1 \input texinfo @c -*- texinfo -*-
2 @documentencoding UTF-8
4 @settitle ffmpeg Documentation
6 @center @titlefont{ffmpeg Documentation}
15 ffmpeg [@var{global_options}] @{[@var{input_file_options}] -i @file{input_file}@} ... @{[@var{output_file_options}] @file{output_file}@} ...
18 @c man begin DESCRIPTION
20 @command{ffmpeg} is a very fast video and audio converter that can also grab from
21 a live audio/video source. It can also convert between arbitrary sample
22 rates and resize video on the fly with a high quality polyphase filter.
24 @command{ffmpeg} reads from an arbitrary number of input "files" (which can be regular
25 files, pipes, network streams, grabbing devices, etc.), specified by the
26 @code{-i} option, and writes to an arbitrary number of output "files", which are
27 specified by a plain output filename. Anything found on the command line which
28 cannot be interpreted as an option is considered to be an output filename.
30 Each input or output file can, in principle, contain any number of streams of
31 different types (video/audio/subtitle/attachment/data). The allowed number and/or
32 types of streams may be limited by the container format. Selecting which
33 streams from which inputs will go into which output is either done automatically
34 or with the @code{-map} option (see the Stream selection chapter).
36 To refer to input files in options, you must use their indices (0-based). E.g.
37 the first input file is @code{0}, the second is @code{1}, etc. Similarly, streams
38 within a file are referred to by their indices. E.g. @code{2:3} refers to the
39 fourth stream in the third input file. Also see the Stream specifiers chapter.
41 As a general rule, options are applied to the next specified
42 file. Therefore, order is important, and you can have the same
43 option on the command line multiple times. Each occurrence is
44 then applied to the next input or output file.
45 Exceptions from this rule are the global options (e.g. verbosity level),
46 which should be specified first.
48 Do not mix input and output files -- first specify all input files, then all
49 output files. Also do not mix options which belong to different files. All
50 options apply ONLY to the next input or output file and are reset between files.
54 To set the video bitrate of the output file to 64 kbit/s:
56 ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi
60 To force the frame rate of the output file to 24 fps:
62 ffmpeg -i input.avi -r 24 output.avi
66 To force the frame rate of the input file (valid for raw formats only)
67 to 1 fps and the frame rate of the output file to 24 fps:
69 ffmpeg -r 1 -i input.m2v -r 24 output.avi
73 The format option may be needed for raw input files.
75 @c man end DESCRIPTION
77 @chapter Detailed description
78 @c man begin DETAILED DESCRIPTION
80 The transcoding process in @command{ffmpeg} for each output can be described by
81 the following diagram:
84 _______ ______________
86 | input | demuxer | encoded data | decoder
87 | file | ---------> | packets | -----+
88 |_______| |______________| |
95 ________ ______________ |
97 | output | <-------- | encoded data | <----+
98 | file | muxer | packets | encoder
99 |________| |______________|
104 @command{ffmpeg} calls the libavformat library (containing demuxers) to read
105 input files and get packets containing encoded data from them. When there are
106 multiple input files, @command{ffmpeg} tries to keep them synchronized by
107 tracking lowest timestamp on any active input stream.
109 Encoded packets are then passed to the decoder (unless streamcopy is selected
110 for the stream, see further for a description). The decoder produces
111 uncompressed frames (raw video/PCM audio/...) which can be processed further by
112 filtering (see next section). After filtering, the frames are passed to the
113 encoder, which encodes them and outputs encoded packets. Finally those are
114 passed to the muxer, which writes the encoded packets to the output file.
117 Before encoding, @command{ffmpeg} can process raw audio and video frames using
118 filters from the libavfilter library. Several chained filters form a filter
119 graph. @command{ffmpeg} distinguishes between two types of filtergraphs:
122 @subsection Simple filtergraphs
123 Simple filtergraphs are those that have exactly one input and output, both of
124 the same type. In the above diagram they can be represented by simply inserting
125 an additional step between decoding and encoding:
128 _________ ______________
130 | decoded | | encoded data |
131 | frames |\ _ | packets |
132 |_________| \ /||______________|
134 simple _\|| | / encoder
135 filtergraph | filtered |/
141 Simple filtergraphs are configured with the per-stream @option{-filter} option
142 (with @option{-vf} and @option{-af} aliases for video and audio respectively).
143 A simple filtergraph for video can look for example like this:
146 _______ _____________ _______ ________
148 | input | ---> | deinterlace | ---> | scale | ---> | output |
149 |_______| |_____________| |_______| |________|
153 Note that some filters change frame properties but not frame contents. E.g. the
154 @code{fps} filter in the example above changes number of frames, but does not
155 touch the frame contents. Another example is the @code{setpts} filter, which
156 only sets timestamps and otherwise passes the frames unchanged.
158 @subsection Complex filtergraphs
159 Complex filtergraphs are those which cannot be described as simply a linear
160 processing chain applied to one stream. This is the case, for example, when the graph has
161 more than one input and/or output, or when output stream type is different from
162 input. They can be represented with the following diagram:
167 | input 0 |\ __________
169 \ _________ /| output 0 |
171 _________ \| complex | /
173 | input 1 |---->| filter |\
174 |_________| | | \ __________
177 _________ / |_________| |__________|
184 Complex filtergraphs are configured with the @option{-filter_complex} option.
185 Note that this option is global, since a complex filtergraph, by its nature,
186 cannot be unambiguously associated with a single stream or file.
188 The @option{-lavfi} option is equivalent to @option{-filter_complex}.
190 A trivial example of a complex filtergraph is the @code{overlay} filter, which
191 has two video inputs and one video output, containing one video overlaid on top
192 of the other. Its audio counterpart is the @code{amix} filter.
