign="top">
5372 <row><entry></entry></row>
5373 <row>
5374 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_CLASS</constant>&nbsp;</entry>
5375 <entry>class</entry>
5376 </row><row><entry spanname="descr">The RF_TUNER class
5377descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
5378description of this control class.</entry>
5379 </row>
5380 <row>
5381 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_BANDWIDTH_AUTO</constant>&nbsp;</entry>
5382 <entry>boolean</entry>
5383 </row>
5384 <row>
5385 <entry spanname="descr">Enables/disables tuner radio channel
5386bandwidth configuration. In automatic mode bandwidth configuration is performed
5387by the driver.</entry>
5388 </row>
5389 <row>
5390 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_BANDWIDTH</constant>&nbsp;</entry>
5391 <entry>integer</entry>
5392 </row>
5393 <row>
5394 <entry spanname="descr">Filter(s) on tuner signal path are used to
5395filter signal according to receiving party needs. Driver configures filters to
5396fulfill desired bandwidth requirement. Used when V4L2_CID_RF_TUNER_BANDWIDTH_AUTO is not
5397set. Unit is in Hz. The range and step are driver-specific.</entry>
5398 </row>
5399 <row>
5400 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_LNA_GAIN_AUTO</constant>&nbsp;</entry>
5401 <entry>boolean</entry>
5402 </row>
5403 <row>
5404 <entry spanname="descr">Enables/disables LNA automatic gain control (AGC)</entry>
5405 </row>
5406 <row>
5407 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO</constant>&nbsp;</entry>
5408 <entry>boolean</entry>
5409 </row>
5410 <row>
5411 <entry spanname="descr">Enables/disables mixer automatic gain control (AGC)</entry>
5412 </row>
5413 <row>
5414 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_IF_GAIN_AUTO</constant>&nbsp;</entry>
5415 <entry>boolean</entry>
5416 </row>
5417 <row>
5418 <entry spanname="descr">Enables/disables IF automatic gain control (AGC)</entry>
5419 </row>
5420 <row>
5421 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_LNA_GAIN</constant>&nbsp;</entry>
5422 <entry>integer</entry>
5423 </row>
5424 <row>
5425 <entry spanname="descr">LNA (low noise amplifier) gain is first
5426gain stage on the RF tuner signal path. It is located very close to tuner
5427antenna input. Used when <constant>V4L2_CID_RF_TUNER_LNA_GAIN_AUTO</constant> is not set.
5428The range and step are driver-specific.</entry>
5429 </row>
5430 <row>
5431 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_MIXER_GAIN</constant>&nbsp;</entry>
5432 <entry>integer</entry>
5433 </row>
5434 <row>
5435 <entry spanname="descr">Mixer gain is second gain stage on the RF
5436tuner signal path. It is located inside mixer block, where RF signal is
5437down-converted by the mixer. Used when <constant>V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO</constant>
5438is not set. The range and step are driver-specific.</entry>
5439 </row>
5440 <row>
5441 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_IF_GAIN</constant>&nbsp;</entry>
5442 <entry>integer</entry>
5443 </row>
5444 <row>
5445 <entry spanname="descr">IF gain is last gain stage on the RF tuner
5446signal path. It is located on output of RF tuner. It controls signal level of
5447intermediate frequency output or baseband output. Used when
5448<constant>V4L2_CID_RF_TUNER_IF_GAIN_AUTO</constant> is not set. The range and step are
5449driver-specific.</entry>
5450 </row>
5451 <row>
5452 <entry spanname="id"><constant>V4L2_CID_RF_TUNER_PLL_LOCK</constant>&nbsp;</entry>
5453 <entry>boolean</entry>
5454 </row>
5455 <row>
5456 <entry spanname="descr">Is synthesizer PLL locked? RF tuner is
5457receiving given frequency when that control is set. This is a read-only control.
5458</entry>
5459 </row>
5460 </tbody>
5461 </tgroup>
5462 </table>
5463 </section>
5464</section>