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,
37 'd' for data and 't' for attachments. If @var{stream_index} is given, then
38 matches stream number @var{stream_index} of this type. Otherwise matches all
40 @item @var{program_id}[:@var{stream_index}]
41 If @var{stream_index} is given, then matches stream number @var{stream_index} in
42 program with id @var{program_id}. Otherwise matches all streams in this program.
44 @section Generic options
46 These options are shared amongst the av* tools.
53 @item -h, -?, -help, --help
60 Show available formats.
62 The fields preceding the format names have the following meanings:
71 Show available codecs.
73 The fields preceding the codec names have the following meanings:
80 Video/audio/subtitle codec
84 Codec supports direct rendering
86 Codec can handle input truncated at random locations instead of only at frame boundaries
90 Show available bitstream filters.
93 Show available protocols.
96 Show available libavfilter filters.
99 Show available pixel formats.
102 Show available sample formats.
104 @item -loglevel @var{loglevel}
105 Set the logging level used by the library.
106 @var{loglevel} is a number or a string containing one of the following values:
118 By default the program logs to stderr, if coloring is supported by the
119 terminal, colors are used to mark errors and warnings. Log coloring
120 can be disabled setting the environment variable
121 @env{FFMPEG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
122 the environment variable @env{FFMPEG_FORCE_COLOR}.
123 The use of the environment variable @env{NO_COLOR} is deprecated and
124 will be dropped in a following FFmpeg version.
130 These options are provided directly by the libavformat, libavdevice and
131 libavcodec libraries. To see the list of available AVOptions, use the
132 @option{-help} option. They are separated into two categories:
135 These options can be set for any container, codec or device. Generic options are
136 listed under AVFormatContext options for containers/devices and under
137 AVCodecContext options for codecs.
139 These options are specific to the given container, device or codec. Private
140 options are listed under their corresponding containers/devices/codecs.
143 For example to write an ID3v2.3 header instead of a default ID3v2.4 to
144 an MP3 file, use the @option{id3v2_version} private option of the MP3
147 ffmpeg -i input.flac -id3v2_version 3 out.mp3
150 All codec AVOptions are obviously per-stream, so the chapter on stream
151 specifiers applies to them
153 Note -nooption syntax cannot be used for boolean AVOptions, use -option
156 Note2 old undocumented way of specifying per-stream AVOptions by prepending
157 v/a/s to the options name is now obsolete and will be removed soon.