1 All the numerical options, if not specified otherwise, accept in input
2 a string representing a number, which may contain one of the
3 International System number postfixes, for example 'K', 'M', 'G'.
4 If 'i' is appended after the postfix, powers of 2 are used instead of
5 powers of 10. The 'B' postfix multiplies the value for 8, and can be
6 appended after another postfix or used alone. This allows using for
7 example 'KB', 'MiB', 'G' and 'B' as postfix.
9 Options which do not take arguments are boolean options, and set the
10 corresponding value to true. They can be set to false by prefixing
11 with "no" the option name, for example using "-nofoo" in the
12 commandline will set to false the boolean option with name "foo".
14 @section Stream specifiers
15 Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
16 are used to precisely specify which stream(s) does a given option belong to.
18 A stream specifier is a string generally appended to the option name and
19 separated from it by a colon. E.g. @code{-codec:a:1 ac3} option contains
20 @code{a:1} stream specifer, which matches the second audio stream. Therefore it
21 would select the ac3 codec for the second audio stream.
23 A stream specifier can match several stream, the option is then applied to all
24 of them. E.g. the stream specifier in @code{-b:a 128k} matches all audio
27 An empty stream specifier matches all streams, for example @code{-codec copy}
28 or @code{-codec: copy} would copy all the streams without reencoding.
30 Possible forms of stream specifiers are:
32 @item @var{stream_index}
33 Matches the stream with this index. E.g. @code{-threads:1 4} would set the
34 thread count for the second stream to 4.
35 @item @var{stream_type}[:@var{stream_index}]
36 @var{stream_type} is one of: 'v' for video, 'a' for audio, 's' for subtitle and
37 'd' for data. If @var{stream_index} is given, then matches stream number
38 @var{stream_index} of this type. Otherwise matches all streams of this type.
39 @item @var{program_id}[:@var{stream_index}]
40 If @var{stream_index} is given, then matches stream number @var{stream_index} in
41 program with id @var{program_id}. Otherwise matches all streams in this program.
43 @section Generic options
45 These options are shared amongst the av* tools.
52 @item -h, -?, -help, --help
59 Show available formats.
61 The fields preceding the format names have the following meanings:
70 Show available codecs.
72 The fields preceding the codec names have the following meanings:
79 Video/audio/subtitle codec
83 Codec supports direct rendering
85 Codec can handle input truncated at random locations instead of only at frame boundaries
89 Show available bitstream filters.
92 Show available protocols.
95 Show available libavfilter filters.
98 Show available pixel formats.
101 Show available sample formats.
103 @item -loglevel @var{loglevel}
104 Set the logging level used by the library.
105 @var{loglevel} is a number or a string containing one of the following values:
117 By default the program logs to stderr, if coloring is supported by the
118 terminal, colors are used to mark errors and warnings. Log coloring
119 can be disabled setting the environment variable
120 @env{FFMPEG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
121 the environment variable @env{FFMPEG_FORCE_COLOR}.
122 The use of the environment variable @env{NO_COLOR} is deprecated and
123 will be dropped in a following FFmpeg version.
129 These options are provided directly by the libavformat, libavdevice and
130 libavcodec libraries. To see the list of available AVOptions, use the
131 @option{-help} option. They are separated into two categories:
134 These options can be set for any container, codec or device. Generic options are
135 listed under AVFormatContext options for containers/devices and under
136 AVCodecContext options for codecs.
138 These options are specific to the given container, device or codec. Private
139 options are listed under their corresponding containers/devices/codecs.
142 For example to write an ID3v2.3 header instead of a default ID3v2.4 to
143 an MP3 file, use the @option{id3v2_version} private option of the MP3
146 ffmpeg -i input.flac -id3v2_version 3 out.mp3
149 All codec AVOptions are obviously per-stream, so the chapter on stream
150 specifiers applies to them
152 Note -nooption syntax cannot be used for boolean AVOptions, use -option
155 Note2 old undocumented way of specifying per-stream AVOptions by prepending
156 v/a/s to the options name is now obsolete and will be removed soon.