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  1. \input texinfo @c -*- texinfo -*-
  2. @settitle ffmpeg Documentation
  3. @titlepage
  4. @center @titlefont{ffmpeg Documentation}
  5. @end titlepage
  6. @top
  7. @contents
  8. @chapter Synopsis
  9. The generic syntax is:
  10. @example
  11. @c man begin SYNOPSIS
  12. ffmpeg [global options] [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
  13. @c man end
  14. @end example
  15. @chapter Description
  16. @c man begin DESCRIPTION
  17. ffmpeg is a very fast video and audio converter that can also grab from
  18. a live audio/video source. It can also convert between arbitrary sample
  19. rates and resize video on the fly with a high quality polyphase filter.
  20. ffmpeg reads from an arbitrary number of input "files" (which can be regular
  21. files, pipes, network streams, grabbing devices, etc.), specified by the
  22. @code{-i} option, and writes to an arbitrary number of output "files", which are
  23. specified by a plain output filename. Anything found on the command line which
  24. cannot be interpreted as an option is considered to be an output filename.
  25. Each input or output file can in principle contain any number of streams of
  26. different types (video/audio/subtitle/attachment/data). Allowed number and/or
  27. types of streams can be limited by the container format. Selecting, which
  28. streams from which inputs go into output, is done either automatically or with
  29. the @code{-map} option (see the Stream selection chapter).
  30. To refer to input files in options, you must use their indices (0-based). E.g.
  31. the first input file is @code{0}, the second is @code{1} etc. Similarly, streams
  32. within a file are referred to by their indices. E.g. @code{2:3} refers to the
  33. fourth stream in the third input file. See also the Stream specifiers chapter.
  34. As a general rule, options are applied to the next specified
  35. file. Therefore, order is important, and you can have the same
  36. option on the command line multiple times. Each occurrence is
  37. then applied to the next input or output file.
  38. Exceptions from this rule are the global options (e.g. verbosity level),
  39. which should be specified first.
  40. Do not mix input and output files -- first specify all input files, then all
  41. output files. Also do not mix options which belong to different files. All
  42. options apply ONLY to the next input or output file and are reset between files.
  43. @itemize
  44. @item
  45. To set the video bitrate of the output file to 64kbit/s:
  46. @example
  47. ffmpeg -i input.avi -b:v 64k output.avi
  48. @end example
  49. @item
  50. To force the frame rate of the output file to 24 fps:
  51. @example
  52. ffmpeg -i input.avi -r 24 output.avi
  53. @end example
  54. @item
  55. To force the frame rate of the input file (valid for raw formats only)
  56. to 1 fps and the frame rate of the output file to 24 fps:
  57. @example
  58. ffmpeg -r 1 -i input.m2v -r 24 output.avi
  59. @end example
  60. @end itemize
  61. The format option may be needed for raw input files.
  62. @c man end DESCRIPTION
  63. @chapter Stream selection
  64. @c man begin STREAM SELECTION
  65. By default ffmpeg includes only one stream of each type (video, audio, subtitle)
  66. present in the input files and adds them to each output file. It picks the
  67. "best" of each based upon the following criteria; for video it is the stream
  68. with the highest resolution, for audio the stream with the most channels, for
  69. subtitle it's the first subtitle stream. In the case where several streams of
  70. the same type rate equally, the lowest numbered stream is chosen.
  71. You can disable some of those defaults by using @code{-vn/-an/-sn} options. For
  72. full manual control, use the @code{-map} option, which disables the defaults just
  73. described.
  74. @c man end STREAM SELECTION
  75. @chapter Options
  76. @c man begin OPTIONS
  77. @include avtools-common-opts.texi
  78. @section Main options
  79. @table @option
  80. @item -f @var{fmt} (@emph{input/output})
  81. Force input or output file format. The format is normally auto detected for input
  82. files and guessed from file extension for output files, so this option is not
  83. needed in most cases.
  84. @item -i @var{filename} (@emph{input})
  85. input file name
  86. @item -y (@emph{global})
  87. Overwrite output files without asking.
  88. @item -n (@emph{global})
  89. Do not overwrite output files but exit if file exists.
  90. @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
  91. @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
  92. Select an encoder (when used before an output file) or a decoder (when used
  93. before an input file) for one or more streams. @var{codec} is the name of a
  94. decoder/encoder or a special value @code{copy} (output only) to indicate that
  95. the stream is not to be re-encoded.
  96. For example
  97. @example
  98. ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
  99. @end example
  100. encodes all video streams with libx264 and copies all audio streams.
  101. For each stream, the last matching @code{c} option is applied, so
  102. @example
  103. ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
  104. @end example
  105. will copy all the streams except the second video, which will be encoded with
  106. libx264, and the 138th audio, which will be encoded with libvorbis.
  107. @item -t @var{duration} (@emph{output})
  108. Stop writing the output after its duration reaches @var{duration}.
  109. @var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form.
