yading@10: =head1 NAME
yading@10: 
yading@10: ffmpeg-formats - FFmpeg formats
yading@10: 
yading@10: =head1 DESCRIPTION
yading@10: 
yading@10: 
yading@10: This document describes the supported formats (muxers and demuxers)
yading@10: provided by the libavformat library.
yading@10: 
yading@10: 
yading@10: 
yading@10: =head1 FORMAT OPTIONS
yading@10: 
yading@10: 
yading@10: The libavformat library provides some generic global options, which
yading@10: can be set on all the muxers and demuxers. In addition each muxer or
yading@10: demuxer may support so-called private options, which are specific for
yading@10: that component.
yading@10: 
yading@10: Options may be set by specifying -I<option> I<value> in the
yading@10: FFmpeg tools, or by setting the value explicitly in the
yading@10: C<AVFormatContext> options or using the F<libavutil/opt.h> API
yading@10: for programmatic use.
yading@10: 
yading@10: The list of supported options follows:
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<avioflags> I<flags> B<(>I<input/output>B<)>
yading@10: 
yading@10: Possible values:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<direct>
yading@10: 
yading@10: Reduce buffering.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<probesize> I<integer> B<(>I<input>B<)>
yading@10: 
yading@10: Set probing size in bytes, i.e. the size of the data to analyze to get
yading@10: stream information. A higher value will allow to detect more
yading@10: information in case it is dispersed into the stream, but will increase
yading@10: latency. Must be an integer not lesser than 32. It is 5000000 by default.
yading@10: 
yading@10: 
yading@10: =item B<packetsize> I<integer> B<(>I<output>B<)>
yading@10: 
yading@10: Set packet size.
yading@10: 
yading@10: 
yading@10: =item B<fflags> I<flags> B<(>I<input/output>B<)>
yading@10: 
yading@10: Set format flags.
yading@10: 
yading@10: Possible values:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<ignidx>
yading@10: 
yading@10: Ignore index.
yading@10: 
yading@10: =item B<genpts>
yading@10: 
yading@10: Generate PTS.
yading@10: 
yading@10: =item B<nofillin>
yading@10: 
yading@10: Do not fill in missing values that can be exactly calculated.
yading@10: 
yading@10: =item B<noparse>
yading@10: 
yading@10: Disable AVParsers, this needs C<+nofillin> too.
yading@10: 
yading@10: =item B<igndts>
yading@10: 
yading@10: Ignore DTS.
yading@10: 
yading@10: =item B<discardcorrupt>
yading@10: 
yading@10: Discard corrupted frames.
yading@10: 
yading@10: =item B<sortdts>
yading@10: 
yading@10: Try to interleave output packets by DTS.
yading@10: 
yading@10: =item B<keepside>
yading@10: 
yading@10: Do not merge side data.
yading@10: 
yading@10: =item B<latm>
yading@10: 
yading@10: Enable RTP MP4A-LATM payload.
yading@10: 
yading@10: =item B<nobuffer>
yading@10: 
yading@10: Reduce the latency introduced by optional buffering
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<analyzeduration> I<integer> B<(>I<input>B<)>
yading@10: 
yading@10: Specify how many microseconds are analyzed to probe the input. A
yading@10: higher value will allow to detect more accurate information, but will
yading@10: increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
yading@10: 
yading@10: 
yading@10: =item B<cryptokey> I<hexadecimal string> B<(>I<input>B<)>
yading@10: 
yading@10: Set decryption key.
yading@10: 
yading@10: 
yading@10: =item B<indexmem> I<integer> B<(>I<input>B<)>
yading@10: 
yading@10: Set max memory used for timestamp index (per stream).
yading@10: 
yading@10: 
yading@10: =item B<rtbufsize> I<integer> B<(>I<input>B<)>
yading@10: 
yading@10: Set max memory used for buffering real-time frames.
yading@10: 
yading@10: 
yading@10: =item B<fdebug> I<flags> B<(>I<input/output>B<)>
yading@10: 
yading@10: Print specific debug info.
yading@10: 
yading@10: Possible values:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<ts>
yading@10: 
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<max_delay> I<integer> B<(>I<input/output>B<)>
yading@10: 
yading@10: Set maximum muxing or demuxing delay in microseconds.
yading@10: 
yading@10: 
yading@10: =item B<fpsprobesize> I<integer> B<(>I<input>B<)>
yading@10: 
yading@10: Set number of frames used to probe fps.
yading@10: 
yading@10: 
yading@10: =item B<audio_preload> I<integer> B<(>I<output>B<)>
yading@10: 
yading@10: Set microseconds by which audio packets should be interleaved earlier.
yading@10: 
yading@10: 
yading@10: =item B<chunk_duration> I<integer> B<(>I<output>B<)>
yading@10: 
yading@10: Set microseconds for each chunk.
yading@10: 
yading@10: 
yading@10: =item B<chunk_size> I<integer> B<(>I<output>B<)>
yading@10: 
yading@10: Set size in bytes for each chunk.
yading@10: 
yading@10: 
yading@10: =item B<err_detect, f_err_detect> I<flags> B<(>I<input>B<)>
yading@10: 
yading@10: Set error detection flags. C<f_err_detect> is deprecated and
yading@10: should be used only via the B<ffmpeg> tool.
yading@10: 
yading@10: Possible values:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<crccheck>
yading@10: 
yading@10: Verify embedded CRCs.
yading@10: 
yading@10: =item B<bitstream>
yading@10: 
yading@10: Detect bitstream specification deviations.
yading@10: 
yading@10: =item B<buffer>
yading@10: 
yading@10: Detect improper bitstream length.
yading@10: 
yading@10: =item B<explode>
yading@10: 
yading@10: Abort decoding on minor error detection.
yading@10: 
yading@10: =item B<careful>
yading@10: 
yading@10: Consider things that violate the spec and have not been seen in the
yading@10: wild as errors.
yading@10: 
yading@10: =item B<compliant>
yading@10: 
yading@10: Consider all spec non compliancies as errors.
yading@10: 
yading@10: =item B<aggressive>
yading@10: 
yading@10: Consider things that a sane encoder should not do as an error.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<use_wallclock_as_timestamps> I<integer> B<(>I<input>B<)>
yading@10: 
yading@10: Use wallclock as timestamps.
yading@10: 
yading@10: 
yading@10: =item B<avoid_negative_ts> I<integer> B<(>I<output>B<)>
yading@10: 
yading@10: Shift timestamps to make them positive. A value of 1 enables shifting,
yading@10: a value of 0 disables it, the default value of -1 enables shifting
yading@10: when required by the target format.
yading@10: 
yading@10: When shifting is enabled, all output timestamps are shifted by the
yading@10: same amount. Audio, video, and subtitles desynching and relative
yading@10: timestamp differences are preserved compared to how they would have
yading@10: been without shifting.
yading@10: 
yading@10: Also note that this affects only leading negative timestamps, and not
yading@10: non-monotonic negative timestamps.
yading@10: 
yading@10: 
yading@10: =item B<flush_packets> I<integer> B<(>I<output>B<)>
yading@10: 
yading@10: Flush the underlying I/O stream after each packet. Default 1 enables it, and
yading@10: has the effect of reducing the latency; 0 disables it and may slightly
yading@10: increase performance in some cases.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: 
yading@10: =head1 DEMUXERS
yading@10: 
yading@10: 
yading@10: Demuxers are configured elements in FFmpeg which allow to read the
yading@10: multimedia streams from a particular type of file.
