| #ifndef foovolumehfoo |
| #define foovolumehfoo |
| |
| /*** |
| This file is part of PulseAudio. |
| |
| Copyright 2004-2006 Lennart Poettering |
| Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB |
| |
| PulseAudio is free software; you can redistribute it and/or modify |
| it under the terms of the GNU Lesser General Public License as published |
| by the Free Software Foundation; either version 2.1 of the License, |
| or (at your option) any later version. |
| |
| PulseAudio is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with PulseAudio; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
| USA. |
| ***/ |
| |
| #include <inttypes.h> |
| #include <limits.h> |
| |
| #include <pulse/cdecl.h> |
| #include <pulse/gccmacro.h> |
| #include <pulse/sample.h> |
| #include <pulse/channelmap.h> |
| #include <pulse/version.h> |
| |
| /** \page volume Volume Control |
| * |
| * \section overv_sec Overview |
| * |
| * Sinks, sources, sink inputs and samples can all have their own volumes. |
| * To deal with these, The PulseAudio library contains a number of functions |
| * that ease handling. |
| * |
| * The basic volume type in PulseAudio is the \ref pa_volume_t type. Most of |
| * the time, applications will use the aggregated pa_cvolume structure that |
| * can store the volume of all channels at once. |
| * |
| * Volumes commonly span between muted (0%), and normal (100%). It is possible |
| * to set volumes to higher than 100%, but clipping might occur. |
| * |
| * \section calc_sec Calculations |
| * |
| * The volumes in PulseAudio are logarithmic in nature and applications |
| * shouldn't perform calculations with them directly. Instead, they should |
| * be converted to and from either dB or a linear scale: |
| * |
| * \li dB - pa_sw_volume_from_dB() / pa_sw_volume_to_dB() |
| * \li Linear - pa_sw_volume_from_linear() / pa_sw_volume_to_linear() |
| * |
| * For simple multiplication, pa_sw_volume_multiply() and |
| * pa_sw_cvolume_multiply() can be used. |
| * |
| * Calculations can only be reliably performed on software volumes |
| * as it is commonly unknown what scale hardware volumes relate to. |
| * |
| * The functions described above are only valid when used with |
| * software volumes. Hence it is usually a better idea to treat all |
| * volume values as opaque with a range from PA_VOLUME_MUTED (0%) to |
| * PA_VOLUME_NORM (100%) and to refrain from any calculations with |
| * them. |
| * |
| * \section conv_sec Convenience Functions |
| * |
| * To handle the pa_cvolume structure, the PulseAudio library provides a |
| * number of convenience functions: |
| * |
| * \li pa_cvolume_valid() - Tests if a pa_cvolume structure is valid. |
| * \li pa_cvolume_equal() - Tests if two pa_cvolume structures are identical. |
| * \li pa_cvolume_channels_equal_to() - Tests if all channels of a pa_cvolume |
| * structure have a given volume. |
| * \li pa_cvolume_is_muted() - Tests if all channels of a pa_cvolume |
| * structure are muted. |
| * \li pa_cvolume_is_norm() - Tests if all channels of a pa_cvolume structure |
| * are at a normal volume. |
| * \li pa_cvolume_set() - Set the first n channels of a pa_cvolume structure to |
| * a certain volume. |
| * \li pa_cvolume_reset() - Set the first n channels of a pa_cvolume structure |
| * to a normal volume. |
| * \li pa_cvolume_mute() - Set the first n channels of a pa_cvolume structure |
| * to a muted volume. |
| * \li pa_cvolume_avg() - Return the average volume of all channels. |
| * \li pa_cvolume_snprint() - Pretty print a pa_cvolume structure. |
| */ |
| |
| /** \file |
| * Constants and routines for volume handling |
| * |
| * See also \subpage volume |
