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1286 lines
48 KiB
\input texinfo @c -*- texinfo -*- |
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@settitle ffmpeg Documentation |
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@titlepage |
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@center @titlefont{ffmpeg Documentation} |
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@end titlepage |
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@top |
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@contents |
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@chapter Synopsis |
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The generic syntax is: |
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@example |
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@c man begin SYNOPSIS |
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ffmpeg [global options] [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}... |
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@c man end |
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@end example |
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@chapter Description |
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@c man begin DESCRIPTION |
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ffmpeg is a very fast video and audio converter that can also grab from |
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a live audio/video source. It can also convert between arbitrary sample |
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rates and resize video on the fly with a high quality polyphase filter. |
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ffmpeg reads from an arbitrary number of input "files" (which can be regular |
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files, pipes, network streams, grabbing devices, etc.), specified by the |
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@code{-i} option, and writes to an arbitrary number of output "files", which are |
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specified by a plain output filename. Anything found on the command line which |
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cannot be interpreted as an option is considered to be an output filename. |
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Each input or output file can in principle contain any number of streams of |
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different types (video/audio/subtitle/attachment/data). Allowed number and/or |
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types of streams can be limited by the container format. Selecting, which |
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streams from which inputs go into output, is done either automatically or with |
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the @code{-map} option (see the Stream selection chapter). |
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To refer to input files in options, you must use their indices (0-based). E.g. |
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the first input file is @code{0}, the second is @code{1} etc. Similarly, streams |
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within a file are referred to by their indices. E.g. @code{2:3} refers to the |
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fourth stream in the third input file. See also the Stream specifiers chapter. |
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As a general rule, options are applied to the next specified |
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file. Therefore, order is important, and you can have the same |
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option on the command line multiple times. Each occurrence is |
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then applied to the next input or output file. |
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Exceptions from this rule are the global options (e.g. verbosity level), |
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which should be specified first. |
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Do not mix input and output files -- first specify all input files, then all |
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output files. Also do not mix options which belong to different files. All |
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options apply ONLY to the next input or output file and are reset between files. |
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@itemize |
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@item |
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To set the video bitrate of the output file to 64kbit/s: |
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@example |
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ffmpeg -i input.avi -b:v 64k output.avi |
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@end example |
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@item |
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To force the frame rate of the output file to 24 fps: |
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@example |
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ffmpeg -i input.avi -r 24 output.avi |
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@end example |
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@item |
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To force the frame rate of the input file (valid for raw formats only) |
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to 1 fps and the frame rate of the output file to 24 fps: |
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@example |
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ffmpeg -r 1 -i input.m2v -r 24 output.avi |
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@end example |
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@end itemize |
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The format option may be needed for raw input files. |
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@c man end DESCRIPTION |
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@chapter Detailed description |
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@c man begin DETAILED DESCRIPTION |
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The transcoding process in @command{ffmpeg} for each output can be described by |
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the following diagram: |
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@example |
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_______ ______________ _________ ______________ ________ |
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| | | | | | | | | | |
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| input | demuxer | encoded data | decoder | decoded | encoder | encoded data | muxer | output | |
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| file | ---------> | packets | ---------> | frames | ---------> | packets | -------> | file | |
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|_______| |______________| |_________| |______________| |________| |
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@end example |
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@command{ffmpeg} calls the libavformat library (containing demuxers) to read |
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input files and get packets containing encoded data from them. When there are |
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multiple input files, @command{ffmpeg} tries to keep them synchronized by |
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tracking lowest timestamp on any active input stream. |
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Encoded packets are then passed to the decoder (unless streamcopy is selected |
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for the stream, see further for a description). The decoder produces |
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uncompressed frames (raw video/PCM audio/...) which can be processed further by |
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filtering (see next section). After filtering the frames are passed to the |
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encoder, which encodes them and outputs encoded packets again. Finally those are |
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passed to the muxer, which writes the encoded packets to the output file. |
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@section Filtering |
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Before encoding, @command{ffmpeg} can process raw audio and video frames using |
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filters from the libavfilter library. Several chained filters form a filter |
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graph. @command{ffmpeg} distinguishes between two types of filtergraphs - |
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simple and complex. |
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@subsection Simple filtergraphs |
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Simple filtergraphs are those that have exactly one input and output, both of |
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the same type. In the above diagram they can be represented by simply inserting |
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an additional step between decoding and encoding: |
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@example |
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_________ __________ ______________ |
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| | | | | | |
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| decoded | simple filtergraph | filtered | encoder | encoded data | |
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| frames | -------------------> | frames | ---------> | packets | |
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|_________| |__________| |______________| |
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@end example |
