| \input texinfo @c -*- texinfo -*- |
| @documentencoding UTF-8 |
| |
| @settitle ffmpeg Documentation |
| @titlepage |
| @center @titlefont{ffmpeg Documentation} |
| @end titlepage |
| |
| @top |
| |
| @contents |
| |
| @chapter Synopsis |
| |
| ffmpeg [@var{global_options}] @{[@var{input_file_options}] -i @file{input_file}@} ... @{[@var{output_file_options}] @file{output_file}@} ... |
| |
| @chapter Description |
| @c man begin DESCRIPTION |
| |
| @command{ffmpeg} is a very fast video and audio converter that can also grab from |
| a live audio/video source. It can also convert between arbitrary sample |
| rates and resize video on the fly with a high quality polyphase filter. |
| |
| @command{ffmpeg} reads from an arbitrary number of input "files" (which can be regular |
| files, pipes, network streams, grabbing devices, etc.), specified by the |
| @code{-i} option, and writes to an arbitrary number of output "files", which are |
| specified by a plain output filename. Anything found on the command line which |
| cannot be interpreted as an option is considered to be an output filename. |
| |
| Each input or output file can, in principle, contain any number of streams of |
| different types (video/audio/subtitle/attachment/data). The allowed number and/or |
| types of streams may be limited by the container format. Selecting which |
| streams from which inputs will go into which output is either done automatically |
| or with the @code{-map} option (see the Stream selection chapter). |
| |
| To refer to input files in options, you must use their indices (0-based). E.g. |
| the first input file is @code{0}, the second is @code{1}, etc. Similarly, streams |
| within a file are referred to by their indices. E.g. @code{2:3} refers to the |
| fourth stream in the third input file. Also see the Stream specifiers chapter. |
| |
| As a general rule, options are applied to the next specified |
| file. Therefore, order is important, and you can have the same |
| option on the command line multiple times. Each occurrence is |
| then applied to the next input or output file. |
| Exceptions from this rule are the global options (e.g. verbosity level), |
| which should be specified first. |
| |
| Do not mix input and output files -- first specify all input files, then all |
| output files. Also do not mix options which belong to different files. All |
| options apply ONLY to the next input or output file and are reset between files. |
| |
| @itemize |
| @item |
| To set the video bitrate of the output file to 64 kbit/s: |
| @example |
| ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi |
| @end example |
| |
| @item |
| To force the frame rate of the output file to 24 fps: |
| @example |
| ffmpeg -i input.avi -r 24 output.avi |
| @end example |
| |
| @item |
| To force the frame rate of the input file (valid for raw formats only) |
| to 1 fps and the frame rate of the output file to 24 fps: |
| @example |
| ffmpeg -r 1 -i input.m2v -r 24 output.avi |
| @end example |
| @end itemize |
| |
| The format option may be needed for raw input files. |
| |
| @c man end DESCRIPTION |
| |
| @chapter Detailed description |
| @c man begin DETAILED DESCRIPTION |
| |
| The transcoding process in @command{ffmpeg} for each output can be described by |
| the following diagram: |
| |
| @verbatim |
| _______ ______________ |
| | | | | |
| | input | demuxer | encoded data | decoder |
| | file | ---------> | packets | -----+ |
| |_______| |______________| | |
| v |
| _________ |
| | | |
| | decoded | |
| | frames | |
| |_________| |
| ________ ______________ | |
| | | | | | |
| | output | <-------- | encoded data | <----+ |
| | file | muxer | packets | encoder |
| |________| |______________| |
| |
| |
| @end verbatim |
| |
| @command{ffmpeg} calls the libavformat library (containing demuxers) to read |
| input files and get packets containing encoded data from them. When there are |
| multiple input files, @command{ffmpeg} tries to keep them synchronized by |
| tracking lowest timestamp on any active input stream. |
| |
| Encoded packets are then passed to the decoder (unless streamcopy is selected |
| for the stream, see further for a description). The decoder produces |
| uncompressed frames (raw video/PCM audio/...) which can be processed further by |
| filtering (see next section). After filtering, the frames are passed to the |
| encoder, which encodes them and outputs encoded packets. Finally those are |
| passed to the muxer, which writes the encoded packets to the output file. |
| |
| @section Filtering |
| Before encoding, @command{ffmpeg} can process raw audio and video frames using |
| filters from the libavfilter library. Several chained filters form a filter |
| graph. @command{ffmpeg} distinguishes between two types of filtergraphs: |
| simple and complex. |
| |
| @subsection Simple filtergraphs |
| Simple filtergraphs are those that have exactly one input and output, both of |
| the same type. In the above diagram they can be represented by simply inserting |
| an additional step between decoding and encoding: |
| |
| @verbatim |
| _________ ______________ |
| | | | | |
| | decoded | | encoded data | |
| | frames |\ _ | packets | |
| |_________| \ /||______________| |
| \ __________ / |
| simple _\|| | / encoder |
| filtergraph | filtered |/ |
| | frames | |
| |__________| |
| |
| @end verbatim |
| |
| Simple filtergraphs are configured with the per-stream @option{-filter} option |
| (with @option{-vf} and @option{-af} aliases for video and audio respectively). |
| A simple filtergraph for video can look for example like this: |
| |
| @verbatim |
| _______ _____________ _______ ________ |
| | | | | | | | | |
| | input | ---> | deinterlace | ---> | scale | ---> | output | |
| |_______| |_____________| |_______| |________| |
| |
| @end verbatim |
| |
| Note that some filters change frame properties but not frame contents. E.g. the |
| @code{fps} filter in the example above changes number of frames, but does not |
| touch the frame contents. Another example is the @code{setpts} filter, which |
| only sets timestamps and otherwise passes the frames unchanged. |
| |
| @subsection Complex filtergraphs |
| Complex filtergraphs are those which cannot be described as simply a linear |
| processing chain applied to one stream. This is the case, for example, when the graph has |
| more than one input and/or output, or when output stream type is different from |
| input. They can be represented with the following diagram: |
| |
| @verbatim |
| _________ |
| | | |
| | input 0 |\ __________ |
| |_________| \ | | |
| \ _________ /| output 0 | |
| \ | | / |__________| |
| _________ \| complex | / |
| | | | |/ |
| | input 1 |---->| filter |\ |
| |_________| | | \ __________ |
| /| graph | \ | | |
| / | | \| output 1 | |
| _________ / |_________| |__________| |
| | | / |
| | input 2 |/ |
| |_________| |
| |
| @end verbatim |
| |
| Complex filtergraphs are configured with the @option{-filter_complex} option. |
| Note that this option is global, since a complex filtergraph, by its nature, |
| cannot be unambiguously associated with a single stream or file. |
| |
| The @option{-lavfi} option is equivalent to @option{-filter_complex}. |
| |
| A trivial example of a complex filtergraph is the @code{overlay} filter, which |
| has two video inputs and one video output, containing one video overlaid on top |
| of the other. Its audio counterpart is the @code{amix} filter. |
| |
| @section Stream copy |
| Stream copy is a mode selected by supplying the @code{copy} parameter to the |
| @option{-codec} option. It makes @command{ffmpeg} omit the decoding and encoding |
| step for the specified stream, so it does only demuxing and muxing. It is useful |
| for changing the container format or modifying container-level metadata. The |
| diagram above will, in this case, simplify to this: |
| |
| @verbatim |
| _______ ______________ ________ |
| | | | | | | |
| | input | demuxer | encoded data | muxer | output | |
| | file | ---------> | packets | -------> | file | |
| |_______| |______________| |________| |
| |
| @end verbatim |
| |
| Since there is no decoding or encoding, it is very fast and there is no quality |
