All the numerical options, if not specified otherwise, accept a string representing a number as input, which may be followed by one of the SI unit prefixes, for example: 'K', 'M', or 'G'. If 'i' is appended to the SI unit prefix, the complete prefix will be interpreted as a unit prefix for binary multiplies, which are based on powers of 1024 instead of powers of 1000. Appending 'B' to the SI unit prefix multiplies the value by 8. This allows using, for example: 'KB', 'MiB', 'G' and 'B' as number suffixes. Options which do not take arguments are boolean options, and set the corresponding value to true. They can be set to false by prefixing the option name with "no". For example using "-nofoo" will set the boolean option with name "foo" to false. @anchor{Stream specifiers} @section Stream specifiers Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers are used to precisely specify which stream(s) a given option belongs to. A stream specifier is a string generally appended to the option name and separated from it by a colon. E.g. @code{-codec:a:1 ac3} contains the @code{a:1} stream specifier, which matches the second audio stream. Therefore, it would select the ac3 codec for the second audio stream. A stream specifier can match several streams, so that the option is applied to all of them. E.g. the stream specifier in @code{-b:a 128k} matches all audio streams. An empty stream specifier matches all streams. For example, @code{-codec copy} or @code{-codec: copy} would copy all the streams without reencoding. Possible forms of stream specifiers are: @table @option @item @var{stream_index} Matches the stream with this index. E.g. @code{-threads:1 4} would set the thread count for the second stream to 4. @item @var{stream_type}[:@var{stream_index}] @var{stream_type} is one of following: 'v' for video, 'a' for audio, 's' for subtitle, 'd' for data, and 't' for attachments. If @var{stream_index} is given, then it matches stream number @var{stream_index} of this type. Otherwise, it matches all streams of this type. @item p:@var{program_id}[:@var{stream_index}] If @var{stream_index} is given, then it matches the stream with number @var{stream_index} in the program with the id @var{program_id}. Otherwise, it matches all streams in the program. @item #@var{stream_id} Matches the stream by a format-specific ID. @end table @section Generic options These options are shared amongst the ff* tools. @table @option @item -L Show license. @item -h, -?, -help, --help [@var{arg}] Show help. An optional parameter may be specified to print help about a specific item. Possible values of @var{arg} are: @table @option @item decoder=@var{decoder_name} Print detailed information about the decoder named @var{decoder_name}. Use the @option{-decoders} option to get a list of all decoders. @item encoder=@var{encoder_name} Print detailed information about the encoder named @var{encoder_name}. Use the @option{-encoders} option to get a list of all encoders. @item demuxer=@var{demuxer_name} Print detailed information about the demuxer named @var{demuxer_name}. Use the @option{-formats} option to get a list of all demuxers and muxers. @item muxer=@var{muxer_name} Print detailed information about the muxer named @var{muxer_name}. Use the @option{-formats} option to get a list of all muxers and demuxers. @end table @item -version Show version. @item -formats Show available formats. @item -codecs Show all codecs known to libavcodec. Note that the term 'codec' is used throughout this documentation as a shortcut for what is more correctly called a media bitstream format. @item -decoders Show available decoders. @item -encoders Show all available encoders. @item -bsfs Show available bitstream filters. @item -protocols Show available protocols. @item -filters Show available libavfilter filters. @item -pix_fmts Show available pixel formats. @item -sample_fmts Show available sample formats. @item -layouts Show channel names and standard channel layouts. @item -loglevel @var{loglevel} | -v @var{loglevel} Set the logging level used by the library. @var{loglevel} is a number or a string containing one of the following values: @table @samp @item quiet Show nothing at all; be silent. @item panic Only show fatal errors which could lead the process to crash, such as and assert failure. This is not currently used for anything. @item fatal Only show fatal errors. These are errors after which the process absolutely cannot continue after. @item error Show all errors, including ones which can be recovered from. @item warning Show all warnings and errors. Any message related to possibly incorrect or unexpected events will be shown. @item info Show informative messages during processing. This is in addition to warnings and errors. This is the default value. @item verbose Same as @code{info}, except more verbose. @item debug Show everything, including debugging information. @end table By default the program logs to stderr, if coloring is supported by the terminal, colors are used to mark errors and warnings. Log coloring can be disabled setting the environment variable @env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting the environment variable @env{AV_LOG_FORCE_COLOR}. The use of the environment variable @env{NO_COLOR} is deprecated and will be dropped in a following FFmpeg version. @item -report Dump full command line and console output to a file named @code{@var{program}-@var{YYYYMMDD}-@var{HHMMSS}.log} in the current directory. This file can be useful for bug reports. It also implies @code{-loglevel verbose}. Setting the environment variable @code{FFREPORT} to any value has the same effect. If the value is a ':'-separated key=value sequence, these options will affect the report; options values must be escaped if they contain special characters or the options delimiter ':' (see the ``Quoting and escaping'' section in the ffmpeg-utils manual). The following option is recognized: @table @option @item file set the file name to use for the report; @code{%p} is expanded to the name of the program, @code{%t} is expanded to a timestamp, @code{%%} is expanded to a plain @code{%} @end table Errors in parsing the environment variable are not fatal, and will not appear in the report. @item -cpuflags flags (@emph{global}) Allows setting and clearing cpu flags. This option is intended for testing. Do not use it unless you know what you're doing. @example ffmpeg -cpuflags -sse+mmx ... ffmpeg -cpuflags mmx ... ffmpeg -cpuflags 0 ... @end example Possible flags for this option are: @table @samp @item x86 @table @samp @item mmx @item mmxext @item sse @item sse2 @item sse2slow @item sse3 @item sse3slow @item ssse3 @item atom @item sse4.1 @item sse4.2 @item avx @item xop @item fma4 @item 3dnow @item 3dnowext @item cmov @end table @item ARM @table @samp @item armv5te @item armv6 @item armv6t2 @item vfp @item vfpv3 @item neon @end table @item PowerPC @table @samp @item altivec @end table @item Specific Processors @table @samp @item pentium2 @item pentium3 @item pentium4 @item k6 @item k62 @item athlon @item athlonxp @item k8 @end table @end table @end table @section AVOptions These options are provided directly by the libavformat, libavdevice and libavcodec libraries. To see the list of available AVOptions, use the @option{-help} option. They are separated into two categories: @table @option @item generic These options can be set for any container, codec or device. Generic options are listed under AVFormatContext options for containers/devices and under AVCodecContext options for codecs. @item private These options are specific to the given container, device or codec. Private options are listed under their corresponding containers/devices/codecs. @end table For example to write an ID3v2.3 header instead of a default ID3v2.4 to an MP3 file, use the @option{id3v2_version} private option of the MP3 muxer: @example ffmpeg -i input.flac -id3v2_version 3 out.mp3 @end example All codec AVOptions are obviously per-stream, so the chapter on stream specifiers applies to them Note @option{-nooption} syntax cannot be used for boolean AVOptions, use @option{-option 0}/@option{-option 1}. Note2 old undocumented way of specifying per-stream AVOptions by prepending v/a/s to the options name is now obsolete and will be removed soon.