ffmpeg/doc/formats.texi

   1 @chapter Format Options
   2 @c man begin FORMAT OPTIONS
   3
   4 The libavformat library provides some generic global options, which
   5 can be set on all the muxers and demuxers. In addition each muxer or
   6 demuxer may support so-called private options, which are specific for
   7 that component.
   8
   9 Options may be set by specifying -@var{option} @var{value} in the
  10 FFmpeg tools, or by setting the value explicitly in the
  11 @code{AVFormatContext} options or using the @file{libavutil/opt.h} API
  12 for programmatic use.
  13
  14 The list of supported options follows:
  15
  16 @table @option
  17 @item avioflags @var{flags} (@emph{input/output})
  18 Possible values:
  19 @table @samp
  20 @item direct
  21 Reduce buffering.
  22 @end table
  23
  24 @item probesize @var{integer} (@emph{input})
  25 Set probing size in bytes, i.e. the size of the data to analyze to get
  26 stream information. A higher value will allow to detect more
  27 information in case it is dispersed into the stream, but will increase
  28 latency. Must be an integer not lesser than 32. It is 5000000 by default.
  29
  30 @item packetsize @var{integer} (@emph{output})
  31 Set packet size.
  32
  33 @item fflags @var{flags} (@emph{input/output})
  34 Set format flags.
  35
  36 Possible values:
  37 @table @samp
  38 @item ignidx
  39 Ignore index.
  40 @item genpts
  41 Generate PTS.
  42 @item nofillin
  43 Do not fill in missing values that can be exactly calculated.
  44 @item noparse
  45 Disable AVParsers, this needs @code{+nofillin} too.
  46 @item igndts
  47 Ignore DTS.
  48 @item discardcorrupt
  49 Discard corrupted frames.
  50 @item sortdts
  51 Try to interleave output packets by DTS.
  52 @item keepside
  53 Do not merge side data.
  54 @item latm
  55 Enable RTP MP4A-LATM payload.
  56 @item nobuffer
  57 Reduce the latency introduced by optional buffering
  58 @item bitexact
  59 Only write platform-, build- and time-independent data.
  60 This ensures that file and data checksums are reproducible and match between
  61 platforms. Its primary use is for regression testing.
  62 @end table
  63
  64 @item seek2any @var{integer} (@emph{input})
  65 Allow seeking to non-keyframes on demuxer level when supported if set to 1.
  66 Default is 0.
  67
  68 @item analyzeduration @var{integer} (@emph{input})
  69 Specify how many microseconds are analyzed to probe the input. A
  70 higher value will allow to detect more accurate information, but will
  71 increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
  72
  73 @item cryptokey @var{hexadecimal string} (@emph{input})
  74 Set decryption key.
  75
  76 @item indexmem @var{integer} (@emph{input})
  77 Set max memory used for timestamp index (per stream).
  78
  79 @item rtbufsize @var{integer} (@emph{input})
  80 Set max memory used for buffering real-time frames.
  81
  82 @item fdebug @var{flags} (@emph{input/output})
  83 Print specific debug info.
  84
  85 Possible values:
  86 @table @samp
  87 @item ts
  88 @end table
  89
  90 @item max_delay @var{integer} (@emph{input/output})
  91 Set maximum muxing or demuxing delay in microseconds.
  92
  93 @item fpsprobesize @var{integer} (@emph{input})
  94 Set number of frames used to probe fps.
  95
  96 @item audio_preload @var{integer} (@emph{output})
  97 Set microseconds by which audio packets should be interleaved earlier.
  98
  99 @item chunk_duration @var{integer} (@emph{output})
 100 Set microseconds for each chunk.
 101
 102 @item chunk_size @var{integer} (@emph{output})
 103 Set size in bytes for each chunk.
 104
 105 @item err_detect, f_err_detect @var{flags} (@emph{input})
 106 Set error detection flags. @code{f_err_detect} is deprecated and
 107 should be used only via the @command{ffmpeg} tool.
 108
 109 Possible values:
 110 @table @samp
 111 @item crccheck
 112 Verify embedded CRCs.
 113 @item bitstream
 114 Detect bitstream specification deviations.
 115 @item buffer
 116 Detect improper bitstream length.
 117 @item explode
 118 Abort decoding on minor error detection.
 119 @item careful
 120 Consider things that violate the spec and have not been seen in the
 121 wild as errors.