  110. @item -fs @var{limit_size} (@emph{output})
  111. Set the file size limit, expressed in bytes.
  112. @item -ss @var{position} (@emph{input/output})
  113. When used as an input option (before @code{-i}), seeks in this input file to
  114. @var{position}. When used as an output option (before an output filename),
  115. decodes but discards input until the timestamps reach @var{position}. This is
  116. slower, but more accurate.
  117. @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
  118. @item -itsoffset @var{offset} (@emph{input})
  119. Set the input time offset in seconds.
  120. @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
  121. The offset is added to the timestamps of the input files.
  122. Specifying a positive offset means that the corresponding
  123. streams are delayed by @var{offset} seconds.
  124. @item -timestamp @var{time} (@emph{output})
  125. Set the recording timestamp in the container.
  126. The syntax for @var{time} is:
  127. @example
  128. now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
  129. @end example
  130. If the value is "now" it takes the current time.
  131. Time is local time unless 'Z' or 'z' is appended, in which case it is
  132. interpreted as UTC.
  133. If the year-month-day part is not specified it takes the current
  134. year-month-day.
  135. @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata})
  136. Set a metadata key/value pair.
  137. An optional @var{metadata_specifier} may be given to set metadata
  138. on streams or chapters. See @code{-map_metadata} documentation for
  139. details.
  140. This option overrides metadata set with @code{-map_metadata}. It is
  141. also possible to delete metadata by using an empty value.
  142. For example, for setting the title in the output file:
  143. @example
  144. ffmpeg -i in.avi -metadata title="my title" out.flv
  145. @end example
  146. To set the language of the first audio stream:
  147. @example
  148. ffmpeg -i INPUT -metadata:s:a:1 language=eng OUTPUT
  149. @end example
  150. @item -target @var{type} (@emph{output})
  151. Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
  152. @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or
  153. @code{film-} to use the corresponding standard. All the format options
  154. (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
  155. @example
  156. ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
  157. @end example
  158. Nevertheless you can specify additional options as long as you know
  159. they do not conflict with the standard, as in:
  160. @example
  161. ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
  162. @end example
  163. @item -dframes @var{number} (@emph{output})
  164. Set the number of data frames to record. This is an alias for @code{-frames:d}.
  165. @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream})
  166. Stop writing to the stream after @var{framecount} frames.
  167. @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
  168. @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
  169. Use fixed quality scale (VBR). The meaning of @var{q} is
  170. codec-dependent.
  171. @item -filter[:@var{stream_specifier}] @var{filter_graph} (@emph{output,per-stream})
  172. @var{filter_graph} is a description of the filter graph to apply to
  173. the stream. Use @code{-filters} to show all the available filters
  174. (including also sources and sinks).
  175. See also the @option{-filter_complex} option if you want to create filter graphs
  176. with multiple inputs and/or outputs.
  177. @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
  178. Specify the preset for matching stream(s).
  179. @item -stats (@emph{global})
  180. Print encoding progress/statistics. On by default.
  181. @item -debug_ts (@emph{global})
  182. Print timestamp information. It is off by default. This option is
  183. mostly useful for testing and debugging purposes, and the output
  184. format may change from one version to another, so it should not be
  185. employed by portable scripts.
  186. See also the option @code{-fdebug ts}.
  187. @item -attach @var{filename} (@emph{output})
  188. Add an attachment to the output file. This is supported by a few formats
  189. like Matroska for e.g. fonts used in rendering subtitles. Attachments
  190. are implemented as a specific type of stream, so this option will add
  191. a new stream to the file. It is then possible to use per-stream options
  192. on this stream in the usual way. Attachment streams created with this
  193. option will be created after all the other streams (i.e. those created
  194. with @code{-map} or automatic mappings).
  195. Note that for Matroska you also have to set the mimetype metadata tag:
  196. @example
  197. ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
  198. @end example
  199. (assuming that the attachment stream will be third in the output file).
  200. @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream})
  201. Extract the matching attachment stream into a file named @var{filename}. If
  202. @var{filename} is empty, then the value of the @code{filename} metadata tag
  203. will be used.
  204. E.g. to extract the first attachment to a file named 'out.ttf':
  205. @example
  206. ffmpeg -dump_attachment:t:0 out.ttf INPUT
  207. @end example
  208. To extract all attachments to files determined by the @code{filename} tag:
  209. @example
  210. ffmpeg -dump_attachment:t "" INPUT
  211. @end example
  212. Technical note -- attachments are implemented as codec extradata, so this
  213. option can actually be used to extract extradata from any stream, not just
  214. attachments.
  215. @end table
  216. @section Video Options
  217. @table @option
  218. @item -vframes @var{number} (@emph{output})
  219. Set the number of video frames to record. This is an alias for @code{-frames:v}.
  220. @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
  221. Set frame rate (Hz value, fraction or abbreviation), (default = 25). For output
  222. streams implies @code{-vsync cfr}.
