All the numerical options, if not specified otherwise, accept in input a string representing a number, which may contain one of the SI unit prefixes, for example ’K’, ’M’, ’G’. If ’i’ is appended after the prefix, binary prefixes are used, which are based on powers of 1024 instead of powers of 1000. The ’B’ postfix multiplies the value by 8, and can be appended after a unit prefix or used alone. This allows using for example ’ KB ’, ’MiB’, ’G’ and ’B’ as number postfix.
Options which do not take arguments are boolean options, and set the corresponding value to true. They can be set to false by prefixing with "no" the option name, for example using "-nofoo" in the command line will set to false the boolean option with name "foo".
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers are used to precisely specify which stream(s) does a given option belong to.
A stream specifier is a string generally appended to the option name and separated from it by a colon. E.g. "-codec:a:1 ac3" option contains "a:1" stream specifier, which matches the second audio stream. Therefore it would select the ac3 codec for the second audio stream.
A stream specifier can match several streams, the option is then applied to all of them. E.g. the stream specifier in "-b:a 128k" matches all audio streams.
An empty stream specifier matches all streams, for example "-codec copy" or "-codec: copy" would copy all the streams without reencoding.
Possible forms of stream specifiers are:
Matches the stream with this index. E.g. "-threads:1 4" would set the thread count for the second stream to 4.
stream_type is one of: ’v’ for video, ’a’ for audio, ’s’ for subtitle, ’d’ for data and ’t’ for attachments. If stream_index is given, then matches stream number stream_index of this type. Otherwise matches all streams of this type.
If stream_index is given, then matches stream number stream_index in program with id program_id. Otherwise matches all streams in this program.
Matches the stream by format-specific ID.
These options are shared amongst the avahi-browse.1.gz avahi-browse-domains.1.gz avahi-publish.1.gz avahi-publish-address.1.gz avahi-publish-service.1.gz avahi-resolve.1.gz avahi-resolve-address.1.gz avahi-resolve-host-name.1.gz avahi-set-host-name.1.gz avconv.1.gz avidemux.1.gz avidemux2_gtk.1.gz avplay.1.gz avprobe.1.gz avserver.1.gz tools.
-h, -?, -help, --help [arg]
Show help. An optional parameter may be specified to print help about a specific item.
Possible values of arg are:
Print detailed information about the decoder named decoder_name. Use the -decoders option to get a list of all decoders.
Print detailed information about the encoder named encoder_name. Use the -encoders option to get a list of all encoders.
Print detailed information about the demuxer named demuxer_name. Use the -formats option to get a list of all demuxers and muxers.
Print detailed information about the muxer named muxer_name. Use the -formats option to get a list of all muxers and demuxers.
Show available formats.
The fields preceding the format names have the following meanings:
Show all codecs known to libavcodec.
Note that the term ’codec’ is used throughout this documentation as a shortcut for what is more correctly called a media bitstream format.
Show available decoders.
Show all available encoders.
Show available bitstream filters.
Show available protocols.
Show available libavfilter filters.
Show available pixel formats.
Show available sample formats.
Show channel names and standard channel layouts.
-loglevel loglevel | -v loglevel
Set the logging level used by the library. loglevel is a number or a string containing one of the following values:
By default the program logs to stderr, if coloring is supported by the terminal, colors are used to mark errors and warnings. Log coloring can be disabled setting the environment variable AV_LOG_FORCE_NOCOLOR or NO_COLOR , or can be forced setting the environment variable AV_LOG_FORCE_COLOR . The use of the environment variable NO_COLOR is deprecated and will be dropped in a following FFmpeg version.
Dump full command line and console output to a file named "program-YYYYMMDD-HHMMSS.log" in the current directory. This file can be useful for bug reports. It also implies "-loglevel verbose".
Setting the environment variable "FFREPORT" to any value has the same effect. If the value is a ’:’-separated key=value sequence, these options will affect the report; options values must be escaped if they contain special characters or the options delimiter ’:’ (see the ’’Quoting and escaping’’ section in the ffmpeg-utils manual). The following option is recognized:
set the file name to use for the report; %p is expanded to the name of the program, %t is expanded to a timestamp, "%%" is expanded to a plain "%"
Errors in parsing the environment variable are not fatal, and will not appear in the report.