195 Stream copy is a mode selected by supplying the @code{copy} parameter to the
196 @option{-codec} option. It makes @command{ffmpeg} omit the decoding and encoding
197 step for the specified stream, so it does only demuxing and muxing. It is useful
198 for changing the container format or modifying container-level metadata. The
199 diagram above will, in this case, simplify to this:
202 _______ ______________ ________
204 | input | demuxer | encoded data | muxer | output |
205 | file | ---------> | packets | -------> | file |
206 |_______| |______________| |________|
210 Since there is no decoding or encoding, it is very fast and there is no quality
211 loss. However, it might not work in some cases because of many factors. Applying
212 filters is obviously also impossible, since filters work on uncompressed data.
214 @c man end DETAILED DESCRIPTION
216 @chapter Stream selection
217 @c man begin STREAM SELECTION
219 By default, @command{ffmpeg} includes only one stream of each type (video, audio, subtitle)
220 present in the input files and adds them to each output file. It picks the
221 "best" of each based upon the following criteria: for video, it is the stream
222 with the highest resolution, for audio, it is the stream with the most channels, for
223 subtitles, it is the first subtitle stream. In the case where several streams of
224 the same type rate equally, the stream with the lowest index is chosen.
226 You can disable some of those defaults by using the @code{-vn/-an/-sn} options. For
227 full manual control, use the @code{-map} option, which disables the defaults just
230 @c man end STREAM SELECTION
235 @include fftools-common-opts.texi
237 @section Main options
241 @item -f @var{fmt} (@emph{input/output})
242 Force input or output file format. The format is normally auto detected for input
243 files and guessed from the file extension for output files, so this option is not
244 needed in most cases.
246 @item -i @var{filename} (@emph{input})
249 @item -y (@emph{global})
250 Overwrite output files without asking.
252 @item -n (@emph{global})
253 Do not overwrite output files, and exit immediately if a specified
254 output file already exists.
256 @item -stream_loop @var{number} (@emph{input})
257 Set number of times input stream shall be looped.
259 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
260 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
261 Select an encoder (when used before an output file) or a decoder (when used
262 before an input file) for one or more streams. @var{codec} is the name of a
263 decoder/encoder or a special value @code{copy} (output only) to indicate that
264 the stream is not to be re-encoded.
268 ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
270 encodes all video streams with libx264 and copies all audio streams.
272 For each stream, the last matching @code{c} option is applied, so
274 ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
276 will copy all the streams except the second video, which will be encoded with
277 libx264, and the 138th audio, which will be encoded with libvorbis.
279 @item -t @var{duration} (@emph{input/output})
280 When used as an input option (before @code{-i}), limit the @var{duration} of
281 data read from the input file.
283 When used as an output option (before an output filename), stop writing the
284 output after its duration reaches @var{duration}.
286 @var{duration} must be a time duration specification,
287 see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
289 -to and -t are mutually exclusive and -t has priority.
291 @item -to @var{position} (@emph{output})
292 Stop writing the output at @var{position}.
293 @var{position} must be a time duration specification,
294 see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
296 -to and -t are mutually exclusive and -t has priority.
298 @item -fs @var{limit_size} (@emph{output})
299 Set the file size limit, expressed in bytes.
301 @item -ss @var{position} (@emph{input/output})
302 When used as an input option (before @code{-i}), seeks in this input file to
303 @var{position}. Note that in most formats it is not possible to seek exactly,
304 so @command{ffmpeg} will seek to the closest seek point before @var{position}.
305 When transcoding and @option{-accurate_seek} is enabled (the default), this
306 extra segment between the seek point and @var{position} will be decoded and
307 discarded. When doing stream copy or when @option{-noaccurate_seek} is used, it
310 When used as an output option (before an output filename), decodes but discards
311 input until the timestamps reach @var{position}.
313 @var{position} must be a time duration specification,
314 see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
316 @item -sseof @var{position} (@emph{input/output})
318 Like the @code{-ss} option but relative to the "end of file". That is negative
319 values are earlier in the file, 0 is at EOF.
321 @item -itsoffset @var{offset} (@emph{input})
322 Set the input time offset.
324 @var{offset} must be a time duration specification,
325 see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
327 The offset is added to the timestamps of the input files. Specifying
328 a positive offset means that the corresponding streams are delayed by
329 the time duration specified in @var{offset}.
331 @item -timestamp @var{date} (@emph{output})
332 Set the recording timestamp in the container.
334 @var{date} must be a date specification,
335 see @ref{date syntax,,the Date section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
337 @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata})
338 Set a metadata key/value pair.
340 An optional @var{metadata_specifier} may be given to set metadata
341 on streams or chapters. See @code{-map_metadata} documentation for
344 This option overrides metadata set with @code{-map_metadata}. It is
345 also possible to delete metadata by using an empty value.
347 For example, for setting the title in the output file:
349 ffmpeg -i in.avi -metadata title="my title" out.flv
352 To set the language of the first audio stream:
354 ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT
357 @item -target @var{type} (@emph{output})
358 Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
359 @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or
360 @code{film-} to use the corresponding standard. All the format options
361 (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
364 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
367 Nevertheless you can specify additional options as long as you know
368 they do not conflict with the standard, as in:
371 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
374 @item -dframes @var{number} (@emph{output})
375 Set the number of data frames to output. This is an alias for @code{-frames:d}.
377 @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream})
378 Stop writing to the stream after @var{framecount} frames.
380 @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
381 @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
382 Use fixed quality scale (VBR). The meaning of @var{q}/@var{qscale} is
384 If @var{qscale} is used without a @var{stream_specifier} then it applies only
385 to the video stream, this is to maintain compatibility with previous behavior
386 and as specifying the same codec specific value to 2 different codecs that is
387 audio and video generally is not what is intended when no stream_specifier is
390 @anchor{filter_option}
391 @item -filter[:@var{stream_specifier}] @var{filtergraph} (@emph{output,per-stream})
392 Create the filtergraph specified by @var{filtergraph} and use it to
395 @var{filtergraph} is a description of the filtergraph to apply to
396 the stream, and must have a single input and a single output of the
397 same type of the stream. In the filtergraph, the input is associated
398 to the label @code{in}, and the output to the label @code{out}. See
399 the ffmpeg-filters manual for more information about the filtergraph
402 See the @ref{filter_complex_option,,-filter_complex option} if you
403 want to create filtergraphs with multiple inputs and/or outputs.