  223. @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
  224. Set frame size. The format is @samp{wxh} (default - same as source).
  225. The following abbreviations are recognized:
  226. @table @samp
  227. @item sqcif
  228. 128x96
  229. @item qcif
  230. 176x144
  231. @item cif
  232. 352x288
  233. @item 4cif
  234. 704x576
  235. @item 16cif
  236. 1408x1152
  237. @item qqvga
  238. 160x120
  239. @item qvga
  240. 320x240
  241. @item vga
  242. 640x480
  243. @item svga
  244. 800x600
  245. @item xga
  246. 1024x768
  247. @item uxga
  248. 1600x1200
  249. @item qxga
  250. 2048x1536
  251. @item sxga
  252. 1280x1024
  253. @item qsxga
  254. 2560x2048
  255. @item hsxga
  256. 5120x4096
  257. @item wvga
  258. 852x480
  259. @item wxga
  260. 1366x768
  261. @item wsxga
  262. 1600x1024
  263. @item wuxga
  264. 1920x1200
  265. @item woxga
  266. 2560x1600
  267. @item wqsxga
  268. 3200x2048
  269. @item wquxga
  270. 3840x2400
  271. @item whsxga
  272. 6400x4096
  273. @item whuxga
  274. 7680x4800
  275. @item cga
  276. 320x200
  277. @item ega
  278. 640x350
  279. @item hd480
  280. 852x480
  281. @item hd720
  282. 1280x720
  283. @item hd1080
  284. 1920x1080
  285. @end table
  286. @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
  287. Set the video display aspect ratio specified by @var{aspect}.
  288. @var{aspect} can be a floating point number string, or a string of the
  289. form @var{num}:@var{den}, where @var{num} and @var{den} are the
  290. numerator and denominator of the aspect ratio. For example "4:3",
  291. "16:9", "1.3333", and "1.7777" are valid argument values.
  292. @item -croptop @var{size}
  293. @item -cropbottom @var{size}
  294. @item -cropleft @var{size}
  295. @item -cropright @var{size}
  296. All the crop options have been removed. Use -vf
  297. crop=width:height:x:y instead.
  298. @item -padtop @var{size}
  299. @item -padbottom @var{size}
  300. @item -padleft @var{size}
  301. @item -padright @var{size}
  302. @item -padcolor @var{hex_color}
  303. All the pad options have been removed. Use -vf
  304. pad=width:height:x:y:color instead.
  305. @item -vn (@emph{output})
  306. Disable video recording.
  307. @item -vcodec @var{codec} (@emph{output})
  308. Set the video codec. This is an alias for @code{-codec:v}.
  309. @item -same_quant
  310. Use same quantizer as source (implies VBR).
  311. Note that this is NOT SAME QUALITY. Do not use this option unless you know you
  312. need it.
  313. @item -pass @var{n}
  314. Select the pass number (1 or 2). It is used to do two-pass
  315. video encoding. The statistics of the video are recorded in the first
  316. pass into a log file (see also the option -passlogfile),
  317. and in the second pass that log file is used to generate the video
  318. at the exact requested bitrate.
  319. On pass 1, you may just deactivate audio and set output to null,
  320. examples for Windows and Unix:
  321. @example
  322. ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
  323. ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
  324. @end example
  325. @item -passlogfile @var{prefix} (@emph{global})
  326. Set two-pass log file name prefix to @var{prefix}, the default file name
  327. prefix is ``ffmpeg2pass''. The complete file name will be
  328. @file{PREFIX-N.log}, where N is a number specific to the output
  329. stream
  330. @item -vlang @var{code}
  331. Set the ISO 639 language code (3 letters) of the current video stream.
  332. @item -vf @var{filter_graph} (@emph{output})
  333. @var{filter_graph} is a description of the filter graph to apply to
  334. the input video.
  335. Use the option "-filters" to show all the available filters (including
  336. also sources and sinks). This is an alias for @code{-filter:v}.
  337. @end table
  338. @section Advanced Video Options
  339. @table @option
  340. @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
  341. Set pixel format. Use @code{-pix_fmts} to show all the supported
  342. pixel formats.
  343. @item -sws_flags @var{flags} (@emph{input/output})
  344. Set SwScaler flags.
  345. @item -vdt @var{n}
  346. Discard threshold.
  347. @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
  348. Rate control override for specific intervals, formatted as "int,int,int"
  349. list separated with slashes. Two first values are the beginning and
  350. end frame numbers, last one is quantizer to use if positive, or quality
  351. factor if negative.
  352. @item -deinterlace
  353. Deinterlace pictures.
  354. This option is deprecated since the deinterlacing is very low quality.
  355. Use the yadif filter with @code{-filter:v yadif}.
  356. @item -ilme
  357. Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
  358. Use this option if your input file is interlaced and you want
  359. to keep the interlaced format for minimum losses.
  360. The alternative is to deinterlace the input stream with
  361. @option{-deinterlace}, but deinterlacing introduces losses.
