159 lines
5.0 KiB
Plaintext
159 lines
5.0 KiB
Plaintext
All the numerical options, if not specified otherwise, accept in input
|
|
a string representing a number, which may contain one of the
|
|
International System number postfixes, for example 'K', 'M', 'G'.
|
|
If 'i' is appended after the postfix, powers of 2 are used instead of
|
|
powers of 10. The 'B' postfix multiplies the value for 8, and can be
|
|
appended after another postfix or used alone. This allows using for
|
|
example 'KB', 'MiB', 'G' and 'B' as postfix.
|
|
|
|
Options which do not take arguments are boolean options, and set the
|
|
corresponding value to true. They can be set to false by prefixing
|
|
with "no" the option name, for example using "-nofoo" in the
|
|
command line will set to false the boolean option with name "foo".
|
|
|
|
@anchor{Stream specifiers}
|
|
@section Stream specifiers
|
|
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
|
|
are used to precisely specify which stream(s) does a given option belong to.
|
|
|
|
A stream specifier is a string generally appended to the option name and
|
|
separated from it by a colon. E.g. @code{-codec:a:1 ac3} option contains
|
|
@code{a:1} stream specifer, which matches the second audio stream. Therefore it
|
|
would select the ac3 codec for the second audio stream.
|
|
|
|
A stream specifier can match several stream, the option is then applied to all
|
|
of them. E.g. the stream specifier in @code{-b:a 128k} matches all audio
|
|
streams.
|
|
|
|
An empty stream specifier matches all streams, for example @code{-codec copy}
|
|
or @code{-codec: copy} would copy all the streams without reencoding.
|
|
|
|
Possible forms of stream specifiers are:
|
|
@table @option
|
|
@item @var{stream_index}
|
|
Matches the stream with this index. E.g. @code{-threads:1 4} would set the
|
|
thread count for the second stream to 4.
|
|
@item @var{stream_type}[:@var{stream_index}]
|
|
@var{stream_type} is one of: 'v' for video, 'a' for audio, 's' for subtitle,
|
|
'd' for data and 't' for attachments. If @var{stream_index} is given, then
|
|
matches stream number @var{stream_index} of this type. Otherwise matches all
|
|
streams of this type.
|
|
@item p:@var{program_id}[:@var{stream_index}]
|
|
If @var{stream_index} is given, then matches stream number @var{stream_index} in
|
|
program with id @var{program_id}. Otherwise matches all streams in this program.
|
|
@end table
|
|
@section Generic options
|
|
|
|
These options are shared amongst the av* tools.
|
|
|
|
@table @option
|
|
|
|
@item -L
|
|
Show license.
|
|
|
|
@item -h, -?, -help, --help
|
|
Show help.
|
|
|
|
@item -version
|
|
Show version.
|
|
|
|
@item -formats
|
|
Show available formats.
|
|
|
|
The fields preceding the format names have the following meanings:
|
|
@table @samp
|
|
@item D
|
|
Decoding available
|
|
@item E
|
|
Encoding available
|
|
@end table
|
|
|
|
@item -codecs
|
|
Show available codecs.
|
|
|
|
The fields preceding the codec names have the following meanings:
|
|
@table @samp
|
|
@item D
|
|
Decoding available
|
|
@item E
|
|
Encoding available
|
|
@item V/A/S
|
|
Video/audio/subtitle codec
|
|
@item S
|
|
Codec supports slices
|
|
@item D
|
|
Codec supports direct rendering
|
|
@item T
|
|
Codec can handle input truncated at random locations instead of only at frame boundaries
|
|
@end table
|
|
|
|
@item -bsfs
|
|
Show available bitstream filters.
|
|
|
|
@item -protocols
|
|
Show available protocols.
|
|
|
|
@item -filters
|
|
Show available libavfilter filters.
|
|
|
|
@item -pix_fmts
|
|
Show available pixel formats.
|
|
|
|
@item -sample_fmts
|
|
Show available sample formats.
|
|
|
|
@item -loglevel @var{loglevel} | -v @var{loglevel}
|
|
Set the logging level used by the library.
|
|
@var{loglevel} is a number or a string containing one of the following values:
|
|
@table @samp
|
|
@item quiet
|
|
@item panic
|
|
@item fatal
|
|
@item error
|
|
@item warning
|
|
@item info
|
|
@item verbose
|
|
@item debug
|
|
@end table
|
|
|
|
By default the program logs to stderr, if coloring is supported by the
|
|
terminal, colors are used to mark errors and warnings. Log coloring
|
|
can be disabled setting the environment variable
|
|
@env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
|
|
the environment variable @env{AV_LOG_FORCE_COLOR}.
|
|
The use of the environment variable @env{NO_COLOR} is deprecated and
|
|
will be dropped in a following Libav version.
|
|
|
|
@end table
|
|
|
|
@section AVOptions
|
|
|
|
These options are provided directly by the libavformat, libavdevice and
|
|
libavcodec libraries. To see the list of available AVOptions, use the
|
|
@option{-help} option. They are separated into two categories:
|
|
@table @option
|
|
@item generic
|
|
These options can be set for any container, codec or device. Generic options
|
|
are listed under AVFormatContext options for containers/devices and under
|
|
AVCodecContext options for codecs.
|
|
@item private
|
|
These options are specific to the given container, device or codec. Private
|
|
options are listed under their corresponding containers/devices/codecs.
|
|
@end table
|
|
|
|
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
|
|
an MP3 file, use the @option{id3v2_version} private option of the MP3
|
|
muxer:
|
|
@example
|
|
avconv -i input.flac -id3v2_version 3 out.mp3
|
|
@end example
|
|
|
|
All codec AVOptions are obviously per-stream, so the chapter on stream
|
|
specifiers applies to them
|
|
|
|
Note @option{-nooption} syntax cannot be used for boolean AVOptions,
|
|
use @option{-option 0}/@option{-option 1}.
|
|
|
|
Note2 old undocumented way of specifying per-stream AVOptions by prepending
|
|
v/a/s to the options name is now obsolete and will be removed soon.
|