\input texinfo @c -*- texinfo -*- @settitle ffmpeg Documentation @titlepage @center @titlefont{ffmpeg Documentation} @end titlepage @top @contents @chapter Synopsis The generic syntax is: @example @c man begin SYNOPSIS ffmpeg [global options] [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}... @c man end @end example @chapter Description @c man begin DESCRIPTION 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. 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). Allowed number and/or types of streams can be limited by the container format. Selecting, which streams from which inputs go into output, is done either 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. See also 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 64kbit/s: @example ffmpeg -i input.avi -b:v 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 Stream selection @c man begin STREAM SELECTION By default 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 the stream with the most channels, for subtitle it's the first subtitle stream. In the case where several streams of the same type rate equally, the lowest numbered stream is chosen. You can disable some of those defaults by using @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 avtools-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 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 but exit if file exists. @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{output}) Stop writing the output after its duration reaches @var{duration}. @var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form. @item -fs @var{limit_size} (@emph{output}) Set the file size limit, expressed in bytes. @item -ss @var{position} (@emph{input/output}) When used as an input option (before @code{-i}), seeks in this input file to @var{position}. When used as an output option (before an output filename), decodes but discards input until the timestamps reach @var{position}. This is slower, but more accurate. @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form. @item -itsoffset @var{offset} (@emph{input}) Set the input time offset in seconds. @code{[-]hh:mm:ss[.xxx]} syntax is also supported. The offset is added to the timestamps of the input files. Specifying a positive offset means that the corresponding streams are delayed by @var{offset} seconds. @item -timestamp @var{time} (@emph{output}) Set the recording timestamp in the container. The syntax for @var{time} is: @example now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...])|(HHMMSS[.m...]))[Z|z]) @end example If the value is "now" it takes the current time. Time is local time unless 'Z' or 'z' is appended, in which case it is interpreted as UTC. If the year-month-day part is not specified it takes the current year-month-day. @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 or chapters. 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:1 language=eng OUTPUT @end example @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 record. 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} is codec-dependent. @item -filter[:@var{stream_specifier}] @var{filter_graph} (@emph{output,per-stream}) @var{filter_graph} is a description of the filter graph to apply to the stream. Use @code{-filters} to show all the available filters (including also sources and sinks). See also the @option{-filter_complex} option if you want to create filter graphs with multiple inputs and/or outputs. @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. On by default. @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 INPUT @end example To extract all attachments to files determined by the @code{filename} tag: @example ffmpeg -dump_attachment:t "" 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. @end table @section Video Options @table @option @item -vframes @var{number} (@emph{output}) Set the number of video frames to record. 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}. As an output option, duplicate or drop input frames to achieve constant output frame rate @var{fps} (note that this actually causes the @code{fps} filter to be inserted to the end of the corresponding filtergraph). @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. @item -croptop @var{size} @item -cropbottom @var{size} @item -cropleft @var{size} @item -cropright @var{size} All the crop options have been removed. Use -vf crop=width:height:x:y instead. @item -padtop @var{size} @item -padbottom @var{size} @item -padleft @var{size} @item -padright @var{size} @item -padcolor @var{hex_color} All the pad options have been removed. Use -vf pad=width:height:x:y:color instead. @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 -same_quant Use same quantizer as source (implies VBR). Note that this is NOT SAME QUALITY. Do not use this option unless you know you need it. @item -pass @var{n} 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{prefix} (@emph{global}) 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 -vlang @var{code} Set the ISO 639 language code (3 letters) of the current video stream. @item -vf @var{filter_graph} (@emph{output}) @var{filter_graph} is a description of the filter graph to apply to the input video. Use the option "-filters" to show all the available filters (including also sources and sinks). This is an alias for @code{-filter:v}. @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 filter graphs 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 -deinterlace Deinterlace pictures. This option is deprecated since the deinterlacing is very low quality. Use the yadif filter with @code{-filter:v yadif}. @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}) Force key frames at the specified timestamps, more precisely at the first frames after each specified time. 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. The timestamps must be specified in ascending order. @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream}) When doing stream copy, copy also non-key frames found at the beginning. @end table @section Audio Options @table @option @item -aframes @var{number} (@emph{output}) Set the number of audio frames to record. 