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.
45 @item i:@var{stream_id}
46 Match the stream by stream id (e.g. PID in MPEG-TS container).
47 @item m:@var{key}[:@var{value}]
48 Matches streams with the metadata tag @var{key} having the specified value. If
49 @var{value} is not given, matches streams that contain the given tag with any
52 Matches streams with usable configuration, the codec must be defined and the
53 essential information such as video dimension or audio sample rate must be present.
55 Note that in @command{avconv}, matching by metadata will only work properly for
58 @section Generic options
60 These options are shared amongst the av* tools.
67 @item -h, -?, -help, --help [@var{arg}]
68 Show help. An optional parameter may be specified to print help about a specific
71 Possible values of @var{arg} are:
73 @item decoder=@var{decoder_name}
74 Print detailed information about the decoder named @var{decoder_name}. Use the
75 @option{-decoders} option to get a list of all decoders.
77 @item encoder=@var{encoder_name}
78 Print detailed information about the encoder named @var{encoder_name}. Use the
79 @option{-encoders} option to get a list of all encoders.
81 @item demuxer=@var{demuxer_name}
82 Print detailed information about the demuxer named @var{demuxer_name}. Use the
83 @option{-formats} option to get a list of all demuxers and muxers.
85 @item muxer=@var{muxer_name}
86 Print detailed information about the muxer named @var{muxer_name}. Use the
87 @option{-formats} option to get a list of all muxers and demuxers.
89 @item filter=@var{filter_name}
90 Print detailed information about the filter name @var{filter_name}. Use the
91 @option{-filters} option to get a list of all filters.
99 Show available formats.
101 The fields preceding the format names have the following meanings:
110 Show all codecs known to libavcodec.
112 Note that the term 'codec' is used throughout this documentation as a shortcut
113 for what is more correctly called a media bitstream format.
116 Show available decoders.
119 Show all available encoders.
122 Show available bitstream filters.
125 Show available protocols.
128 Show available libavfilter filters.
131 Show available pixel formats.
134 Show available sample formats.
136 @item -loglevel @var{loglevel} | -v @var{loglevel}
137 Set the logging level used by the library.
138 @var{loglevel} is a number or a string containing one of the following values:
151 By default the program logs to stderr, if coloring is supported by the
152 terminal, colors are used to mark errors and warnings. Log coloring
153 can be disabled setting the environment variable
154 @env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
155 the environment variable @env{AV_LOG_FORCE_COLOR}.
156 The use of the environment variable @env{NO_COLOR} is deprecated and
157 will be dropped in a following Libav version.
159 @item -cpuflags mask (@emph{global})
160 Set a mask that's applied to autodetected CPU flags. This option is intended
161 for testing. Do not use it unless you know what you're doing.
167 These options are provided directly by the libavformat, libavdevice and
168 libavcodec libraries. To see the list of available AVOptions, use the
169 @option{-help} option. They are separated into two categories:
172 These options can be set for any container, codec or device. Generic options
173 are listed under AVFormatContext options for containers/devices and under
174 AVCodecContext options for codecs.
176 These options are specific to the given container, device or codec. Private
177 options are listed under their corresponding containers/devices/codecs.
180 For example to write an ID3v2.3 header instead of a default ID3v2.4 to
181 an MP3 file, use the @option{id3v2_version} private option of the MP3
184 avconv -i input.flac -id3v2_version 3 out.mp3
187 All codec AVOptions are obviously per-stream, so the chapter on stream
188 specifiers applies to them
190 Note @option{-nooption} syntax cannot be used for boolean AVOptions,
191 use @option{-option 0}/@option{-option 1}.
193 Note2 old undocumented way of specifying per-stream AVOptions by prepending
194 v/a/s to the options name is now obsolete and will be removed soon.
196 @include avoptions_codec.texi
197 @include avoptions_format.texi