405 @item -filter_script[:@var{stream_specifier}] @var{filename} (@emph{output,per-stream})
406 This option is similar to @option{-filter}, the only difference is that its
407 argument is the name of the file from which a filtergraph description is to be
410 @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
411 Specify the preset for matching stream(s).
413 @item -stats (@emph{global})
414 Print encoding progress/statistics. It is on by default, to explicitly
415 disable it you need to specify @code{-nostats}.
417 @item -progress @var{url} (@emph{global})
418 Send program-friendly progress information to @var{url}.
420 Progress information is written approximately every second and at the end of
421 the encoding process. It is made of "@var{key}=@var{value}" lines. @var{key}
422 consists of only alphanumeric characters. The last key of a sequence of
423 progress information is always "progress".
426 Enable interaction on standard input. On by default unless standard input is
427 used as an input. To explicitly disable interaction you need to specify
430 Disabling interaction on standard input is useful, for example, if
431 ffmpeg is in the background process group. Roughly the same result can
432 be achieved with @code{ffmpeg ... < /dev/null} but it requires a
435 @item -debug_ts (@emph{global})
436 Print timestamp information. It is off by default. This option is
437 mostly useful for testing and debugging purposes, and the output
438 format may change from one version to another, so it should not be
439 employed by portable scripts.
441 See also the option @code{-fdebug ts}.
443 @item -attach @var{filename} (@emph{output})
444 Add an attachment to the output file. This is supported by a few formats
445 like Matroska for e.g. fonts used in rendering subtitles. Attachments
446 are implemented as a specific type of stream, so this option will add
447 a new stream to the file. It is then possible to use per-stream options
448 on this stream in the usual way. Attachment streams created with this
449 option will be created after all the other streams (i.e. those created
450 with @code{-map} or automatic mappings).
452 Note that for Matroska you also have to set the mimetype metadata tag:
454 ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
456 (assuming that the attachment stream will be third in the output file).
458 @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream})
459 Extract the matching attachment stream into a file named @var{filename}. If
460 @var{filename} is empty, then the value of the @code{filename} metadata tag
463 E.g. to extract the first attachment to a file named 'out.ttf':
465 ffmpeg -dump_attachment:t:0 out.ttf -i INPUT
467 To extract all attachments to files determined by the @code{filename} tag:
469 ffmpeg -dump_attachment:t "" -i INPUT
472 Technical note -- attachments are implemented as codec extradata, so this
473 option can actually be used to extract extradata from any stream, not just
477 Disable automatically rotating video based on file metadata.
481 @section Video Options
484 @item -vframes @var{number} (@emph{output})
485 Set the number of video frames to output. This is an alias for @code{-frames:v}.
486 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
487 Set frame rate (Hz value, fraction or abbreviation).
489 As an input option, ignore any timestamps stored in the file and instead
490 generate timestamps assuming constant frame rate @var{fps}.
491 This is not the same as the @option{-framerate} option used for some input formats
492 like image2 or v4l2 (it used to be the same in older versions of FFmpeg).
493 If in doubt use @option{-framerate} instead of the input option @option{-r}.
495 As an output option, duplicate or drop input frames to achieve constant output
496 frame rate @var{fps}.
498 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
501 As an input option, this is a shortcut for the @option{video_size} private
502 option, recognized by some demuxers for which the frame size is either not
503 stored in the file or is configurable -- e.g. raw video or video grabbers.
505 As an output option, this inserts the @code{scale} video filter to the
506 @emph{end} of the corresponding filtergraph. Please use the @code{scale} filter
507 directly to insert it at the beginning or some other place.
509 The format is @samp{wxh} (default - same as source).
511 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
512 Set the video display aspect ratio specified by @var{aspect}.
514 @var{aspect} can be a floating point number string, or a string of the
515 form @var{num}:@var{den}, where @var{num} and @var{den} are the
516 numerator and denominator of the aspect ratio. For example "4:3",
517 "16:9", "1.3333", and "1.7777" are valid argument values.
519 If used together with @option{-vcodec copy}, it will affect the aspect ratio
520 stored at container level, but not the aspect ratio stored in encoded
521 frames, if it exists.
523 @item -vn (@emph{output})
524 Disable video recording.
526 @item -vcodec @var{codec} (@emph{output})
527 Set the video codec. This is an alias for @code{-codec:v}.
529 @item -pass[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
530 Select the pass number (1 or 2). It is used to do two-pass
531 video encoding. The statistics of the video are recorded in the first
532 pass into a log file (see also the option -passlogfile),
533 and in the second pass that log file is used to generate the video
534 at the exact requested bitrate.
535 On pass 1, you may just deactivate audio and set output to null,
536 examples for Windows and Unix:
538 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
539 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
542 @item -passlogfile[:@var{stream_specifier}] @var{prefix} (@emph{output,per-stream})
543 Set two-pass log file name prefix to @var{prefix}, the default file name
544 prefix is ``ffmpeg2pass''. The complete file name will be
545 @file{PREFIX-N.log}, where N is a number specific to the output
548 @item -vf @var{filtergraph} (@emph{output})
549 Create the filtergraph specified by @var{filtergraph} and use it to
552 This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter option}.
555 @section Advanced Video options
558 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
559 Set pixel format. Use @code{-pix_fmts} to show all the supported
561 If the selected pixel format can not be selected, ffmpeg will print a
562 warning and select the best pixel format supported by the encoder.
