1 \input texinfo @c -*- texinfo -*-
3 @settitle ffmpeg Documentation
5 @center @titlefont{ffmpeg Documentation}
14 The generic syntax is:
18 ffmpeg [global options] [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
23 @c man begin DESCRIPTION
25 ffmpeg is a very fast video and audio converter that can also grab from
26 a live audio/video source. It can also convert between arbitrary sample
27 rates and resize video on the fly with a high quality polyphase filter.
29 As a general rule, options are applied to the next specified
30 file. Therefore, order is important, and you can have the same
31 option on the command line multiple times. Each occurrence is
32 then applied to the next input or output file.
33 Exceptions from this rule are the global options (e.g. verbosity level),
34 which should be specified first.
38 To set the video bitrate of the output file to 64kbit/s:
40 ffmpeg -i input.avi -b:v 64k output.avi
44 To force the frame rate of the output file to 24 fps:
46 ffmpeg -i input.avi -r 24 output.avi
50 To force the frame rate of the input file (valid for raw formats only)
51 to 1 fps and the frame rate of the output file to 24 fps:
53 ffmpeg -r 1 -i input.m2v -r 24 output.avi
57 The format option may be needed for raw input files.
59 @c man end DESCRIPTION
61 @chapter Stream selection
62 @c man begin STREAM SELECTION
64 By default ffmpeg includes only one stream of each type (video, audio, subtitle)
65 present in the input files and adds them to each output file. It picks the
66 "best" of each based upon the following criteria; for video it is the stream
67 with the highest resolution, for audio the stream with the most channels, for
68 subtitle it's the first subtitle stream. In the case where several streams of
69 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
75 @c man end STREAM SELECTION
80 @include avtools-common-opts.texi
86 @item -f @var{fmt} (@emph{input/output})
87 Force input or output file format. The format is normally autodetected for input
88 files and guessed from file extension for output files, so this option is not
91 @item -i @var{filename} (@emph{input})
94 @item -y (@emph{global})
95 Overwrite output files without asking.
97 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
98 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
99 Select an encoder (when used before an output file) or a decoder (when used
100 before an input file) for one or more streams. @var{codec} is the name of a
101 decoder/encoder or a special value @code{copy} (output only) to indicate that
102 the stream is not to be reencoded.
106 ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
108 encodes all video streams with libx264 and copies all audio streams.
110 For each stream, the last matching @code{c} option is applied, so
112 ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
114 will copy all the streams except the second video, which will be encoded with
115 libx264, and the 138th audio, which will be encoded with libvorbis.
117 @item -t @var{duration} (@emph{output})
118 Stop writing the output after its duration reaches @var{duration}.
119 @var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form.
121 @item -fs @var{limit_size} (@emph{output})
122 Set the file size limit.
124 @item -ss @var{position} (@emph{input/output})
125 When used as an input option (before @code{-i}), seeks in this input file to
126 @var{position}. When used as an output option (before an output filename),
127 decodes but discards input until the timestamps reach @var{position}. This is
128 slower, but more accurate.
130 @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
132 @item -itsoffset @var{offset} (@emph{input})
133 Set the input time offset in seconds.
134 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
135 The offset is added to the timestamps of the input files.
136 Specifying a positive offset means that the corresponding
137 streams are delayed by @var{offset} seconds.
139 @item -timestamp @var{time} (@emph{output})
140 Set the recording timestamp in the container.
141 The syntax for @var{time} is:
143 now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
145 If the value is "now" it takes the current time.
146 Time is local time unless 'Z' or 'z' is appended, in which case it is
148 If the year-month-day part is not specified it takes the current
151 @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata})
152 Set a metadata key/value pair.
154 An optional @var{metadata_specifier} may be given to set metadata
155 on streams or chapters. See @code{-map_metadata} documentation for
158 This option overrides metadata set with @code{-map_metadata}. It is
159 also possible to delete metadata by using an empty value.
161 For example, for setting the title in the output file:
163 ffmpeg -i in.avi -metadata title="my title" out.flv
166 To set the language of the second stream:
168 ffmpeg -i INPUT -metadata:s:1 language=eng OUTPUT
171 @item -v @var{number} (@emph{global})
172 This option is deprecated and has no effect, use -loglevel
173 to set verbosity level.
175 @item -target @var{type} (@emph{output})
176 Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
177 @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or
178 @code{film-} to use the corresponding standard. All the format options
179 (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
182 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
185 Nevertheless you can specify additional options as long as you know
186 they do not conflict with the standard, as in:
189 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
192 @item -dframes @var{number} (@emph{output})
193 Set the number of data frames to record. This is an alias for @code{-frames:d}.
195 @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream})
196 Stop writing to the stream after @var{framecount} frames.
198 @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
199 @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
200 Use fixed quality scale (VBR). The meaning of @var{q} is
203 @item -filter[:@var{stream_specifier}] @var{filter_graph}
204 @var{filter_graph} is a description of the filter graph to apply to
205 the stream. Use @code{-filters} to show all the available filters
206 (including also sources and sinks).