yading@10: 
yading@10: When you configure your FFmpeg build, all the supported demuxers
yading@10: are enabled by default. You can list all available ones using the
yading@10: configure option C<--list-demuxers>.
yading@10: 
yading@10: You can disable all the demuxers using the configure option
yading@10: C<--disable-demuxers>, and selectively enable a single demuxer with
yading@10: the option C<--enable-demuxer=I<DEMUXER>>, or disable it
yading@10: with the option C<--disable-demuxer=I<DEMUXER>>.
yading@10: 
yading@10: The option C<-formats> of the ff* tools will display the list of
yading@10: enabled demuxers.
yading@10: 
yading@10: The description of some of the currently available demuxers follows.
yading@10: 
yading@10: 
yading@10: =head2 applehttp
yading@10: 
yading@10: 
yading@10: Apple HTTP Live Streaming demuxer.
yading@10: 
yading@10: This demuxer presents all AVStreams from all variant streams.
yading@10: The id field is set to the bitrate variant index number. By setting
yading@10: the discard flags on AVStreams (by pressing 'a' or 'v' in ffplay),
yading@10: the caller can decide which variant streams to actually receive.
yading@10: The total bitrate of the variant that the stream belongs to is
yading@10: available in a metadata key named "variant_bitrate".
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 concat
yading@10: 
yading@10: 
yading@10: Virtual concatenation script demuxer.
yading@10: 
yading@10: This demuxer reads a list of files and other directives from a text file and
yading@10: demuxes them one after the other, as if all their packet had been muxed
yading@10: together.
yading@10: 
yading@10: The timestamps in the files are adjusted so that the first file starts at 0
yading@10: and each next file starts where the previous one finishes. Note that it is
yading@10: done globally and may cause gaps if all streams do not have exactly the same
yading@10: length.
yading@10: 
yading@10: All files must have the same streams (same codecs, same time base, etc.).
yading@10: 
yading@10: The duration of each file is used to adjust the timestamps of the next file:
yading@10: if the duration is incorrect (because it was computed using the bit-rate or
yading@10: because the file is truncated, for example), it can cause artifacts. The
yading@10: C<duration> directive can be used to override the duration stored in
yading@10: each file.
yading@10: 
yading@10: 
yading@10: =head3 Syntax
yading@10: 
yading@10: 
yading@10: The script is a text file in extended-ASCII, with one directive per line.
yading@10: Empty lines, leading spaces and lines starting with '#' are ignored. The
yading@10: following directive is recognized:
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<C<file I<path>>>
yading@10: 
yading@10: Path to a file to read; special characters and spaces must be escaped with
yading@10: backslash or single quotes.
yading@10: 
yading@10: All subsequent directives apply to that file.
yading@10: 
yading@10: 
yading@10: =item B<C<ffconcat version 1.0>>
yading@10: 
yading@10: Identify the script type and version. It also sets the B<safe> option
yading@10: to 1 if it was to its default -1.
yading@10: 
yading@10: To make FFmpeg recognize the format automatically, this directive must
yading@10: appears exactly as is (no extra space or byte-order-mark) on the very first
yading@10: line of the script.
yading@10: 
yading@10: 
yading@10: =item B<C<duration I<dur>>>
yading@10: 
yading@10: Duration of the file. This information can be specified from the file;
yading@10: specifying it here may be more efficient or help if the information from the
yading@10: file is not available or accurate.
yading@10: 
yading@10: If the duration is set for all files, then it is possible to seek in the
yading@10: whole concatenated video.
yading@10: 
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =head3 Options
yading@10: 
yading@10: 
yading@10: This demuxer accepts the following option:
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<safe>
yading@10: 
yading@10: If set to 1, reject unsafe file paths. A file path is considered safe if it
yading@10: does not contain a protocol specification and is relative and all components
yading@10: only contain characters from the portable character set (letters, digits,
yading@10: period, underscore and hyphen) and have no period at the beginning of a
yading@10: component.
yading@10: 
yading@10: If set to 0, any file name is accepted.
yading@10: 
yading@10: The default is -1, it is equivalent to 1 if the format was automatically
yading@10: probed and 0 otherwise.
yading@10: 
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 libquvi
yading@10: 
yading@10: 
yading@10: Play media from Internet services using the quvi project.
yading@10: 
yading@10: The demuxer accepts a B<format> option to request a specific quality. It
yading@10: is by default set to I<best>.
yading@10: 
yading@10: See E<lt>B<http://quvi.sourceforge.net/>E<gt> for more information.
yading@10: 
yading@10: FFmpeg needs to be built with C<--enable-libquvi> for this demuxer to be
yading@10: enabled.
yading@10: 
yading@10: 
yading@10: =head2 image2
yading@10: 
yading@10: 
yading@10: Image file demuxer.
yading@10: 
yading@10: This demuxer reads from a list of image files specified by a pattern.
yading@10: The syntax and meaning of the pattern is specified by the
yading@10: option I<pattern_type>.
yading@10: 
yading@10: The pattern may contain a suffix which is used to automatically
yading@10: determine the format of the images contained in the files.
yading@10: 
yading@10: The size, the pixel format, and the format of each image must be the
yading@10: same for all the files in the sequence.
yading@10: 
yading@10: This demuxer accepts the following options:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<framerate>
yading@10: 
yading@10: Set the frame rate for the video stream. It defaults to 25.
yading@10: 
yading@10: =item B<loop>
yading@10: 
yading@10: If set to 1, loop over the input. Default value is 0.
yading@10: 
yading@10: =item B<pattern_type>
yading@10: 
yading@10: Select the pattern type used to interpret the provided filename.
yading@10: 
yading@10: I<pattern_type> accepts one of the following values.
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<sequence>
yading@10: 
yading@10: Select a sequence pattern type, used to specify a sequence of files
yading@10: indexed by sequential numbers.
yading@10: 
yading@10: A sequence pattern may contain the string "%d" or "%0I<N>d", which
yading@10: specifies the position of the characters representing a sequential
yading@10: number in each filename matched by the pattern. If the form
yading@10: "%d0I<N>d" is used, the string representing the number in each
yading@10: filename is 0-padded and I<N> is the total number of 0-padded
yading@10: digits representing the number. The literal character '%' can be
yading@10: specified in the pattern with the string "%%".
yading@10: 
yading@10: If the sequence pattern contains "%d" or "%0I<N>d", the first filename of
yading@10: the file list specified by the pattern must contain a number
yading@10: inclusively contained between I<start_number> and
yading@10: I<start_number>+I<start_number_range>-1, and all the following
yading@10: numbers must be sequential.
yading@10: 
yading@10: For example the pattern "img-%03d.bmp" will match a sequence of
yading@10: filenames of the form F<img-001.bmp>, F<img-002.bmp>, ...,
yading@10: F<img-010.bmp>, etc.; the pattern "i%%m%%g-%d.jpg" will match a
yading@10: sequence of filenames of the form F<i%m%g-1.jpg>,
yading@10: F<i%m%g-2.jpg>, ..., F<i%m%g-10.jpg>, etc.