| loss. However, it might not work in some cases because of many factors. Applying |
| filters is obviously also impossible, since filters work on uncompressed data. |
| |
| @c man end DETAILED DESCRIPTION |
| |
| @chapter Stream selection |
| @c man begin STREAM SELECTION |
| |
| By default, @command{ffmpeg} includes only one stream of each type (video, audio, subtitle) |
| present in the input files and adds them to each output file. It picks the |
| "best" of each based upon the following criteria: for video, it is the stream |
| with the highest resolution, for audio, it is the stream with the most channels, for |
| subtitles, it is the first subtitle stream. In the case where several streams of |
| the same type rate equally, the stream with the lowest index is chosen. |
| |
| You can disable some of those defaults by using the @code{-vn/-an/-sn} options. For |
| full manual control, use the @code{-map} option, which disables the defaults just |
| described. |
| |
| @c man end STREAM SELECTION |
| |
| @chapter Options |
| @c man begin OPTIONS |
| |
| @include fftools-common-opts.texi |
| |
| @section Main options |
| |
| @table @option |
| |
| @item -f @var{fmt} (@emph{input/output}) |
| Force input or output file format. The format is normally auto detected for input |
| files and guessed from the file extension for output files, so this option is not |
| needed in most cases. |
| |
| @item -i @var{filename} (@emph{input}) |
| input file name |
| |
| @item -y (@emph{global}) |
| Overwrite output files without asking. |
| |
| @item -n (@emph{global}) |
| Do not overwrite output files, and exit immediately if a specified |
| output file already exists. |
| |
| @item -stream_loop @var{number} (@emph{input}) |
| Set number of times input stream shall be looped. Loop 0 means no loop, |
| loop -1 means infinite loop. |
| |
| @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream}) |
| @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream}) |
| Select an encoder (when used before an output file) or a decoder (when used |
| before an input file) for one or more streams. @var{codec} is the name of a |
| decoder/encoder or a special value @code{copy} (output only) to indicate that |
| the stream is not to be re-encoded. |
| |
| For example |
| @example |
| ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT |
| @end example |
| encodes all video streams with libx264 and copies all audio streams. |
| |
| For each stream, the last matching @code{c} option is applied, so |
| @example |
| ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT |
| @end example |
| will copy all the streams except the second video, which will be encoded with |
| libx264, and the 138th audio, which will be encoded with libvorbis. |
| |
| @item -t @var{duration} (@emph{input/output}) |
| When used as an input option (before @code{-i}), limit the @var{duration} of |
| data read from the input file. |
| |
| When used as an output option (before an output filename), stop writing the |
| output after its duration reaches @var{duration}. |
| |
| @var{duration} must be a time duration specification, |
| see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| |
| -to and -t are mutually exclusive and -t has priority. |
| |
| @item -to @var{position} (@emph{output}) |
| Stop writing the output at @var{position}. |
| @var{position} must be a time duration specification, |
| see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| |
| -to and -t are mutually exclusive and -t has priority. |
| |
| @item -fs @var{limit_size} (@emph{output}) |
| Set the file size limit, expressed in bytes. No further chunk of bytes is written |
| after the limit is exceeded. The size of the output file is slightly more than the |
| requested file size. |
| |
| @item -ss @var{position} (@emph{input/output}) |
| When used as an input option (before @code{-i}), seeks in this input file to |
| @var{position}. Note that in most formats it is not possible to seek exactly, |
| so @command{ffmpeg} will seek to the closest seek point before @var{position}. |
| When transcoding and @option{-accurate_seek} is enabled (the default), this |
| extra segment between the seek point and @var{position} will be decoded and |
| discarded. When doing stream copy or when @option{-noaccurate_seek} is used, it |
| will be preserved. |
| |
| When used as an output option (before an output filename), decodes but discards |
| input until the timestamps reach @var{position}. |
| |
| @var{position} must be a time duration specification, |
| see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| |
| @item -sseof @var{position} (@emph{input/output}) |
| |
| Like the @code{-ss} option but relative to the "end of file". That is negative |
| values are earlier in the file, 0 is at EOF. |
| |
| @item -itsoffset @var{offset} (@emph{input}) |
| Set the input time offset. |
| |
| @var{offset} must be a time duration specification, |
| see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| |
| The offset is added to the timestamps of the input files. Specifying |
| a positive offset means that the corresponding streams are delayed by |
| the time duration specified in @var{offset}. |
| |
| @item -timestamp @var{date} (@emph{output}) |
| Set the recording timestamp in the container. |
| |
| @var{date} must be a date specification, |
| see @ref{date syntax,,the Date section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| |
| @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata}) |
| Set a metadata key/value pair. |
| |
| An optional @var{metadata_specifier} may be given to set metadata |
| on streams, chapters or programs. See @code{-map_metadata} |
| documentation for details. |
| |
| This option overrides metadata set with @code{-map_metadata}. It is |
| also possible to delete metadata by using an empty value. |
| |
| For example, for setting the title in the output file: |
| @example |
| ffmpeg -i in.avi -metadata title="my title" out.flv |
| @end example |
| |
| To set the language of the first audio stream: |
| @example |
| ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT |
| @end example |
| |
| @item -program [title=@var{title}:][program_num=@var{program_num}:]st=@var{stream}[:st=@var{stream}...] (@emph{output}) |
| |
| Creates a program with the specified @var{title}, @var{program_num} and adds the specified |
| @var{stream}(s) to it. |
| |
| @item -target @var{type} (@emph{output}) |
| Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv}, |
| @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or |
| @code{film-} to use the corresponding standard. All the format options |
| (bitrate, codecs, buffer sizes) are then set automatically. You can just type: |
| |
| @example |
| ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg |
| @end example |
| |
| Nevertheless you can specify additional options as long as you know |
| they do not conflict with the standard, as in: |
| |
| @example |
| ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg |
| @end example |
| |
| @item -dframes @var{number} (@emph{output}) |
| Set the number of data frames to output. This is an alias for @code{-frames:d}. |
| |
| @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream}) |
| Stop writing to the stream after @var{framecount} frames. |
| |
| @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream}) |
| @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream}) |
| Use fixed quality scale (VBR). The meaning of @var{q}/@var{qscale} is |
| codec-dependent. |
| If @var{qscale} is used without a @var{stream_specifier} then it applies only |
| to the video stream, this is to maintain compatibility with previous behavior |
| and as specifying the same codec specific value to 2 different codecs that is |
| audio and video generally is not what is intended when no stream_specifier is |
| used. |
| |
| @anchor{filter_option} |
| @item -filter[:@var{stream_specifier}] @var{filtergraph} (@emph{output,per-stream}) |
| Create the filtergraph specified by @var{filtergraph} and use it to |
| filter the stream. |
| |
| @var{filtergraph} is a description of the filtergraph to apply to |