563 If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error
564 if the requested pixel format can not be selected, and automatic conversions
565 inside filtergraphs are disabled.
566 If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format
567 as the input (or graph output) and automatic conversions are disabled.
569 @item -sws_flags @var{flags} (@emph{input/output})
574 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
575 Rate control override for specific intervals, formatted as "int,int,int"
576 list separated with slashes. Two first values are the beginning and
577 end frame numbers, last one is quantizer to use if positive, or quality
581 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
582 Use this option if your input file is interlaced and you want
583 to keep the interlaced format for minimum losses.
584 The alternative is to deinterlace the input stream with
585 @option{-deinterlace}, but deinterlacing introduces losses.
587 Calculate PSNR of compressed frames.
589 Dump video coding statistics to @file{vstats_HHMMSS.log}.
590 @item -vstats_file @var{file}
591 Dump video coding statistics to @var{file}.
592 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
593 top=1/bottom=0/auto=-1 field first
594 @item -dc @var{precision}
596 @item -vtag @var{fourcc/tag} (@emph{output})
597 Force video tag/fourcc. This is an alias for @code{-tag:v}.
598 @item -qphist (@emph{global})
600 @item -vbsf @var{bitstream_filter}
603 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
604 @item -force_key_frames[:@var{stream_specifier}] expr:@var{expr} (@emph{output,per-stream})
605 Force key frames at the specified timestamps, more precisely at the first
606 frames after each specified time.
608 If the argument is prefixed with @code{expr:}, the string @var{expr}
609 is interpreted like an expression and is evaluated for each frame. A
610 key frame is forced in case the evaluation is non-zero.
612 If one of the times is "@code{chapters}[@var{delta}]", it is expanded into
613 the time of the beginning of all chapters in the file, shifted by
614 @var{delta}, expressed as a time in seconds.
615 This option can be useful to ensure that a seek point is present at a
616 chapter mark or any other designated place in the output file.
618 For example, to insert a key frame at 5 minutes, plus key frames 0.1 second
619 before the beginning of every chapter:
621 -force_key_frames 0:05:00,chapters-0.1
624 The expression in @var{expr} can contain the following constants:
627 the number of current processed frame, starting from 0
629 the number of forced frames
631 the number of the previous forced frame, it is @code{NAN} when no
632 keyframe was forced yet
634 the time of the previous forced frame, it is @code{NAN} when no
635 keyframe was forced yet
637 the time of the current processed frame
640 For example to force a key frame every 5 seconds, you can specify:
642 -force_key_frames expr:gte(t,n_forced*5)
645 To force a key frame 5 seconds after the time of the last forced one,
646 starting from second 13:
648 -force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))
651 Note that forcing too many keyframes is very harmful for the lookahead
652 algorithms of certain encoders: using fixed-GOP options or similar
653 would be more efficient.
655 @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
656 When doing stream copy, copy also non-key frames found at the
659 @item -hwaccel[:@var{stream_specifier}] @var{hwaccel} (@emph{input,per-stream})
660 Use hardware acceleration to decode the matching stream(s). The allowed values
661 of @var{hwaccel} are:
664 Do not use any hardware acceleration (the default).
667 Automatically select the hardware acceleration method.
670 Use Apple VDA hardware acceleration.
673 Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.
676 Use DXVA2 (DirectX Video Acceleration) hardware acceleration.
679 This option has no effect if the selected hwaccel is not available or not
680 supported by the chosen decoder.
682 Note that most acceleration methods are intended for playback and will not be
683 faster than software decoding on modern CPUs. Additionally, @command{ffmpeg}
684 will usually need to copy the decoded frames from the GPU memory into the system
685 memory, resulting in further performance loss. This option is thus mainly
688 @item -hwaccel_device[:@var{stream_specifier}] @var{hwaccel_device} (@emph{input,per-stream})
689 Select a device to use for hardware acceleration.
691 This option only makes sense when the @option{-hwaccel} option is also
692 specified. Its exact meaning depends on the specific hardware acceleration
697 For VDPAU, this option specifies the X11 display/screen to use. If this option
698 is not specified, the value of the @var{DISPLAY} environment variable is used
701 For DXVA2, this option should contain the number of the display adapter to use.
702 If this option is not specified, the default adapter is used.
706 List all hardware acceleration methods supported in this build of ffmpeg.
710 @section Audio Options
713 @item -aframes @var{number} (@emph{output})
714 Set the number of audio frames to output. This is an alias for @code{-frames:a}.
715 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
716 Set the audio sampling frequency. For output streams it is set by
717 default to the frequency of the corresponding input stream. For input
718 streams this option only makes sense for audio grabbing devices and raw
719 demuxers and is mapped to the corresponding demuxer options.
720 @item -aq @var{q} (@emph{output})
721 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
722 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
723 Set the number of audio channels. For output streams it is set by
724 default to the number of input audio channels. For input streams
725 this option only makes sense for audio grabbing devices and raw demuxers
726 and is mapped to the corresponding demuxer options.
727 @item -an (@emph{output})
728 Disable audio recording.
729 @item -acodec @var{codec} (@emph{input/output})
730 Set the audio codec. This is an alias for @code{-codec:a}.
731 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
732 Set the audio sample format. Use @code{-sample_fmts} to get a list
733 of supported sample formats.
735 @item -af @var{filtergraph} (@emph{output})
736 Create the filtergraph specified by @var{filtergraph} and use it to
739 This is an alias for @code{-filter:a}, see the @ref{filter_option,,-filter option}.
742 @section Advanced Audio options
745 @item -atag @var{fourcc/tag} (@emph{output})
746 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
747 @item -absf @var{bitstream_filter}
749 @item -guess_layout_max @var{channels} (@emph{input,per-stream})
750 If some input channel layout is not known, try to guess only if it
751 corresponds to at most the specified number of channels. For example, 2
752 tells to @command{ffmpeg} to recognize 1 channel as mono and 2 channels as
753 stereo but not 6 channels as 5.1. The default is to always try to guess. Use
754 0 to disable all guessing.