yading@10: 
yading@10: Note that the pattern must not necessarily contain "%d" or
yading@10: "%0I<N>d", for example to convert a single image file
yading@10: F<img.jpeg> you can employ the command:
yading@10: 	
yading@10: 	ffmpeg -i img.jpeg img.png
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<glob>
yading@10: 
yading@10: Select a glob wildcard pattern type.
yading@10: 
yading@10: The pattern is interpreted like a C<glob()> pattern. This is only
yading@10: selectable if libavformat was compiled with globbing support.
yading@10: 
yading@10: 
yading@10: =item B<glob_sequence> I<(deprecated, will be removed)>
yading@10: 
yading@10: Select a mixed glob wildcard/sequence pattern.
yading@10: 
yading@10: If your version of libavformat was compiled with globbing support, and
yading@10: the provided pattern contains at least one glob meta character among
yading@10: C<%*?[]{}> that is preceded by an unescaped "%", the pattern is
yading@10: interpreted like a C<glob()> pattern, otherwise it is interpreted
yading@10: like a sequence pattern.
yading@10: 
yading@10: All glob special characters C<%*?[]{}> must be prefixed
yading@10: with "%". To escape a literal "%" you shall use "%%".
yading@10: 
yading@10: For example the pattern C<foo-%*.jpeg> will match all the
yading@10: filenames prefixed by "foo-" and terminating with ".jpeg", and
yading@10: C<foo-%?%?%?.jpeg> will match all the filenames prefixed with
yading@10: "foo-", followed by a sequence of three characters, and terminating
yading@10: with ".jpeg".
yading@10: 
yading@10: This pattern type is deprecated in favor of I<glob> and
yading@10: I<sequence>.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: Default value is I<glob_sequence>.
yading@10: 
yading@10: =item B<pixel_format>
yading@10: 
yading@10: Set the pixel format of the images to read. If not specified the pixel
yading@10: format is guessed from the first image file in the sequence.
yading@10: 
yading@10: =item B<start_number>
yading@10: 
yading@10: Set the index of the file matched by the image file pattern to start
yading@10: to read from. Default value is 0.
yading@10: 
yading@10: =item B<start_number_range>
yading@10: 
yading@10: Set the index interval range to check when looking for the first image
yading@10: file in the sequence, starting from I<start_number>. Default value
yading@10: is 5.
yading@10: 
yading@10: =item B<video_size>
yading@10: 
yading@10: Set the video size of the images to read. If not specified the video
yading@10: size is guessed from the first image file in the sequence.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =head3 Examples
yading@10: 
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: Use B<ffmpeg> for creating a video from the images in the file
yading@10: sequence F<img-001.jpeg>, F<img-002.jpeg>, ..., assuming an
yading@10: input frame rate of 10 frames per second:
yading@10: 	
yading@10: 	ffmpeg -i 'img-%03d.jpeg' -r 10 out.mkv
yading@10: 
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: As above, but start by reading from a file with index 100 in the sequence:
yading@10: 	
yading@10: 	ffmpeg -start_number 100 -i 'img-%03d.jpeg' -r 10 out.mkv
yading@10: 
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: Read images matching the "*.png" glob pattern , that is all the files
yading@10: terminating with the ".png" suffix:
yading@10: 	
yading@10: 	ffmpeg -pattern_type glob -i "*.png" -r 10 out.mkv
yading@10: 
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 rawvideo
yading@10: 
yading@10: 
yading@10: Raw video demuxer.
yading@10: 
yading@10: This demuxer allows to read raw video data. Since there is no header
yading@10: specifying the assumed video parameters, the user must specify them
yading@10: in order to be able to decode the data correctly.
yading@10: 
yading@10: This demuxer accepts the following options:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<framerate>
yading@10: 
yading@10: Set input video frame rate. Default value is 25.
yading@10: 
yading@10: 
yading@10: =item B<pixel_format>
yading@10: 
yading@10: Set the input video pixel format. Default value is C<yuv420p>.
yading@10: 
yading@10: 
yading@10: =item B<video_size>
yading@10: 
yading@10: Set the input video size. This value must be specified explicitly.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: For example to read a rawvideo file F<input.raw> with
yading@10: B<ffplay>, assuming a pixel format of C<rgb24>, a video
yading@10: size of C<320x240>, and a frame rate of 10 images per second, use
yading@10: the command:
yading@10: 	
yading@10: 	ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 sbg
yading@10: 
yading@10: 
yading@10: SBaGen script demuxer.
yading@10: 
yading@10: This demuxer reads the script language used by SBaGen
yading@10: E<lt>B<http://uazu.net/sbagen/>E<gt> to generate binaural beats sessions. A SBG
yading@10: script looks like that:
yading@10: 	
yading@10: 	-SE
yading@10: 	a: 300-2.5/3 440+4.5/0
yading@10: 	b: 300-2.5/0 440+4.5/3
yading@10: 	off: -
yading@10: 	NOW      == a
yading@10: 	+0:07:00 == b
yading@10: 	+0:14:00 == a
yading@10: 	+0:21:00 == b
yading@10: 	+0:30:00    off
yading@10: 
yading@10: 
yading@10: A SBG script can mix absolute and relative timestamps. If the script uses
yading@10: either only absolute timestamps (including the script start time) or only
yading@10: relative ones, then its layout is fixed, and the conversion is
yading@10: straightforward. On the other hand, if the script mixes both kind of
yading@10: timestamps, then the I<NOW> reference for relative timestamps will be
yading@10: taken from the current time of day at the time the script is read, and the
yading@10: script layout will be frozen according to that reference. That means that if
yading@10: the script is directly played, the actual times will match the absolute
yading@10: timestamps up to the sound controller's clock accuracy, but if the user
yading@10: somehow pauses the playback or seeks, all times will be shifted accordingly.
yading@10: 
yading@10: 
yading@10: =head2 tedcaptions
yading@10: 
yading@10: 
yading@10: JSON captions used for E<lt>B<http://www.ted.com/>E<gt>.
yading@10: 
yading@10: TED does not provide links to the captions, but they can be guessed from the
yading@10: page. The file F<tools/bookmarklets.html> from the FFmpeg source tree
yading@10: contains a bookmarklet to expose them.
yading@10: 
yading@10: This demuxer accepts the following option:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<start_time>
yading@10: 
yading@10: Set the start time of the TED talk, in milliseconds. The default is 15000
yading@10: (15s). It is used to sync the captions with the downloadable videos, because
yading@10: they include a 15s intro.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: Example: convert the captions to a format most players understand:
yading@10: 	
yading@10: 	ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
yading@10: 
yading@10: 
yading@10: 
yading@10: =head1 MUXERS
yading@10: 
yading@10: 
yading@10: Muxers are configured elements in FFmpeg which allow writing
yading@10: multimedia streams to a particular type of file.
yading@10: 
yading@10: When you configure your FFmpeg build, all the supported muxers
yading@10: are enabled by default. You can list all available muxers using the
yading@10: configure option C<--list-muxers>.
yading@10: 
yading@10: You can disable all the muxers with the configure option
yading@10: C<--disable-muxers> and selectively enable / disable single muxers
yading@10: with the options C<--enable-muxer=I<MUXER>> /
yading@10: C<--disable-muxer=I<MUXER>>.
yading@10: 
yading@10: The option C<-formats> of the ff* tools will display the list of
yading@10: enabled muxers.
yading@10: 
yading@10: A description of some of the currently available muxers follows.