  362. @item -psnr
  363. Calculate PSNR of compressed frames.
  364. @item -vstats
  365. Dump video coding statistics to @file{vstats_HHMMSS.log}.
  366. @item -vstats_file @var{file}
  367. Dump video coding statistics to @var{file}.
  368. @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
  369. top=1/bottom=0/auto=-1 field first
  370. @item -dc @var{precision}
  371. Intra_dc_precision.
  372. @item -vtag @var{fourcc/tag} (@emph{output})
  373. Force video tag/fourcc. This is an alias for @code{-tag:v}.
  374. @item -qphist (@emph{global})
  375. Show QP histogram
  376. @item -vbsf @var{bitstream_filter}
  377. Deprecated see -bsf
  378. @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
  379. Force key frames at the specified timestamps, more precisely at the first
  380. frames after each specified time.
  381. This option can be useful to ensure that a seek point is present at a
  382. chapter mark or any other designated place in the output file.
  383. The timestamps must be specified in ascending order.
  384. @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
  385. When doing stream copy, copy also non-key frames found at the
  386. beginning.
  387. @end table
  388. @section Audio Options
  389. @table @option
  390. @item -aframes @var{number} (@emph{output})
  391. Set the number of audio frames to record. This is an alias for @code{-frames:a}.
  392. @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
  393. Set the audio sampling frequency. For output streams it is set by
  394. default to the frequency of the corresponding input stream. For input
  395. streams this option only makes sense for audio grabbing devices and raw
  396. demuxers and is mapped to the corresponding demuxer options.
  397. @item -aq @var{q} (@emph{output})
  398. Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
  399. @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
  400. Set the number of audio channels. For output streams it is set by
  401. default to the number of input audio channels. For input streams
  402. this option only makes sense for audio grabbing devices and raw demuxers
  403. and is mapped to the corresponding demuxer options.
  404. @item -an (@emph{output})
  405. Disable audio recording.
  406. @item -acodec @var{codec} (@emph{input/output})
  407. Set the audio codec. This is an alias for @code{-codec:a}.
  408. @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
  409. Set the audio sample format. Use @code{-sample_fmts} to get a list
  410. of supported sample formats.
  411. @end table
  412. @section Advanced Audio options:
  413. @table @option
  414. @item -atag @var{fourcc/tag} (@emph{output})
  415. Force audio tag/fourcc. This is an alias for @code{-tag:a}.
  416. @item -absf @var{bitstream_filter}
  417. Deprecated, see -bsf
  418. @end table
  419. @section Subtitle options:
  420. @table @option
  421. @item -slang @var{code}
  422. Set the ISO 639 language code (3 letters) of the current subtitle stream.
  423. @item -scodec @var{codec} (@emph{input/output})
  424. Set the subtitle codec. This is an alias for @code{-codec:s}.
  425. @item -sn (@emph{output})
  426. Disable subtitle recording.
  427. @item -sbsf @var{bitstream_filter}
  428. Deprecated, see -bsf
  429. @end table
  430. @section Audio/Video grab options
  431. @table @option
  432. @item -isync (@emph{global})
  433. Synchronize read on input.
  434. @end table
  435. @section Advanced options
  436. @table @option
  437. @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
  438. Designate one or more input streams as a source for the output file. Each input
  439. stream is identified by the input file index @var{input_file_id} and
  440. the input stream index @var{input_stream_id} within the input
  441. file. Both indices start at 0. If specified,
  442. @var{sync_file_id}:@var{stream_specifier} sets which input stream
  443. is used as a presentation sync reference.
  444. The first @code{-map} option on the command line specifies the
  445. source for output stream 0, the second @code{-map} option specifies
  446. the source for output stream 1, etc.
  447. A @code{-} character before the stream identifier creates a "negative" mapping.
  448. It disables matching streams from already created mappings.
  449. An alternative @var{[linklabel]} form will map outputs from complex filter
  450. graphs (see the @option{-filter_complex} option) to the output file.
  451. @var{linklabel} must correspond to a defined output link label in the graph.
  452. For example, to map ALL streams from the first input file to output
  453. @example
  454. ffmpeg -i INPUT -map 0 output
  455. @end example
  456. For example, if you have two audio streams in the first input file,
  457. these streams are identified by "0:0" and "0:1". You can use
  458. @code{-map} to select which streams to place in an output file. For
  459. example:
  460. @example
  461. ffmpeg -i INPUT -map 0:1 out.wav
  462. @end example
  463. will map the input stream in @file{INPUT} identified by "0:1" to
  464. the (single) output stream in @file{out.wav}.
  465. For example, to select the stream with index 2 from input file
  466. @file{a.mov} (specified by the identifier "0:2"), and stream with
  467. index 6 from input @file{b.mov} (specified by the identifier "1:6"),
  468. and copy them to the output file @file{out.mov}:
  469. @example
  470. ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
  471. @end example
  472. To select all video and the third audio stream from an input file:
  473. @example
  474. ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
  475. @end example
  476. To map all the streams except the second audio, use negative mappings
  477. @example
  478. ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
  479. @end example
  480. Note that using this option disables the default mappings for this output file.
  481. @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
  482. Map an audio channel from a given input to an output. If
  483. @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will
  484. be mapped on all the audio streams.
