[libav.git] / doc / avtools-common-opts.texi
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 commandline will set to false the boolean option with name "foo".
14 @section Stream specifiers
15 Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
16 are used to precisely specify which stream(s) does a given option belong to.
18 A stream specifier is a string generally appended to the option name and
19 separated from it by a colon. E.g. @code{-codec:a:1 ac3} option contains
20 @code{a:1} stream specifer, which matches the second audio stream. Therefore it
21 would select the ac3 codec for the second audio stream.
23 A stream specifier can match several stream, the option is then applied to all
24 of them. E.g. the stream specifier in @code{-b:a 128k} matches all audio
25 streams.
27 An empty stream specifier matches all streams, for example @code{-codec copy}
28 or @code{-codec: copy} would copy all the streams without reencoding.
30 Possible forms of stream specifiers are:
31 @table @option
32 @item @var{stream_index}
33 Matches the stream with this index. E.g. @code{-threads:1 4} would set the
34 thread count for the second stream to 4.
35 @item @var{stream_type}[:@var{stream_index}]
36 @var{stream_type} is one of: 'v' for video, 'a' for audio, 's' for subtitle,
37 'd' for data and 't' for attachments. If @var{stream_index} is given, then
38 matches stream number @var{stream_index} of this type. Otherwise matches all
39 streams of this type.
40 @item @var{program_id}[:@var{stream_index}]
41 If @var{stream_index} is given, then matches stream number @var{stream_index} in
42 program with id @var{program_id}. Otherwise matches all streams in this program.
43 @end table
44 @section Generic options
46 These options are shared amongst the av* tools.
48 @table @option
50 @item -L
51 Show license.
53 @item -h, -?, -help, --help
54 Show help.
56 @item -version
57 Show version.
59 @item -formats
60 Show available formats.
62 The fields preceding the format names have the following meanings:
63 @table @samp
64 @item D
65 Decoding available
66 @item E
67 Encoding available
68 @end table
70 @item -codecs
71 Show available codecs.
73 The fields preceding the codec names have the following meanings:
74 @table @samp
75 @item D
76 Decoding available
77 @item E
78 Encoding available
79 @item V/A/S
80 Video/audio/subtitle codec
81 @item S
82 Codec supports slices
83 @item D
84 Codec supports direct rendering
85 @item T
86 Codec can handle input truncated at random locations instead of only at frame boundaries
87 @end table
89 @item -bsfs
90 Show available bitstream filters.
92 @item -protocols
93 Show available protocols.
95 @item -filters
96 Show available libavfilter filters.
98 @item -pix_fmts
99 Show available pixel formats.
101 @item -sample_fmts
102 Show available sample formats.
104 @item -loglevel @var{loglevel}
105 Set the logging level used by the library.
106 @var{loglevel} is a number or a string containing one of the following values:
107 @table @samp
108 @item quiet
109 @item panic
110 @item fatal
111 @item error
112 @item warning
113 @item info
114 @item verbose
115 @item debug
116 @end table
118 By default the program logs to stderr, if coloring is supported by the
119 terminal, colors are used to mark errors and warnings. Log coloring
120 can be disabled setting the environment variable
121 @env{FFMPEG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
122 the environment variable @env{FFMPEG_FORCE_COLOR}.
123 The use of the environment variable @env{NO_COLOR} is deprecated and
124 will be dropped in a following Libav version.
126 @end table
128 @section AVOptions
130 These options are provided directly by the libavformat, libavdevice and
131 libavcodec libraries. To see the list of available AVOptions, use the
132 @option{-help} option. They are separated into two categories:
133 @table @option
134 @item generic
135 These options can be set for any container, codec or device. Generic options are
136 listed under AVFormatContext options for containers/devices and under
137 AVCodecContext options for codecs.
138 @item private
139 These options are specific to the given container, device or codec. Private
140 options are listed under their corresponding containers/devices/codecs.
141 @end table
143 For example to write an ID3v2.3 header instead of a default ID3v2.4 to
144 an MP3 file, use the @option{id3v2_version} private option of the MP3
145 muxer:
146 @example
147 ffmpeg -i input.flac -id3v2_version 3 out.mp3
148 @end example
150 All codec AVOptions are obviously per-stream, so the chapter on stream
151 specifiers applies to them
153 Note -nooption syntax cannot be used for boolean AVOptions, use -option
154 0/-option 1.
156 Note2 old undocumented way of specifying per-stream AVOptions by prepending
157 v/a/s to the options name is now obsolete and will be removed soon.