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Simple filtergraphs are configured with the per-stream @option{-filter} option |
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(with @option{-vf} and @option{-af} aliases for video and audio respectively). |
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A simple filtergraph for video can look for example like this: |
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@example |
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_______ _____________ _______ _____ ________ |
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| | | | | | | | | | |
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| input | ---> | deinterlace | ---> | scale | ---> | fps | ---> | output | |
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|_______| |_____________| |_______| |_____| |________| |
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@end example |
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Note that some filters change frame properties but not frame contents. E.g. the |
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@code{fps} filter in the example above changes number of frames, but does not |
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touch the frame contents. Another example is the @code{setpts} filter, which |
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only sets timestamps and otherwise passes the frames unchanged. |
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@subsection Complex filtergraphs |
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Complex filtergraphs are those which cannot be described as simply a linear |
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processing chain applied to one stream. This is the case e.g. when the graph has |
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more than one input and/or output, or when output stream type is different from |
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input. They can be represented with the following diagram: |
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@example |
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_________ |
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| | |
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| input 0 |\ __________ |
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|_________| \ | | |
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\ _________ /| output 0 | |
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\ | | / |__________| |
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_________ \| complex | / |
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| | | |/ |
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| input 1 |---->| filter |\ |
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|_________| | | \ __________ |
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/| graph | \ | | |
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/ | | \| output 1 | |
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_________ / |_________| |__________| |
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| | / |
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| input 2 |/ |
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|_________| |
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@end example |
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Complex filtergraphs are configured with the @option{-filter_complex} option. |
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Note that this option is global, since a complex filtergraph by its nature |
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cannot be unambiguously associated with a single stream or file. |
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A trivial example of a complex filtergraph is the @code{overlay} filter, which |
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has two video inputs and one video output, containing one video overlaid on top |
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of the other. Its audio counterpart is the @code{amix} filter. |
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@section Stream copy |
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Stream copy is a mode selected by supplying the @code{copy} parameter to the |
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@option{-codec} option. It makes @command{ffmpeg} omit the decoding and encoding |
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step for the specified stream, so it does only demuxing and muxing. It is useful |
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for changing the container format or modifying container-level metadata. The |
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diagram above will in this case simplify to this: |
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@example |
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_______ ______________ ________ |
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| | | | | | |
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| input | demuxer | encoded data | muxer | output | |
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| file | ---------> | packets | -------> | file | |
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|_______| |______________| |________| |
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@end example |
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Since there is no decoding or encoding, it is very fast and there is no quality |
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loss. However it might not work in some cases because of many factors. Applying |
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filters is obviously also impossible, since filters work on uncompressed data. |
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@c man end DETAILED DESCRIPTION |
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@chapter Stream selection |
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@c man begin STREAM SELECTION |
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By default ffmpeg includes only one stream of each type (video, audio, subtitle) |
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present in the input files and adds them to each output file. It picks the |
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"best" of each based upon the following criteria; for video it is the stream |
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with the highest resolution, for audio the stream with the most channels, for |
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subtitle it's the first subtitle stream. In the case where several streams of |
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the same type rate equally, the lowest numbered stream is chosen. |
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You can disable some of those defaults by using @code{-vn/-an/-sn} options. For |
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full manual control, use the @code{-map} option, which disables the defaults just |
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described. |
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@c man end STREAM SELECTION |
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@chapter Options |
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@c man begin OPTIONS |
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@include avtools-common-opts.texi |
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@section Main options |
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@table @option |
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@item -f @var{fmt} (@emph{input/output}) |
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Force input or output file format. The format is normally auto detected for input |
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files and guessed from file extension for output files, so this option is not |
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needed in most cases. |
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@item -i @var{filename} (@emph{input}) |
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input file name |
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@item -y (@emph{global}) |
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Overwrite output files without asking. |
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@item -n (@emph{global}) |
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Do not overwrite output files but exit if file exists. |
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@item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream}) |
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@itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream}) |
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Select an encoder (when used before an output file) or a decoder (when used |
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before an input file) for one or more streams. @var{codec} is the name of a |
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decoder/encoder or a special value @code{copy} (output only) to indicate that |
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the stream is not to be re-encoded. |
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For example |
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@example |
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ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT |
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@end example |
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encodes all video streams with libx264 and copies all audio streams. |
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For each stream, the last matching @code{c} option is applied, so |
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@example |
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ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT |
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@end example |
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will copy all the streams except the second video, which will be encoded with |