757 @section Subtitle options
760 @item -scodec @var{codec} (@emph{input/output})
761 Set the subtitle codec. This is an alias for @code{-codec:s}.
762 @item -sn (@emph{output})
763 Disable subtitle recording.
764 @item -sbsf @var{bitstream_filter}
768 @section Advanced Subtitle options
772 @item -fix_sub_duration
773 Fix subtitles durations. For each subtitle, wait for the next packet in the
774 same stream and adjust the duration of the first to avoid overlap. This is
775 necessary with some subtitles codecs, especially DVB subtitles, because the
776 duration in the original packet is only a rough estimate and the end is
777 actually marked by an empty subtitle frame. Failing to use this option when
778 necessary can result in exaggerated durations or muxing failures due to
779 non-monotonic timestamps.
781 Note that this option will delay the output of all data until the next
782 subtitle packet is decoded: it may increase memory consumption and latency a
785 @item -canvas_size @var{size}
786 Set the size of the canvas used to render subtitles.
790 @section Advanced options
793 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
795 Designate one or more input streams as a source for the output file. Each input
796 stream is identified by the input file index @var{input_file_id} and
797 the input stream index @var{input_stream_id} within the input
798 file. Both indices start at 0. If specified,
799 @var{sync_file_id}:@var{stream_specifier} sets which input stream
800 is used as a presentation sync reference.
802 The first @code{-map} option on the command line specifies the
803 source for output stream 0, the second @code{-map} option specifies
804 the source for output stream 1, etc.
806 A @code{-} character before the stream identifier creates a "negative" mapping.
807 It disables matching streams from already created mappings.
809 An alternative @var{[linklabel]} form will map outputs from complex filter
810 graphs (see the @option{-filter_complex} option) to the output file.
811 @var{linklabel} must correspond to a defined output link label in the graph.
813 For example, to map ALL streams from the first input file to output
815 ffmpeg -i INPUT -map 0 output
818 For example, if you have two audio streams in the first input file,
819 these streams are identified by "0:0" and "0:1". You can use
820 @code{-map} to select which streams to place in an output file. For
823 ffmpeg -i INPUT -map 0:1 out.wav
825 will map the input stream in @file{INPUT} identified by "0:1" to
826 the (single) output stream in @file{out.wav}.
828 For example, to select the stream with index 2 from input file
829 @file{a.mov} (specified by the identifier "0:2"), and stream with
830 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
831 and copy them to the output file @file{out.mov}:
833 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
836 To select all video and the third audio stream from an input file:
838 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
841 To map all the streams except the second audio, use negative mappings
843 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
846 To pick the English audio stream:
848 ffmpeg -i INPUT -map 0:m:language:eng OUTPUT
851 Note that using this option disables the default mappings for this output file.
853 @item -ignore_unknown
854 Ignore input streams with unknown type instead of failing if copying
855 such streams is attempted.
858 Allow input streams with unknown type to be copied instead of failing if copying
859 such streams is attempted.
861 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
862 Map an audio channel from a given input to an output. If
863 @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will
864 be mapped on all the audio streams.
866 Using "-1" instead of
867 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
870 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
871 two audio channels with the following command:
873 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
876 If you want to mute the first channel and keep the second:
878 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
881 The order of the "-map_channel" option specifies the order of the channels in
882 the output stream. The output channel layout is guessed from the number of
883 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
884 in combination of "-map_channel" makes the channel gain levels to be updated if
885 input and output channel layouts don't match (for instance two "-map_channel"
886 options and "-ac 6").
888 You can also extract each channel of an input to specific outputs; the following
889 command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0)
890 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs:
892 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
895 The following example splits the channels of a stereo input into two separate
896 streams, which are put into the same output file:
898 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
901 Note that currently each output stream can only contain channels from a single
902 input stream; you can't for example use "-map_channel" to pick multiple input
903 audio channels contained in different streams (from the same or different files)
904 and merge them into a single output stream. It is therefore not currently
905 possible, for example, to turn two separate mono streams into a single stereo
906 stream. However splitting a stereo stream into two single channel mono streams
909 If you need this feature, a possible workaround is to use the @emph{amerge}
910 filter. For example, if you need to merge a media (here @file{input.mkv}) with 2
911 mono audio streams into one single stereo channel audio stream (and keep the
912 video stream), you can use the following command:
914 ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
917 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
918 Set metadata information of the next output file from @var{infile}. Note that
919 those are file indices (zero-based), not filenames.
920 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
921 A metadata specifier can have the following forms:
924 global metadata, i.e. metadata that applies to the whole file
926 @item @var{s}[:@var{stream_spec}]
927 per-stream metadata. @var{stream_spec} is a stream specifier as described
928 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
929 matching stream is copied from. In an output metadata specifier, all matching
930 streams are copied to.
932 @item @var{c}:@var{chapter_index}
933 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
935 @item @var{p}:@var{program_index}
936 per-program metadata. @var{program_index} is the zero-based program index.
938 If metadata specifier is omitted, it defaults to global.
940 By default, global metadata is copied from the first input file,
941 per-stream and per-chapter metadata is copied along with streams/chapters. These
942 default mappings are disabled by creating any mapping of the relevant type. A negative
943 file index can be used to create a dummy mapping that just disables automatic copying.
945 For example to copy metadata from the first stream of the input file to global metadata
948 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
951 To do the reverse, i.e. copy global metadata to all audio streams:
953 ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
955 Note that simple @code{0} would work as well in this example, since global
956 metadata is assumed by default.
958 @item -map_chapters @var{input_file_index} (@emph{output})
959 Copy chapters from input file with index @var{input_file_index} to the next
960 output file. If no chapter mapping is specified, then chapters are copied from
961 the first input file with at least one chapter. Use a negative file index to
962 disable any chapter copying.