| */ |
| |
| PA_C_DECL_BEGIN |
| |
| /** Volume specification: |
| * PA_VOLUME_MUTED: silence; |
| * < PA_VOLUME_NORM: decreased volume; |
| * PA_VOLUME_NORM: normal volume; |
| * > PA_VOLUME_NORM: increased volume */ |
| typedef uint32_t pa_volume_t; |
| |
| /** Normal volume (100%, 0 dB) */ |
| #define PA_VOLUME_NORM ((pa_volume_t) 0x10000U) |
| |
| /** Muted (minimal valid) volume (0%, -inf dB) */ |
| #define PA_VOLUME_MUTED ((pa_volume_t) 0U) |
| |
| /** Maximum valid volume we can store. \since 0.9.15 */ |
| #define PA_VOLUME_MAX ((pa_volume_t) UINT32_MAX/2) |
| |
| /** Recommended maximum volume to show in user facing UIs. |
| * Note: UIs should deal gracefully with volumes greater than this value |
| * and not cause feedback loops etc. - i.e. if the volume is more than |
| * this, the UI should not limit it and push the limited value back to |
| * the server. \since 0.9.23 */ |
| #define PA_VOLUME_UI_MAX (pa_sw_volume_from_dB(+11.0)) |
| |
| /** Special 'invalid' volume. \since 0.9.16 */ |
| #define PA_VOLUME_INVALID ((pa_volume_t) UINT32_MAX) |
| |
| /** Check if volume is valid. \since 1.0 */ |
| #define PA_VOLUME_IS_VALID(v) ((v) <= PA_VOLUME_MAX) |
| |
| /** Clamp volume to the permitted range. \since 1.0 */ |
| #define PA_CLAMP_VOLUME(v) (PA_CLAMP_UNLIKELY((v), PA_VOLUME_MUTED, PA_VOLUME_MAX)) |
| |
| /** A structure encapsulating a per-channel volume */ |
| typedef struct pa_cvolume { |
| uint8_t channels; /**< Number of channels */ |
| pa_volume_t values[PA_CHANNELS_MAX]; /**< Per-channel volume */ |
| } pa_cvolume; |
| |
| /** Return non-zero when *a == *b */ |
| int pa_cvolume_equal(const pa_cvolume *a, const pa_cvolume *b) PA_GCC_PURE; |
| |
| /** Initialize the specified volume and return a pointer to |
| * it. The sample spec will have a defined state but |
| * pa_cvolume_valid() will fail for it. \since 0.9.13 */ |
| pa_cvolume* pa_cvolume_init(pa_cvolume *a); |
| |
| /** Set the volume of the first n channels to PA_VOLUME_NORM */ |
| #define pa_cvolume_reset(a, n) pa_cvolume_set((a), (n), PA_VOLUME_NORM) |
| |
| /** Set the volume of the first n channels to PA_VOLUME_MUTED */ |
| #define pa_cvolume_mute(a, n) pa_cvolume_set((a), (n), PA_VOLUME_MUTED) |
| |
| /** Set the volume of the specified number of channels to the volume v */ |
| pa_cvolume* pa_cvolume_set(pa_cvolume *a, unsigned channels, pa_volume_t v); |
| |
| /** Maximum length of the strings returned by |
| * pa_cvolume_snprint(). Please note that this value can change with |
| * any release without warning and without being considered API or ABI |
| * breakage. You should not use this definition anywhere where it |
| * might become part of an ABI.*/ |
| #define PA_CVOLUME_SNPRINT_MAX 320 |
| |
| /** Pretty print a volume structure */ |
| char *pa_cvolume_snprint(char *s, size_t l, const pa_cvolume *c); |
| |
| /** Maximum length of the strings returned by |
| * pa_sw_cvolume_snprint_dB(). Please note that this value can change with |
| * any release without warning and without being considered API or ABI |
| * breakage. You should not use this definition anywhere where it |
| * might become part of an ABI. \since 0.9.13 */ |
| #define PA_SW_CVOLUME_SNPRINT_DB_MAX 448 |
| |
| /** Pretty print a volume structure but show dB values. \since 0.9.13 */ |
| char *pa_sw_cvolume_snprint_dB(char *s, size_t l, const pa_cvolume *c); |
| |
| /** Maximum length of the strings returned by |
| * pa_volume_snprint(). Please note that this value can change with |
| * any release without warning and without being considered API or ABI |
| * breakage. You should not use this definition anywhere where it |
| * might become part of an ABI. \since 0.9.15 */ |