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 crc
yading@10: 
yading@10: 
yading@10: CRC (Cyclic Redundancy Check) testing format.
yading@10: 
yading@10: This muxer computes and prints the Adler-32 CRC of all the input audio
yading@10: and video frames. By default audio frames are converted to signed
yading@10: 16-bit raw audio and video frames to raw video before computing the
yading@10: CRC.
yading@10: 
yading@10: The output of the muxer consists of a single line of the form:
yading@10: CRC=0xI<CRC>, where I<CRC> is a hexadecimal number 0-padded to
yading@10: 8 digits containing the CRC for all the decoded input frames.
yading@10: 
yading@10: For example to compute the CRC of the input, and store it in the file
yading@10: F<out.crc>:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -f crc out.crc
yading@10: 
yading@10: 
yading@10: You can print the CRC to stdout with the command:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -f crc -
yading@10: 
yading@10: 
yading@10: You can select the output format of each frame with B<ffmpeg> by
yading@10: specifying the audio and video codec and format. For example to
yading@10: compute the CRC of the input audio converted to PCM unsigned 8-bit
yading@10: and the input video converted to MPEG-2 video, use the command:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
yading@10: 
yading@10: 
yading@10: See also the framecrc muxer.
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 framecrc
yading@10: 
yading@10: 
yading@10: Per-packet CRC (Cyclic Redundancy Check) testing format.
yading@10: 
yading@10: This muxer computes and prints the Adler-32 CRC for each audio
yading@10: and video packet. By default audio frames are converted to signed
yading@10: 16-bit raw audio and video frames to raw video before computing the
yading@10: CRC.
yading@10: 
yading@10: The output of the muxer consists of a line for each audio and video
yading@10: packet of the form:
yading@10: 	
yading@10: 	<stream_index>, <packet_dts>, <packet_pts>, <packet_duration>, <packet_size>, 0x<CRC>
yading@10: 
yading@10: 
yading@10: I<CRC> is a hexadecimal number 0-padded to 8 digits containing the
yading@10: CRC of the packet.
yading@10: 
yading@10: For example to compute the CRC of the audio and video frames in
yading@10: F<INPUT>, converted to raw audio and video packets, and store it
yading@10: in the file F<out.crc>:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -f framecrc out.crc
yading@10: 
yading@10: 
yading@10: To print the information to stdout, use the command:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -f framecrc -
yading@10: 
yading@10: 
yading@10: With B<ffmpeg>, you can select the output format to which the
yading@10: audio and video frames are encoded before computing the CRC for each
yading@10: packet by specifying the audio and video codec. For example, to
yading@10: compute the CRC of each decoded input audio frame converted to PCM
yading@10: unsigned 8-bit and of each decoded input video frame converted to
yading@10: MPEG-2 video, use the command:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
yading@10: 
yading@10: 
yading@10: See also the crc muxer.
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 framemd5
yading@10: 
yading@10: 
yading@10: Per-packet MD5 testing format.
yading@10: 
yading@10: This muxer computes and prints the MD5 hash for each audio
yading@10: and video packet. By default audio frames are converted to signed
yading@10: 16-bit raw audio and video frames to raw video before computing the
yading@10: hash.
yading@10: 
yading@10: The output of the muxer consists of a line for each audio and video
yading@10: packet of the form:
yading@10: 	
yading@10: 	<stream_index>, <packet_dts>, <packet_pts>, <packet_duration>, <packet_size>, <MD5>
yading@10: 
yading@10: 
yading@10: I<MD5> is a hexadecimal number representing the computed MD5 hash
yading@10: for the packet.
yading@10: 
yading@10: For example to compute the MD5 of the audio and video frames in
yading@10: F<INPUT>, converted to raw audio and video packets, and store it
yading@10: in the file F<out.md5>:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -f framemd5 out.md5
yading@10: 
yading@10: 
yading@10: To print the information to stdout, use the command:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -f framemd5 -
yading@10: 
yading@10: 
yading@10: See also the md5 muxer.
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 hls
yading@10: 
yading@10: 
yading@10: Apple HTTP Live Streaming muxer that segments MPEG-TS according to
yading@10: the HTTP Live Streaming specification.
yading@10: 
yading@10: It creates a playlist file and numbered segment files. The output
yading@10: filename specifies the playlist filename; the segment filenames
yading@10: receive the same basename as the playlist, a sequential number and
yading@10: a .ts extension.
yading@10: 
yading@10: 	
yading@10: 	ffmpeg -i in.nut out.m3u8
yading@10: 
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<-hls_time> I<seconds>
yading@10: 
yading@10: Set the segment length in seconds.
yading@10: 
yading@10: =item B<-hls_list_size> I<size>
yading@10: 
yading@10: Set the maximum number of playlist entries.
yading@10: 
yading@10: =item B<-hls_wrap> I<wrap>
yading@10: 
yading@10: Set the number after which index wraps.
yading@10: 
yading@10: =item B<-start_number> I<number>
yading@10: 
yading@10: Start the sequence from I<number>.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 ico
yading@10: 
yading@10: 
yading@10: ICO file muxer.
yading@10: 
yading@10: Microsoft's icon file format (ICO) has some strict limitations that should be noted:
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: Size cannot exceed 256 pixels in any dimension
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: Only BMP and PNG images can be stored
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: If a BMP image is used, it must be one of the following pixel formats:
yading@10: 	
yading@10: 	BMP Bit Depth      FFmpeg Pixel Format
yading@10: 	1bit               pal8
yading@10: 	4bit               pal8
yading@10: 	8bit               pal8
yading@10: 	16bit              rgb555le
yading@10: 	24bit              bgr24
yading@10: 	32bit              bgra
yading@10: 
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: If a PNG image is used, it must use the rgba pixel format
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 image2
yading@10: 
yading@10: 
yading@10: Image file muxer.
yading@10: 
yading@10: The image file muxer writes video frames to image files.
yading@10: 
yading@10: The output filenames are specified by a pattern, which can be used to
yading@10: produce sequentially numbered series of files.
yading@10: The pattern may contain the string "%d" or "%0I<N>d", this string
yading@10: specifies the position of the characters representing a numbering in
yading@10: the filenames. If the form "%0I<N>d" is used, the string
yading@10: representing the number in each filename is 0-padded to I<N>
yading@10: digits. The literal character '%' can be specified in the pattern with
yading@10: the string "%%".
yading@10: 
yading@10: If the pattern contains "%d" or "%0I<N>d", the first filename of
yading@10: the file list specified will contain the number 1, all the following
yading@10: numbers will be sequential.
yading@10: 
yading@10: The pattern may contain a suffix which is used to automatically
yading@10: determine the format of the image files to write.
yading@10: 
yading@10: For example the pattern "img-%03d.bmp" will specify a sequence of
yading@10: filenames of the form F<img-001.bmp>, F<img-002.bmp>, ...,
yading@10: F<img-010.bmp>, etc.
yading@10: The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
yading@10: form F<img%-1.jpg>, F<img%-2.jpg>, ..., F<img%-10.jpg>,
yading@10: etc.