964 @item -benchmark (@emph{global})
965 Show benchmarking information at the end of an encode.
966 Shows CPU time used and maximum memory consumption.
967 Maximum memory consumption is not supported on all systems,
968 it will usually display as 0 if not supported.
969 @item -benchmark_all (@emph{global})
970 Show benchmarking information during the encode.
971 Shows CPU time used in various steps (audio/video encode/decode).
972 @item -timelimit @var{duration} (@emph{global})
973 Exit after ffmpeg has been running for @var{duration} seconds.
974 @item -dump (@emph{global})
975 Dump each input packet to stderr.
976 @item -hex (@emph{global})
977 When dumping packets, also dump the payload.
978 @item -re (@emph{input})
979 Read input at native frame rate. Mainly used to simulate a grab device.
980 or live input stream (e.g. when reading from a file). Should not be used
981 with actual grab devices or live input streams (where it can cause packet
983 By default @command{ffmpeg} attempts to read the input(s) as fast as possible.
984 This option will slow down the reading of the input(s) to the native frame rate
985 of the input(s). It is useful for real-time output (e.g. live streaming).
987 Loop over the input stream. Currently it works only for image
988 streams. This option is used for automatic FFserver testing.
989 This option is deprecated, use -loop 1.
990 @item -loop_output @var{number_of_times}
991 Repeatedly loop output for formats that support looping such as animated GIF
992 (0 will loop the output infinitely).
993 This option is deprecated, use -loop.
994 @item -vsync @var{parameter}
996 For compatibility reasons old values can be specified as numbers.
997 Newly added values will have to be specified as strings always.
1000 @item 0, passthrough
1001 Each frame is passed with its timestamp from the demuxer to the muxer.
1003 Frames will be duplicated and dropped to achieve exactly the requested
1004 constant frame rate.
1006 Frames are passed through with their timestamp or dropped so as to
1007 prevent 2 frames from having the same timestamp.
1009 As passthrough but destroys all timestamps, making the muxer generate
1010 fresh timestamps based on frame-rate.
1012 Chooses between 1 and 2 depending on muxer capabilities. This is the
1016 Note that the timestamps may be further modified by the muxer, after this.
1017 For example, in the case that the format option @option{avoid_negative_ts}
1020 With -map you can select from which stream the timestamps should be
1021 taken. You can leave either video or audio unchanged and sync the
1022 remaining stream(s) to the unchanged one.
1024 @item -frame_drop_threshold @var{parameter}
1025 Frame drop threshold, which specifies how much behind video frames can
1026 be before they are dropped. In frame rate units, so 1.0 is one frame.
1027 The default is -1.1. One possible usecase is to avoid framedrops in case
1028 of noisy timestamps or to increase frame drop precision in case of exact
1031 @item -async @var{samples_per_second}
1032 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
1033 the parameter is the maximum samples per second by which the audio is changed.
1034 -async 1 is a special case where only the start of the audio stream is corrected
1035 without any later correction.
1037 Note that the timestamps may be further modified by the muxer, after this.
1038 For example, in the case that the format option @option{avoid_negative_ts}
1041 This option has been deprecated. Use the @code{aresample} audio filter instead.
1044 Do not process input timestamps, but keep their values without trying
1045 to sanitize them. In particular, do not remove the initial start time
1048 Note that, depending on the @option{vsync} option or on specific muxer
1049 processing (e.g. in case the format option @option{avoid_negative_ts}
1050 is enabled) the output timestamps may mismatch with the input
1051 timestamps even when this option is selected.
1053 @item -start_at_zero
1054 When used with @option{copyts}, shift input timestamps so they start at zero.
1056 This means that using e.g. @code{-ss 50} will make output timestamps start at
1057 50 seconds, regardless of what timestamp the input file started at.
1059 @item -copytb @var{mode}
1060 Specify how to set the encoder timebase when stream copying. @var{mode} is an
1061 integer numeric value, and can assume one of the following values:
1065 Use the demuxer timebase.
1067 The time base is copied to the output encoder from the corresponding input
1068 demuxer. This is sometimes required to avoid non monotonically increasing
1069 timestamps when copying video streams with variable frame rate.
1072 Use the decoder timebase.
1074 The time base is copied to the output encoder from the corresponding input
1078 Try to make the choice automatically, in order to generate a sane output.
1081 Default value is -1.
1083 @item -shortest (@emph{output})
1084 Finish encoding when the shortest input stream ends.
1085 @item -dts_delta_threshold
1086 Timestamp discontinuity delta threshold.
1087 @item -muxdelay @var{seconds} (@emph{input})
1088 Set the maximum demux-decode delay.
1089 @item -muxpreload @var{seconds} (@emph{input})
1090 Set the initial demux-decode delay.
1091 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
1092 Assign a new stream-id value to an output stream. This option should be
1093 specified prior to the output filename to which it applies.
1094 For the situation where multiple output files exist, a streamid
1095 may be reassigned to a different value.
1097 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
1098 an output mpegts file:
1100 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
1103 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
1104 Set bitstream filters for matching streams. @var{bitstream_filters} is
1105 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
1106 to get the list of bitstream filters.
1108 ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
1111 ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
1114 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{input/output,per-stream})
1115 Force a tag/fourcc for matching streams.
1117 @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff}
1118 Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';'
1121 ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
1124 @anchor{filter_complex_option}
1125 @item -filter_complex @var{filtergraph} (@emph{global})
1126 Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
1127 outputs. For simple graphs -- those with one input and one output of the same
1128 type -- see the @option{-filter} options. @var{filtergraph} is a description of
1129 the filtergraph, as described in the ``Filtergraph syntax'' section of the
1130 ffmpeg-filters manual.
