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![Mulvya](/assets/img/avatar_default.png)
Signed-off-by: Mulvya <mulvya@gmail.com> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
617 lines
21 KiB
Plaintext
617 lines
21 KiB
Plaintext
@chapter Demuxers
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@c man begin DEMUXERS
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Demuxers are configured elements in FFmpeg that can read the
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multimedia streams from a particular type of file.
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When you configure your FFmpeg build, all the supported demuxers
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are enabled by default. You can list all available ones using the
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configure option @code{--list-demuxers}.
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You can disable all the demuxers using the configure option
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@code{--disable-demuxers}, and selectively enable a single demuxer with
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the option @code{--enable-demuxer=@var{DEMUXER}}, or disable it
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with the option @code{--disable-demuxer=@var{DEMUXER}}.
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The option @code{-demuxers} of the ff* tools will display the list of
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enabled demuxers. Use @code{-formats} to view a combined list of
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enabled demuxers and muxers.
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The description of some of the currently available demuxers follows.
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@section aa
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Audible Format 2, 3, and 4 demuxer.
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This demuxer is used to demux Audible Format 2, 3, and 4 (.aa) files.
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@section applehttp
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Apple HTTP Live Streaming demuxer.
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This demuxer presents all AVStreams from all variant streams.
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The id field is set to the bitrate variant index number. By setting
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the discard flags on AVStreams (by pressing 'a' or 'v' in ffplay),
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the caller can decide which variant streams to actually receive.
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The total bitrate of the variant that the stream belongs to is
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available in a metadata key named "variant_bitrate".
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@section apng
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Animated Portable Network Graphics demuxer.
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This demuxer is used to demux APNG files.
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All headers, but the PNG signature, up to (but not including) the first
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fcTL chunk are transmitted as extradata.
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Frames are then split as being all the chunks between two fcTL ones, or
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between the last fcTL and IEND chunks.
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@table @option
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@item -ignore_loop @var{bool}
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Ignore the loop variable in the file if set.
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@item -max_fps @var{int}
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Maximum framerate in frames per second (0 for no limit).
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@item -default_fps @var{int}
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Default framerate in frames per second when none is specified in the file
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(0 meaning as fast as possible).
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@end table
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@section asf
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Advanced Systems Format demuxer.
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This demuxer is used to demux ASF files and MMS network streams.
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@table @option
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@item -no_resync_search @var{bool}
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Do not try to resynchronize by looking for a certain optional start code.
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@end table
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@anchor{concat}
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@section concat
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Virtual concatenation script demuxer.
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This demuxer reads a list of files and other directives from a text file and
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demuxes them one after the other, as if all their packets had been muxed
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together.
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The timestamps in the files are adjusted so that the first file starts at 0
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and each next file starts where the previous one finishes. Note that it is
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done globally and may cause gaps if all streams do not have exactly the same
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length.
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All files must have the same streams (same codecs, same time base, etc.).
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The duration of each file is used to adjust the timestamps of the next file:
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if the duration is incorrect (because it was computed using the bit-rate or
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because the file is truncated, for example), it can cause artifacts. The
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@code{duration} directive can be used to override the duration stored in
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each file.
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@subsection Syntax
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The script is a text file in extended-ASCII, with one directive per line.
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Empty lines, leading spaces and lines starting with '#' are ignored. The
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following directive is recognized:
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@table @option
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@item @code{file @var{path}}
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Path to a file to read; special characters and spaces must be escaped with
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backslash or single quotes.
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All subsequent file-related directives apply to that file.
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@item @code{ffconcat version 1.0}
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Identify the script type and version. It also sets the @option{safe} option
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to 1 if it was -1.
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To make FFmpeg recognize the format automatically, this directive must
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appear exactly as is (no extra space or byte-order-mark) on the very first
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line of the script.
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@item @code{duration @var{dur}}
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Duration of the file. This information can be specified from the file;
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specifying it here may be more efficient or help if the information from the
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file is not available or accurate.
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If the duration is set for all files, then it is possible to seek in the
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whole concatenated video.