yading@10: 
yading@10: The following example shows how to use B<ffmpeg> for creating a
yading@10: sequence of files F<img-001.jpeg>, F<img-002.jpeg>, ...,
yading@10: taking one image every second from the input video:
yading@10: 	
yading@10: 	ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
yading@10: 
yading@10: 
yading@10: Note that with B<ffmpeg>, if the format is not specified with the
yading@10: C<-f> option and the output filename specifies an image file
yading@10: format, the image2 muxer is automatically selected, so the previous
yading@10: command can be written as:
yading@10: 	
yading@10: 	ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
yading@10: 
yading@10: 
yading@10: Note also that the pattern must not necessarily contain "%d" or
yading@10: "%0I<N>d", for example to create a single image file
yading@10: F<img.jpeg> from the input video you can employ the command:
yading@10: 	
yading@10: 	ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
yading@10: 
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<start_number> I<number>
yading@10: 
yading@10: Start the sequence from I<number>. Default value is 1. Must be a
yading@10: positive number.
yading@10: 
yading@10: 
yading@10: =item B<-update> I<number>
yading@10: 
yading@10: If I<number> is nonzero, the filename will always be interpreted as just a
yading@10: filename, not a pattern, and this file will be continuously overwritten with new
yading@10: images.
yading@10: 
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: The image muxer supports the .Y.U.V image file format. This format is
yading@10: special in that that each image frame consists of three files, for
yading@10: each of the YUV420P components. To read or write this image file format,
yading@10: specify the name of the '.Y' file. The muxer will automatically open the
yading@10: '.U' and '.V' files as required.
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 md5
yading@10: 
yading@10: 
yading@10: MD5 testing format.
yading@10: 
yading@10: This muxer computes and prints the MD5 hash of all the input audio
yading@10: and video frames. By default audio frames are converted to signed
yading@10: 16-bit raw audio and video frames to raw video before computing the
yading@10: hash.
yading@10: 
yading@10: The output of the muxer consists of a single line of the form:
yading@10: MD5=I<MD5>, where I<MD5> is a hexadecimal number representing
yading@10: the computed MD5 hash.
yading@10: 
yading@10: For example to compute the MD5 hash of the input converted to raw
yading@10: audio and video, and store it in the file F<out.md5>:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -f md5 out.md5
yading@10: 
yading@10: 
yading@10: You can print the MD5 to stdout with the command:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -f md5 -
yading@10: 
yading@10: 
yading@10: See also the framemd5 muxer.
yading@10: 
yading@10: 
yading@10: =head2 MOV/MP4/ISMV
yading@10: 
yading@10: 
yading@10: The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
yading@10: file has all the metadata about all packets stored in one location
yading@10: (written at the end of the file, it can be moved to the start for
yading@10: better playback by adding I<faststart> to the I<movflags>, or
yading@10: using the B<qt-faststart> tool). A fragmented
yading@10: file consists of a number of fragments, where packets and metadata
yading@10: about these packets are stored together. Writing a fragmented
yading@10: file has the advantage that the file is decodable even if the
yading@10: writing is interrupted (while a normal MOV/MP4 is undecodable if
yading@10: it is not properly finished), and it requires less memory when writing
yading@10: very long files (since writing normal MOV/MP4 files stores info about
yading@10: every single packet in memory until the file is closed). The downside
yading@10: is that it is less compatible with other applications.
yading@10: 
yading@10: Fragmentation is enabled by setting one of the AVOptions that define
yading@10: how to cut the file into fragments:
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<-moov_size> I<bytes>
yading@10: 
yading@10: Reserves space for the moov atom at the beginning of the file instead of placing the
yading@10: moov atom at the end. If the space reserved is insufficient, muxing will fail.
yading@10: 
yading@10: =item B<-movflags frag_keyframe>
yading@10: 
yading@10: Start a new fragment at each video keyframe.
yading@10: 
yading@10: =item B<-frag_duration> I<duration>
yading@10: 
yading@10: Create fragments that are I<duration> microseconds long.
yading@10: 
yading@10: =item B<-frag_size> I<size>
yading@10: 
yading@10: Create fragments that contain up to I<size> bytes of payload data.
yading@10: 
yading@10: =item B<-movflags frag_custom>
yading@10: 
yading@10: Allow the caller to manually choose when to cut fragments, by
yading@10: calling C<av_write_frame(ctx, NULL)> to write a fragment with
yading@10: the packets written so far. (This is only useful with other
yading@10: applications integrating libavformat, not from B<ffmpeg>.)
yading@10: 
yading@10: =item B<-min_frag_duration> I<duration>
yading@10: 
yading@10: Don't create fragments that are shorter than I<duration> microseconds long.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: If more than one condition is specified, fragments are cut when
yading@10: one of the specified conditions is fulfilled. The exception to this is
yading@10: C<-min_frag_duration>, which has to be fulfilled for any of the other
yading@10: conditions to apply.
yading@10: 
yading@10: Additionally, the way the output file is written can be adjusted
yading@10: through a few other options:
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<-movflags empty_moov>
yading@10: 
yading@10: Write an initial moov atom directly at the start of the file, without
yading@10: describing any samples in it. Generally, an mdat/moov pair is written
yading@10: at the start of the file, as a normal MOV/MP4 file, containing only
yading@10: a short portion of the file. With this option set, there is no initial
yading@10: mdat atom, and the moov atom only describes the tracks but has
yading@10: a zero duration.
yading@10: 
yading@10: Files written with this option set do not work in QuickTime.
yading@10: This option is implicitly set when writing ismv (Smooth Streaming) files.
yading@10: 
yading@10: =item B<-movflags separate_moof>
yading@10: 
yading@10: Write a separate moof (movie fragment) atom for each track. Normally,
yading@10: packets for all tracks are written in a moof atom (which is slightly
yading@10: more efficient), but with this option set, the muxer writes one moof/mdat
yading@10: pair for each track, making it easier to separate tracks.
yading@10: 
yading@10: This option is implicitly set when writing ismv (Smooth Streaming) files.
yading@10: 
yading@10: =item B<-movflags faststart>
yading@10: 
yading@10: Run a second pass moving the moov atom on top of the file. This
yading@10: operation can take a while, and will not work in various situations such
yading@10: as fragmented output, thus it is not enabled by default.
yading@10: 
yading@10: =item B<-movflags rtphint>
yading@10: 
yading@10: Add RTP hinting tracks to the output file.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: Smooth Streaming content can be pushed in real time to a publishing
yading@10: point on IIS with this muxer. Example:
yading@10: 	
yading@10: 	ffmpeg -re <<normal input/transcoding options>> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 mpegts
yading@10: 
yading@10: 
yading@10: MPEG transport stream muxer.
yading@10: 
yading@10: This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
yading@10: 
yading@10: The muxer options are:
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<-mpegts_original_network_id> I<number>
yading@10: 
yading@10: Set the original_network_id (default 0x0001). This is unique identifier
yading@10: of a network in DVB. Its main use is in the unique identification of a
yading@10: service through the path Original_Network_ID, Transport_Stream_ID.
yading@10: 
yading@10: =item B<-mpegts_transport_stream_id> I<number>
yading@10: 
yading@10: Set the transport_stream_id (default 0x0001). This identifies a
yading@10: transponder in DVB.
yading@10: 
yading@10: =item B<-mpegts_service_id> I<number>
yading@10: 
yading@10: Set the service_id (default 0x0001) also known as program in DVB.
yading@10: 
yading@10: =item B<-mpegts_pmt_start_pid> I<number>
yading@10: 
yading@10: Set the first PID for PMT (default 0x1000, max 0x1f00).
yading@10: 
yading@10: =item B<-mpegts_start_pid> I<number>
yading@10: 
yading@10: Set the first PID for data packets (default 0x0100, max 0x0f00).