1132 Input link labels must refer to input streams using the
1133 @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map}
1134 uses). If @var{stream_specifier} matches multiple streams, the first one will be
1135 used. An unlabeled input will be connected to the first unused input stream of
1138 Output link labels are referred to with @option{-map}. Unlabeled outputs are
1139 added to the first output file.
1141 Note that with this option it is possible to use only lavfi sources without
1144 For example, to overlay an image over video
1146 ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
1149 Here @code{[0:v]} refers to the first video stream in the first input file,
1150 which is linked to the first (main) input of the overlay filter. Similarly the
1151 first video stream in the second input is linked to the second (overlay) input
1154 Assuming there is only one video stream in each input file, we can omit input
1155 labels, so the above is equivalent to
1157 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
1161 Furthermore we can omit the output label and the single output from the filter
1162 graph will be added to the output file automatically, so we can simply write
1164 ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
1167 To generate 5 seconds of pure red video using lavfi @code{color} source:
1169 ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
1172 @item -lavfi @var{filtergraph} (@emph{global})
1173 Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
1174 outputs. Equivalent to @option{-filter_complex}.
1176 @item -filter_complex_script @var{filename} (@emph{global})
1177 This option is similar to @option{-filter_complex}, the only difference is that
1178 its argument is the name of the file from which a complex filtergraph
1179 description is to be read.
1181 @item -accurate_seek (@emph{input})
1182 This option enables or disables accurate seeking in input files with the
1183 @option{-ss} option. It is enabled by default, so seeking is accurate when
1184 transcoding. Use @option{-noaccurate_seek} to disable it, which may be useful
1185 e.g. when copying some streams and transcoding the others.
1187 @item -seek_timestamp (@emph{input})
1188 This option enables or disables seeking by timestamp in input files with the
1189 @option{-ss} option. It is disabled by default. If enabled, the argument
1190 to the @option{-ss} option is considered an actual timestamp, and is not
1191 offset by the start time of the file. This matters only for files which do
1192 not start from timestamp 0, such as transport streams.
1194 @item -thread_queue_size @var{size} (@emph{input})
1195 This option sets the maximum number of queued packets when reading from the
1196 file or device. With low latency / high rate live streams, packets may be
1197 discarded if they are not read in a timely manner; raising this value can
1200 @item -override_ffserver (@emph{global})
1201 Overrides the input specifications from @command{ffserver}. Using this
1202 option you can map any input stream to @command{ffserver} and control
1203 many aspects of the encoding from @command{ffmpeg}. Without this
1204 option @command{ffmpeg} will transmit to @command{ffserver} what is
1205 requested by @command{ffserver}.
1207 The option is intended for cases where features are needed that cannot be
1208 specified to @command{ffserver} but can be to @command{ffmpeg}.
1210 @item -sdp_file @var{file} (@emph{global})
1211 Print sdp information to @var{file}.
1212 This allows dumping sdp information when at least one output isn't an
1215 @item -discard (@emph{input})
1216 Allows discarding specific streams or frames of streams at the demuxer.
1217 Not all demuxers support this.
1224 Default, which discards no frames.
1227 Discard all non-reference frames.
1230 Discard all bidirectional frames.
1233 Discard all frames excepts keyframes.
1239 @item -xerror (@emph{global})
1240 Stop and exit on error
1244 As a special exception, you can use a bitmap subtitle stream as input: it
1245 will be converted into a video with the same size as the largest video in
1246 the file, or 720x576 if no video is present. Note that this is an
1247 experimental and temporary solution. It will be removed once libavfilter has
1248 proper support for subtitles.
1250 For example, to hardcode subtitles on top of a DVB-T recording stored in
1251 MPEG-TS format, delaying the subtitles by 1 second:
1253 ffmpeg -i input.ts -filter_complex \
1254 '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
1255 -sn -map '#0x2dc' output.mkv
1257 (0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,
1258 audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)
1260 @section Preset files
1261 A preset file contains a sequence of @var{option}=@var{value} pairs,
1262 one for each line, specifying a sequence of options which would be
1263 awkward to specify on the command line. Lines starting with the hash
1264 ('#') character are ignored and are used to provide comments. Check
1265 the @file{presets} directory in the FFmpeg source tree for examples.
1267 There are two types of preset files: ffpreset and avpreset files.
1269 @subsection ffpreset files
1270 ffpreset files are specified with the @code{vpre}, @code{apre},
1271 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
1272 filename of the preset instead of a preset name as input and can be
1273 used for any kind of codec. For the @code{vpre}, @code{apre}, and
1274 @code{spre} options, the options specified in a preset file are
1275 applied to the currently selected codec of the same type as the preset
1278 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
1279 preset options identifies the preset file to use according to the
1282 First ffmpeg searches for a file named @var{arg}.ffpreset in the
1283 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
1284 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
1285 or in a @file{ffpresets} folder along the executable on win32,
1286 in that order. For example, if the argument is @code{libvpx-1080p}, it will
1287 search for the file @file{libvpx-1080p.ffpreset}.
1289 If no such file is found, then ffmpeg will search for a file named
1290 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
1291 directories, where @var{codec_name} is the name of the codec to which
1292 the preset file options will be applied. For example, if you select
1293 the video codec with @code{-vcodec libvpx} and use @code{-vpre 1080p},
1294 then it will search for the file @file{libvpx-1080p.ffpreset}.
1296 @subsection avpreset files
1297 avpreset files are specified with the @code{pre} option. They work similar to
1298 ffpreset files, but they only allow encoder- specific options. Therefore, an
1299 @var{option}=@var{value} pair specifying an encoder cannot be used.
1301 When the @code{pre} option is specified, ffmpeg will look for files with the
1302 suffix .avpreset in the directories @file{$AVCONV_DATADIR} (if set), and
1303 @file{$HOME/.avconv}, and in the datadir defined at configuration time (usually
1304 @file{PREFIX/share/ffmpeg}), in that order.
