|
|
|
@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 allow to detect 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 packetsize @var{integer} (@emph{output})
|
|
|
|
Set packet size.
|
|
|
|
|
|
|
|
@item fflags @var{flags} (@emph{input/output})
|
|
|
|
Set format flags.
|
|
|
|
|
|
|
|
Possible values:
|
|
|
|
@table @samp
|
|
|
|
@item ignidx
|
|
|
|
Ignore index.
|
|
|
|
@item genpts
|
|
|
|
Generate PTS.
|
|
|
|
@item nofillin
|
|
|
|
Do not fill in missing values that can be exactly calculated.
|
|
|
|
@item noparse
|
|
|
|
Disable AVParsers, this needs @code{+nofillin} too.
|
|
|
|
@item igndts
|
|
|
|
Ignore DTS.
|
|
|
|
@item discardcorrupt
|
|
|
|
Discard corrupted frames.
|
|
|
|
@item sortdts
|
|
|
|
Try to interleave output packets by DTS.
|
|
|
|
@item keepside
|
|
|
|
Do not merge side data.
|
|
|
|
@item latm
|
|
|
|
Enable RTP MP4A-LATM payload.
|
|
|
|
@item nobuffer
|
|
|
|
Reduce the latency introduced by optional buffering
|
|
|
|
@end table
|
|
|
|
|
|
|
|
@item analyzeduration @var{integer} (@emph{input})
|
|
|
|
Specify how many microseconds are analyzed to probe the input. A
|
|
|
|
higher value will allow to detect 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 use_wallclock_as_timestamps @var{integer} (@emph{input})
|
|
|
|
Use wallclock as timestamps.
|
|
|
|
|
|
|
|
@item avoid_negative_ts @var{integer} (@emph{output})
|
|
|
|
Shift timestamps to make them non-negative. A value of 1 enables shifting,
|
|
|
|
a value of 0 disables it, the default value of -1 enables shifting
|
|
|
|
when required by the target format.
|
|
|
|
|
|
|
|
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.
|
|
|
|
|
|
|
|
Also note that this affects only leading negative timestamps, and not
|
|
|
|
non-monotonic negative timestamps.
|
|
|
|
|
|
|
|
@item flush_packets @var{integer} (@emph{output})
|
|
|
|
Flush the underlying I/O stream after each packet. Default 1 enables it, and
|
|
|
|
has the effect of reducing the latency; 0 disables it and may slightly
|
|
|
|
increase performance in some cases.
|
|
|
|
@end table
|
|
|
|
|
|
|
|
@c man end FORMAT OPTIONS
|
|
|
|
|
|
|
|
@include demuxers.texi
|
|
|
|
@include muxers.texi
|
|
|
|
@include metadata.texi
|