  485. Using "-1" instead of
  486. @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
  487. channel.
  488. For example, assuming @var{INPUT} is a stereo audio file, you can switch the
  489. two audio channels with the following command:
  490. @example
  491. ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
  492. @end example
  493. If you want to mute the first channel and keep the second:
  494. @example
  495. ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
  496. @end example
  497. The order of the "-map_channel" option specifies the order of the channels in
  498. the output stream. The output channel layout is guessed from the number of
  499. channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
  500. in combination of "-map_channel" makes the channel gain levels to be updated if
  501. input and output channel layouts don't match (for instance two "-map_channel"
  502. options and "-ac 6").
  503. You can also extract each channel of an input to specific outputs; the following
  504. command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0)
  505. to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs:
  506. @example
  507. ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
  508. @end example
  509. The following example splits the channels of a stereo input into two separate
  510. streams, which are put into the same output file:
  511. @example
  512. ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg
  513. @end example
  514. Note that currently each output stream can only contain channels from a single
  515. input stream; you can't for example use "-map_channel" to pick multiple input
  516. audio channels contained in different streams (from the same or different files)
  517. and merge them into a single output stream. It is therefore not currently
  518. possible, for example, to turn two separate mono streams into a single stereo
  519. stream. However splitting a stereo stream into two single channel mono streams
  520. is possible.
  521. If you need this feature, a possible workaround is to use the @emph{amerge}
  522. filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
  523. mono audio streams into one single stereo channel audio stream (and keep the
  524. video stream), you can use the following command:
  525. @example
  526. ffmpeg -i input.mkv -f lavfi -i "
  527. amovie=input.mkv:si=1 [a1];
  528. amovie=input.mkv:si=2 [a2];
  529. [a1][a2] amerge" -c:a pcm_s16le -c:v copy output.mkv
  530. @end example
  531. @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
  532. Set metadata information of the next output file from @var{infile}. Note that
  533. those are file indices (zero-based), not filenames.
  534. Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
  535. A metadata specifier can have the following forms:
  536. @table @option
  537. @item @var{g}
  538. global metadata, i.e. metadata that applies to the whole file
  539. @item @var{s}[:@var{stream_spec}]
  540. per-stream metadata. @var{stream_spec} is a stream specifier as described
  541. in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
  542. matching stream is copied from. In an output metadata specifier, all matching
  543. streams are copied to.
  544. @item @var{c}:@var{chapter_index}
  545. per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
  546. @item @var{p}:@var{program_index}
  547. per-program metadata. @var{program_index} is the zero-based program index.
  548. @end table
  549. If metadata specifier is omitted, it defaults to global.
  550. By default, global metadata is copied from the first input file,
  551. per-stream and per-chapter metadata is copied along with streams/chapters. These
  552. default mappings are disabled by creating any mapping of the relevant type. A negative
  553. file index can be used to create a dummy mapping that just disables automatic copying.
  554. For example to copy metadata from the first stream of the input file to global metadata
  555. of the output file:
  556. @example
  557. ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
  558. @end example
  559. To do the reverse, i.e. copy global metadata to all audio streams:
  560. @example
  561. ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
  562. @end example
  563. Note that simple @code{0} would work as well in this example, since global
  564. metadata is assumed by default.
  565. @item -map_chapters @var{input_file_index} (@emph{output})
  566. Copy chapters from input file with index @var{input_file_index} to the next
  567. output file. If no chapter mapping is specified, then chapters are copied from
  568. the first input file with at least one chapter. Use a negative file index to
  569. disable any chapter copying.
  570. @item -debug @var{category}
  571. Print specific debug info.
  572. @var{category} is a number or a string containing one of the following values:
  573. @table @samp
  574. @item bitstream
  575. @item buffers
  576. picture buffer allocations
  577. @item bugs
  578. @item dct_coeff
  579. @item er
  580. error recognition
  581. @item mb_type
  582. macroblock (MB) type
  583. @item mmco
  584. memory management control operations (H.264)
  585. @item mv
  586. motion vector
  587. @item pict
  588. picture info
  589. @item pts
  590. @item qp
  591. per-block quantization parameter (QP)
  592. @item rc
  593. rate control
  594. @item skip
  595. @item startcode
  596. @item thread_ops
  597. threading operations
  598. @item vis_mb_type
  599. visualize block types
  600. @item vis_qp
  601. visualize quantization parameter (QP), lower QP are tinted greener
  602. @end table
  603. @item -benchmark (@emph{global})
  604. Show benchmarking information at the end of an encode.
  605. Shows CPU time used and maximum memory consumption.
  606. Maximum memory consumption is not supported on all systems,
  607. it will usually display as 0 if not supported.