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@item @code{inpoint @var{timestamp}}
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In point of the file. When the demuxer opens the file it instantly seeks to the
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specified timestamp. Seeking is done so that all streams can be presented
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successfully at In point.
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This directive works best with intra frame codecs, because for non-intra frame
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ones you will usually get extra packets before the actual In point and the
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decoded content will most likely contain frames before In point too.
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For each file, packets before the file In point will have timestamps less than
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the calculated start timestamp of the file (negative in case of the first
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file), and the duration of the files (if not specified by the @code{duration}
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directive) will be reduced based on their specified In point.
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Because of potential packets before the specified In point, packet timestamps
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may overlap between two concatenated files.
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@item @code{outpoint @var{timestamp}}
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Out point of the file. When the demuxer reaches the specified decoding
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timestamp in any of the streams, it handles it as an end of file condition and
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skips the current and all the remaining packets from all streams.
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Out point is exclusive, which means that the demuxer will not output packets
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with a decoding timestamp greater or equal to Out point.
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This directive works best with intra frame codecs and formats where all streams
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are tightly interleaved. For non-intra frame codecs you will usually get
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additional packets with presentation timestamp after Out point therefore the
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decoded content will most likely contain frames after Out point too. If your
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streams are not tightly interleaved you may not get all the packets from all
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streams before Out point and you may only will be able to decode the earliest
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stream until Out point.
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The duration of the files (if not specified by the @code{duration}
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directive) will be reduced based on their specified Out point.
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@item @code{file_packet_metadata @var{key=value}}
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Metadata of the packets of the file. The specified metadata will be set for
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each file packet. You can specify this directive multiple times to add multiple
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metadata entries.
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@item @code{stream}
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Introduce a stream in the virtual file.
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All subsequent stream-related directives apply to the last introduced
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stream.
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Some streams properties must be set in order to allow identifying the
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matching streams in the subfiles.
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If no streams are defined in the script, the streams from the first file are
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copied.
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@item @code{exact_stream_id @var{id}}
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Set the id of the stream.
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If this directive is given, the string with the corresponding id in the
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subfiles will be used.
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This is especially useful for MPEG-PS (VOB) files, where the order of the
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streams is not reliable.
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@end table
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@subsection Options
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This demuxer accepts the following option:
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@table @option
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@item safe
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If set to 1, reject unsafe file paths. A file path is considered safe if it
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does not contain a protocol specification and is relative and all components
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only contain characters from the portable character set (letters, digits,
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period, underscore and hyphen) and have no period at the beginning of a
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component.
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If set to 0, any file name is accepted.
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The default is 1.
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-1 is equivalent to 1 if the format was automatically
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probed and 0 otherwise.
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@item auto_convert
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If set to 1, try to perform automatic conversions on packet data to make the
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streams concatenable.
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The default is 1.
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Currently, the only conversion is adding the h264_mp4toannexb bitstream
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filter to H.264 streams in MP4 format. This is necessary in particular if
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there are resolution changes.
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@item segment_time_metadata
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If set to 1, every packet will contain the @var{lavf.concat.start_time} and the
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@var{lavf.concat.duration} packet metadata values which are the start_time and
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the duration of the respective file segments in the concatenated output
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expressed in microseconds. The duration metadata is only set if it is known
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based on the concat file.
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The default is 0.
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@end table
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@subsection Examples
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@itemize
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@item
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Use absolute filenames and include some comments:
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@example
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# my first filename
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file /mnt/share/file-1.wav
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# my second filename including whitespace
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file '/mnt/share/file 2.wav'
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# my third filename including whitespace plus single quote
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file '/mnt/share/file 3'\''.wav'
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@end example
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@item
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Allow for input format auto-probing, use safe filenames and set the duration of
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the first file:
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@example
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ffconcat version 1.0
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file file-1.wav
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duration 20.0
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file subdir/file-2.wav
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@end example
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@end itemize
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@section flv, live_flv
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Adobe Flash Video Format demuxer.
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This demuxer is used to demux FLV files and RTMP network streams. In case of live network streams, if you force format, you may use live_flv option instead of flv to survive timestamp discontinuities.
