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 specifer, 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 stream, 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.
47 @section Generic options
49 These options are shared amongst the av* tools.
56 @item -h, -?, -help, --help
63 Show available formats.
65 The fields preceding the format names have the following meanings:
74 Show available codecs.
76 The fields preceding the codec names have the following meanings:
83 Video/audio/subtitle codec
87 Codec supports direct rendering
89 Codec can handle input truncated at random locations instead of only at frame boundaries
93 Show available bitstream filters.
96 Show available protocols.
99 Show available libavfilter filters.
102 Show available pixel formats.
105 Show available sample formats.
107 @item -loglevel @var{loglevel} | -v @var{loglevel}
108 Set the logging level used by the library.
109 @var{loglevel} is a number or a string containing one of the following values:
121 By default the program logs to stderr, if coloring is supported by the
122 terminal, colors are used to mark errors and warnings. Log coloring
123 can be disabled setting the environment variable
124 @env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
125 the environment variable @env{AV_LOG_FORCE_COLOR}.
126 The use of the environment variable @env{NO_COLOR} is deprecated and
127 will be dropped in a following FFmpeg version.
130 Dump full command line and console output to a file named
131 @code{@var{program}-@var{YYYYMMDD}-@var{HHMMSS}.log} in the current
133 This file can be useful for bug reports.
134 It also implies @code{-loglevel verbose}.
136 Note: setting the environment variable @code{FFREPORT} to any value has the
139 @item -cpuflags flags (@emph{global})
140 Allows setting and clearing cpu flags. This option is intended
141 for testing. Do not use it unless you know what you're doing.
143 ffmpeg -cpuflags -sse+mmx ...
144 ffmpeg -cpuflags mmx ...
145 ffmpeg -cpuflags 0 ...
152 These options are provided directly by the libavformat, libavdevice and
153 libavcodec libraries. To see the list of available AVOptions, use the
154 @option{-help} option. They are separated into two categories:
157 These options can be set for any container, codec or device. Generic options
158 are listed under AVFormatContext options for containers/devices and under
159 AVCodecContext options for codecs.
161 These options are specific to the given container, device or codec. Private
162 options are listed under their corresponding containers/devices/codecs.
165 For example to write an ID3v2.3 header instead of a default ID3v2.4 to
166 an MP3 file, use the @option{id3v2_version} private option of the MP3
169 ffmpeg -i input.flac -id3v2_version 3 out.mp3
172 All codec AVOptions are obviously per-stream, so the chapter on stream
173 specifiers applies to them
175 Note @option{-nooption} syntax cannot be used for boolean AVOptions,
176 use @option{-option 0}/@option{-option 1}.
178 Note2 old undocumented way of specifying per-stream AVOptions by prepending
179 v/a/s to the options name is now obsolete and will be removed soon.
181 @include avoptions_codec.texi
182 @include avoptions_format.texi