 122 @item compliant
 123 Consider all spec non compliancies as errors.
 124 @item aggressive
 125 Consider things that a sane encoder should not do as an error.
 126 @end table
 127
 128 @item use_wallclock_as_timestamps @var{integer} (@emph{input})
 129 Use wallclock as timestamps.
 130
 131 @item avoid_negative_ts @var{integer} (@emph{output})
 132
 133 Possible values:
 134 @table @samp
 135 @item make_non_negative
 136 Shift timestamps to make them non-negative.
 137 Also note that this affects only leading negative timestamps, and not
 138 non-monotonic negative timestamps.
 139 @item make_zero
 140 Shift timestamps so that the first timestamp is 0.
 141 @item auto (default)
 142 Enables shifting when required by the target format.
 143 @item disabled
 144 Disables shifting of timestamp.
 145 @end table
 146
 147 When shifting is enabled, all output timestamps are shifted by the
 148 same amount. Audio, video, and subtitles desynching and relative
 149 timestamp differences are preserved compared to how they would have
 150 been without shifting.
 151
 152 @item skip_initial_bytes @var{integer} (@emph{input})
 153 Set number of bytes to skip before reading header and frames if set to 1.
 154 Default is 0.
 155
 156 @item correct_ts_overflow @var{integer} (@emph{input})
 157 Correct single timestamp overflows if set to 1. Default is 1.
 158
 159 @item flush_packets @var{integer} (@emph{output})
 160 Flush the underlying I/O stream after each packet. Default 1 enables it, and
 161 has the effect of reducing the latency; 0 disables it and may slightly
 162 increase performance in some cases.
 163
 164 @item output_ts_offset @var{offset} (@emph{output})
 165 Set the output time offset.
 166
 167 @var{offset} must be a time duration specification,
 168 see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
 169
 170 The offset is added by the muxer to the output timestamps.
 171
 172 Specifying a positive offset means that the corresponding streams are
 173 delayed bt the time duration specified in @var{offset}. Default value
 174 is @code{0} (meaning that no offset is applied).
 175
 176 @item format_whitelist @var{list} (@emph{input})
 177 "," separated List of allowed demuxers. By default all are allowed.
 178
 179 @item dump_separator @var{string} (@emph{input})
 180 Separator used to separate the fields printed on the command line about the
 181 Stream parameters.
 182 For example to separate the fields with newlines and indention:
 183 @example
 184 ffprobe -dump_separator "
 185                           "  -i ~/videos/matrixbench_mpeg2.mpg
 186 @end example
 187 @end table
 188
 189 @c man end FORMAT OPTIONS
 190
 191 @anchor{Format stream specifiers}
 192 @section Format stream specifiers
 193
 194 Format stream specifiers allow selection of one or more streams that
 195 match specific properties.
 196
 197 Possible forms of stream specifiers are:
 198 @table @option
 199 @item @var{stream_index}
 200 Matches the stream with this index.
 201
 202 @item @var{stream_type}[:@var{stream_index}]
 203 @var{stream_type} is one of following: 'v' for video, 'a' for audio,
 204 's' for subtitle, 'd' for data, and 't' for attachments. If
 205 @var{stream_index} is given, then it matches the stream number
 206 @var{stream_index} of this type. Otherwise, it matches all streams of
 207 this type.
 208
 209 @item p:@var{program_id}[:@var{stream_index}]
 210 If @var{stream_index} is given, then it matches the stream with number
 211 @var{stream_index} in the program with the id
 212 @var{program_id}. Otherwise, it matches all streams in the program.
 213
 214 @item #@var{stream_id}
 215 Matches the stream by a format-specific ID.
 216 @end table
 217
 218 The exact semantics of stream specifiers is defined by the
 219 @code{avformat_match_stream_specifier()} function declared in the
 220 @file{libavformat/avformat.h} header.
 221
 222 @ifclear config-writeonly
 223 @include demuxers.texi
 224 @end ifclear
 225 @ifclear config-readonly
 226 @include muxers.texi
 227 @end ifclear
 228 @include metadata.texi