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: The recognized metadata settings in mpegts muxer are C<service_provider>
yading@10: and C<service_name>. If they are not set the default for
yading@10: C<service_provider> is "FFmpeg" and the default for
yading@10: C<service_name> is "Service01".
yading@10: 
yading@10: 	
yading@10: 	ffmpeg -i file.mpg -c copy \
yading@10: 	     -mpegts_original_network_id 0x1122 \
yading@10: 	     -mpegts_transport_stream_id 0x3344 \
yading@10: 	     -mpegts_service_id 0x5566 \
yading@10: 	     -mpegts_pmt_start_pid 0x1500 \
yading@10: 	     -mpegts_start_pid 0x150 \
yading@10: 	     -metadata service_provider="Some provider" \
yading@10: 	     -metadata service_name="Some Channel" \
yading@10: 	     -y out.ts
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 null
yading@10: 
yading@10: 
yading@10: Null muxer.
yading@10: 
yading@10: This muxer does not generate any output file, it is mainly useful for
yading@10: testing or benchmarking purposes.
yading@10: 
yading@10: For example to benchmark decoding with B<ffmpeg> you can use the
yading@10: command:
yading@10: 	
yading@10: 	ffmpeg -benchmark -i INPUT -f null out.null
yading@10: 
yading@10: 
yading@10: Note that the above command does not read or write the F<out.null>
yading@10: file, but specifying the output file is required by the B<ffmpeg>
yading@10: syntax.
yading@10: 
yading@10: Alternatively you can write the command as:
yading@10: 	
yading@10: 	ffmpeg -benchmark -i INPUT -f null -
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 matroska
yading@10: 
yading@10: 
yading@10: Matroska container muxer.
yading@10: 
yading@10: This muxer implements the matroska and webm container specs.
yading@10: 
yading@10: The recognized metadata settings in this muxer are:
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<title=>I<title name>
yading@10: 
yading@10: Name provided to a single track
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<language=>I<language name>
yading@10: 
yading@10: Specifies the language of the track in the Matroska languages form
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: 
yading@10: =item B<stereo_mode=>I<mode>
yading@10: 
yading@10: Stereo 3D video layout of two views in a single video track
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<mono>
yading@10: 
yading@10: video is not stereo
yading@10: 
yading@10: =item B<left_right>
yading@10: 
yading@10: Both views are arranged side by side, Left-eye view is on the left
yading@10: 
yading@10: =item B<bottom_top>
yading@10: 
yading@10: Both views are arranged in top-bottom orientation, Left-eye view is at bottom
yading@10: 
yading@10: =item B<top_bottom>
yading@10: 
yading@10: Both views are arranged in top-bottom orientation, Left-eye view is on top
yading@10: 
yading@10: =item B<checkerboard_rl>
yading@10: 
yading@10: Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
yading@10: 
yading@10: =item B<checkerboard_lr>
yading@10: 
yading@10: Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
yading@10: 
yading@10: =item B<row_interleaved_rl>
yading@10: 
yading@10: Each view is constituted by a row based interleaving, Right-eye view is first row
yading@10: 
yading@10: =item B<row_interleaved_lr>
yading@10: 
yading@10: Each view is constituted by a row based interleaving, Left-eye view is first row
yading@10: 
yading@10: =item B<col_interleaved_rl>
yading@10: 
yading@10: Both views are arranged in a column based interleaving manner, Right-eye view is first column
yading@10: 
yading@10: =item B<col_interleaved_lr>
yading@10: 
yading@10: Both views are arranged in a column based interleaving manner, Left-eye view is first column
yading@10: 
yading@10: =item B<anaglyph_cyan_red>
yading@10: 
yading@10: All frames are in anaglyph format viewable through red-cyan filters
yading@10: 
yading@10: =item B<right_left>
yading@10: 
yading@10: Both views are arranged side by side, Right-eye view is on the left
yading@10: 
yading@10: =item B<anaglyph_green_magenta>
yading@10: 
yading@10: All frames are in anaglyph format viewable through green-magenta filters
yading@10: 
yading@10: =item B<block_lr>
yading@10: 
yading@10: Both eyes laced in one Block, Left-eye view is first
yading@10: 
yading@10: =item B<block_rl>
yading@10: 
yading@10: Both eyes laced in one Block, Right-eye view is first
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: For example a 3D WebM clip can be created using the following command line:
yading@10: 	
yading@10: 	ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 segment, stream_segment, ssegment
yading@10: 
yading@10: 
yading@10: Basic stream segmenter.
yading@10: 
yading@10: The segmenter muxer outputs streams to a number of separate files of nearly
yading@10: fixed duration. Output filename pattern can be set in a fashion similar to
yading@10: image2.
yading@10: 
yading@10: C<stream_segment> is a variant of the muxer used to write to
yading@10: streaming output formats, i.e. which do not require global headers,
yading@10: and is recommended for outputting e.g. to MPEG transport stream segments.
yading@10: C<ssegment> is a shorter alias for C<stream_segment>.
yading@10: 
yading@10: Every segment starts with a keyframe of the selected reference stream,
yading@10: which is set through the B<reference_stream> option.
yading@10: 
yading@10: Note that if you want accurate splitting for a video file, you need to
yading@10: make the input key frames correspond to the exact splitting times
yading@10: expected by the segmenter, or the segment muxer will start the new
yading@10: segment with the key frame found next after the specified start
yading@10: time.
yading@10: 
yading@10: The segment muxer works best with a single constant frame rate video.
yading@10: 
yading@10: Optionally it can generate a list of the created segments, by setting
yading@10: the option I<segment_list>. The list type is specified by the
yading@10: I<segment_list_type> option.
yading@10: 
yading@10: The segment muxer supports the following options:
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<reference_stream> I<specifier>
yading@10: 
yading@10: Set the reference stream, as specified by the string I<specifier>.
yading@10: If I<specifier> is set to C<auto>, the reference is choosen
yading@10: automatically. Otherwise it must be a stream specifier (see the ``Stream
yading@10: specifiers'' chapter in the ffmpeg manual) which specifies the
yading@10: reference stream. The default value is ``auto''.
yading@10: 
yading@10: 
yading@10: =item B<segment_format> I<format>
yading@10: 
yading@10: Override the inner container format, by default it is guessed by the filename
yading@10: extension.
yading@10: 
yading@10: 
yading@10: =item B<segment_list> I<name>
yading@10: 
yading@10: Generate also a listfile named I<name>. If not specified no
yading@10: listfile is generated.
yading@10: 
yading@10: 
yading@10: =item B<segment_list_flags> I<flags>
yading@10: 
yading@10: Set flags affecting the segment list generation.
yading@10: 
yading@10: It currently supports the following flags:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item I<cache>
yading@10: 
yading@10: Allow caching (only affects M3U8 list files).