| the stream, and must have a single input and a single output of the |
| same type of the stream. In the filtergraph, the input is associated |
| to the label @code{in}, and the output to the label @code{out}. See |
| the ffmpeg-filters manual for more information about the filtergraph |
| syntax. |
| |
| See the @ref{filter_complex_option,,-filter_complex option} if you |
| want to create filtergraphs with multiple inputs and/or outputs. |
| |
| @item -filter_script[:@var{stream_specifier}] @var{filename} (@emph{output,per-stream}) |
| This option is similar to @option{-filter}, the only difference is that its |
| argument is the name of the file from which a filtergraph description is to be |
| read. |
| |
| @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream}) |
| Specify the preset for matching stream(s). |
| |
| @item -stats (@emph{global}) |
| Print encoding progress/statistics. It is on by default, to explicitly |
| disable it you need to specify @code{-nostats}. |
| |
| @item -progress @var{url} (@emph{global}) |
| Send program-friendly progress information to @var{url}. |
| |
| Progress information is written approximately every second and at the end of |
| the encoding process. It is made of "@var{key}=@var{value}" lines. @var{key} |
| consists of only alphanumeric characters. The last key of a sequence of |
| progress information is always "progress". |
| |
| @item -stdin |
| Enable interaction on standard input. On by default unless standard input is |
| used as an input. To explicitly disable interaction you need to specify |
| @code{-nostdin}. |
| |
| Disabling interaction on standard input is useful, for example, if |
| ffmpeg is in the background process group. Roughly the same result can |
| be achieved with @code{ffmpeg ... < /dev/null} but it requires a |
| shell. |
| |
| @item -debug_ts (@emph{global}) |
| Print timestamp information. It is off by default. This option is |
| mostly useful for testing and debugging purposes, and the output |
| format may change from one version to another, so it should not be |
| employed by portable scripts. |
| |
| See also the option @code{-fdebug ts}. |
| |
| @item -attach @var{filename} (@emph{output}) |
| Add an attachment to the output file. This is supported by a few formats |
| like Matroska for e.g. fonts used in rendering subtitles. Attachments |
| are implemented as a specific type of stream, so this option will add |
| a new stream to the file. It is then possible to use per-stream options |
| on this stream in the usual way. Attachment streams created with this |
| option will be created after all the other streams (i.e. those created |
| with @code{-map} or automatic mappings). |
| |
| Note that for Matroska you also have to set the mimetype metadata tag: |
| @example |
| ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv |
| @end example |
| (assuming that the attachment stream will be third in the output file). |
| |
| @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream}) |
| Extract the matching attachment stream into a file named @var{filename}. If |
| @var{filename} is empty, then the value of the @code{filename} metadata tag |
| will be used. |
| |
| E.g. to extract the first attachment to a file named 'out.ttf': |
| @example |
| ffmpeg -dump_attachment:t:0 out.ttf -i INPUT |
| @end example |
| To extract all attachments to files determined by the @code{filename} tag: |
| @example |
| ffmpeg -dump_attachment:t "" -i INPUT |
| @end example |
| |
| Technical note -- attachments are implemented as codec extradata, so this |
| option can actually be used to extract extradata from any stream, not just |
| attachments. |
| |
| @item -noautorotate |
| Disable automatically rotating video based on file metadata. |
| |
| @end table |
| |
| @section Video Options |
| |
| @table @option |
| @item -vframes @var{number} (@emph{output}) |
| Set the number of video frames to output. This is an alias for @code{-frames:v}. |
| @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream}) |
| Set frame rate (Hz value, fraction or abbreviation). |
| |
| As an input option, ignore any timestamps stored in the file and instead |
| generate timestamps assuming constant frame rate @var{fps}. |
| This is not the same as the @option{-framerate} option used for some input formats |
| like image2 or v4l2 (it used to be the same in older versions of FFmpeg). |
| If in doubt use @option{-framerate} instead of the input option @option{-r}. |
| |
| As an output option, duplicate or drop input frames to achieve constant output |
| frame rate @var{fps}. |
| |
| @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream}) |
| Set frame size. |
| |
| As an input option, this is a shortcut for the @option{video_size} private |
| option, recognized by some demuxers for which the frame size is either not |
| stored in the file or is configurable -- e.g. raw video or video grabbers. |
| |
| As an output option, this inserts the @code{scale} video filter to the |
| @emph{end} of the corresponding filtergraph. Please use the @code{scale} filter |
| directly to insert it at the beginning or some other place. |
| |
| The format is @samp{wxh} (default - same as source). |
| |
| @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream}) |
| Set the video display aspect ratio specified by @var{aspect}. |
| |
| @var{aspect} can be a floating point number string, or a string of the |
| form @var{num}:@var{den}, where @var{num} and @var{den} are the |
| numerator and denominator of the aspect ratio. For example "4:3", |
| "16:9", "1.3333", and "1.7777" are valid argument values. |
| |
| If used together with @option{-vcodec copy}, it will affect the aspect ratio |
| stored at container level, but not the aspect ratio stored in encoded |
| frames, if it exists. |
| |
| @item -vn (@emph{output}) |
| Disable video recording. |
| |
| @item -vcodec @var{codec} (@emph{output}) |
| Set the video codec. This is an alias for @code{-codec:v}. |
| |
| @item -pass[:@var{stream_specifier}] @var{n} (@emph{output,per-stream}) |
| Select the pass number (1 or 2). It is used to do two-pass |
| video encoding. The statistics of the video are recorded in the first |
| pass into a log file (see also the option -passlogfile), |
| and in the second pass that log file is used to generate the video |
| at the exact requested bitrate. |
| On pass 1, you may just deactivate audio and set output to null, |
| examples for Windows and Unix: |
| @example |
| ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL |
| ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null |
| @end example |
| |
| @item -passlogfile[:@var{stream_specifier}] @var{prefix} (@emph{output,per-stream}) |
| Set two-pass log file name prefix to @var{prefix}, the default file name |
| prefix is ``ffmpeg2pass''. The complete file name will be |
| @file{PREFIX-N.log}, where N is a number specific to the output |
| stream |
| |
| @item -vf @var{filtergraph} (@emph{output}) |
| Create the filtergraph specified by @var{filtergraph} and use it to |
| filter the stream. |
| |
| This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter option}. |
| @end table |
| |
| @section Advanced Video options |
| |
| @table @option |
| @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream}) |
| Set pixel format. Use @code{-pix_fmts} to show all the supported |
| pixel formats. |
| If the selected pixel format can not be selected, ffmpeg will print a |
| warning and select the best pixel format supported by the encoder. |
| If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error |
| if the requested pixel format can not be selected, and automatic conversions |
| inside filtergraphs are disabled. |
| If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format |
| as the input (or graph output) and automatic conversions are disabled. |
| |
| @item -sws_flags @var{flags} (@emph{input/output}) |
| Set SwScaler flags. |
| @item -vdt @var{n} |
| Discard threshold. |
| |
| @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream}) |
| Rate control override for specific intervals, formatted as "int,int,int" |
| list separated with slashes. Two first values are the beginning and |