| #define PA_VOLUME_SNPRINT_MAX 10 |
| |
| /** Pretty print a volume \since 0.9.15 */ |
| char *pa_volume_snprint(char *s, size_t l, pa_volume_t v); |
| |
| /** Maximum length of the strings returned by |
| * pa_sw_volume_snprint_dB(). Please note that this value can change with |
| * any release without warning and without being considered API or ABI |
| * breakage. You should not use this definition anywhere where it |
| * might become part of an ABI. \since 0.9.15 */ |
| #define PA_SW_VOLUME_SNPRINT_DB_MAX 10 |
| |
| /** Pretty print a volume but show dB values. \since 0.9.15 */ |
| char *pa_sw_volume_snprint_dB(char *s, size_t l, pa_volume_t v); |
| |
| /** Return the average volume of all channels */ |
| pa_volume_t pa_cvolume_avg(const pa_cvolume *a) PA_GCC_PURE; |
| |
| /** Return the average volume of all channels that are included in the |
| * specified channel map with the specified channel position mask. If |
| * cm is NULL this call is identical to pa_cvolume_avg(). If no |
| * channel is selected the returned value will be |
| * PA_VOLUME_MUTED. \since 0.9.16 */ |
| pa_volume_t pa_cvolume_avg_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE; |
| |
| /** Return the maximum volume of all channels. \since 0.9.12 */ |
| pa_volume_t pa_cvolume_max(const pa_cvolume *a) PA_GCC_PURE; |
| |
| /** Return the maximum volume of all channels that are included in the |
| * specified channel map with the specified channel position mask. If |
| * cm is NULL this call is identical to pa_cvolume_max(). If no |
| * channel is selected the returned value will be PA_VOLUME_MUTED. |
| * \since 0.9.16 */ |
| pa_volume_t pa_cvolume_max_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE; |
| |
| /** Return the minimum volume of all channels. \since 0.9.16 */ |
| pa_volume_t pa_cvolume_min(const pa_cvolume *a) PA_GCC_PURE; |
| |
| /** Return the minimum volume of all channels that are included in the |
| * specified channel map with the specified channel position mask. If |
| * cm is NULL this call is identical to pa_cvolume_min(). If no |
| * channel is selected the returned value will be PA_VOLUME_MUTED. |
| * \since 0.9.16 */ |
| pa_volume_t pa_cvolume_min_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE; |
| |
| /** Return TRUE when the passed cvolume structure is valid, FALSE otherwise */ |
| int pa_cvolume_valid(const pa_cvolume *v) PA_GCC_PURE; |
| |
| /** Return non-zero if the volume of all channels is equal to the specified value */ |
| int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v) PA_GCC_PURE; |
| |
| /** Return 1 if the specified volume has all channels muted */ |
| #define pa_cvolume_is_muted(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_MUTED) |
| |
| /** Return 1 if the specified volume has all channels on normal level */ |
| #define pa_cvolume_is_norm(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_NORM) |
| |
| /** Multiply two volume specifications, return the result. This uses |
| * PA_VOLUME_NORM as neutral element of multiplication. This is only |
| * valid for software volumes! */ |
| pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b) PA_GCC_CONST; |
| |
| /** Multiply two per-channel volumes and return the result in |
| * *dest. This is only valid for software volumes! a, b and dest may |
| * point to the same structure. */ |
| pa_cvolume *pa_sw_cvolume_multiply(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b); |
| |
| /** Multiply a per-channel volume with a scalar volume and return the |
| * result in *dest. This is only valid for software volumes! a |
| * and dest may point to the same structure. \since |
| * 0.9.16 */ |