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@example
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ffmpeg -f flv -i myfile.flv ...
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ffmpeg -f live_flv -i rtmp://<any.server>/anything/key ....
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@end example
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@table @option
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@item -flv_metadata @var{bool}
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Allocate the streams according to the onMetaData array content.
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@end table
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@section gif
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Animated GIF demuxer.
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It accepts the following options:
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@table @option
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@item min_delay
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Set the minimum valid delay between frames in hundredths of seconds.
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Range is 0 to 6000. Default value is 2.
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@item max_gif_delay
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Set the maximum valid delay between frames in hundredth of seconds.
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Range is 0 to 65535. Default value is 65535 (nearly eleven minutes),
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the maximum value allowed by the specification.
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@item default_delay
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Set the default delay between frames in hundredths of seconds.
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Range is 0 to 6000. Default value is 10.
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@item ignore_loop
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GIF files can contain information to loop a certain number of times (or
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infinitely). If @option{ignore_loop} is set to 1, then the loop setting
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from the input will be ignored and looping will not occur. If set to 0,
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then looping will occur and will cycle the number of times according to
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the GIF. Default value is 1.
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@end table
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For example, with the overlay filter, place an infinitely looping GIF
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over another video:
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@example
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ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
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@end example
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Note that in the above example the shortest option for overlay filter is
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used to end the output video at the length of the shortest input file,
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which in this case is @file{input.mp4} as the GIF in this example loops
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infinitely.
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@section image2
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Image file demuxer.
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This demuxer reads from a list of image files specified by a pattern.
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The syntax and meaning of the pattern is specified by the
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option @var{pattern_type}.
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The pattern may contain a suffix which is used to automatically
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determine the format of the images contained in the files.
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The size, the pixel format, and the format of each image must be the
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same for all the files in the sequence.
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This demuxer accepts the following options:
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@table @option
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@item framerate
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Set the frame rate for the video stream. It defaults to 25.
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@item loop
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If set to 1, loop over the input. Default value is 0.
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@item pattern_type
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Select the pattern type used to interpret the provided filename.
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@var{pattern_type} accepts one of the following values.
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@table @option
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@item none
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Disable pattern matching, therefore the video will only contain the specified
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image. You should use this option if you do not want to create sequences from
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multiple images and your filenames may contain special pattern characters.
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@item sequence
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Select a sequence pattern type, used to specify a sequence of files
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indexed by sequential numbers.
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A sequence pattern may contain the string "%d" or "%0@var{N}d", which
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specifies the position of the characters representing a sequential
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number in each filename matched by the pattern. If the form
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"%d0@var{N}d" is used, the string representing the number in each
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filename is 0-padded and @var{N} is the total number of 0-padded
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digits representing the number. The literal character '%' can be
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specified in the pattern with the string "%%".
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If the sequence pattern contains "%d" or "%0@var{N}d", the first filename of
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the file list specified by the pattern must contain a number
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inclusively contained between @var{start_number} and
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@var{start_number}+@var{start_number_range}-1, and all the following
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numbers must be sequential.
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For example the pattern "img-%03d.bmp" will match a sequence of
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filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
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@file{img-010.bmp}, etc.; the pattern "i%%m%%g-%d.jpg" will match a
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sequence of filenames of the form @file{i%m%g-1.jpg},
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@file{i%m%g-2.jpg}, ..., @file{i%m%g-10.jpg}, etc.
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Note that the pattern must not necessarily contain "%d" or
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"%0@var{N}d", for example to convert a single image file
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@file{img.jpeg} you can employ the command:
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@example
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ffmpeg -i img.jpeg img.png
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@end example
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@item glob
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Select a glob wildcard pattern type.
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The pattern is interpreted like a @code{glob()} pattern. This is only
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selectable if libavformat was compiled with globbing support.
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@item glob_sequence @emph{(deprecated, will be removed)}
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Select a mixed glob wildcard/sequence pattern.
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If your version of libavformat was compiled with globbing support, and
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the provided pattern contains at least one glob meta character among
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@code{%*?[]@{@}} that is preceded by an unescaped "%", the pattern is
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interpreted like a @code{glob()} pattern, otherwise it is interpreted
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like a sequence pattern.
