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  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.
  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".
  13. @anchor{Stream specifiers}
  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.
  17. A stream specifier is a string generally appended to the option name and
  18. separated from it by a colon. E.g. @code{-codec:a:1 ac3} option contains
  19. @code{a:1} stream specifer, which matches the second audio stream. Therefore it
  20. would select the ac3 codec for the second audio stream.
  21. A stream specifier can match several stream, the option is then applied to all
  22. of them. E.g. the stream specifier in @code{-b:a 128k} matches all audio
  23. streams.
  24. An empty stream specifier matches all streams, for example @code{-codec copy}
  25. or @code{-codec: copy} would copy all the streams without reencoding.
  26. Possible forms of stream specifiers are:
  27. @table @option
  28. @item @var{stream_index}
  29. Matches the stream with this index. E.g. @code{-threads:1 4} would set the
  30. thread count for the second stream to 4.
  31. @item @var{stream_type}[:@var{stream_index}]
  32. @var{stream_type} is one of: 'v' for video, 'a' for audio, 's' for subtitle,
  33. 'd' for data and 't' for attachments. If @var{stream_index} is given, then
  34. matches stream number @var{stream_index} of this type. Otherwise matches all
  35. streams of this type.
  36. @item p:@var{program_id}[:@var{stream_index}]
  37. If @var{stream_index} is given, then matches stream number @var{stream_index} in
  38. program with id @var{program_id}. Otherwise matches all streams in this program.
  39. @end table
  40. @section Generic options
  41. These options are shared amongst the av* tools.
  42. @table @option
  43. @item -L
  44. Show license.
  45. @item -h, -?, -help, --help [@var{arg}]
  46. Show help. An optional parameter may be specified to print help about a specific
  47. item.
  48. Possible values of @var{arg} are:
  49. @table @option
  50. @item decoder=@var{decoder_name}
  51. Print detailed information about the decoder named @var{decoder_name}. Use the
  52. @option{-decoders} option to get a list of all decoders.
  53. @item encoder=@var{encoder_name}
  54. Print detailed information about the encoder named @var{encoder_name}. Use the
  55. @option{-encoders} option to get a list of all encoders.
  56. @item demuxer=@var{demuxer_name}
  57. Print detailed information about the demuxer named @var{demuxer_name}. Use the
  58. @option{-formats} option to get a list of all demuxers and muxers.
  59. @item muxer=@var{muxer_name}
  60. Print detailed information about the muxer named @var{muxer_name}. Use the
  61. @option{-formats} option to get a list of all muxers and demuxers.
  62. @end table
  63. @item -version
  64. Show version.
  65. @item -formats
  66. Show available formats.
  67. The fields preceding the format names have the following meanings:
  68. @table @samp
  69. @item D
  70. Decoding available
  71. @item E
  72. Encoding available
  73. @end table
  74. @item -codecs
  75. Show all codecs known to libavcodec.
  76. Note that the term 'codec' is used throughout this documentation as a shortcut
  77. for what is more correctly called a media bitstream format.
  78. @item -decoders
  79. Show available decoders.
  80. @item -encoders
  81. Show all available encoders.
  82. @item -bsfs
  83. Show available bitstream filters.
  84. @item -protocols
  85. Show available protocols.
  86. @item -filters
  87. Show available libavfilter filters.
  88. @item -pix_fmts
  89. Show available pixel formats.
  90. @item -sample_fmts
  91. Show available sample formats.
  92. @item -loglevel @var{loglevel} | -v @var{loglevel}
  93. Set the logging level used by the library.
  94. @var{loglevel} is a number or a string containing one of the following values:
  95. @table @samp
  96. @item quiet
  97. @item panic
  98. @item fatal
  99. @item error
  100. @item warning
  101. @item info
  102. @item verbose
  103. @item debug
  104. @end table
  105. By default the program logs to stderr, if coloring is supported by the
  106. terminal, colors are used to mark errors and warnings. Log coloring
  107. can be disabled setting the environment variable
  108. @env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
  109. the environment variable @env{AV_LOG_FORCE_COLOR}.
  110. The use of the environment variable @env{NO_COLOR} is deprecated and
  111. will be dropped in a following Libav version.
  112. @end table
  113. @section AVOptions
  114. These options are provided directly by the libavformat, libavdevice and
  115. libavcodec libraries. To see the list of available AVOptions, use the
  116. @option{-help} option. They are separated into two categories:
  117. @table @option
  118. @item generic
  119. These options can be set for any container, codec or device. Generic options
  120. are listed under AVFormatContext options for containers/devices and under
  121. AVCodecContext options for codecs.
  122. @item private
  123. These options are specific to the given container, device or codec. Private
  124. options are listed under their corresponding containers/devices/codecs.
  125. @end table
  126. For example to write an ID3v2.3 header instead of a default ID3v2.4 to
  127. an MP3 file, use the @option{id3v2_version} private option of the MP3
  128. muxer:
  129. @example
  130. avconv -i input.flac -id3v2_version 3 out.mp3
  131. @end example
  132. All codec AVOptions are obviously per-stream, so the chapter on stream
  133. specifiers applies to them
  134. Note @option{-nooption} syntax cannot be used for boolean AVOptions,
  135. use @option{-option 0}/@option{-option 1}.
  136. Note2 old undocumented way of specifying per-stream AVOptions by prepending
  137. v/a/s to the options name is now obsolete and will be removed soon.
  138. @include avoptions_codec.texi
  139. @include avoptions_format.texi