  608. @item -benchmark_all (@emph{global})
  609. Show benchmarking information during the encode.
  610. Shows CPU time used in various steps (audio/video encode/decode).
  611. @item -timelimit @var{duration} (@emph{global})
  612. Exit after ffmpeg has been running for @var{duration} seconds.
  613. @item -dump (@emph{global})
  614. Dump each input packet to stderr.
  615. @item -hex (@emph{global})
  616. When dumping packets, also dump the payload.
  617. @item -re (@emph{input})
  618. Read input at native frame rate. Mainly used to simulate a grab device.
  619. @item -loop_input
  620. Loop over the input stream. Currently it works only for image
  621. streams. This option is used for automatic FFserver testing.
  622. This option is deprecated, use -loop 1.
  623. @item -loop_output @var{number_of_times}
  624. Repeatedly loop output for formats that support looping such as animated GIF
  625. (0 will loop the output infinitely).
  626. This option is deprecated, use -loop.
  627. @item -vsync @var{parameter}
  628. Video sync method.
  629. For compatibility reasons old values can be specified as numbers.
  630. Newly added values will have to be specified as strings always.
  631. @table @option
  632. @item 0, passthrough
  633. Each frame is passed with its timestamp from the demuxer to the muxer.
  634. @item 1, cfr
  635. Frames will be duplicated and dropped to achieve exactly the requested
  636. constant framerate.
  637. @item 2, vfr
  638. Frames are passed through with their timestamp or dropped so as to
  639. prevent 2 frames from having the same timestamp.
  640. @item drop
  641. As passthrough but destroys all timestamps, making the muxer generate
  642. fresh timestamps based on frame-rate.
  643. @item -1, auto
  644. Chooses between 1 and 2 depending on muxer capabilities. This is the
  645. default method.
  646. @end table
  647. With -map you can select from which stream the timestamps should be
  648. taken. You can leave either video or audio unchanged and sync the
  649. remaining stream(s) to the unchanged one.
  650. @item -async @var{samples_per_second}
  651. Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
  652. the parameter is the maximum samples per second by which the audio is changed.
  653. -async 1 is a special case where only the start of the audio stream is corrected
  654. without any later correction.
  655. @item -copyts
  656. Copy timestamps from input to output.
  657. @item -copytb @var{mode}
  658. Specify how to set the encoder timebase when stream copying. @var{mode} is an
  659. integer numeric value, and can assume one of the following values:
  660. @table @option
  661. @item 1
  662. Use the demuxer timebase.
  663. The time base is copied to the output encoder from the corresponding input
  664. demuxer. This is sometimes required to avoid non monotonically increasing
  665. timestamps when copying video streams with variable frame rate.
  666. @item 0
  667. Use the decoder timebase.
  668. The time base is copied to the output encoder from the corresponding input
  669. decoder.
  670. @item -1
  671. Try to make the choice automatically, in order to generate a sane output.
  672. @end table
  673. Default value is -1.
  674. @item -shortest
  675. Finish encoding when the shortest input stream ends.
  676. @item -dts_delta_threshold
  677. Timestamp discontinuity delta threshold.
  678. @item -muxdelay @var{seconds} (@emph{input})
  679. Set the maximum demux-decode delay.
  680. @item -muxpreload @var{seconds} (@emph{input})
  681. Set the initial demux-decode delay.
  682. @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
  683. Assign a new stream-id value to an output stream. This option should be
  684. specified prior to the output filename to which it applies.
  685. For the situation where multiple output files exist, a streamid
  686. may be reassigned to a different value.
  687. For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
  688. an output mpegts file:
  689. @example
  690. ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
  691. @end example
  692. @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
  693. Set bitstream filters for matching streams. @var{bistream_filters} is
  694. a comma-separated list of bitstream filters. Use the @code{-bsfs} option
  695. to get the list of bitstream filters.
  696. @example
  697. ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
  698. @end example
  699. @example
  700. ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
  701. @end example
  702. @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
  703. Force a tag/fourcc for matching streams.
  704. @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
  705. Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
  706. (or '.') for drop.
  707. @example
  708. ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
  709. @end example
  710. @item -filter_complex @var{filtergraph} (@emph{global})
  711. Define a complex filter graph, i.e. one with arbitrary number of inputs and/or
  712. outputs. For simple graphs -- those with one input and one output of the same
  713. type -- see the @option{-filter} options. @var{filtergraph} is a description of
  714. the filter graph, as described in @ref{Filtergraph syntax}.
  715. Input link labels must refer to input streams using the
  716. @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map}
  717. uses). If @var{stream_specifier} matches multiple streams, the first one will be
  718. used. An unlabeled input will be connected to the first unused input stream of
  719. the matching type.
  720. Output link labels are referred to with @option{-map}. Unlabeled outputs are
  721. added to the first output file.