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All glob special characters @code{%*?[]@{@}} must be prefixed
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with "%". To escape a literal "%" you shall use "%%".
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For example the pattern @code{foo-%*.jpeg} will match all the
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filenames prefixed by "foo-" and terminating with ".jpeg", and
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@code{foo-%?%?%?.jpeg} will match all the filenames prefixed with
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"foo-", followed by a sequence of three characters, and terminating
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with ".jpeg".
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This pattern type is deprecated in favor of @var{glob} and
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@var{sequence}.
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@end table
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Default value is @var{glob_sequence}.
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@item pixel_format
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Set the pixel format of the images to read. If not specified the pixel
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format is guessed from the first image file in the sequence.
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@item start_number
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Set the index of the file matched by the image file pattern to start
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to read from. Default value is 0.
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@item start_number_range
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Set the index interval range to check when looking for the first image
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file in the sequence, starting from @var{start_number}. Default value
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is 5.
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@item ts_from_file
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If set to 1, will set frame timestamp to modification time of image file. Note
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that monotonity of timestamps is not provided: images go in the same order as
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without this option. Default value is 0.
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If set to 2, will set frame timestamp to the modification time of the image file in
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nanosecond precision.
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@item video_size
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Set the video size of the images to read. If not specified the video
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size is guessed from the first image file in the sequence.
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@end table
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@subsection Examples
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@itemize
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@item
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Use @command{ffmpeg} for creating a video from the images in the file
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sequence @file{img-001.jpeg}, @file{img-002.jpeg}, ..., assuming an
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input frame rate of 10 frames per second:
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@example
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ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
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@end example
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@item
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As above, but start by reading from a file with index 100 in the sequence:
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@example
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ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
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@end example
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@item
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Read images matching the "*.png" glob pattern , that is all the files
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terminating with the ".png" suffix:
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@example
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ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
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@end example
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@end itemize
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@section libgme
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The Game Music Emu library is a collection of video game music file emulators.
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See @url{http://code.google.com/p/game-music-emu/} for more information.
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Some files have multiple tracks. The demuxer will pick the first track by
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default. The @option{track_index} option can be used to select a different
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track. Track indexes start at 0. The demuxer exports the number of tracks as
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@var{tracks} meta data entry.
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For very large files, the @option{max_size} option may have to be adjusted.
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@section libopenmpt
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libopenmpt based module demuxer
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See @url{https://lib.openmpt.org/libopenmpt/} for more information.
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Some files have multiple subsongs (tracks) this can be set with the @option{subsong}
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option.
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It accepts the following options:
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@table @option
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@item subsong
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Set the subsong index. This can be either 'all', 'auto', or the index of the
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subsong. Subsong indexes start at 0. The default is 'auto'.
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The default value is to let libopenmpt choose.
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@item layout
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Set the channel layout. Valid values are 1, 2, and 4 channel layouts.
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The default value is STEREO.
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@item sample_rate
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Set the sample rate for libopenmpt to output.
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Range is from 1000 to INT_MAX. The value default is 48000.
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@end table
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@section mov/mp4/3gp/QuickTime
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QuickTime / MP4 demuxer.
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This demuxer accepts the following options:
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@table @option
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@item enable_drefs
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Enable loading of external tracks, disabled by default.
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Enabling this can theoretically leak information in some use cases.
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@item use_absolute_path
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Allows loading of external tracks via absolute paths, disabled by default.
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Enabling this poses a security risk. It should only be enabled if the source
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is known to be non malicious.
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@end table
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@section mpegts
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MPEG-2 transport stream demuxer.
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This demuxer accepts the following options:
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@table @option
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@item resync_size
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Set size limit for looking up a new synchronization. Default value is
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65536.
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@item fix_teletext_pts
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Override teletext packet PTS and DTS values with the timestamps calculated
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from the PCR of the first program which the teletext stream is part of and is
|
|
not discarded. Default value is 1, set this option to 0 if you want your
|
|
teletext packet PTS and DTS values untouched.
|
|
|
|
@item ts_packetsize
|
|
Output option carrying the raw packet size in bytes.
|
|
Show the detected raw packet size, cannot be set by the user.
|
|
|
|
@item scan_all_pmts
|
|
Scan and combine all PMTs. The value is an integer with value from -1
|
|
to 1 (-1 means automatic setting, 1 means enabled, 0 means
|
|
disabled). Default value is -1.
|
|
@end table
|
|
|
|
@section mpjpeg
|
|
|
|
MJPEG encapsulated in multi-part MIME demuxer.
|
|
|
|
This demuxer allows reading of MJPEG, where each frame is represented as a part of
|
|
multipart/x-mixed-replace stream.
|
|
@table @option
|
|
|
|
@item strict_mime_boundary
|
|
Default implementation applies a relaxed standard to multi-part MIME boundary detection,
|
|
to prevent regression with numerous existing endpoints not generating a proper MIME
|
|
MJPEG stream. Turning this option on by setting it to 1 will result in a stricter check
|
|
of the boundary value.
|
|
@end table
|
|
|
|
@section rawvideo
|
|
|
|
Raw video demuxer.
|
|
|
|
This demuxer allows one to read raw video data. Since there is no header
|
|
specifying the assumed video parameters, the user must specify them
|
|
in order to be able to decode the data correctly.
|
|
|
|
This demuxer accepts the following options:
|
|
@table @option
|
|
|
|
@item framerate
|
|
Set input video frame rate. Default value is 25.
|
|
|
|
@item pixel_format
|
|
Set the input video pixel format. Default value is @code{yuv420p}.
|
|
|
|
@item video_size
|
|
Set the input video size. This value must be specified explicitly.
|
|
@end table
|
|
|
|
For example to read a rawvideo file @file{input.raw} with
|
|
@command{ffplay}, assuming a pixel format of @code{rgb24}, a video
|
|
size of @code{320x240}, and a frame rate of 10 images per second, use
|
|
the command:
|
|
@example
|
|
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
|
|
@end example
|
|
|
|
@section sbg
|
|
|
|
SBaGen script demuxer.
|
|
|
|
This demuxer reads the script language used by SBaGen
|
|
@url{http://uazu.net/sbagen/} to generate binaural beats sessions. A SBG
|
|
script looks like that:
|
|
@example
|
|
-SE
|
|
a: 300-2.5/3 440+4.5/0
|
|
b: 300-2.5/0 440+4.5/3
|
|
off: -
|
|
NOW == a
|
|
+0:07:00 == b
|
|
+0:14:00 == a
|
|
+0:21:00 == b
|
|
+0:30:00 off
|
|
@end example
|
|
|
|
A SBG script can mix absolute and relative timestamps. If the script uses
|
|
either only absolute timestamps (including the script start time) or only
|
|
relative ones, then its layout is fixed, and the conversion is
|
|
straightforward. On the other hand, if the script mixes both kind of
|
|
timestamps, then the @var{NOW} reference for relative timestamps will be
|
|
taken from the current time of day at the time the script is read, and the
|
|
script layout will be frozen according to that reference. That means that if
|
|
the script is directly played, the actual times will match the absolute
|
|
timestamps up to the sound controller's clock accuracy, but if the user
|
|
somehow pauses the playback or seeks, all times will be shifted accordingly.
|
|
|
|
@section tedcaptions
|
|
|
|
JSON captions used for @url{http://www.ted.com/, TED Talks}.
|
|
|
|
TED does not provide links to the captions, but they can be guessed from the
|
|
page. The file @file{tools/bookmarklets.html} from the FFmpeg source tree
|
|
contains a bookmarklet to expose them.
|
|
|
|
This demuxer accepts the following option:
|
|
@table @option
|
|
@item start_time
|
|
Set the start time of the TED talk, in milliseconds. The default is 15000
|
|
(15s). It is used to sync the captions with the downloadable videos, because
|
|
they include a 15s intro.
|
|
@end table
|
|
|
|
Example: convert the captions to a format most players understand:
|
|
@example
|
|
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
|
|
@end example
|
|
|
|
@c man end DEMUXERS
|