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 SI unit prefixes, for example 'K', 'M', 'G'.
4 If 'i' is appended after the prefix, binary prefixes are used,
5 which are based on powers of 1024 instead of powers of 1000.
6 The 'B' postfix multiplies the value by 8, and can be
7 appended after a unit prefix or used alone. This allows using for
8 example 'KB', 'MiB', 'G' and 'B' as number postfix.
10 Options which do not take arguments are boolean options, and set the
11 corresponding value to true. They can be set to false by prefixing
12 with "no" the option name, for example using "-nofoo" in the
13 command line will set to false the boolean option with name "foo".
15 @anchor{Stream specifiers}
16 @section Stream specifiers
17 Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
18 are used to precisely specify which stream(s) does a given option belong to.
20 A stream specifier is a string generally appended to the option name and
21 separated from it by a colon. E.g. @code{-codec:a:1 ac3} option contains
22 @code{a:1} stream specifer, which matches the second audio stream. Therefore it
23 would select the ac3 codec for the second audio stream.
25 A stream specifier can match several stream, the option is then applied to all
26 of them. E.g. the stream specifier in @code{-b:a 128k} matches all audio
29 An empty stream specifier matches all streams, for example @code{-codec copy}
30 or @code{-codec: copy} would copy all the streams without reencoding.
32 Possible forms of stream specifiers are:
34 @item @var{stream_index}
35 Matches the stream with this index. E.g. @code{-threads:1 4} would set the
36 thread count for the second stream to 4.
37 @item @var{stream_type}[:@var{stream_index}]
38 @var{stream_type} is one of: 'v' for video, 'a' for audio, 's' for subtitle,
39 'd' for data and 't' for attachments. If @var{stream_index} is given, then
40 matches stream number @var{stream_index} of this type. Otherwise matches all
42 @item p:@var{program_id}[:@var{stream_index}]
43 If @var{stream_index} is given, then matches stream number @var{stream_index} in
44 program with id @var{program_id}. Otherwise matches all streams in this program.
46 @section Generic options
48 These options are shared amongst the av* tools.
55 @item -h, -?, -help, --help [@var{arg}]
56 Show help. An optional parameter may be specified to print help about a specific
59 Possible values of @var{arg} are:
61 @item decoder=@var{decoder_name}
62 Print detailed information about the decoder named @var{decoder_name}. Use the
63 @option{-decoders} option to get a list of all decoders.
65 @item encoder=@var{encoder_name}
66 Print detailed information about the encoder named @var{encoder_name}. Use the
67 @option{-encoders} option to get a list of all encoders.
69 @item demuxer=@var{demuxer_name}
70 Print detailed information about the demuxer named @var{demuxer_name}. Use the
71 @option{-formats} option to get a list of all demuxers and muxers.
73 @item muxer=@var{muxer_name}
74 Print detailed information about the muxer named @var{muxer_name}. Use the
75 @option{-formats} option to get a list of all muxers and demuxers.
77 @item filter=@var{filter_name}
78 Print detailed information about the filter name @var{filter_name}. Use the
79 @option{-filters} option to get a list of all filters.
87 Show available formats.
89 The fields preceding the format names have the following meanings:
98 Show all codecs known to libavcodec.
100 Note that the term 'codec' is used throughout this documentation as a shortcut
101 for what is more correctly called a media bitstream format.
104 Show available decoders.
107 Show all available encoders.
110 Show available bitstream filters.
113 Show available protocols.
116 Show available libavfilter filters.
119 Show available pixel formats.
122 Show available sample formats.
124 @item -loglevel @var{loglevel} | -v @var{loglevel}
125 Set the logging level used by the library.
126 @var{loglevel} is a number or a string containing one of the following values:
138 By default the program logs to stderr, if coloring is supported by the
139 terminal, colors are used to mark errors and warnings. Log coloring
140 can be disabled setting the environment variable
141 @env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
142 the environment variable @env{AV_LOG_FORCE_COLOR}.
143 The use of the environment variable @env{NO_COLOR} is deprecated and
144 will be dropped in a following Libav version.
150 These options are provided directly by the libavformat, libavdevice and
151 libavcodec libraries. To see the list of available AVOptions, use the
152 @option{-help} option. They are separated into two categories:
155 These options can be set for any container, codec or device. Generic options
156 are listed under AVFormatContext options for containers/devices and under
157 AVCodecContext options for codecs.
159 These options are specific to the given container, device or codec. Private
160 options are listed under their corresponding containers/devices/codecs.
163 For example to write an ID3v2.3 header instead of a default ID3v2.4 to
164 an MP3 file, use the @option{id3v2_version} private option of the MP3
167 avconv -i input.flac -id3v2_version 3 out.mp3
170 All codec AVOptions are obviously per-stream, so the chapter on stream
171 specifiers applies to them
173 Note @option{-nooption} syntax cannot be used for boolean AVOptions,
174 use @option{-option 0}/@option{-option 1}.
176 Note2 old undocumented way of specifying per-stream AVOptions by prepending
177 v/a/s to the options name is now obsolete and will be removed soon.
179 @include avoptions_codec.texi
180 @include avoptions_format.texi