  722. For example, to overlay an image over video
  723. @example
  724. ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
  725. '[out]' out.mkv
  726. @end example
  727. Here @code{[0:v]} refers to the first video stream in the first input file,
  728. which is linked to the first (main) input of the overlay filter. Similarly the
  729. first video stream in the second input is linked to the second (overlay) input
  730. of overlay.
  731. Assuming there is only one video stream in each input file, we can omit input
  732. labels, so the above is equivalent to
  733. @example
  734. ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
  735. '[out]' out.mkv
  736. @end example
  737. Furthermore we can omit the output label and the single output from the filter
  738. graph will be added to the output file automatically, so we can simply write
  739. @example
  740. ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
  741. @end example
  742. @end table
  743. @section Preset files
  744. A preset file contains a sequence of @var{option}=@var{value} pairs,
  745. one for each line, specifying a sequence of options which would be
  746. awkward to specify on the command line. Lines starting with the hash
  747. ('#') character are ignored and are used to provide comments. Check
  748. the @file{presets} directory in the FFmpeg source tree for examples.
  749. Preset files are specified with the @code{vpre}, @code{apre},
  750. @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
  751. filename of the preset instead of a preset name as input and can be
  752. used for any kind of codec. For the @code{vpre}, @code{apre}, and
  753. @code{spre} options, the options specified in a preset file are
  754. applied to the currently selected codec of the same type as the preset
  755. option.
  756. The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
  757. preset options identifies the preset file to use according to the
  758. following rules:
  759. First ffmpeg searches for a file named @var{arg}.ffpreset in the
  760. directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
  761. the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
  762. or in a @file{ffpresets} folder along the executable on win32,
  763. in that order. For example, if the argument is @code{libx264-max}, it will
  764. search for the file @file{libx264-max.ffpreset}.
  765. If no such file is found, then ffmpeg will search for a file named
  766. @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
  767. directories, where @var{codec_name} is the name of the codec to which
  768. the preset file options will be applied. For example, if you select
  769. the video codec with @code{-vcodec libx264} and use @code{-vpre max},
  770. then it will search for the file @file{libx264-max.ffpreset}.
  771. @c man end OPTIONS
  772. @chapter Tips
  773. @c man begin TIPS
  774. @itemize
  775. @item
  776. For streaming at very low bitrate application, use a low frame rate
  777. and a small GOP size. This is especially true for RealVideo where
  778. the Linux player does not seem to be very fast, so it can miss
  779. frames. An example is:
  780. @example
  781. ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
  782. @end example
  783. @item
  784. The parameter 'q' which is displayed while encoding is the current
  785. quantizer. The value 1 indicates that a very good quality could
  786. be achieved. The value 31 indicates the worst quality. If q=31 appears
  787. too often, it means that the encoder cannot compress enough to meet
  788. your bitrate. You must either increase the bitrate, decrease the
  789. frame rate or decrease the frame size.
  790. @item
  791. If your computer is not fast enough, you can speed up the
  792. compression at the expense of the compression ratio. You can use
  793. '-me zero' to speed up motion estimation, and '-intra' to disable
  794. motion estimation completely (you have only I-frames, which means it
  795. is about as good as JPEG compression).
  796. @item
  797. To have very low audio bitrates, reduce the sampling frequency
  798. (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
  799. @item
  800. To have a constant quality (but a variable bitrate), use the option
  801. '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
  802. quality).
  803. @end itemize
  804. @c man end TIPS
  805. @chapter Examples
  806. @c man begin EXAMPLES
  807. @section Preset files
  808. A preset file contains a sequence of @var{option=value} pairs, one for
  809. each line, specifying a sequence of options which can be specified also on
  810. the command line. Lines starting with the hash ('#') character are ignored and
  811. are used to provide comments. Empty lines are also ignored. Check the
  812. @file{presets} directory in the FFmpeg source tree for examples.
  813. Preset files are specified with the @code{pre} option, this option takes a
  814. preset name as input. FFmpeg searches for a file named @var{preset_name}.avpreset in
  815. the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
  816. the data directory defined at configuration time (usually @file{$PREFIX/share/ffmpeg})
  817. in that order. For example, if the argument is @code{libx264-max}, it will
  818. search for the file @file{libx264-max.avpreset}.
  819. @section Video and Audio grabbing
  820. If you specify the input format and device then ffmpeg can grab video
  821. and audio directly.
  822. @example
  823. ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
  824. @end example
  825. Or with an ALSA audio source (mono input, card id 1) instead of OSS:
  826. @example
  827. ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
  828. @end example
  829. Note that you must activate the right video source and channel before
  830. launching ffmpeg with any TV viewer such as
  831. @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
  832. have to set the audio recording levels correctly with a
  833. standard mixer.
  834. @section X11 grabbing
  835. Grab the X11 display with ffmpeg via
  836. @example
  837. ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
  838. @end example
  839. 0.0 is display.screen number of your X11 server, same as
  840. the DISPLAY environment variable.
  841. @example
  842. ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
  843. @end example
  844. 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
  845. variable. 10 is the x-offset and 20 the y-offset for the grabbing.