1306 First ffmpeg searches for a file named @var{codec_name}-@var{arg}.avpreset in
1307 the above-mentioned directories, where @var{codec_name} is the name of the codec
1308 to which the preset file options will be applied. For example, if you select the
1309 video codec with @code{-vcodec libvpx} and use @code{-pre 1080p}, then it will
1310 search for the file @file{libvpx-1080p.avpreset}.
1312 If no such file is found, then ffmpeg will search for a file named
1313 @var{arg}.avpreset in the same directories.
1318 @c man begin EXAMPLES
1320 @section Video and Audio grabbing
1322 If you specify the input format and device then ffmpeg can grab video
1326 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
1329 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
1331 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1334 Note that you must activate the right video source and channel before
1335 launching ffmpeg with any TV viewer such as
1336 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1337 have to set the audio recording levels correctly with a
1340 @section X11 grabbing
1342 Grab the X11 display with ffmpeg via
1345 ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg
1348 0.0 is display.screen number of your X11 server, same as
1349 the DISPLAY environment variable.
1352 ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg
1355 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1356 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1358 @section Video and Audio file format conversion
1360 Any supported file format and protocol can serve as input to ffmpeg:
1365 You can use YUV files as input:
1368 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1371 It will use the files:
1373 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1374 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1377 The Y files use twice the resolution of the U and V files. They are
1378 raw files, without header. They can be generated by all decent video
1379 decoders. You must specify the size of the image with the @option{-s} option
1380 if ffmpeg cannot guess it.
1383 You can input from a raw YUV420P file:
1386 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1389 test.yuv is a file containing raw YUV planar data. Each frame is composed
1390 of the Y plane followed by the U and V planes at half vertical and
1391 horizontal resolution.
1394 You can output to a raw YUV420P file:
1397 ffmpeg -i mydivx.avi hugefile.yuv
1401 You can set several input files and output files:
1404 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1407 Converts the audio file a.wav and the raw YUV video file a.yuv
1411 You can also do audio and video conversions at the same time:
1414 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1417 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1420 You can encode to several formats at the same time and define a
1421 mapping from input stream to output streams:
1424 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1427 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1428 file:index' specifies which input stream is used for each output
1429 stream, in the order of the definition of output streams.
1432 You can transcode decrypted VOBs:
1435 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
1438 This is a typical DVD ripping example; the input is a VOB file, the
1439 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1440 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1441 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1442 input video. Furthermore, the audio stream is MP3-encoded so you need
1443 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1444 The mapping is particularly useful for DVD transcoding
1445 to get the desired audio language.
1447 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1450 You can extract images from a video, or create a video from many images:
1452 For extracting images from a video:
1454 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1457 This will extract one video frame per second from the video and will
1458 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1459 etc. Images will be rescaled to fit the new WxH values.
1461 If you want to extract just a limited number of frames, you can use the
1462 above command in combination with the -vframes or -t option, or in
1463 combination with -ss to start extracting from a certain point in time.
1465 For creating a video from many images:
1467 ffmpeg -f image2 -framerate 12 -i foo-%03d.jpeg -s WxH foo.avi
1470 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1471 composed of three digits padded with zeroes to express the sequence
1472 number. It is the same syntax supported by the C printf function, but
1473 only formats accepting a normal integer are suitable.
1475 When importing an image sequence, -i also supports expanding
1476 shell-like wildcard patterns (globbing) internally, by selecting the
1477 image2-specific @code{-pattern_type glob} option.
1479 For example, for creating a video from filenames matching the glob pattern
1482 ffmpeg -f image2 -pattern_type glob -framerate 12 -i 'foo-*.jpeg' -s WxH foo.avi
1486 You can put many streams of the same type in the output:
1489 ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut
1492 The resulting output file @file{test12.nut} will contain the first four streams
1493 from the input files in reverse order.
1496 To force CBR video output:
1498 ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
1502 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
1503 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
1505 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
1511 @include config.texi
1513 @ifset config-avutil
1516 @ifset config-avcodec
1517 @include codecs.texi
1518 @include bitstream_filters.texi
1520 @ifset config-avformat
1521 @include formats.texi
1522 @include protocols.texi
1524 @ifset config-avdevice
1525 @include devices.texi
1527 @ifset config-swresample
1528 @include resampler.texi
1530 @ifset config-swscale
1531 @include scaler.texi
1533 @ifset config-avfilter
1534 @include filters.texi
1542 @url{ffmpeg.html,ffmpeg}
1544 @ifset config-not-all
1545 @url{ffmpeg-all.html,ffmpeg-all},
1547 @url{ffplay.html,ffplay}, @url{ffprobe.html,ffprobe}, @url{ffserver.html,ffserver},
1548 @url{ffmpeg-utils.html,ffmpeg-utils},
1549 @url{ffmpeg-scaler.html,ffmpeg-scaler},
1550 @url{ffmpeg-resampler.html,ffmpeg-resampler},
1551 @url{ffmpeg-codecs.html,ffmpeg-codecs},
1552 @url{ffmpeg-bitstream-filters.html,ffmpeg-bitstream-filters},
1553 @url{ffmpeg-formats.html,ffmpeg-formats},
1554 @url{ffmpeg-devices.html,ffmpeg-devices},
1555 @url{ffmpeg-protocols.html,ffmpeg-protocols},
1556 @url{ffmpeg-filters.html,ffmpeg-filters}
1563 @ifset config-not-all
1566 ffplay(1), ffprobe(1), ffserver(1),
1567 ffmpeg-utils(1), ffmpeg-scaler(1), ffmpeg-resampler(1),
1568 ffmpeg-codecs(1), ffmpeg-bitstream-filters(1), ffmpeg-formats(1),
1569 ffmpeg-devices(1), ffmpeg-protocols(1), ffmpeg-filters(1)
1572 @include authors.texi
1577 @settitle ffmpeg video converter