| end frame numbers, last one is quantizer to use if positive, or quality |
| factor if negative. |
| |
| @item -ilme |
| Force interlacing support in encoder (MPEG-2 and MPEG-4 only). |
| Use this option if your input file is interlaced and you want |
| to keep the interlaced format for minimum losses. |
| The alternative is to deinterlace the input stream with |
| @option{-deinterlace}, but deinterlacing introduces losses. |
| @item -psnr |
| Calculate PSNR of compressed frames. |
| @item -vstats |
| Dump video coding statistics to @file{vstats_HHMMSS.log}. |
| @item -vstats_file @var{file} |
| Dump video coding statistics to @var{file}. |
| @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream}) |
| top=1/bottom=0/auto=-1 field first |
| @item -dc @var{precision} |
| Intra_dc_precision. |
| @item -vtag @var{fourcc/tag} (@emph{output}) |
| Force video tag/fourcc. This is an alias for @code{-tag:v}. |
| @item -qphist (@emph{global}) |
| Show QP histogram |
| @item -vbsf @var{bitstream_filter} |
| Deprecated see -bsf |
| |
| @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream}) |
| @item -force_key_frames[:@var{stream_specifier}] expr:@var{expr} (@emph{output,per-stream}) |
| Force key frames at the specified timestamps, more precisely at the first |
| frames after each specified time. |
| |
| If the argument is prefixed with @code{expr:}, the string @var{expr} |
| is interpreted like an expression and is evaluated for each frame. A |
| key frame is forced in case the evaluation is non-zero. |
| |
| If one of the times is "@code{chapters}[@var{delta}]", it is expanded into |
| the time of the beginning of all chapters in the file, shifted by |
| @var{delta}, expressed as a time in seconds. |
| This option can be useful to ensure that a seek point is present at a |
| chapter mark or any other designated place in the output file. |
| |
| For example, to insert a key frame at 5 minutes, plus key frames 0.1 second |
| before the beginning of every chapter: |
| @example |
| -force_key_frames 0:05:00,chapters-0.1 |
| @end example |
| |
| The expression in @var{expr} can contain the following constants: |
| @table @option |
| @item n |
| the number of current processed frame, starting from 0 |
| @item n_forced |
| the number of forced frames |
| @item prev_forced_n |
| the number of the previous forced frame, it is @code{NAN} when no |
| keyframe was forced yet |
| @item prev_forced_t |
| the time of the previous forced frame, it is @code{NAN} when no |
| keyframe was forced yet |
| @item t |
| the time of the current processed frame |
| @end table |
| |
| For example to force a key frame every 5 seconds, you can specify: |
| @example |
| -force_key_frames expr:gte(t,n_forced*5) |
| @end example |
| |
| To force a key frame 5 seconds after the time of the last forced one, |
| starting from second 13: |
| @example |
| -force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5)) |
| @end example |
| |
| Note that forcing too many keyframes is very harmful for the lookahead |
| algorithms of certain encoders: using fixed-GOP options or similar |
| would be more efficient. |
| |
| @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream}) |
| When doing stream copy, copy also non-key frames found at the |
| beginning. |
| |
| @item -hwaccel[:@var{stream_specifier}] @var{hwaccel} (@emph{input,per-stream}) |
| Use hardware acceleration to decode the matching stream(s). The allowed values |
| of @var{hwaccel} are: |
| @table @option |
| @item none |
| Do not use any hardware acceleration (the default). |
| |
| @item auto |
| Automatically select the hardware acceleration method. |
| |
| @item vda |
| Use Apple VDA hardware acceleration. |
| |
| @item vdpau |
| Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration. |
| |
| @item dxva2 |
| Use DXVA2 (DirectX Video Acceleration) hardware acceleration. |
| |
| @item qsv |
| Use the Intel QuickSync Video acceleration for video transcoding. |
| |
| Unlike most other values, this option does not enable accelerated decoding (that |
| is used automatically whenever a qsv decoder is selected), but accelerated |
| transcoding, without copying the frames into the system memory. |
| |
| For it to work, both the decoder and the encoder must support QSV acceleration |
| and no filters must be used. |
| @end table |
| |
| This option has no effect if the selected hwaccel is not available or not |
| supported by the chosen decoder. |
| |
| Note that most acceleration methods are intended for playback and will not be |
| faster than software decoding on modern CPUs. Additionally, @command{ffmpeg} |
| will usually need to copy the decoded frames from the GPU memory into the system |
| memory, resulting in further performance loss. This option is thus mainly |
| useful for testing. |
| |
| @item -hwaccel_device[:@var{stream_specifier}] @var{hwaccel_device} (@emph{input,per-stream}) |
| Select a device to use for hardware acceleration. |
| |
| This option only makes sense when the @option{-hwaccel} option is also |
| specified. Its exact meaning depends on the specific hardware acceleration |
| method chosen. |
| |
| @table @option |
| @item vdpau |
| For VDPAU, this option specifies the X11 display/screen to use. If this option |
| is not specified, the value of the @var{DISPLAY} environment variable is used |
| |
| @item dxva2 |
| For DXVA2, this option should contain the number of the display adapter to use. |
| If this option is not specified, the default adapter is used. |
| |
| @item qsv |
| For QSV, this option corresponds to the valus of MFX_IMPL_* . Allowed values |
| are: |
| @table @option |
| @item auto |
| @item sw |
| @item hw |
| @item auto_any |
| @item hw_any |
| @item hw2 |
| @item hw3 |
| @item hw4 |
| @end table |
| @end table |
| |
| @item -hwaccels |
| List all hardware acceleration methods supported in this build of ffmpeg. |
| |
| @end table |
| |
| @section Audio Options |
| |
| @table @option |
| @item -aframes @var{number} (@emph{output}) |
| Set the number of audio frames to output. This is an alias for @code{-frames:a}. |
| @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream}) |
| Set the audio sampling frequency. For output streams it is set by |
| default to the frequency of the corresponding input stream. For input |
| streams this option only makes sense for audio grabbing devices and raw |
| demuxers and is mapped to the corresponding demuxer options. |
| @item -aq @var{q} (@emph{output}) |
| Set the audio quality (codec-specific, VBR). This is an alias for -q:a. |
| @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream}) |
| Set the number of audio channels. For output streams it is set by |
| default to the number of input audio channels. For input streams |
| this option only makes sense for audio grabbing devices and raw demuxers |
| and is mapped to the corresponding demuxer options. |
| @item -an (@emph{output}) |
| Disable audio recording. |
| @item -acodec @var{codec} (@emph{input/output}) |
| Set the audio codec. This is an alias for @code{-codec:a}. |
| @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream}) |
| Set the audio sample format. Use @code{-sample_fmts} to get a list |
| of supported sample formats. |
| |
| @item -af @var{filtergraph} (@emph{output}) |
| Create the filtergraph specified by @var{filtergraph} and use it to |
| filter the stream. |
| |
| This is an alias for @code{-filter:a}, see the @ref{filter_option,,-filter option}. |
| @end table |
| |
| @section Advanced Audio options |
| |
| @table @option |
| @item -atag @var{fourcc/tag} (@emph{output}) |
| Force audio tag/fourcc. This is an alias for @code{-tag:a}. |
| @item -absf @var{bitstream_filter} |
| Deprecated, see -bsf |
| @item -guess_layout_max @var{channels} (@emph{input,per-stream}) |
| If some input channel layout is not known, try to guess only if it |
| corresponds to at most the specified number of channels. For example, 2 |
| tells to @command{ffmpeg} to recognize 1 channel as mono and 2 channels as |
| stereo but not 6 channels as 5.1. The default is to always try to guess. Use |
| 0 to disable all guessing. |
| @end table |
| |
| @section Subtitle options |
| |
| @table @option |