| pa_cvolume *pa_sw_cvolume_multiply_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b); |
| |
| /** Divide two volume specifications, return the result. This uses |
| * PA_VOLUME_NORM as neutral element of division. This is only valid |
| * for software volumes! If a division by zero is tried the result |
| * will be 0. \since 0.9.13 */ |
| pa_volume_t pa_sw_volume_divide(pa_volume_t a, pa_volume_t b) PA_GCC_CONST; |
| |
| /** Divide two per-channel volumes and return the result in |
| * *dest. This is only valid for software volumes! a, b |
| * and dest may point to the same structure. \since 0.9.13 */ |
| pa_cvolume *pa_sw_cvolume_divide(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b); |
| |
| /** Divide a per-channel volume by a scalar volume and return the |
| * result in *dest. This is only valid for software volumes! a |
| * and dest may point to the same structure. \since |
| * 0.9.16 */ |
| pa_cvolume *pa_sw_cvolume_divide_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b); |
| |
| /** Convert a decibel value to a volume (amplitude, not power). This is only valid for software volumes! */ |
| pa_volume_t pa_sw_volume_from_dB(double f) PA_GCC_CONST; |
| |
| /** Convert a volume to a decibel value (amplitude, not power). This is only valid for software volumes! */ |
| double pa_sw_volume_to_dB(pa_volume_t v) PA_GCC_CONST; |
| |
| /** Convert a linear factor to a volume. 0.0 and less is muted while |
| * 1.0 is PA_VOLUME_NORM. This is only valid for software volumes! */ |
| pa_volume_t pa_sw_volume_from_linear(double v) PA_GCC_CONST; |
| |
| /** Convert a volume to a linear factor. This is only valid for software volumes! */ |
| double pa_sw_volume_to_linear(pa_volume_t v) PA_GCC_CONST; |
| |
| #ifdef INFINITY |
| #define PA_DECIBEL_MININFTY ((double) -INFINITY) |
| #else |
| /** This floor value is used as minus infinity when using pa_sw_volume_to_dB() / pa_sw_volume_from_dB(). */ |
| #define PA_DECIBEL_MININFTY ((double) -200.0) |
| #endif |
| |
| /** Remap a volume from one channel mapping to a different channel mapping. \since 0.9.12 */ |
| pa_cvolume *pa_cvolume_remap(pa_cvolume *v, const pa_channel_map *from, const pa_channel_map *to); |
| |
| /** Return non-zero if the specified volume is compatible with the |
| * specified sample spec. \since 0.9.13 */ |
| int pa_cvolume_compatible(const pa_cvolume *v, const pa_sample_spec *ss) PA_GCC_PURE; |
| |
| /** Return non-zero if the specified volume is compatible with the |
| * specified sample spec. \since 0.9.15 */ |
| int pa_cvolume_compatible_with_channel_map(const pa_cvolume *v, const pa_channel_map *cm) PA_GCC_PURE; |
| |
| /** Calculate a 'balance' value for the specified volume with the |
| * specified channel map. The return value will range from -1.0f |
| * (left) to +1.0f (right). If no balance value is applicable to this |
| * channel map the return value will always be 0.0f. See |
| * pa_channel_map_can_balance(). \since 0.9.15 */ |
| float pa_cvolume_get_balance(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE; |
| |
| /** Adjust the 'balance' value for the specified volume with the |
| * specified channel map. v will be modified in place and |
| * returned. The balance is a value between -1.0f and +1.0f. This |
| * operation might not be reversible! Also, after this call |
| * pa_cvolume_get_balance() is not guaranteed to actually return the |
| * requested balance value (e.g. when the input volume was zero anyway for |
| * all channels). If no balance value is applicable to |
| * this channel map the volume will not be modified. See |
| * pa_channel_map_can_balance(). \since 0.9.15 */ |