yading@10: 
yading@10: 
yading@10: =item I<live>
yading@10: 
yading@10: Allow live-friendly file generation.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: Default value is C<cache>.
yading@10: 
yading@10: 
yading@10: =item B<segment_list_size> I<size>
yading@10: 
yading@10: Update the list file so that it contains at most the last I<size>
yading@10: segments. If 0 the list file will contain all the segments. Default
yading@10: value is 0.
yading@10: 
yading@10: 
yading@10: =item B<segment_list type> I<type>
yading@10: 
yading@10: Specify the format for the segment list file.
yading@10: 
yading@10: The following values are recognized:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<flat>
yading@10: 
yading@10: Generate a flat list for the created segments, one segment per line.
yading@10: 
yading@10: 
yading@10: =item B<csv, ext>
yading@10: 
yading@10: Generate a list for the created segments, one segment per line,
yading@10: each line matching the format (comma-separated values):
yading@10: 	
yading@10: 	<segment_filename>,<segment_start_time>,<segment_end_time>
yading@10: 
yading@10: 
yading@10: I<segment_filename> is the name of the output file generated by the
yading@10: muxer according to the provided pattern. CSV escaping (according to
yading@10: RFC4180) is applied if required.
yading@10: 
yading@10: I<segment_start_time> and I<segment_end_time> specify
yading@10: the segment start and end time expressed in seconds.
yading@10: 
yading@10: A list file with the suffix C<".csv"> or C<".ext"> will
yading@10: auto-select this format.
yading@10: 
yading@10: C<ext> is deprecated in favor or C<csv>.
yading@10: 
yading@10: 
yading@10: =item B<ffconcat>
yading@10: 
yading@10: Generate an ffconcat file for the created segments. The resulting file
yading@10: can be read using the FFmpeg concat demuxer.
yading@10: 
yading@10: A list file with the suffix C<".ffcat"> or C<".ffconcat"> will
yading@10: auto-select this format.
yading@10: 
yading@10: 
yading@10: =item B<m3u8>
yading@10: 
yading@10: Generate an extended M3U8 file, version 3, compliant with
yading@10: E<lt>B<http://tools.ietf.org/id/draft-pantos-http-live-streaming>E<gt>.
yading@10: 
yading@10: A list file with the suffix C<".m3u8"> will auto-select this format.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: If not specified the type is guessed from the list file name suffix.
yading@10: 
yading@10: 
yading@10: =item B<segment_time> I<time>
yading@10: 
yading@10: Set segment duration to I<time>, the value must be a duration
yading@10: specification. Default value is "2". See also the
yading@10: B<segment_times> option.
yading@10: 
yading@10: Note that splitting may not be accurate, unless you force the
yading@10: reference stream key-frames at the given time. See the introductory
yading@10: notice and the examples below.
yading@10: 
yading@10: 
yading@10: =item B<segment_time_delta> I<delta>
yading@10: 
yading@10: Specify the accuracy time when selecting the start time for a
yading@10: segment, expressed as a duration specification. Default value is "0".
yading@10: 
yading@10: When delta is specified a key-frame will start a new segment if its
yading@10: PTS satisfies the relation:
yading@10: 	
yading@10: 	PTS >= start_time - time_delta
yading@10: 
yading@10: 
yading@10: This option is useful when splitting video content, which is always
yading@10: split at GOP boundaries, in case a key frame is found just before the
yading@10: specified split time.
yading@10: 
yading@10: In particular may be used in combination with the F<ffmpeg> option
yading@10: I<force_key_frames>. The key frame times specified by
yading@10: I<force_key_frames> may not be set accurately because of rounding
yading@10: issues, with the consequence that a key frame time may result set just
yading@10: before the specified time. For constant frame rate videos a value of
yading@10: 1/2*I<frame_rate> should address the worst case mismatch between
yading@10: the specified time and the time set by I<force_key_frames>.
yading@10: 
yading@10: 
yading@10: =item B<segment_times> I<times>
yading@10: 
yading@10: Specify a list of split points. I<times> contains a list of comma
yading@10: separated duration specifications, in increasing order. See also
yading@10: the B<segment_time> option.
yading@10: 
yading@10: 
yading@10: =item B<segment_frames> I<frames>
yading@10: 
yading@10: Specify a list of split video frame numbers. I<frames> contains a
yading@10: list of comma separated integer numbers, in increasing order.
yading@10: 
yading@10: This option specifies to start a new segment whenever a reference
yading@10: stream key frame is found and the sequential number (starting from 0)
yading@10: of the frame is greater or equal to the next value in the list.
yading@10: 
yading@10: 
yading@10: =item B<segment_wrap> I<limit>
yading@10: 
yading@10: Wrap around segment index once it reaches I<limit>.
yading@10: 
yading@10: 
yading@10: =item B<segment_start_number> I<number>
yading@10: 
yading@10: Set the sequence number of the first segment. Defaults to C<0>.
yading@10: 
yading@10: 
yading@10: =item B<reset_timestamps> I<1|0>
yading@10: 
yading@10: Reset timestamps at the begin of each segment, so that each segment
yading@10: will start with near-zero timestamps. It is meant to ease the playback
yading@10: of the generated segments. May not work with some combinations of
yading@10: muxers/codecs. It is set to C<0> by default.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =head3 Examples
yading@10: 
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: To remux the content of file F<in.mkv> to a list of segments
yading@10: F<out-000.nut>, F<out-001.nut>, etc., and write the list of
yading@10: generated segments to F<out.list>:
yading@10: 	
yading@10: 	ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut
yading@10: 
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: As the example above, but segment the input file according to the split
yading@10: points specified by the I<segment_times> option:
yading@10: 	
yading@10: 	ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 out%03d.nut
yading@10: 
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: As the example above, but use the C<ffmpeg> I<force_key_frames>
yading@10: option to force key frames in the input at the specified location, together
yading@10: with the segment option I<segment_time_delta> to account for
yading@10: possible roundings operated when setting key frame times.
yading@10: 	
yading@10: 	ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \
yading@10: 	-f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut
yading@10: 
yading@10: In order to force key frames on the input file, transcoding is
yading@10: required.
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: Segment the input file by splitting the input file according to the
yading@10: frame numbers sequence specified with the I<segment_frames> option:
yading@10: 	
yading@10: 	ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut
yading@10: 
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: To convert the F<in.mkv> to TS segments using the C<libx264>
yading@10: and C<libfaac> encoders:
yading@10: 	
yading@10: 	ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a libfaac -f ssegment -segment_list out.list out%03d.ts
yading@10: 
yading@10: 
yading@10: 
yading@10: =item *
yading@10: 
yading@10: Segment the input file, and create an M3U8 live playlist (can be used
yading@10: as live HLS source):
yading@10: 	
yading@10: 	ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \
yading@10: 	-segment_list_flags +live -segment_time 10 out%03d.mkv
yading@10: 
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 mp3
yading@10: 
yading@10: 
yading@10: The MP3 muxer writes a raw MP3 stream with an ID3v2 header at the beginning and
yading@10: optionally an ID3v1 tag at the end. ID3v2.3 and ID3v2.4 are supported, the
yading@10: C<id3v2_version> option controls which one is used. The legacy ID3v1 tag is
yading@10: not written by default, but may be enabled with the C<write_id3v1> option.
