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 [@var{arg}]
58 Show help. An optional parameter may be specified to print help about a specific
61 Possible values of @var{arg} are:
63 @item decoder=@var{decoder_name}
64 Print detailed information about the decoder named @var{decoder_name}. Use the
65 @option{-decoders} option to get a list of all decoders.
67 @item encoder=@var{encoder_name}
68 Print detailed information about the encoder named @var{encoder_name}. Use the
69 @option{-encoders} option to get a list of all encoders.
71 @item demuxer=@var{demuxer_name}
72 Print detailed information about the demuxer named @var{demuxer_name}. Use the
73 @option{-formats} option to get a list of all demuxers and muxers.
75 @item muxer=@var{muxer_name}
76 Print detailed information about the muxer named @var{muxer_name}. Use the
77 @option{-formats} option to get a list of all muxers and demuxers.
85 Show available formats.
87 The fields preceding the format names have the following meanings:
96 Show all codecs known to libavcodec.
98 Note that the term 'codec' is used throughout this documentation as a shortcut
99 for what is more correctly called a media bitstream format.
102 Show available decoders.
105 Show all available encoders.
108 Show available bitstream filters.
111 Show available protocols.
114 Show available libavfilter filters.
117 Show available pixel formats.
120 Show available sample formats.
123 Show channel names and standard channel layouts.
125 @item -loglevel @var{loglevel} | -v @var{loglevel}
126 Set the logging level used by the library.
127 @var{loglevel} is a number or a string containing one of the following values:
139 By default the program logs to stderr, if coloring is supported by the
140 terminal, colors are used to mark errors and warnings. Log coloring
141 can be disabled setting the environment variable
142 @env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
143 the environment variable @env{AV_LOG_FORCE_COLOR}.
144 The use of the environment variable @env{NO_COLOR} is deprecated and
145 will be dropped in a following FFmpeg version.
148 Dump full command line and console output to a file named
149 @code{@var{program}-@var{YYYYMMDD}-@var{HHMMSS}.log} in the current
151 This file can be useful for bug reports.
152 It also implies @code{-loglevel verbose}.
154 Setting the environment variable @code{FFREPORT} to any value has the same
155 effect. If the value is a ':'-separated key=value sequence, these options
156 will affect the report; options values must be
157 @ref{quoting_and_escaping, escaped} if they contain special characters or
158 the options delimiter ':'. The following option is recognized:
161 set the file name to use for the report; @code{%p} is expanded to the name
162 of the program, @code{%t} is expanded to a timestamp, @code{%%} is expanded
166 Errors in parsing the environment variable are not fatal, and will not
167 appear in the report.
169 @item -cpuflags flags (@emph{global})
170 Allows setting and clearing cpu flags. This option is intended
171 for testing. Do not use it unless you know what you're doing.
173 ffmpeg -cpuflags -sse+mmx ...
174 ffmpeg -cpuflags mmx ...
175 ffmpeg -cpuflags 0 ...
182 These options are provided directly by the libavformat, libavdevice and
183 libavcodec libraries. To see the list of available AVOptions, use the
184 @option{-help} option. They are separated into two categories:
187 These options can be set for any container, codec or device. Generic options
188 are listed under AVFormatContext options for containers/devices and under
189 AVCodecContext options for codecs.
191 These options are specific to the given container, device or codec. Private
192 options are listed under their corresponding containers/devices/codecs.
195 For example to write an ID3v2.3 header instead of a default ID3v2.4 to
196 an MP3 file, use the @option{id3v2_version} private option of the MP3
199 ffmpeg -i input.flac -id3v2_version 3 out.mp3
202 All codec AVOptions are obviously per-stream, so the chapter on stream
203 specifiers applies to them
205 Note @option{-nooption} syntax cannot be used for boolean AVOptions,
206 use @option{-option 0}/@option{-option 1}.
208 Note2 old undocumented way of specifying per-stream AVOptions by prepending
209 v/a/s to the options name is now obsolete and will be removed soon.
211 @include avoptions_codec.texi
212 @include avoptions_format.texi