| @item -scodec @var{codec} (@emph{input/output}) |
| Set the subtitle codec. This is an alias for @code{-codec:s}. |
| @item -sn (@emph{output}) |
| Disable subtitle recording. |
| @item -sbsf @var{bitstream_filter} |
| Deprecated, see -bsf |
| @end table |
| |
| @section Advanced Subtitle options |
| |
| @table @option |
| |
| @item -fix_sub_duration |
| Fix subtitles durations. For each subtitle, wait for the next packet in the |
| same stream and adjust the duration of the first to avoid overlap. This is |
| necessary with some subtitles codecs, especially DVB subtitles, because the |
| duration in the original packet is only a rough estimate and the end is |
| actually marked by an empty subtitle frame. Failing to use this option when |
| necessary can result in exaggerated durations or muxing failures due to |
| non-monotonic timestamps. |
| |
| Note that this option will delay the output of all data until the next |
| subtitle packet is decoded: it may increase memory consumption and latency a |
| lot. |
| |
| @item -canvas_size @var{size} |
| Set the size of the canvas used to render subtitles. |
| |
| @end table |
| |
| @section Advanced options |
| |
| @table @option |
| @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output}) |
| |
| Designate one or more input streams as a source for the output file. Each input |
| stream is identified by the input file index @var{input_file_id} and |
| the input stream index @var{input_stream_id} within the input |
| file. Both indices start at 0. If specified, |
| @var{sync_file_id}:@var{stream_specifier} sets which input stream |
| is used as a presentation sync reference. |
| |
| The first @code{-map} option on the command line specifies the |
| source for output stream 0, the second @code{-map} option specifies |
| the source for output stream 1, etc. |
| |
| A @code{-} character before the stream identifier creates a "negative" mapping. |
| It disables matching streams from already created mappings. |
| |
| An alternative @var{[linklabel]} form will map outputs from complex filter |
| graphs (see the @option{-filter_complex} option) to the output file. |
| @var{linklabel} must correspond to a defined output link label in the graph. |
| |
| For example, to map ALL streams from the first input file to output |
| @example |
| ffmpeg -i INPUT -map 0 output |
| @end example |
| |
| For example, if you have two audio streams in the first input file, |
| these streams are identified by "0:0" and "0:1". You can use |
| @code{-map} to select which streams to place in an output file. For |
| example: |
| @example |
| ffmpeg -i INPUT -map 0:1 out.wav |
| @end example |
| will map the input stream in @file{INPUT} identified by "0:1" to |
| the (single) output stream in @file{out.wav}. |
| |
| For example, to select the stream with index 2 from input file |
| @file{a.mov} (specified by the identifier "0:2"), and stream with |
| index 6 from input @file{b.mov} (specified by the identifier "1:6"), |
| and copy them to the output file @file{out.mov}: |
| @example |
| ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov |
| @end example |
| |
| To select all video and the third audio stream from an input file: |
| @example |
| ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT |
| @end example |
| |
| To map all the streams except the second audio, use negative mappings |
| @example |
| ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT |
| @end example |
| |
| To pick the English audio stream: |
| @example |
| ffmpeg -i INPUT -map 0:m:language:eng OUTPUT |
| @end example |
| |
| Note that using this option disables the default mappings for this output file. |
| |
| @item -ignore_unknown |
| Ignore input streams with unknown type instead of failing if copying |
| such streams is attempted. |
| |
| @item -copy_unknown |
| Allow input streams with unknown type to be copied instead of failing if copying |
| such streams is attempted. |
| |
| @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}] |
| Map an audio channel from a given input to an output. If |
| @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will |
| be mapped on all the audio streams. |
| |
| Using "-1" instead of |
| @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted |
| channel. |
| |
| For example, assuming @var{INPUT} is a stereo audio file, you can switch the |
| two audio channels with the following command: |
| @example |
| ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT |
| @end example |
| |
| If you want to mute the first channel and keep the second: |
| @example |
| ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT |
| @end example |
| |
| The order of the "-map_channel" option specifies the order of the channels in |
| the output stream. The output channel layout is guessed from the number of |
| channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac" |
| in combination of "-map_channel" makes the channel gain levels to be updated if |
| input and output channel layouts don't match (for instance two "-map_channel" |
| options and "-ac 6"). |
| |
| You can also extract each channel of an input to specific outputs; the following |
| command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0) |
| to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs: |
| @example |
| ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1 |
| @end example |
| |
| The following example splits the channels of a stereo input into two separate |
| streams, which are put into the same output file: |
| @example |
| ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg |
| @end example |
| |
| Note that currently each output stream can only contain channels from a single |
| input stream; you can't for example use "-map_channel" to pick multiple input |
| audio channels contained in different streams (from the same or different files) |
| and merge them into a single output stream. It is therefore not currently |
| possible, for example, to turn two separate mono streams into a single stereo |
| stream. However splitting a stereo stream into two single channel mono streams |
| is possible. |
| |
| If you need this feature, a possible workaround is to use the @emph{amerge} |
| filter. For example, if you need to merge a media (here @file{input.mkv}) with 2 |
| mono audio streams into one single stereo channel audio stream (and keep the |
| video stream), you can use the following command: |
| @example |
| ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv |
| @end example |
| |
| @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata}) |
| Set metadata information of the next output file from @var{infile}. Note that |
| those are file indices (zero-based), not filenames. |
| Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy. |
| A metadata specifier can have the following forms: |
| @table @option |
| @item @var{g} |
| global metadata, i.e. metadata that applies to the whole file |
| |
| @item @var{s}[:@var{stream_spec}] |
| per-stream metadata. @var{stream_spec} is a stream specifier as described |
| in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first |
| matching stream is copied from. In an output metadata specifier, all matching |
| streams are copied to. |
| |
| @item @var{c}:@var{chapter_index} |
| per-chapter metadata. @var{chapter_index} is the zero-based chapter index. |
| |
| @item @var{p}:@var{program_index} |
| per-program metadata. @var{program_index} is the zero-based program index. |
| @end table |
| If metadata specifier is omitted, it defaults to global. |
| |
| By default, global metadata is copied from the first input file, |
| per-stream and per-chapter metadata is copied along with streams/chapters. These |
| default mappings are disabled by creating any mapping of the relevant type. A negative |
| file index can be used to create a dummy mapping that just disables automatic copying. |
| |
| For example to copy metadata from the first stream of the input file to global metadata |
| of the output file: |
| @example |
| ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3 |
| @end example |
| |
| To do the reverse, i.e. copy global metadata to all audio streams: |
| @example |
| ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv |
| @end example |
| Note that simple @code{0} would work as well in this example, since global |
| metadata is assumed by default. |
| |
| @item -map_chapters @var{input_file_index} (@emph{output}) |
| Copy chapters from input file with index @var{input_file_index} to the next |
| output file. If no chapter mapping is specified, then chapters are copied from |
| the first input file with at least one chapter. Use a negative file index to |
| disable any chapter copying. |
| |
| @item -benchmark (@emph{global}) |
| Show benchmarking information at the end of an encode. |
| Shows CPU time used and maximum memory consumption. |
| Maximum memory consumption is not supported on all systems, |
| it will usually display as 0 if not supported. |
| @item -benchmark_all (@emph{global}) |
| Show benchmarking information during the encode. |
| Shows CPU time used in various steps (audio/video encode/decode). |
| @item -timelimit @var{duration} (@emph{global}) |
| Exit after ffmpeg has been running for @var{duration} seconds. |
| @item -dump (@emph{global}) |
| Dump each input packet to stderr. |
| @item -hex (@emph{global}) |
| When dumping packets, also dump the payload. |
| @item -re (@emph{input}) |
| Read input at native frame rate. Mainly used to simulate a grab device. |
| or live input stream (e.g. when reading from a file). Should not be used |
| with actual grab devices or live input streams (where it can cause packet |
| loss). |
| By default @command{ffmpeg} attempts to read the input(s) as fast as possible. |
| This option will slow down the reading of the input(s) to the native frame rate |
| of the input(s). It is useful for real-time output (e.g. live streaming). |
| @item -loop_input |
| Loop over the input stream. Currently it works only for image |
| streams. This option is used for automatic FFserver testing. |
| This option is deprecated, use -loop 1. |
| @item -loop_output @var{number_of_times} |
| Repeatedly loop output for formats that support looping such as animated GIF |
| (0 will loop the output infinitely). |
| This option is deprecated, use -loop. |
| @item -vsync @var{parameter} |
| Video sync method. |
| For compatibility reasons old values can be specified as numbers. |
| Newly added values will have to be specified as strings always. |
| |
| @table @option |
| @item 0, passthrough |
| Each frame is passed with its timestamp from the demuxer to the muxer. |
| @item 1, cfr |
| Frames will be duplicated and dropped to achieve exactly the requested |
| constant frame rate. |
| @item 2, vfr |
| Frames are passed through with their timestamp or dropped so as to |
| prevent 2 frames from having the same timestamp. |
| @item drop |
| As passthrough but destroys all timestamps, making the muxer generate |
| fresh timestamps based on frame-rate. |
| @item -1, auto |
| Chooses between 1 and 2 depending on muxer capabilities. This is the |
| default method. |
| @end table |
| |
| Note that the timestamps may be further modified by the muxer, after this. |
| For example, in the case that the format option @option{avoid_negative_ts} |
| is enabled. |
| |
| With -map you can select from which stream the timestamps should be |
| taken. You can leave either video or audio unchanged and sync the |
| remaining stream(s) to the unchanged one. |
| |
| @item -frame_drop_threshold @var{parameter} |
| Frame drop threshold, which specifies how much behind video frames can |
| be before they are dropped. In frame rate units, so 1.0 is one frame. |
| The default is -1.1. One possible usecase is to avoid framedrops in case |
| of noisy timestamps or to increase frame drop precision in case of exact |
| timestamps. |
| |
| @item -async @var{samples_per_second} |
| Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps, |
| the parameter is the maximum samples per second by which the audio is changed. |
| -async 1 is a special case where only the start of the audio stream is corrected |
| without any later correction. |
| |
| Note that the timestamps may be further modified by the muxer, after this. |
| For example, in the case that the format option @option{avoid_negative_ts} |
| is enabled. |
| |
| This option has been deprecated. Use the @code{aresample} audio filter instead. |
| |
| @item -copyts |
| Do not process input timestamps, but keep their values without trying |
| to sanitize them. In particular, do not remove the initial start time |
| offset value. |
| |
| Note that, depending on the @option{vsync} option or on specific muxer |
| processing (e.g. in case the format option @option{avoid_negative_ts} |
| is enabled) the output timestamps may mismatch with the input |
| timestamps even when this option is selected. |
| |
| @item -start_at_zero |
| When used with @option{copyts}, shift input timestamps so they start at zero. |
| |
| This means that using e.g. @code{-ss 50} will make output timestamps start at |
| 50 seconds, regardless of what timestamp the input file started at. |
| |
| @item -copytb @var{mode} |
| Specify how to set the encoder timebase when stream copying. @var{mode} is an |
| integer numeric value, and can assume one of the following values: |
| |
| @table @option |
| @item 1 |
| Use the demuxer timebase. |
| |
| The time base is copied to the output encoder from the corresponding input |
| demuxer. This is sometimes required to avoid non monotonically increasing |
| timestamps when copying video streams with variable frame rate. |
| |
| @item 0 |
| Use the decoder timebase. |
| |
| The time base is copied to the output encoder from the corresponding input |
| decoder. |
| |
| @item -1 |
| Try to make the choice automatically, in order to generate a sane output. |
| @end table |
| |
| Default value is -1. |
| |
| @item -shortest (@emph{output}) |
| Finish encoding when the shortest input stream ends. |
| @item -dts_delta_threshold |
| Timestamp discontinuity delta threshold. |
| @item -muxdelay @var{seconds} (@emph{input}) |
| Set the maximum demux-decode delay. |
| @item -muxpreload @var{seconds} (@emph{input}) |
| Set the initial demux-decode delay. |
| @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output}) |
| Assign a new stream-id value to an output stream. This option should be |
| specified prior to the output filename to which it applies. |
| For the situation where multiple output files exist, a streamid |
| may be reassigned to a different value. |
| |
| For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for |
| an output mpegts file: |
| @example |
| ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts |
| @end example |
| |
| @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream}) |
| Set bitstream filters for matching streams. @var{bitstream_filters} is |
| a comma-separated list of bitstream filters. Use the @code{-bsfs} option |
| to get the list of bitstream filters. |
| @example |
| ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264 |
| @end example |
| @example |
| ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt |
| @end example |
| |
| @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{input/output,per-stream}) |
| Force a tag/fourcc for matching streams. |
| |
| @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff} |
| Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';' |
| (or '.') for drop. |
| @example |
| ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg |
| @end example |
| |
| @anchor{filter_complex_option} |
| @item -filter_complex @var{filtergraph} (@emph{global}) |
| Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or |
| outputs. For simple graphs -- those with one input and one output of the same |
| type -- see the @option{-filter} options. @var{filtergraph} is a description of |
| the filtergraph, as described in the ``Filtergraph syntax'' section of the |
| ffmpeg-filters manual. |
| |
| Input link labels must refer to input streams using the |
| @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map} |
| uses). If @var{stream_specifier} matches multiple streams, the first one will be |
| used. An unlabeled input will be connected to the first unused input stream of |
| the matching type. |
| |