yading@10: 
yading@10: For seekable output the muxer also writes a Xing frame at the beginning, which
yading@10: contains the number of frames in the file. It is useful for computing duration
yading@10: of VBR files.
yading@10: 
yading@10: The muxer supports writing ID3v2 attached pictures (APIC frames). The pictures
yading@10: are supplied to the muxer in form of a video stream with a single packet. There
yading@10: can be any number of those streams, each will correspond to a single APIC frame.
yading@10: The stream metadata tags I<title> and I<comment> map to APIC
yading@10: I<description> and I<picture type> respectively. See
yading@10: E<lt>B<http://id3.org/id3v2.4.0-frames>E<gt> for allowed picture types.
yading@10: 
yading@10: Note that the APIC frames must be written at the beginning, so the muxer will
yading@10: buffer the audio frames until it gets all the pictures. It is therefore advised
yading@10: to provide the pictures as soon as possible to avoid excessive buffering.
yading@10: 
yading@10: Examples:
yading@10: 
yading@10: Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
yading@10: 	
yading@10: 	ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
yading@10: 
yading@10: 
yading@10: To attach a picture to an mp3 file select both the audio and the picture stream
yading@10: with C<map>:
yading@10: 	
yading@10: 	ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
yading@10: 	-metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 ogg
yading@10: 
yading@10: 
yading@10: Ogg container muxer.
yading@10: 
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: =item B<-page_duration> I<duration>
yading@10: 
yading@10: Preferred page duration, in microseconds. The muxer will attempt to create
yading@10: pages that are approximately I<duration> microseconds long. This allows the
yading@10: user to compromise between seek granularity and container overhead. The default
yading@10: is 1 second. A value of 0 will fill all segments, making pages as large as
yading@10: possible. A value of 1 will effectively use 1 packet-per-page in most
yading@10: situations, giving a small seek granularity at the cost of additional container
yading@10: overhead.
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: 
yading@10: =head2 tee
yading@10: 
yading@10: 
yading@10: The tee muxer can be used to write the same data to several files or any
yading@10: other kind of muxer. It can be used, for example, to both stream a video to
yading@10: the network and save it to disk at the same time.
yading@10: 
yading@10: It is different from specifying several outputs to the B<ffmpeg>
yading@10: command-line tool because the audio and video data will be encoded only once
yading@10: with the tee muxer; encoding can be a very expensive process. It is not
yading@10: useful when using the libavformat API directly because it is then possible
yading@10: to feed the same packets to several muxers directly.
yading@10: 
yading@10: The slave outputs are specified in the file name given to the muxer,
yading@10: separated by '|'. If any of the slave name contains the '|' separator,
yading@10: leading or trailing spaces or any special character, it must be
yading@10: escaped (see the ``Quoting and escaping'' section in the ffmpeg-utils
yading@10: manual).
yading@10: 
yading@10: Options can be specified for each slave by prepending them as a list of
yading@10: I<key>=I<value> pairs separated by ':', between square brackets. If
yading@10: the options values contain a special character or the ':' separator, they
yading@10: must be escaped; note that this is a second level escaping.
yading@10: 
yading@10: Example: encode something and both archive it in a WebM file and stream it
yading@10: as MPEG-TS over UDP (the streams need to be explicitly mapped):
yading@10: 
yading@10: 	
yading@10: 	ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
yading@10: 	  "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
yading@10: 
yading@10: 
yading@10: Note: some codecs may need different options depending on the output format;
yading@10: the auto-detection of this can not work with the tee muxer. The main example
yading@10: is the B<global_header> flag.
yading@10: 
yading@10: 
yading@10: =head1 METADATA
yading@10: 
yading@10: 
yading@10: FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
yading@10: INI-like text file and then load it back using the metadata muxer/demuxer.
yading@10: 
yading@10: The file format is as follows:
yading@10: 
yading@10: =over 4
yading@10: 
yading@10: 
yading@10: 
yading@10: =item 1.
yading@10: 
yading@10: A file consists of a header and a number of metadata tags divided into sections,
yading@10: each on its own line.
yading@10: 
yading@10: 
yading@10: =item 2.
yading@10: 
yading@10: The header is a ';FFMETADATA' string, followed by a version number (now 1).
yading@10: 
yading@10: 
yading@10: =item 3.
yading@10: 
yading@10: Metadata tags are of the form 'key=value'
yading@10: 
yading@10: 
yading@10: =item 4.
yading@10: 
yading@10: Immediately after header follows global metadata
yading@10: 
yading@10: 
yading@10: =item 5.
yading@10: 
yading@10: After global metadata there may be sections with per-stream/per-chapter
yading@10: metadata.
yading@10: 
yading@10: 
yading@10: =item 6.
yading@10: 
yading@10: A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
yading@10: brackets ('[', ']') and ends with next section or end of file.
yading@10: 
yading@10: 
yading@10: =item 7.
yading@10: 
yading@10: At the beginning of a chapter section there may be an optional timebase to be
yading@10: used for start/end values. It must be in form 'TIMEBASE=num/den', where num and
yading@10: den are integers. If the timebase is missing then start/end times are assumed to
yading@10: be in milliseconds.
yading@10: Next a chapter section must contain chapter start and end times in form
yading@10: 'START=num', 'END=num', where num is a positive integer.
yading@10: 
yading@10: 
yading@10: =item 8.
yading@10: 
yading@10: Empty lines and lines starting with ';' or '#' are ignored.
yading@10: 
yading@10: 
yading@10: =item 9.
yading@10: 
yading@10: Metadata keys or values containing special characters ('=', ';', '#', '\' and a
yading@10: newline) must be escaped with a backslash '\'.
yading@10: 
yading@10: 
yading@10: =item 10.
yading@10: 
yading@10: Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
yading@10: the tag (in the example above key is 'foo ', value is ' bar').
yading@10: 
yading@10: =back
yading@10: 
yading@10: 
yading@10: A ffmetadata file might look like this:
yading@10: 	
yading@10: 	;FFMETADATA1
yading@10: 	title=bike\\shed
yading@10: 	;this is a comment
yading@10: 	artist=FFmpeg troll team
yading@10: 	
yading@10: 	[CHAPTER]
yading@10: 	TIMEBASE=1/1000
yading@10: 	START=0
yading@10: 	#chapter ends at 0:01:00
yading@10: 	END=60000
yading@10: 	title=chapter \#1
yading@10: 	[STREAM]
yading@10: 	title=multi\
yading@10: 	line
yading@10: 
yading@10: 
yading@10: 
yading@10: =head1 SEE ALSO
yading@10: 
yading@10: 
yading@10: 
yading@10: ffmpeg(1), ffplay(1), ffprobe(1), ffserver(1), libavformat(3)
yading@10: 
yading@10: 
yading@10: =head1 AUTHORS
yading@10: 
yading@10: 
yading@10: The FFmpeg developers.
yading@10: 
yading@10: For details about the authorship, see the Git history of the project
yading@10: (git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
yading@10: B<git log> in the FFmpeg source directory, or browsing the
yading@10: online repository at E<lt>B<http://source.ffmpeg.org>E<gt>.
yading@10: 
yading@10: Maintainers for the specific components are listed in the file
yading@10: F<MAINTAINERS> in the source code tree.
yading@10: 
yading@10: 
yading@10: