doc/formats.texi - manifest_repos/ffmpeg - Git at Google

 @chapter Format Options
 @c man begin FORMAT OPTIONS

 The libavformat library provides some generic global options, which
 can be set on all the muxers and demuxers. In addition each muxer or
 demuxer may support so-called private options, which are specific for
 that component.

 Options may be set by specifying -@var{option} @var{value} in the
 FFmpeg tools, or by setting the value explicitly in the
 @code{AVFormatContext} options or using the @file{libavutil/opt.h} API
 for programmatic use.

 The list of supported options follows:

 @table @option
 @item avioflags @var{flags} (@emph{input/output})
 Possible values:
 @table @samp
 @item direct
 Reduce buffering.
 @end table

 @item probesize @var{integer} (@emph{input})
 Set probing size in bytes, i.e. the size of the data to analyze to get
 stream information. A higher value will enable detecting more
 information in case it is dispersed into the stream, but will increase
 latency. Must be an integer not lesser than 32. It is 5000000 by default.

 @item max_probe_packets @var{integer} (@emph{input})
 Set the maximum number of buffered packets when probing a codec.
 Default is 2500 packets.

 @item packetsize @var{integer} (@emph{output})
 Set packet size.

 @item fflags @var{flags}
 Set format flags. Some are implemented for a limited number of formats.

 Possible values for input files:
 @table @samp
 @item discardcorrupt
 Discard corrupted packets.
 @item fastseek
 Enable fast, but inaccurate seeks for some formats.
 @item genpts
 Generate missing PTS if DTS is present.
 @item igndts
 Ignore DTS if PTS is set. Inert when nofillin is set.
 @item ignidx
 Ignore index.
 @item keepside (@emph{deprecated},@emph{inert})
 @item nobuffer
 Reduce the latency introduced by buffering during initial input streams analysis.
 @item nofillin
 Do not fill in missing values in packet fields that can be exactly calculated.
 @item noparse
 Disable AVParsers, this needs @code{+nofillin} too.
 @item sortdts
 Try to interleave output packets by DTS. At present, available only for AVIs with an index.
 @end table

 Possible values for output files:
 @table @samp
 @item autobsf
 Automatically apply bitstream filters as required by the output format. Enabled by default.
 @item bitexact
 Only write platform-, build- and time-independent data.
 This ensures that file and data checksums are reproducible and match between
 platforms. Its primary use is for regression testing.
 @item flush_packets
 Write out packets immediately.
 @item latm (@emph{deprecated},@emph{inert})
 @item shortest
 Stop muxing at the end of the shortest stream.
 It may be needed to increase max_interleave_delta to avoid flushing the longer
 streams before EOF.
 @end table

 @item seek2any @var{integer} (@emph{input})
 Allow seeking to non-keyframes on demuxer level when supported if set to 1.
 Default is 0.

 @item analyzeduration @var{integer} (@emph{input})
 Specify how many microseconds are analyzed to probe the input. A
 higher value will enable detecting more accurate information, but will
 increase latency. It defaults to 5,000,000 microseconds = 5 seconds.

 @item cryptokey @var{hexadecimal string} (@emph{input})
 Set decryption key.

 @item indexmem @var{integer} (@emph{input})
 Set max memory used for timestamp index (per stream).

 @item rtbufsize @var{integer} (@emph{input})
 Set max memory used for buffering real-time frames.

 @item fdebug @var{flags} (@emph{input/output})
 Print specific debug info.

 Possible values:
 @table @samp
 @item ts
 @end table

 @item max_delay @var{integer} (@emph{input/output})
 Set maximum muxing or demuxing delay in microseconds.

 @item fpsprobesize @var{integer} (@emph{input})
 Set number of frames used to probe fps.

 @item audio_preload @var{integer} (@emph{output})
 Set microseconds by which audio packets should be interleaved earlier.

 @item chunk_duration @var{integer} (@emph{output})
 Set microseconds for each chunk.

 @item chunk_size @var{integer} (@emph{output})
 Set size in bytes for each chunk.

 @item err_detect, f_err_detect @var{flags} (@emph{input})
 Set error detection flags. @code{f_err_detect} is deprecated and
 should be used only via the @command{ffmpeg} tool.

 Possible values:
 @table @samp
 @item crccheck
 Verify embedded CRCs.
 @item bitstream
 Detect bitstream specification deviations.
 @item buffer
 Detect improper bitstream length.
 @item explode
 Abort decoding on minor error detection.
 @item careful
 Consider things that violate the spec and have not been seen in the
 wild as errors.
 @item compliant
 Consider all spec non compliancies as errors.
 @item aggressive
 Consider things that a sane encoder should not do as an error.
 @end table

 @item max_interleave_delta @var{integer} (@emph{output})
 Set maximum buffering duration for interleaving. The duration is
 expressed in microseconds, and defaults to 10000000 (10 seconds).

 To ensure all the streams are interleaved correctly, libavformat will
 wait until it has at least one packet for each stream before actually
 writing any packets to the output file. When some streams are
 "sparse" (i.e. there are large gaps between successive packets), this
 can result in excessive buffering.

 This field specifies the maximum difference between the timestamps of the
 first and the last packet in the muxing queue, above which libavformat
 will output a packet regardless of whether it has queued a packet for all
 the streams.

 If set to 0, libavformat will continue buffering packets until it has
 a packet for each stream, regardless of the maximum timestamp
 difference between the buffered packets.

 @item use_wallclock_as_timestamps @var{integer} (@emph{input})
 Use wallclock as timestamps if set to 1. Default is 0.

 @item avoid_negative_ts @var{integer} (@emph{output})

 Possible values:
 @table @samp
 @item make_non_negative
 Shift timestamps to make them non-negative.
 Also note that this affects only leading negative timestamps, and not
 non-monotonic negative timestamps.
 @item make_zero
 Shift timestamps so that the first timestamp is 0.
 @item auto (default)
 Enables shifting when required by the target format.
 @item disabled
 Disables shifting of timestamp.
 @end table

 When shifting is enabled, all output timestamps are shifted by the
 same amount. Audio, video, and subtitles desynching and relative
 timestamp differences are preserved compared to how they would have
 been without shifting.

 @item skip_initial_bytes @var{integer} (@emph{input})
 Set number of bytes to skip before reading header and frames if set to 1.
 Default is 0.

 @item correct_ts_overflow @var{integer} (@emph{input})
 Correct single timestamp overflows if set to 1. Default is 1.

 @item flush_packets @var{integer} (@emph{output})
 Flush the underlying I/O stream after each packet. Default is -1 (auto), which
 means that the underlying protocol will decide, 1 enables it, and has the
 effect of reducing the latency, 0 disables it and may increase IO throughput in
 some cases.

 @item output_ts_offset @var{offset} (@emph{output})
 Set the output time offset.

 @var{offset} must be a time duration specification,
 see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.

 The offset is added by the muxer to the output timestamps.

 Specifying a positive offset means that the corresponding streams are
 delayed bt the time duration specified in @var{offset}. Default value
 is @code{0} (meaning that no offset is applied).

 @item format_whitelist @var{list} (@emph{input})
 "," separated list of allowed demuxers. By default all are allowed.

 @item dump_separator @var{string} (@emph{input})
 Separator used to separate the fields printed on the command line about the
 Stream parameters.
 For example, to separate the fields with newlines and indentation:
 @example
 ffprobe -dump_separator "
                           "  -i ~/videos/matrixbench_mpeg2.mpg
 @end example

 @item max_streams @var{integer} (@emph{input})
 Specifies the maximum number of streams. This can be used to reject files that
 would require too many resources due to a large number of streams.

 @item skip_estimate_duration_from_pts @var{bool} (@emph{input})
 Skip estimation of input duration when calculated using PTS.
 At present, applicable for MPEG-PS and MPEG-TS.

 @item strict, f_strict @var{integer} (@emph{input/output})
 Specify how strictly to follow the standards. @code{f_strict} is deprecated and
 should be used only via the @command{ffmpeg} tool.

 Possible values:
 @table @samp
 @item very
 strictly conform to an older more strict version of the spec or reference software
 @item strict
 strictly conform to all the things in the spec no matter what consequences
 @item normal

 @item unofficial
 allow unofficial extensions
 @item experimental
 allow non standardized experimental things, experimental
 (unfinished/work in progress/not well tested) decoders and encoders.
 Note: experimental decoders can pose a security risk, do not use this for
 decoding untrusted input.
 @end table

 @end table

 @c man end FORMAT OPTIONS

 @anchor{Format stream specifiers}
 @section Format stream specifiers

 Format stream specifiers allow selection of one or more streams that
 match specific properties.

 The exact semantics of stream specifiers is defined by the
 @code{avformat_match_stream_specifier()} function declared in the
 @file{libavformat/avformat.h} header and documented in the
 @ref{Stream specifiers,,Stream specifiers section in the ffmpeg(1) manual,ffmpeg}.

 @ifclear config-writeonly
 @include demuxers.texi
 @end ifclear
 @ifclear config-readonly
 @include muxers.texi
 @end ifclear
 @include metadata.texi
	@chapter Format Options
	@c man begin FORMAT OPTIONS

	The libavformat library provides some generic global options, which
	can be set on all the muxers and demuxers. In addition each muxer or
	demuxer may support so-called private options, which are specific for
	that component.

	Options may be set by specifying -@var{option} @var{value} in the
	FFmpeg tools, or by setting the value explicitly in the
	@code{AVFormatContext} options or using the @file{libavutil/opt.h} API
	for programmatic use.

	The list of supported options follows:

	@table @option
	@item avioflags @var{flags} (@emph{input/output})
	Possible values:
	@table @samp
	@item direct
	Reduce buffering.
	@end table

	@item probesize @var{integer} (@emph{input})
	Set probing size in bytes, i.e. the size of the data to analyze to get
	stream information. A higher value will enable detecting more
	information in case it is dispersed into the stream, but will increase
	latency. Must be an integer not lesser than 32. It is 5000000 by default.

	@item max_probe_packets @var{integer} (@emph{input})
	Set the maximum number of buffered packets when probing a codec.
	Default is 2500 packets.

	@item packetsize @var{integer} (@emph{output})
	Set packet size.

	@item fflags @var{flags}
	Set format flags. Some are implemented for a limited number of formats.

	Possible values for input files:
	@table @samp
	@item discardcorrupt
	Discard corrupted packets.
	@item fastseek
	Enable fast, but inaccurate seeks for some formats.
	@item genpts
	Generate missing PTS if DTS is present.
	@item igndts
	Ignore DTS if PTS is set. Inert when nofillin is set.
	@item ignidx
	Ignore index.
	@item keepside (@emph{deprecated},@emph{inert})
	@item nobuffer
	Reduce the latency introduced by buffering during initial input streams analysis.
	@item nofillin
	Do not fill in missing values in packet fields that can be exactly calculated.
	@item noparse
	Disable AVParsers, this needs @code{+nofillin} too.
	@item sortdts
	Try to interleave output packets by DTS. At present, available only for AVIs with an index.
	@end table

	Possible values for output files:
	@table @samp
	@item autobsf
	Automatically apply bitstream filters as required by the output format. Enabled by default.
	@item bitexact
	Only write platform-, build- and time-independent data.
	This ensures that file and data checksums are reproducible and match between
	platforms. Its primary use is for regression testing.
	@item flush_packets
	Write out packets immediately.
	@item latm (@emph{deprecated},@emph{inert})
	@item shortest
	Stop muxing at the end of the shortest stream.
	It may be needed to increase max_interleave_delta to avoid flushing the longer
	streams before EOF.
	@end table

	@item seek2any @var{integer} (@emph{input})
	Allow seeking to non-keyframes on demuxer level when supported if set to 1.
	Default is 0.

	@item analyzeduration @var{integer} (@emph{input})
	Specify how many microseconds are analyzed to probe the input. A
	higher value will enable detecting more accurate information, but will
	increase latency. It defaults to 5,000,000 microseconds = 5 seconds.

	@item cryptokey @var{hexadecimal string} (@emph{input})
	Set decryption key.

	@item indexmem @var{integer} (@emph{input})
	Set max memory used for timestamp index (per stream).

	@item rtbufsize @var{integer} (@emph{input})
	Set max memory used for buffering real-time frames.

	@item fdebug @var{flags} (@emph{input/output})
	Print specific debug info.

	Possible values:
	@table @samp
	@item ts
	@end table

	@item max_delay @var{integer} (@emph{input/output})
	Set maximum muxing or demuxing delay in microseconds.

	@item fpsprobesize @var{integer} (@emph{input})
	Set number of frames used to probe fps.

	@item audio_preload @var{integer} (@emph{output})
	Set microseconds by which audio packets should be interleaved earlier.

	@item chunk_duration @var{integer} (@emph{output})
	Set microseconds for each chunk.

	@item chunk_size @var{integer} (@emph{output})
	Set size in bytes for each chunk.

	@item err_detect, f_err_detect @var{flags} (@emph{input})
	Set error detection flags. @code{f_err_detect} is deprecated and
	should be used only via the @command{ffmpeg} tool.

	Possible values:
	@table @samp
	@item crccheck
	Verify embedded CRCs.
	@item bitstream
	Detect bitstream specification deviations.
	@item buffer
	Detect improper bitstream length.
	@item explode
	Abort decoding on minor error detection.
	@item careful
	Consider things that violate the spec and have not been seen in the
	wild as errors.
	@item compliant
	Consider all spec non compliancies as errors.
	@item aggressive
	Consider things that a sane encoder should not do as an error.
	@end table

	@item max_interleave_delta @var{integer} (@emph{output})
	Set maximum buffering duration for interleaving. The duration is
	expressed in microseconds, and defaults to 10000000 (10 seconds).