  846. @section Video and Audio file format conversion
  847. Any supported file format and protocol can serve as input to ffmpeg:
  848. Examples:
  849. @itemize
  850. @item
  851. You can use YUV files as input:
  852. @example
  853. ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
  854. @end example
  855. It will use the files:
  856. @example
  857. /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
  858. /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
  859. @end example
  860. The Y files use twice the resolution of the U and V files. They are
  861. raw files, without header. They can be generated by all decent video
  862. decoders. You must specify the size of the image with the @option{-s} option
  863. if ffmpeg cannot guess it.
  864. @item
  865. You can input from a raw YUV420P file:
  866. @example
  867. ffmpeg -i /tmp/test.yuv /tmp/out.avi
  868. @end example
  869. test.yuv is a file containing raw YUV planar data. Each frame is composed
  870. of the Y plane followed by the U and V planes at half vertical and
  871. horizontal resolution.
  872. @item
  873. You can output to a raw YUV420P file:
  874. @example
  875. ffmpeg -i mydivx.avi hugefile.yuv
  876. @end example
  877. @item
  878. You can set several input files and output files:
  879. @example
  880. ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
  881. @end example
  882. Converts the audio file a.wav and the raw YUV video file a.yuv
  883. to MPEG file a.mpg.
  884. @item
  885. You can also do audio and video conversions at the same time:
  886. @example
  887. ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
  888. @end example
  889. Converts a.wav to MPEG audio at 22050 Hz sample rate.
  890. @item
  891. You can encode to several formats at the same time and define a
  892. mapping from input stream to output streams:
  893. @example
  894. ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
  895. @end example
  896. Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
  897. file:index' specifies which input stream is used for each output
  898. stream, in the order of the definition of output streams.
  899. @item
  900. You can transcode decrypted VOBs:
  901. @example
  902. ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
  903. @end example
  904. This is a typical DVD ripping example; the input is a VOB file, the
  905. output an AVI file with MPEG-4 video and MP3 audio. Note that in this
  906. command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
  907. GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
  908. input video. Furthermore, the audio stream is MP3-encoded so you need
  909. to enable LAME support by passing @code{--enable-libmp3lame} to configure.
  910. The mapping is particularly useful for DVD transcoding
  911. to get the desired audio language.
  912. NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
  913. @item
  914. You can extract images from a video, or create a video from many images:
  915. For extracting images from a video:
  916. @example
  917. ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
  918. @end example
  919. This will extract one video frame per second from the video and will
  920. output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
  921. etc. Images will be rescaled to fit the new WxH values.
  922. If you want to extract just a limited number of frames, you can use the
  923. above command in combination with the -vframes or -t option, or in
  924. combination with -ss to start extracting from a certain point in time.
  925. For creating a video from many images:
  926. @example
  927. ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
  928. @end example
  929. The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
  930. composed of three digits padded with zeroes to express the sequence
  931. number. It is the same syntax supported by the C printf function, but
  932. only formats accepting a normal integer are suitable.
  933. When importing an image sequence, -i also supports expanding shell-like
  934. wildcard patterns (globbing) internally. To lower the chance of interfering
  935. with your actual file names and the shell's glob expansion, you are required
  936. to activate glob meta characters by prefixing them with a single @code{%}
  937. character, like in @code{foo-%*.jpeg}, @code{foo-%?%?%?.jpeg} or
  938. @code{foo-00%[234%]%*.jpeg}.
  939. If your filename actually contains a character sequence of a @code{%} character
  940. followed by a glob character, you must double the @code{%} character to escape
  941. it. Imagine your files begin with @code{%?-foo-}, then you could use a glob
  942. pattern like @code{%%?-foo-%*.jpeg}. For input patterns that could be both a
  943. printf or a glob pattern, ffmpeg will assume it is a glob pattern.
  944. @item
  945. You can put many streams of the same type in the output:
  946. @example
  947. ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
  948. @end example
  949. The resulting output file @file{test12.avi} will contain first four streams from
  950. the input file in reverse order.
  951. @item
  952. To force CBR video output:
  953. @example
  954. ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
  955. @end example
  956. @item
  957. The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
  958. but you may use the QP2LAMBDA constant to easily convert from 'q' units:
  959. @example
  960. ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
  961. @end example
  962. @end itemize
  963. @c man end EXAMPLES
  964. @include eval.texi
  965. @include decoders.texi
  966. @include encoders.texi
  967. @include demuxers.texi
  968. @include muxers.texi
  969. @include indevs.texi
  970. @include outdevs.texi
  971. @include protocols.texi
  972. @include bitstream_filters.texi
  973. @include filters.texi
  974. @include metadata.texi
  975. @ignore
  976. @setfilename ffmpeg
  977. @settitle ffmpeg video converter
  978. @c man begin SEEALSO
  979. ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
  980. @c man end
  981. @c man begin AUTHORS
  982. See git history
  983. @c man end
  984. @end ignore
  985. @bye