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{filter_graph} (@emph{output}) @var{filter_graph} is a description of the filter graph to apply to the input audio. Use the option "-filters" to show all the available filters (including also sources and sinks). This is an alias for @code{-filter:a}. @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 @end table @section Subtitle options: @table @option @item -slang @var{code} Set the ISO 639 language code (3 letters) of the current subtitle stream. @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 Audio/Video grab options @table @option @item -isync (@emph{global}) Synchronize read on input. @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 Note that using this option disables the default mappings for this output file. @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 -f lavfi -i " amovie=input.mkv:si=1 [a1]; amovie=input.mkv:si=2 [a2]; [a1][a2] 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 -debug @var{category} Print specific debug info. @var{category} is a number or a string containing one of the following values: @table @samp @item bitstream @item buffers picture buffer allocations @item bugs @item dct_coeff @item er error recognition @item mb_type macroblock (MB) type @item mmco memory management control operations (H.264) @item mv motion vector @item pict picture info @item pts @item qp per-block quantization parameter (QP) @item rc rate control @item skip @item startcode @item thread_ops threading operations @item vis_mb_type visualize block types @item vis_qp visualize quantization parameter (QP), lower QP are tinted greener @end table @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. @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 framerate. @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 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 -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. This option has been deprecated. Use the @code{asyncts} audio filter instead. @item -copyts Copy timestamps from input to output. @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 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{bistream_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{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 @item -filter_complex @var{filtergraph} (@emph{global}) Define a complex filter graph, 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 filter graph, as described in @ref{Filtergraph syntax}. 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. 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 @end table @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. Preset 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{libx264-max}, it will search for the file @file{libx264-max.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 libx264} and use @code{-vpre max}, then it will search for the file @file{libx264-max.ffpreset}. @c man end OPTIONS @chapter Tips @c man begin TIPS @itemize @item For streaming at very low bitrate application, use a low frame rate and a small GOP size. This is especially true for RealVideo where the Linux player does not seem to be very fast, so it can miss frames. An example is: @example ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm @end example @item The parameter 'q' which is displayed while encoding is the current quantizer. The value 1 indicates that a very good quality could be achieved. The value 31 indicates the worst quality. If q=31 appears too often, it means that the encoder cannot compress enough to meet your bitrate. You must either increase the bitrate, decrease the frame rate or decrease the frame size. @item If your computer is not fast enough, you can speed up the compression at the expense of the compression ratio. You can use '-me zero' to speed up motion estimation, and '-g 0' to disable motion estimation completely (you have only I-frames, which means it is about as good as JPEG compression). @item To have very low audio bitrates, reduce the sampling frequency (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3). @item To have a constant quality (but a variable bitrate), use the option '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst quality). @end itemize @c man end TIPS @chapter Examples @c man begin EXAMPLES @section Preset files A preset file contains a sequence of @var{option=value} pairs, one for each line, specifying a sequence of options which can be specified also on the command line. Lines starting with the hash ('#') character are ignored and are used to provide comments. Empty lines are also ignored. Check the @file{presets} directory in the FFmpeg source tree for examples. Preset files are specified with the @code{pre} option, this option takes a preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg}) in that order. For example, if the argument is @code{libx264-max}, it will search for the file @file{libx264-max.avpreset}. @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 -s cif -r 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 -s cif -r 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 -i foo-%03d.jpeg -r 12 -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. To lower the chance of interfering with your actual file names and the shell's glob expansion, you are required to activate glob meta characters by prefixing them with a single @code{%} character, like in @code{foo-%*.jpeg}, @code{foo-%?%?%?.jpeg} or @code{foo-00%[234%]%*.jpeg}. If your filename actually contains a character sequence of a @code{%} character followed by a glob character, you must double the @code{%} character to escape it. Imagine your files begin with @code{%?-foo-}, then you could use a glob pattern like @code{%%?-foo-%*.jpeg}. For input patterns that could be both a printf or a glob pattern, ffmpeg will assume it is a glob pattern. @item You can put many streams of the same type in the output: @example ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut @end example The resulting output file @file{test12.avi} will contain first four streams from the input file 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 syntax.texi @include eval.texi @include decoders.texi @include encoders.texi @include demuxers.texi @include muxers.texi @include indevs.texi @include outdevs.texi @include protocols.texi @include bitstream_filters.texi @include filters.texi @include metadata.texi @ignore @setfilename ffmpeg @settitle ffmpeg video converter @c man begin SEEALSO ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation @c man end @c man begin AUTHORS See git history @c man end @end ignore @bye