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libx264, and the 138th audio, which will be encoded with libvorbis. |
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@item -t @var{duration} (@emph{output}) |
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Stop writing the output after its duration reaches @var{duration}. |
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@var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form. |
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@item -fs @var{limit_size} (@emph{output}) |
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Set the file size limit, expressed in bytes. |
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@item -ss @var{position} (@emph{input/output}) |
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When used as an input option (before @code{-i}), seeks in this input file to |
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@var{position}. When used as an output option (before an output filename), |
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decodes but discards input until the timestamps reach @var{position}. This is |
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slower, but more accurate. |
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@var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form. |
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@item -itsoffset @var{offset} (@emph{input}) |
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Set the input time offset in seconds. |
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@code{[-]hh:mm:ss[.xxx]} syntax is also supported. |
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The offset is added to the timestamps of the input files. |
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Specifying a positive offset means that the corresponding |
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streams are delayed by @var{offset} seconds. |
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@item -timestamp @var{time} (@emph{output}) |
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Set the recording timestamp in the container. |
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The syntax for @var{time} is: |
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@example |
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now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...])|(HHMMSS[.m...]))[Z|z]) |
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@end example |
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If the value is "now" it takes the current time. |
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Time is local time unless 'Z' or 'z' is appended, in which case it is |
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interpreted as UTC. |
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If the year-month-day part is not specified it takes the current |
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year-month-day. |
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@item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata}) |
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Set a metadata key/value pair. |
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An optional @var{metadata_specifier} may be given to set metadata |
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on streams or chapters. See @code{-map_metadata} documentation for |
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details. |
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This option overrides metadata set with @code{-map_metadata}. It is |
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also possible to delete metadata by using an empty value. |
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For example, for setting the title in the output file: |
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@example |
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ffmpeg -i in.avi -metadata title="my title" out.flv |
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@end example |
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To set the language of the first audio stream: |
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@example |
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ffmpeg -i INPUT -metadata:s:a:1 language=eng OUTPUT |
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@end example |
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@item -target @var{type} (@emph{output}) |
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Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv}, |
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@code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or |
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@code{film-} to use the corresponding standard. All the format options |
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(bitrate, codecs, buffer sizes) are then set automatically. You can just type: |
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@example |
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ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg |
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@end example |
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Nevertheless you can specify additional options as long as you know |
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they do not conflict with the standard, as in: |
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@example |
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ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg |
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@end example |
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@item -dframes @var{number} (@emph{output}) |
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Set the number of data frames to record. This is an alias for @code{-frames:d}. |
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@item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream}) |
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Stop writing to the stream after @var{framecount} frames. |
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@item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream}) |
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@itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream}) |
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Use fixed quality scale (VBR). The meaning of @var{q} is |
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codec-dependent. |
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@item -filter[:@var{stream_specifier}] @var{filter_graph} (@emph{output,per-stream}) |
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@var{filter_graph} is a description of the filter graph to apply to |
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the stream. Use @code{-filters} to show all the available filters |
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(including also sources and sinks). |
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See also the @option{-filter_complex} option if you want to create filter graphs |
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with multiple inputs and/or outputs. |
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@item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream}) |
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Specify the preset for matching stream(s). |
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@item -stats (@emph{global}) |
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Print encoding progress/statistics. On by default. |
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@item -debug_ts (@emph{global}) |
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Print timestamp information. It is off by default. This option is |
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mostly useful for testing and debugging purposes, and the output |
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format may change from one version to another, so it should not be |
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employed by portable scripts. |
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See also the option @code{-fdebug ts}. |
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@item -attach @var{filename} (@emph{output}) |
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Add an attachment to the output file. This is supported by a few formats |
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like Matroska for e.g. fonts used in rendering subtitles. Attachments |
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are implemented as a specific type of stream, so this option will add |
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a new stream to the file. It is then possible to use per-stream options |
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on this stream in the usual way. Attachment streams created with this |
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option will be created after all the other streams (i.e. those created |
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with @code{-map} or automatic mappings). |
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Note that for Matroska you also have to set the mimetype metadata tag: |
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@example |
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ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv |
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@end example |
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(assuming that the attachment stream will be third in the output file). |
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@item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream}) |
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Extract the matching attachment stream into a file named @var{filename}. If |
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@var{filename} is empty, then the value of the @code{filename} metadata tag |
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will be used. |