| Output link labels are referred to with @option{-map}. Unlabeled outputs are |
| added to the first output file. |
| |
| Note that with this option it is possible to use only lavfi sources without |
| normal input files. |
| |
| For example, to overlay an image over video |
| @example |
| ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map |
| '[out]' out.mkv |
| @end example |
| Here @code{[0:v]} refers to the first video stream in the first input file, |
| which is linked to the first (main) input of the overlay filter. Similarly the |
| first video stream in the second input is linked to the second (overlay) input |
| of overlay. |
| |
| Assuming there is only one video stream in each input file, we can omit input |
| labels, so the above is equivalent to |
| @example |
| ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map |
| '[out]' out.mkv |
| @end example |
| |
| Furthermore we can omit the output label and the single output from the filter |
| graph will be added to the output file automatically, so we can simply write |
| @example |
| ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv |
| @end example |
| |
| To generate 5 seconds of pure red video using lavfi @code{color} source: |
| @example |
| ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv |
| @end example |
| |
| @item -lavfi @var{filtergraph} (@emph{global}) |
| Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or |
| outputs. Equivalent to @option{-filter_complex}. |
| |
| @item -filter_complex_script @var{filename} (@emph{global}) |
| This option is similar to @option{-filter_complex}, the only difference is that |
| its argument is the name of the file from which a complex filtergraph |
| description is to be read. |
| |
| @item -accurate_seek (@emph{input}) |
| This option enables or disables accurate seeking in input files with the |
| @option{-ss} option. It is enabled by default, so seeking is accurate when |
| transcoding. Use @option{-noaccurate_seek} to disable it, which may be useful |
| e.g. when copying some streams and transcoding the others. |
| |
| @item -seek_timestamp (@emph{input}) |
| This option enables or disables seeking by timestamp in input files with the |
| @option{-ss} option. It is disabled by default. If enabled, the argument |
| to the @option{-ss} option is considered an actual timestamp, and is not |
| offset by the start time of the file. This matters only for files which do |
| not start from timestamp 0, such as transport streams. |
| |
| @item -thread_queue_size @var{size} (@emph{input}) |
| This option sets the maximum number of queued packets when reading from the |
| file or device. With low latency / high rate live streams, packets may be |
| discarded if they are not read in a timely manner; raising this value can |
| avoid it. |
| |
| @item -override_ffserver (@emph{global}) |
| Overrides the input specifications from @command{ffserver}. Using this |
| option you can map any input stream to @command{ffserver} and control |
| many aspects of the encoding from @command{ffmpeg}. Without this |
| option @command{ffmpeg} will transmit to @command{ffserver} what is |
| requested by @command{ffserver}. |
| |
| The option is intended for cases where features are needed that cannot be |
| specified to @command{ffserver} but can be to @command{ffmpeg}. |
| |
| @item -sdp_file @var{file} (@emph{global}) |
| Print sdp information for an output stream to @var{file}. |
| This allows dumping sdp information when at least one output isn't an |
| rtp stream. (Requires at least one of the output formats to be rtp). |
| |
| @item -discard (@emph{input}) |
| Allows discarding specific streams or frames of streams at the demuxer. |
| Not all demuxers support this. |
| |
| @table @option |
| @item none |
| Discard no frame. |
| |
| @item default |
| Default, which discards no frames. |
| |
| @item noref |
| Discard all non-reference frames. |
| |
| @item bidir |
| Discard all bidirectional frames. |
| |
| @item nokey |
| Discard all frames excepts keyframes. |
| |
| @item all |
| Discard all frames. |
| @end table |
| |
| @item -abort_on @var{flags} (@emph{global}) |
| Stop and abort on various conditions. The following flags are available: |
| |
| @table @option |
| @item empty_output |
| No packets were passed to the muxer, the output is empty. |
| @end table |
| |
| @item -xerror (@emph{global}) |
| Stop and exit on error |
| |
| @end table |
| |
| As a special exception, you can use a bitmap subtitle stream as input: it |
| will be converted into a video with the same size as the largest video in |
| the file, or 720x576 if no video is present. Note that this is an |
| experimental and temporary solution. It will be removed once libavfilter has |
| proper support for subtitles. |
| |
| For example, to hardcode subtitles on top of a DVB-T recording stored in |
| MPEG-TS format, delaying the subtitles by 1 second: |
| @example |
| ffmpeg -i input.ts -filter_complex \ |
| '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \ |
| -sn -map '#0x2dc' output.mkv |
| @end example |
| (0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video, |
| audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too) |
| |
| @section Preset files |
| A preset file contains a sequence of @var{option}=@var{value} pairs, |
| one for each line, specifying a sequence of options which would be |
| awkward to specify on the command line. Lines starting with the hash |
| ('#') character are ignored and are used to provide comments. Check |
| the @file{presets} directory in the FFmpeg source tree for examples. |
| |
| There are two types of preset files: ffpreset and avpreset files. |
| |
| @subsection ffpreset files |
| ffpreset files are specified with the @code{vpre}, @code{apre}, |
| @code{spre}, and @code{fpre} options. The @code{fpre} option takes the |
| filename of the preset instead of a preset name as input and can be |
| used for any kind of codec. For the @code{vpre}, @code{apre}, and |
| @code{spre} options, the options specified in a preset file are |
| applied to the currently selected codec of the same type as the preset |
| option. |
| |
| The argument passed to the @code{vpre}, @code{apre}, and @code{spre} |
| preset options identifies the preset file to use according to the |
| following rules: |
| |
| First ffmpeg searches for a file named @var{arg}.ffpreset in the |
| directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in |
| the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg}) |
| or in a @file{ffpresets} folder along the executable on win32, |
| in that order. For example, if the argument is @code{libvpx-1080p}, it will |
| search for the file @file{libvpx-1080p.ffpreset}. |
| |
| If no such file is found, then ffmpeg will search for a file named |
| @var{codec_name}-@var{arg}.ffpreset in the above-mentioned |
| directories, where @var{codec_name} is the name of the codec to which |
| the preset file options will be applied. For example, if you select |
| the video codec with @code{-vcodec libvpx} and use @code{-vpre 1080p}, |
| then it will search for the file @file{libvpx-1080p.ffpreset}. |
| |
| @subsection avpreset files |
| avpreset files are specified with the @code{pre} option. They work similar to |
| ffpreset files, but they only allow encoder- specific options. Therefore, an |
| @var{option}=@var{value} pair specifying an encoder cannot be used. |
| |
| When the @code{pre} option is specified, ffmpeg will look for files with the |
| suffix .avpreset in the directories @file{$AVCONV_DATADIR} (if set), and |
| @file{$HOME/.avconv}, and in the datadir defined at configuration time (usually |
| @file{PREFIX/share/ffmpeg}), in that order. |
| |
| First ffmpeg searches for a file named @var{codec_name}-@var{arg}.avpreset in |
| the above-mentioned directories, where @var{codec_name} is the name of the codec |
| to which the preset file options will be applied. For example, if you select the |
| video codec with @code{-vcodec libvpx} and use @code{-pre 1080p}, then it will |
| search for the file @file{libvpx-1080p.avpreset}. |
| |
| If no such file is found, then ffmpeg will search for a file named |
| @var{arg}.avpreset in the same directories. |