-cpuflags flags (global)
Allows setting and clearing cpu flags. This option is intended for testing. Do not use it unless you know what you’re doing.
ffmpeg -cpuflags -sse+mmx ... ffmpeg -cpuflags mmx ... ffmpeg -cpuflags 0 ...
These options are provided directly by the libavformat, libavdevice and libavcodec libraries. To see the list of available AVOptions, use the -help option. They are separated into two categories:
These options can be set for any container, codec or device. Generic options are listed under AVFormatContext options for containers/devices and under AVCodecContext options for codecs.
These options are specific to the given container, device or codec. Private options are listed under their corresponding containers/devices/codecs.
For example to write an ID3v2.3 header instead of a default ID3v2.4 to an MP3 file, use the id3v2_version private option of the MP3 muxer:
ffmpeg -i input.flac -id3v2_version 3 out.mp3
All codec AVOptions are obviously per-stream, so the chapter on stream specifiers applies to them
Note -nooption syntax cannot be used for boolean AVOptions, use -option 0/-option 1.
Note2 old undocumented way of specifying per-stream AVOptions by prepending v/a/s to the options name is now obsolete and will be removed soon.
-f fmt (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.
-i filename (input)
input file name
Overwrite output files without asking.
Do not overwrite output files but exit if file exists.
-c[:stream_specifier] codec (input/output,per-stream)
-codec[:stream_specifier] codec (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. codec is the name of a decoder/encoder or a special value "copy" (output only) to indicate that the stream is not to be re-encoded.
ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
encodes all video streams with libx264 and copies all audio streams.
For each stream, the last matching "c" option is applied, so
ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
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.
-t duration (output)
Stop writing the output after its duration reaches duration. duration may be a number in seconds, or in "hh:mm:ss[.xxx]" form.
-to and -t are mutually exclusive and -t has priority.
-to position (output)
Stop writing the output at position. position may be a number in seconds, or in "hh:mm:ss[.xxx]" form.
-to and -t are mutually exclusive and -t has priority.
-fs limit_size (output)
Set the file size limit, expressed in bytes.
-ss position (input/output)
When used as an input option (before "-i"), seeks in this input file to position. When used as an output option (before an output filename), decodes but discards input until the timestamps reach position. This is slower, but more accurate.
position may be either in seconds or in "hh:mm:ss[.xxx]" form.
-itsoffset offset (input)
Set the input time offset in seconds. "[-]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 offset seconds.
-timestamp time (output)
Set the recording timestamp in the container. The syntax for time is:
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.
-metadata[:metadata_specifier] key=value (output,per-metadata)
Set a metadata key/value pair.
An optional metadata_specifier may be given to set metadata on streams or chapters. See "-map_metadata" documentation for details.
This option overrides metadata set with "-map_metadata". It is also possible to delete metadata by using an empty value.
For example, for setting the title in the output file:
ffmpeg -i in.avi -metadata title="my title" out.flv
To set the language of the first audio stream:
ffmpeg -i INPUT -metadata:s:a:1 language=eng OUTPUT
-target type (output)
Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50"). type may be prefixed with "pal-", "ntsc-" or "film-" to use the corresponding standard. All the format options (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
Nevertheless you can specify additional options as long as you know they do not conflict with the standard, as in:
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
-dframes number (output)
Set the number of data frames to record. This is an alias for "-frames:d".
-frames[:stream_specifier] framecount (output,per-stream)
Stop writing to the stream after framecount frames.
-q[:stream_specifier] q (output,per-stream)
-qscale[:stream_specifier] q (output,per-stream)
Use fixed quality scale ( VBR ). The meaning of q is codec-dependent.
-filter[:stream_specifier] filter_graph (output,per-stream)
Create the filter graph specified by filter_graph and use it to filter the stream.
filter_graph is a description of the filter graph to apply to the stream, and must have a single input and a single output of the same type of the stream. In the filter graph, the input is associated to the label "in", and the output to the label "out". See the ffmpeg-filters manual for more information about the filtergraph syntax.