| pa_cvolume* pa_cvolume_set_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance); |
| |
| /** Calculate a 'fade' value (i.e. 'balance' between front and rear) |
| * for the specified volume with the specified channel map. The return |
| * value will range from -1.0f (rear) to +1.0f (left). If no fade |
| * value is applicable to this channel map the return value will |
| * always be 0.0f. See pa_channel_map_can_fade(). \since 0.9.15 */ |
| float pa_cvolume_get_fade(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE; |
| |
| /** Adjust the 'fade' value (i.e. 'balance' between front and rear) |
| * for the specified volume with the specified channel map. v will be |
| * modified in place and returned. The balance is a value between |
| * -1.0f and +1.0f. This operation might not be reversible! Also, |
| * after this call pa_cvolume_get_fade() is not guaranteed to actually |
| * return the requested fade value (e.g. when the input volume was |
| * zero anyway for all channels). If no fade value is applicable to |
| * this channel map the volume will not be modified. See |
| * pa_channel_map_can_fade(). \since 0.9.15 */ |
| pa_cvolume* pa_cvolume_set_fade(pa_cvolume *v, const pa_channel_map *map, float new_fade); |
| |
| /** Scale the passed pa_cvolume structure so that the maximum volume |
| * of all channels equals max. The proportions between the channel |
| * volumes are kept. \since 0.9.15 */ |
| pa_cvolume* pa_cvolume_scale(pa_cvolume *v, pa_volume_t max); |
| |
| /** Scale the passed pa_cvolume structure so that the maximum volume |
| * of all channels selected via cm/mask equals max. This also modifies |
| * the volume of those channels that are unmasked. The proportions |
| * between the channel volumes are kept. \since 0.9.16 */ |
| pa_cvolume* pa_cvolume_scale_mask(pa_cvolume *v, pa_volume_t max, pa_channel_map *cm, pa_channel_position_mask_t mask); |
| |
| /** Set the passed volume to all channels at the specified channel |
| * position. Will return the updated volume struct, or NULL if there |
| * is no channel at the position specified. You can check if a channel |
| * map includes a specific position by calling |
| * pa_channel_map_has_position(). \since 0.9.16 */ |
| pa_cvolume* pa_cvolume_set_position(pa_cvolume *cv, const pa_channel_map *map, pa_channel_position_t t, pa_volume_t v); |
| |
| /** Get the maximum volume of all channels at the specified channel |
| * position. Will return 0 if there is no channel at the position |
| * specified. You can check if a channel map includes a specific |
| * position by calling pa_channel_map_has_position(). \since 0.9.16 */ |
| pa_volume_t pa_cvolume_get_position(pa_cvolume *cv, const pa_channel_map *map, pa_channel_position_t t) PA_GCC_PURE; |
| |
| /** This goes through all channels in a and b and sets the |
| * corresponding channel in dest to the greater volume of both. a, b |
| * and dest may point to the same structure. \since 0.9.16 */ |
| pa_cvolume* pa_cvolume_merge(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b); |
| |
| /** Increase the volume passed in by 'inc', but not exceeding 'limit'. |
| * The proportions between the channels are kept. \since 0.9.19 */ |
| pa_cvolume* pa_cvolume_inc_clamp(pa_cvolume *v, pa_volume_t inc, pa_volume_t limit); |
| |
| /** Increase the volume passed in by 'inc'. The proportions between |
| * the channels are kept. \since 0.9.16 */ |
| pa_cvolume* pa_cvolume_inc(pa_cvolume *v, pa_volume_t inc); |
| |
| /** Increase the volume passed in by 'inc'. The proportions between |
| * the channels are kept. \since 0.9.16 */ |
| pa_cvolume* pa_cvolume_dec(pa_cvolume *v, pa_volume_t dec); |
| |
| PA_C_DECL_END |
| |
| #endif |