210 @section Video Options
213 @item -vframes @var{number} (@emph{output})
214 Set the number of video frames to record. This is an alias for @code{-frames:v}.
215 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
216 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
217 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
218 Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
219 The following abbreviations are recognized:
281 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
282 Set the video display aspect ratio specified by @var{aspect}.
284 @var{aspect} can be a floating point number string, or a string of the
285 form @var{num}:@var{den}, where @var{num} and @var{den} are the
286 numerator and denominator of the aspect ratio. For example "4:3",
287 "16:9", "1.3333", and "1.7777" are valid argument values.
289 @item -croptop @var{size}
290 @item -cropbottom @var{size}
291 @item -cropleft @var{size}
292 @item -cropright @var{size}
293 All the crop options have been removed. Use -vf
294 crop=width:height:x:y instead.
296 @item -padtop @var{size}
297 @item -padbottom @var{size}
298 @item -padleft @var{size}
299 @item -padright @var{size}
300 @item -padcolor @var{hex_color}
301 All the pad options have been removed. Use -vf
302 pad=width:height:x:y:color instead.
304 @item -vn (@emph{output})
305 Disable video recording.
306 @item -bt @var{tolerance}
307 Set video bitrate tolerance (in bits, default 4000k).
308 Has a minimum value of: (target_bitrate/target_framerate).
309 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
310 willing to deviate from the target average bitrate value. This is
311 not related to min/max bitrate. Lowering tolerance too much has
312 an adverse effect on quality.
313 @item -maxrate @var{bitrate}
314 Set max video bitrate (in bit/s).
315 Requires -bufsize to be set.
316 @item -minrate @var{bitrate}
317 Set min video bitrate (in bit/s).
318 Most useful in setting up a CBR encode:
320 ffmpeg -i myfile.avi -b:v 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
322 It is of little use elsewise.
323 @item -bufsize @var{size}
324 Set video buffer verifier buffer size (in bits).
325 @item -vcodec @var{codec} (@emph{output})
326 Set the video codec. This is an alias for @code{-codec:v}.
328 Use same quantizer as source (implies VBR).
330 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
334 Select the pass number (1 or 2). It is used to do two-pass
335 video encoding. The statistics of the video are recorded in the first
336 pass into a log file (see also the option -passlogfile),
337 and in the second pass that log file is used to generate the video
338 at the exact requested bitrate.
339 On pass 1, you may just deactivate audio and set output to null,
340 examples for Windows and Unix:
342 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
343 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
346 @item -passlogfile @var{prefix} (@emph{global})
347 Set two-pass log file name prefix to @var{prefix}, the default file name
348 prefix is ``ffmpeg2pass''. The complete file name will be
349 @file{PREFIX-N.log}, where N is a number specific to the output
352 @item -vlang @var{code}
353 Set the ISO 639 language code (3 letters) of the current video stream.
355 @item -vf @var{filter_graph} (@emph{output})
356 @var{filter_graph} is a description of the filter graph to apply to
358 Use the option "-filters" to show all the available filters (including
359 also sources and sinks). This is an alias for @code{-filter:v}.
363 @section Advanced Video Options
366 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
367 Set pixel format. Use @code{-pix_fmts} to show all the supported
369 @item -sws_flags @var{flags} (@emph{input/output})
371 @item -g @var{gop_size}
372 Set the group of pictures size.
378 minimum video quantizer scale (VBR)
380 maximum video quantizer scale (VBR)
382 maximum difference between the quantizer scales (VBR)
383 @item -qblur @var{blur}
384 video quantizer scale blur (VBR) (range 0.0 - 1.0)
385 @item -qcomp @var{compression}
386 video quantizer scale compression (VBR) (default 0.5).
387 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
389 @item -lmin @var{lambda}
390 minimum video lagrange factor (VBR)
391 @item -lmax @var{lambda}
392 max video lagrange factor (VBR)
393 @item -mblmin @var{lambda}
394 minimum macroblock quantizer scale (VBR)
395 @item -mblmax @var{lambda}
396 maximum macroblock quantizer scale (VBR)
398 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
399 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
401 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
404 @item -rc_init_cplx @var{complexity}
405 initial complexity for single pass encoding
406 @item -b_qfactor @var{factor}
407 qp factor between P- and B-frames
408 @item -i_qfactor @var{factor}
409 qp factor between P- and I-frames
410 @item -b_qoffset @var{offset}
411 qp offset between P- and B-frames
412 @item -i_qoffset @var{offset}
413 qp offset between P- and I-frames
414 @item -rc_eq @var{equation}
415 Set rate control equation (see section "Expression Evaluation")
416 (default = @code{tex^qComp}).