See the -filter_complex option if you want to create filter graphs with multiple inputs and/or outputs.
-pre[:stream_specifier] preset_name (output,per-stream)
Specify the preset for matching stream(s).
Print encoding progress/statistics. On by default.
-progress url (global)
Send program-friendly progress information to url.
Progress information is written approximately every second and at the end of the encoding process. It is made of "key=value" lines. key consists of only alphanumeric characters. The last key of a sequence of progress information is always "progress".
Enable interaction on standard input. On by default unless standard input is used as an input. To explicitly disable interaction you need to specify "-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 "ffmpeg ... < /dev/null" but it requires a shell.
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 "-fdebug ts".
-attach filename (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 "-map" or automatic mappings).
Note that for Matroska you also have to set the mimetype metadata tag:
ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
(assuming that the attachment stream will be third in the output file).
-dump_attachment[:stream_specifier] filename (input,per-stream)
Extract the matching attachment stream into a file named filename. If filename is empty, then the value of the "filename" metadata tag will be used.
E.g. to extract the first attachment to a file named ’out.ttf’:
ffmpeg -dump_attachment:t:0 out.ttf -i INPUT
To extract all attachments to files determined by the "filename" tag:
ffmpeg -dump_attachment:t "" -i INPUT
Technical note -- attachments are implemented as codec extradata, so this option can actually be used to extract extradata from any stream, not just attachments.
-vframes number (output)
Set the number of video frames to record. This is an alias for "-frames:v".
-r[:stream_specifier] fps (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 fps.
As an output option, duplicate or drop input frames to achieve constant output frame rate fps.
-s[:stream_specifier] size (input/output,per-stream)
Set frame size.
As an input option, this is a shortcut for the 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 "scale" video filter to the end of the corresponding filtergraph. Please use the "scale" filter directly to insert it at the beginning or some other place.
The format is wxh (default - same as source).
-aspect[:stream_specifier] aspect (output,per-stream)
Set the video display aspect ratio specified by aspect.
aspect can be a floating point number string, or a string of the form num:den, where num and 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.
Disable video recording.
-vcodec codec (output)
Set the video codec. This is an alias for "-codec:v".
-pass[:stream_specifier] n (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:
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
-passlogfile[:stream_specifier] prefix (output,per-stream)
Set two-pass log file name prefix to prefix, the default file name prefix is ’’ffmpeg2pass’’. The complete file name will be PREFIX-N .log, where N is a number specific to the output stream
Set the ISO 639 language code (3 letters) of the current video stream.
-vf filter_graph (output)
Create the filter graph specified by filter_graph and use it to filter the stream.
This is an alias for "-filter:v", see the -filter option.
Advanced Video Options
-pix_fmt[:stream_specifier] format (input/output,per-stream)
Set pixel format. Use "-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 pix_fmt is prefixed by a "+", ffmpeg will exit with an error if the requested pixel format can not be selected, and automatic conversions inside filter graphs are disabled. If pix_fmt is a single "+", ffmpeg selects the same pixel format as the input (or graph output) and automatic conversions are disabled.
-sws_flags flags (input/output)
Set SwScaler flags.
-rc_override[:stream_specifier] override (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.
Deinterlace pictures. This option is deprecated since the deinterlacing is very low quality. Use the yadif filter with "-filter:v yadif".
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 -deinterlace, but deinterlacing introduces losses.
Calculate PSNR of compressed frames.
Dump video coding statistics to vstats_HHMMSS.log.
Dump video coding statistics to file.
-top[:stream_specifier] n (output,per-stream)
top=1/bottom=0/auto=-1 field first
-vtag fourcc/tag (output)
Force video tag/fourcc. This is an alias for "-tag:v".