| |
| @c man end OPTIONS |
| |
| @chapter Examples |
| @c man begin EXAMPLES |
| |
| @section Video and Audio grabbing |
| |
| If you specify the input format and device then ffmpeg can grab video |
| and audio directly. |
| |
| @example |
| ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg |
| @end example |
| |
| Or with an ALSA audio source (mono input, card id 1) instead of OSS: |
| @example |
| ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg |
| @end example |
| |
| Note that you must activate the right video source and channel before |
| launching ffmpeg with any TV viewer such as |
| @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also |
| have to set the audio recording levels correctly with a |
| standard mixer. |
| |
| @section X11 grabbing |
| |
| Grab the X11 display with ffmpeg via |
| |
| @example |
| ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg |
| @end example |
| |
| 0.0 is display.screen number of your X11 server, same as |
| the DISPLAY environment variable. |
| |
| @example |
| ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg |
| @end example |
| |
| 0.0 is display.screen number of your X11 server, same as the DISPLAY environment |
| variable. 10 is the x-offset and 20 the y-offset for the grabbing. |
| |
| @section Video and Audio file format conversion |
| |
| Any supported file format and protocol can serve as input to ffmpeg: |
| |
| Examples: |
| @itemize |
| @item |
| You can use YUV files as input: |
| |
| @example |
| ffmpeg -i /tmp/test%d.Y /tmp/out.mpg |
| @end example |
| |
| It will use the files: |
| @example |
| /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V, |
| /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc... |
| @end example |
| |
| The Y files use twice the resolution of the U and V files. They are |
| raw files, without header. They can be generated by all decent video |
| decoders. You must specify the size of the image with the @option{-s} option |
| if ffmpeg cannot guess it. |
| |
| @item |
| You can input from a raw YUV420P file: |
| |
| @example |
| ffmpeg -i /tmp/test.yuv /tmp/out.avi |
| @end example |
| |
| test.yuv is a file containing raw YUV planar data. Each frame is composed |
| of the Y plane followed by the U and V planes at half vertical and |
| horizontal resolution. |
| |
| @item |
| You can output to a raw YUV420P file: |
| |
| @example |
| ffmpeg -i mydivx.avi hugefile.yuv |
| @end example |
| |
| @item |
| You can set several input files and output files: |
| |
| @example |
| ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg |
| @end example |
| |
| Converts the audio file a.wav and the raw YUV video file a.yuv |
| to MPEG file a.mpg. |
| |
| @item |
| You can also do audio and video conversions at the same time: |
| |
| @example |
| ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2 |
| @end example |
| |
| Converts a.wav to MPEG audio at 22050 Hz sample rate. |
| |
| @item |
| You can encode to several formats at the same time and define a |
| mapping from input stream to output streams: |
| |
| @example |
| ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2 |
| @end example |
| |
| Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map |
| file:index' specifies which input stream is used for each output |
| stream, in the order of the definition of output streams. |
| |
| @item |
| You can transcode decrypted VOBs: |
| |
| @example |
| ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi |
| @end example |
| |
| This is a typical DVD ripping example; the input is a VOB file, the |
| output an AVI file with MPEG-4 video and MP3 audio. Note that in this |
| command we use B-frames so the MPEG-4 stream is DivX5 compatible, and |
| GOP size is 300 which means one intra frame every 10 seconds for 29.97fps |
| input video. Furthermore, the audio stream is MP3-encoded so you need |
| to enable LAME support by passing @code{--enable-libmp3lame} to configure. |
| The mapping is particularly useful for DVD transcoding |
| to get the desired audio language. |
| |
| NOTE: To see the supported input formats, use @code{ffmpeg -formats}. |
| |
| @item |
| You can extract images from a video, or create a video from many images: |
| |
| For extracting images from a video: |
| @example |
| ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg |
| @end example |
| |
| This will extract one video frame per second from the video and will |
| output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg}, |
| etc. Images will be rescaled to fit the new WxH values. |
| |
| If you want to extract just a limited number of frames, you can use the |
| above command in combination with the -vframes or -t option, or in |
| combination with -ss to start extracting from a certain point in time. |
| |
| For creating a video from many images: |
| @example |
| ffmpeg -f image2 -framerate 12 -i foo-%03d.jpeg -s WxH foo.avi |
| @end example |
| |
| The syntax @code{foo-%03d.jpeg} specifies to use a decimal number |
| composed of three digits padded with zeroes to express the sequence |
| number. It is the same syntax supported by the C printf function, but |
| only formats accepting a normal integer are suitable. |
| |
| When importing an image sequence, -i also supports expanding |
| shell-like wildcard patterns (globbing) internally, by selecting the |
| image2-specific @code{-pattern_type glob} option. |
| |
| For example, for creating a video from filenames matching the glob pattern |
| @code{foo-*.jpeg}: |
| @example |
| ffmpeg -f image2 -pattern_type glob -framerate 12 -i 'foo-*.jpeg' -s WxH foo.avi |
| @end example |
| |
| @item |
| You can put many streams of the same type in the output: |
| |
| @example |
| ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut |
| @end example |
| |
| The resulting output file @file{test12.nut} will contain the first four streams |
| from the input files in reverse order. |
| |
| @item |
| To force CBR video output: |
| @example |
| ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v |
| @end example |
| |
| @item |
| The four options lmin, lmax, mblmin and mblmax use 'lambda' units, |
| but you may use the QP2LAMBDA constant to easily convert from 'q' units: |
| @example |
| ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext |
| @end example |
| |
| @end itemize |
| @c man end EXAMPLES |
| |
| @include config.texi |
| @ifset config-all |
| @ifset config-avutil |
| @include utils.texi |
| @end ifset |
| @ifset config-avcodec |
| @include codecs.texi |
| @include bitstream_filters.texi |
| @end ifset |
| @ifset config-avformat |
| @include formats.texi |
| @include protocols.texi |
| @end ifset |
| @ifset config-avdevice |
| @include devices.texi |
| @end ifset |
| @ifset config-swresample |
| @include resampler.texi |
| @end ifset |
| @ifset config-swscale |
| @include scaler.texi |
| @end ifset |
| @ifset config-avfilter |
| @include filters.texi |
| @end ifset |
| @end ifset |
| |
| @chapter See Also |
| |
| @ifhtml |
| @ifset config-all |
| @url{ffmpeg.html,ffmpeg} |
| @end ifset |
| @ifset config-not-all |
| @url{ffmpeg-all.html,ffmpeg-all}, |
| @end ifset |
| @url{ffplay.html,ffplay}, @url{ffprobe.html,ffprobe}, @url{ffserver.html,ffserver}, |
| @url{ffmpeg-utils.html,ffmpeg-utils}, |
| @url{ffmpeg-scaler.html,ffmpeg-scaler}, |
| @url{ffmpeg-resampler.html,ffmpeg-resampler}, |
| @url{ffmpeg-codecs.html,ffmpeg-codecs}, |
| @url{ffmpeg-bitstream-filters.html,ffmpeg-bitstream-filters}, |
| @url{ffmpeg-formats.html,ffmpeg-formats}, |
| @url{ffmpeg-devices.html,ffmpeg-devices}, |
| @url{ffmpeg-protocols.html,ffmpeg-protocols}, |
| @url{ffmpeg-filters.html,ffmpeg-filters} |
| @end ifhtml |
| |
| @ifnothtml |
| @ifset config-all |
| ffmpeg(1), |
| @end ifset |
| @ifset config-not-all |
| ffmpeg-all(1), |
| @end ifset |
| ffplay(1), ffprobe(1), ffserver(1), |
| ffmpeg-utils(1), ffmpeg-scaler(1), ffmpeg-resampler(1), |
| ffmpeg-codecs(1), ffmpeg-bitstream-filters(1), ffmpeg-formats(1), |
| ffmpeg-devices(1), ffmpeg-protocols(1), ffmpeg-filters(1) |
| @end ifnothtml |
| |
| @include authors.texi |
| |
| @ignore |
| |
| @setfilename ffmpeg |
| @settitle ffmpeg video converter |
| |
| @end ignore |
| |
| @bye |