	To ensure all the streams are interleaved correctly, libavformat will
	wait until it has at least one packet for each stream before actually
	writing any packets to the output file. When some streams are
	"sparse" (i.e. there are large gaps between successive packets), this
	can result in excessive buffering.

	This field specifies the maximum difference between the timestamps of the
	first and the last packet in the muxing queue, above which libavformat
	will output a packet regardless of whether it has queued a packet for all
	the streams.

	If set to 0, libavformat will continue buffering packets until it has
	a packet for each stream, regardless of the maximum timestamp
	difference between the buffered packets.

	@item use_wallclock_as_timestamps @var{integer} (@emph{input})
	Use wallclock as timestamps if set to 1. Default is 0.

	@item avoid_negative_ts @var{integer} (@emph{output})

	Possible values:
	@table @samp
	@item make_non_negative
	Shift timestamps to make them non-negative.
	Also note that this affects only leading negative timestamps, and not
	non-monotonic negative timestamps.
	@item make_zero
	Shift timestamps so that the first timestamp is 0.
	@item auto (default)
	Enables shifting when required by the target format.
	@item disabled
	Disables shifting of timestamp.
	@end table

	When shifting is enabled, all output timestamps are shifted by the
	same amount. Audio, video, and subtitles desynching and relative
	timestamp differences are preserved compared to how they would have
	been without shifting.

	@item skip_initial_bytes @var{integer} (@emph{input})
	Set number of bytes to skip before reading header and frames if set to 1.
	Default is 0.

	@item correct_ts_overflow @var{integer} (@emph{input})
	Correct single timestamp overflows if set to 1. Default is 1.

	@item flush_packets @var{integer} (@emph{output})
	Flush the underlying I/O stream after each packet. Default is -1 (auto), which
	means that the underlying protocol will decide, 1 enables it, and has the
	effect of reducing the latency, 0 disables it and may increase IO throughput in
	some cases.

	@item output_ts_offset @var{offset} (@emph{output})
	Set the output time offset.

	@var{offset} must be a time duration specification,
	see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.

	The offset is added by the muxer to the output timestamps.

	Specifying a positive offset means that the corresponding streams are
	delayed bt the time duration specified in @var{offset}. Default value
	is @code{0} (meaning that no offset is applied).

	@item format_whitelist @var{list} (@emph{input})
	"," separated list of allowed demuxers. By default all are allowed.

	@item dump_separator @var{string} (@emph{input})
	Separator used to separate the fields printed on the command line about the
	Stream parameters.
	For example, to separate the fields with newlines and indentation:
	@example
	ffprobe -dump_separator "
	" -i ~/videos/matrixbench_mpeg2.mpg
	@end example

	@item max_streams @var{integer} (@emph{input})
	Specifies the maximum number of streams. This can be used to reject files that
	would require too many resources due to a large number of streams.

	@item skip_estimate_duration_from_pts @var{bool} (@emph{input})
	Skip estimation of input duration when calculated using PTS.
	At present, applicable for MPEG-PS and MPEG-TS.

	@item strict, f_strict @var{integer} (@emph{input/output})
	Specify how strictly to follow the standards. @code{f_strict} is deprecated and
	should be used only via the @command{ffmpeg} tool.

	Possible values:
	@table @samp
	@item very
	strictly conform to an older more strict version of the spec or reference software
	@item strict
	strictly conform to all the things in the spec no matter what consequences
	@item normal

	@item unofficial
	allow unofficial extensions
	@item experimental
	allow non standardized experimental things, experimental
	(unfinished/work in progress/not well tested) decoders and encoders.
	Note: experimental decoders can pose a security risk, do not use this for
	decoding untrusted input.
	@end table

	@end table

	@c man end FORMAT OPTIONS

	@anchor{Format stream specifiers}
	@section Format stream specifiers

	Format stream specifiers allow selection of one or more streams that
	match specific properties.

	The exact semantics of stream specifiers is defined by the
	@code{avformat_match_stream_specifier()} function declared in the
	@file{libavformat/avformat.h} header and documented in the
	@ref{Stream specifiers,,Stream specifiers section in the ffmpeg(1) manual,ffmpeg}.

	@ifclear config-writeonly
	@include demuxers.texi
	@end ifclear
	@ifclear config-readonly
	@include muxers.texi
	@end ifclear
	@include metadata.texi