Show QP histogram
Deprecated see -bsf
-force_key_frames[:stream_specifier] time[,time...] (output,per-stream)
-force_key_frames[:stream_specifier] expr:expr (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 "expr:", the string 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 ""chapters"[delta]", it is expanded into the time of the beginning of all chapters in the file, shifted by 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:
The expression in expr can contain the following constants:
the number of current processed frame, starting from 0
the number of forced frames
the number of the previous forced frame, it is "NAN" when no keyframe was forced yet
the time of the previous forced frame, it is "NAN" when no keyframe was forced yet
the time of the current processed frame
For example to force a key frame every 5 seconds, you can specify:
To force a key frame 5 seconds after the time of the last forced one, starting from second 13:
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.
When doing stream copy, copy also non-key frames found at the beginning.
-aframes number (output)
Set the number of audio frames to record. This is an alias for "-frames:a".
-ar[:stream_specifier] freq (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.
-aq q (output)
Set the audio quality (codec-specific, VBR ). This is an alias for -q:a.
-ac[:stream_specifier] channels (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.
Disable audio recording.
-acodec codec (input/output)
Set the audio codec. This is an alias for "-codec:a".
-sample_fmt[:stream_specifier] sample_fmt (output,per-stream)
Set the audio sample format. Use "-sample_fmts" to get a list of supported sample formats.
-af filter_graph (output)
Create the filter graph specified by filter_graph and use it to filter the stream.
This is an alias for "-filter:a", see the -filter option.
Advanced Audio options:
-atag fourcc/tag (output)
Force audio tag/fourcc. This is an alias for "-tag:a".
Deprecated, see -bsf
-guess_layout_max channels (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 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.
Set the ISO 639 language code (3 letters) of the current subtitle stream.
-scodec codec (input/output)
Set the subtitle codec. This is an alias for "-codec:s".
Disable subtitle recording.
Deprecated, see -bsf
Advanced Subtitle options:
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.
Designate one or more input streams as a source for the output file. Each input stream is identified by the input file index input_file_id and the input stream index input_stream_id within the input file. Both indices start at 0. If specified, sync_file_id:stream_specifier sets which input stream is used as a presentation sync reference.
The first "-map" option on the command line specifies the source for output stream 0, the second "-map" option specifies the source for output stream 1, etc.
A "-" character before the stream identifier creates a "negative" mapping. It disables matching streams from already created mappings.
An alternative [linklabel] form will map outputs from complex filter graphs (see the -filter_complex option) to the output file. 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
ffmpeg -i INPUT -map 0 output
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 "-map" to select which streams to place in an output file. For example:
ffmpeg -i INPUT -map 0:1 out.wav
will map the input stream in INPUT identified by "0:1" to the (single) output stream in out.wav.
For example, to select the stream with index 2 from input file a.mov (specified by the identifier "0:2"), and stream with index 6 from input b.mov (specified by the identifier "1:6"), and copy them to the output file out.mov:
ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
To select all video and the third audio stream from an input file:
ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
To map all the streams except the second audio, use negative mappings
ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
Note that using this option disables the default mappings for this output file.
Map an audio channel from a given input to an output. If output_file_id.stream_specifier is not set, the audio channel will be mapped on all the audio streams.
Using "-1" instead of input_file_id.stream_specifier.channel_id will map a muted channel.
For example, assuming INPUT is a stereo audio file, you can switch the two audio channels with the following command:
ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
If you want to mute the first channel and keep the second:
ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
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 INPUT audio stream (file 0, stream 0) to the respective OUTPUT_CH0 and OUTPUT_CH1 outputs:
ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
The following example splits the channels of a stereo input into two separate streams, which are put into the same output file:
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
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 amerge filter. For example, if you need to merge a media (here 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:
ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
Set metadata information of the next output file from infile. Note that those are file indices (zero-based), not filenames. Optional metadata_spec_in/out parameters specify, which metadata to copy. A metadata specifier can have the following forms:
global metadata, i.e. metadata that applies to the whole file
per-stream metadata. stream_spec is a stream specifier as described in the 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.
per-chapter metadata. chapter_index is the zero-based chapter index.
per-program metadata. program_index is the zero-based program index.
