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 command line will set to false the boolean option with name "foo".
14 @anchor{Stream specifiers}
15 @section Stream specifiers
16 Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
17 are used to precisely specify which stream(s) does a given option belong to.
19 A stream specifier is a string generally appended to the option name and
20 separated from it by a colon. E.g. @code{-codec:a:1 ac3} option contains
21 @code{a:1} stream specifier, which matches the second audio stream. Therefore it
22 would select the ac3 codec for the second audio stream.
24 A stream specifier can match several streams, the option is then applied to all
25 of them. E.g. the stream specifier in @code{-b:a 128k} matches all audio
28 An empty stream specifier matches all streams, for example @code{-codec copy}
29 or @code{-codec: copy} would copy all the streams without reencoding.
31 Possible forms of stream specifiers are:
33 @item @var{stream_index}
34 Matches the stream with this index. E.g. @code{-threads:1 4} would set the
35 thread count for the second stream to 4.
36 @item @var{stream_type}[:@var{stream_index}]
37 @var{stream_type} is one of: 'v' for video, 'a' for audio, 's' for subtitle,
38 'd' for data and 't' for attachments. If @var{stream_index} is given, then
39 matches stream number @var{stream_index} of this type. Otherwise matches all
41 @item p:@var{program_id}[:@var{stream_index}]
42 If @var{stream_index} is given, then matches stream number @var{stream_index} in
43 program with id @var{program_id}. Otherwise matches all streams in this program.
44 @item #@var{stream_id}
45 Matches the stream by format-specific ID.
48 @section Generic options
50 These options are shared amongst the av* tools.
57 @item -h, -?, -help, --help
64 Show available formats.
66 The fields preceding the format names have the following meanings:
75 Show all codecs known to libavcodec.
77 Note that the term 'codec' is used throughout this documentation as a shortcut
78 for what is more correctly called a media bitstream format.
81 Show available decoders.
84 Show all available encoders.
87 Show available bitstream filters.
90 Show available protocols.
93 Show available libavfilter filters.
96 Show available pixel formats.
99 Show available sample formats.
101 @item -loglevel @var{loglevel} | -v @var{loglevel}
102 Set the logging level used by the library.
103 @var{loglevel} is a number or a string containing one of the following values:
115 By default the program logs to stderr, if coloring is supported by the
116 terminal, colors are used to mark errors and warnings. Log coloring
117 can be disabled setting the environment variable
118 @env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
119 the environment variable @env{AV_LOG_FORCE_COLOR}.
120 The use of the environment variable @env{NO_COLOR} is deprecated and
121 will be dropped in a following FFmpeg version.
124 Dump full command line and console output to a file named
125 @code{@var{program}-@var{YYYYMMDD}-@var{HHMMSS}.log} in the current
127 This file can be useful for bug reports.
128 It also implies @code{-loglevel verbose}.
130 Note: setting the environment variable @code{FFREPORT} to any value has the
133 @item -cpuflags flags (@emph{global})
134 Allows setting and clearing cpu flags. This option is intended
135 for testing. Do not use it unless you know what you're doing.
137 ffmpeg -cpuflags -sse+mmx ...
138 ffmpeg -cpuflags mmx ...
139 ffmpeg -cpuflags 0 ...
146 These options are provided directly by the libavformat, libavdevice and
147 libavcodec libraries. To see the list of available AVOptions, use the
148 @option{-help} option. They are separated into two categories:
151 These options can be set for any container, codec or device. Generic options
152 are listed under AVFormatContext options for containers/devices and under
153 AVCodecContext options for codecs.
155 These options are specific to the given container, device or codec. Private
156 options are listed under their corresponding containers/devices/codecs.
159 For example to write an ID3v2.3 header instead of a default ID3v2.4 to
160 an MP3 file, use the @option{id3v2_version} private option of the MP3
163 ffmpeg -i input.flac -id3v2_version 3 out.mp3
166 All codec AVOptions are obviously per-stream, so the chapter on stream
167 specifiers applies to them
169 Note @option{-nooption} syntax cannot be used for boolean AVOptions,
170 use @option{-option 0}/@option{-option 1}.
172 Note2 old undocumented way of specifying per-stream AVOptions by prepending
173 v/a/s to the options name is now obsolete and will be removed soon.
175 @include avoptions_codec.texi
176 @include avoptions_format.texi