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E.g. to extract the first attachment to a file named 'out.ttf': |
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@example |
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ffmpeg -dump_attachment:t:0 out.ttf INPUT |
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@end example |
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To extract all attachments to files determined by the @code{filename} tag: |
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@example |
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ffmpeg -dump_attachment:t "" INPUT |
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@end example |
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Technical note -- attachments are implemented as codec extradata, so this |
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option can actually be used to extract extradata from any stream, not just |
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attachments. |
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@end table |
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@section Video Options |
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@table @option |
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@item -vframes @var{number} (@emph{output}) |
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Set the number of video frames to record. This is an alias for @code{-frames:v}. |
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@item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream}) |
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Set frame rate (Hz value, fraction or abbreviation). |
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As an input option, ignore any timestamps stored in the file and instead |
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generate timestamps assuming constant frame rate @var{fps}. |
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As an output option, duplicate or drop input frames to achieve constant output |
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frame rate @var{fps} (note that this actually causes the @code{fps} filter to be |
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inserted to the end of the corresponding filtergraph). |
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@item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream}) |
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Set frame size. |
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As an input option, this is a shortcut for the @option{video_size} private |
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option, recognized by some demuxers for which the frame size is either not |
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stored in the file or is configurable -- e.g. raw video or video grabbers. |
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As an output option, this inserts the @code{scale} video filter to the |
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@emph{end} of the corresponding filtergraph. Please use the @code{scale} filter |
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directly to insert it at the beginning or some other place. |
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The format is @samp{wxh} (default - same as source). |
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@item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream}) |
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Set the video display aspect ratio specified by @var{aspect}. |
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@var{aspect} can be a floating point number string, or a string of the |
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form @var{num}:@var{den}, where @var{num} and @var{den} are the |
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numerator and denominator of the aspect ratio. For example "4:3", |
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"16:9", "1.3333", and "1.7777" are valid argument values. |
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@item -croptop @var{size} |
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@item -cropbottom @var{size} |
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@item -cropleft @var{size} |
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@item -cropright @var{size} |
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All the crop options have been removed. Use -vf |
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crop=width:height:x:y instead. |
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@item -padtop @var{size} |
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@item -padbottom @var{size} |
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@item -padleft @var{size} |
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@item -padright @var{size} |
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@item -padcolor @var{hex_color} |
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All the pad options have been removed. Use -vf |
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pad=width:height:x:y:color instead. |
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@item -vn (@emph{output}) |
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Disable video recording. |
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@item -vcodec @var{codec} (@emph{output}) |
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Set the video codec. This is an alias for @code{-codec:v}. |
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@item -same_quant |
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Use same quantizer as source (implies VBR). |
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Note that this is NOT SAME QUALITY. Do not use this option unless you know you |
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need it. |
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@item -pass @var{n} |
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Select the pass number (1 or 2). It is used to do two-pass |
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video encoding. The statistics of the video are recorded in the first |
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pass into a log file (see also the option -passlogfile), |
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and in the second pass that log file is used to generate the video |
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at the exact requested bitrate. |
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On pass 1, you may just deactivate audio and set output to null, |
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examples for Windows and Unix: |
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@example |
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ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL |
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ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null |
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@end example |
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@item -passlogfile @var{prefix} (@emph{global}) |
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Set two-pass log file name prefix to @var{prefix}, the default file name |
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prefix is ``ffmpeg2pass''. The complete file name will be |
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@file{PREFIX-N.log}, where N is a number specific to the output |
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stream |
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@item -vlang @var{code} |
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Set the ISO 639 language code (3 letters) of the current video stream. |
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@item -vf @var{filter_graph} (@emph{output}) |
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@var{filter_graph} is a description of the filter graph to apply to |
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the input video. |
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Use the option "-filters" to show all the available filters (including |
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also sources and sinks). This is an alias for @code{-filter:v}. |
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@end table |
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@section Advanced Video Options |
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@table @option |
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@item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream}) |
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Set pixel format. Use @code{-pix_fmts} to show all the supported |
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pixel formats. |
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If the selected pixel format can not be selected, ffmpeg will print a |
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warning and select the best pixel format supported by the encoder. |
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If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error |
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if the requested pixel format can not be selected, and automatic conversions |
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inside filter graphs are disabled. |
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If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format |
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as the input (or graph output) and automatic conversions are disabled. |
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@item -sws_flags @var{flags} (@emph{input/output}) |
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Set SwScaler flags. |
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@item -vdt @var{n} |
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Discard threshold. |
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|
|
@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{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}. |
|
@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
|
|
|