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:
ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
To do the reverse, i.e. copy global metadata to all audio streams:
ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
Note that simple 0 would work as well in this example, since global metadata is assumed by default.
-map_chapters input_file_index (output)
Copy chapters from input file with index 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.
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.
Show benchmarking information during the encode. Shows CPU time used in various steps (audio/video encode/decode).
-timelimit duration (global)
Exit after ffmpeg has been running for duration seconds.
Dump each input packet to stderr.
When dumping packets, also dump the payload.
Read input at native frame rate. Mainly used to simulate a grab device. By default 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). If your input(s) is coming from some other live streaming source (through HTTP or UDP for example) the server might already be in real-time, thus the option will likely not be required. On the other hand, this is meaningful if your input(s) is a file you are trying to push in real-time.
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.
Repeatedly loop output for formats that support looping such as animated GIF (0 will loop the output infinitely). This option is deprecated, use -loop.
Video sync method. For compatibility reasons old values can be specified as numbers. Newly added values will have to be specified as strings always.
Each frame is passed with its timestamp from the demuxer to the muxer.
Frames will be duplicated and dropped to achieve exactly the requested constant framerate.
Frames are passed through with their timestamp or dropped so as to prevent 2 frames from having the same timestamp.
As passthrough but destroys all timestamps, making the muxer generate fresh timestamps based on frame-rate.
Chooses between 1 and 2 depending on muxer capabilities. This is the default method.
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.
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 "aresample" audio filter instead.
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 vsync option or on specific muxer processing, the output timestamps may mismatch with the input timestamps even when this option is selected.
Specify how to set the encoder timebase when stream copying. mode is an integer numeric value, and can assume one of the following values:
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.
Use the decoder timebase.
The time base is copied to the output encoder from the corresponding input decoder.
Try to make the choice automatically, in order to generate a sane output.
Default value is -1.
Finish encoding when the shortest input stream ends.
Timestamp discontinuity delta threshold.
-muxdelay seconds (input)
Set the maximum demux-decode delay.
-muxpreload seconds (input)
Set the initial demux-decode delay.
-streamid output-stream-index:new-value (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:
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
-bsf[:stream_specifier] bitstream_filters (output,per-stream)
Set bitstream filters for matching streams. bitstream_filters is a comma-separated list of bitstream filters. Use the "-bsfs" option to get the list of bitstream filters.
ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
-tag[:stream_specifier] codec_tag (per-stream)
Force a tag/fourcc for matching streams.
-timecode hh:mm:ss SEP ff
Specify Timecode for writing. SEP is ’:’ for non drop timecode and ’;’ (or ’.’) for drop.
ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
-filter_complex filtergraph (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 -filter options. filtergraph is a description of the filter graph, as described in the ’’Filtergraph syntax’’ section of the ffmpeg-filters manual.
Input link labels must refer to input streams using the "[file_index:stream_specifier]" syntax (i.e. the same as -map uses). If 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 -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
ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map '[out]' out.mkv
Here "[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
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map '[out]' out.mkv
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
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
To generate 5 seconds of pure red video using lavfi "color" source:
ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
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:
ffmpeg -i input.ts -filter_complex \ '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \ -sn -map '#0x2dc' output.mkv
(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)
A preset file contains a sequence of option=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 presets directory in the FFmpeg source tree for examples.
Preset files are specified with the "vpre", "apre", "spre", and "fpre" options. The "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 "vpre", "apre", and "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 "vpre", "apre", and "spre" preset options identifies the preset file to use according to the following rules:
First ffmpeg searches for a file named arg.ffpreset in the directories $FFMPEG_DATADIR (if set), and $HOME/.ffmpeg, and in the datadir defined at configuration time (usually PREFIX/share/ffmpeg) or in a ffpresets folder along the executable on win32, in that order. For example, if the argument is "libvpx-1080p", it will search for the file libvpx-1080p.ffpreset.
If no such file is found, then ffmpeg will search for a file named codec_name-arg.ffpreset in the above-mentioned directories, where 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 "-vcodec libvpx" and use "-vpre 1080p", then it will search for the file libvpx-1080p.ffpreset.