418 When computing the rate control equation expression, besides the
419 standard functions defined in the section "Expression Evaluation", the
420 following functions are available:
426 and the following constants are available:
448 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
449 Rate control override for specific intervals, formated as "int,int,int"
450 list separated with slashes. Two first values are the beginning and
451 end frame numbers, last one is quantizer to use if positive, or quality
453 @item -me_method @var{method}
454 Set motion estimation method to @var{method}.
455 Available methods are (from lowest to best quality):
458 Try just the (0, 0) vector.
467 exhaustive search (slow and marginally better than epzs)
470 @item -dct_algo @var{algo}
471 Set DCT algorithm to @var{algo}. Available values are:
474 FF_DCT_AUTO (default)
487 @item -idct_algo @var{algo}
488 Set IDCT algorithm to @var{algo}. Available values are:
491 FF_IDCT_AUTO (default)
515 Set error resilience to @var{n}.
518 FF_ER_CAREFUL (default)
524 FF_ER_VERY_AGGRESSIVE
527 @item -ec @var{bit_mask}
528 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
529 the following values:
532 FF_EC_GUESS_MVS (default = enabled)
534 FF_EC_DEBLOCK (default = enabled)
537 @item -bf @var{frames}
538 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
539 @item -mbd @var{mode}
543 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in ffmpeg).
545 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
547 FF_MB_DECISION_RD: rate distortion
551 Use four motion vector by macroblock (MPEG-4 only).
553 Use data partitioning (MPEG-4 only).
554 @item -bug @var{param}
555 Work around encoder bugs that are not auto-detected.
556 @item -strict @var{strictness}
557 How strictly to follow the standards.
559 Enable Advanced intra coding (h263+).
561 Enable Unlimited Motion Vector (h263+)
564 Deinterlace pictures.
566 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
567 Use this option if your input file is interlaced and you want
568 to keep the interlaced format for minimum losses.
569 The alternative is to deinterlace the input stream with
570 @option{-deinterlace}, but deinterlacing introduces losses.
572 Calculate PSNR of compressed frames.
574 Dump video coding statistics to @file{vstats_HHMMSS.log}.
575 @item -vstats_file @var{file}
576 Dump video coding statistics to @var{file}.
577 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
578 top=1/bottom=0/auto=-1 field first
579 @item -dc @var{precision}
581 @item -vtag @var{fourcc/tag} (@emph{output})
582 Force video tag/fourcc. This is an alias for @code{-tag:v}.
583 @item -qphist (@emph{global})
585 @item -vbsf @var{bitstream_filter}
587 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
588 Force key frames at the specified timestamps, more precisely at the first
589 frames after each specified time.
590 This option can be useful to ensure that a seek point is present at a
591 chapter mark or any other designated place in the output file.
592 The timestamps must be specified in ascending order.
595 @section Audio Options
598 @item -aframes @var{number} (@emph{output})
599 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
600 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
601 Set the audio sampling frequency. For output streams it is set by
602 default to the frequency of the corresponding input stream. For input
603 streams this option only makes sense for audio grabbing devices and raw
604 demuxers and is mapped to the corresponding demuxer options.
605 @item -aq @var{q} (@emph{output})
606 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
607 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
608 Set the number of audio channels. For output streams it is set by
609 default to the number of input audio channels. For input streams
610 this option only makes sense for audio grabbing devices and raw demuxers
611 and is mapped to the corresponding demuxer options.
612 @item -an (@emph{output})
613 Disable audio recording.
614 @item -acodec @var{codec} (@emph{input/output})
615 Set the audio codec. This is an alias for @code{-codec:a}.
616 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
617 Set the audio sample format. Use @code{-help sample_fmts} to get a list
618 of supported sample formats.
621 @section Advanced Audio options:
624 @item -atag @var{fourcc/tag} (@emph{output})
625 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
626 @item -audio_service_type @var{type}
627 Set the type of service that the audio stream contains.
630 Main Audio Service (default)
648 @item -absf @var{bitstream_filter}
652 @section Subtitle options:
655 @item -slang @var{code}
656 Set the ISO 639 language code (3 letters) of the current subtitle stream.
657 @item -scodec @var{codec} (@emph{input/output})
658 Set the subtitle codec. This is an alias for @code{-codec:s}.
659 @item -sn (@emph{output})
660 Disable subtitle recording.
661 @item -sbsf @var{bitstream_filter}
665 @section Audio/Video grab options
668 @item -isync (@emph{global})
669 Synchronize read on input.
672 @section Advanced options
675 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] (@emph{output})
677 Designate one or more input streams as a source for the output file. Each input
678 stream is identified by the input file index @var{input_file_id} and
679 the input stream index @var{input_stream_id} within the input
680 file. Both indices start at 0. If specified,
681 @var{sync_file_id}:@var{stream_specifier} sets which input stream
682 is used as a presentation sync reference.
684 The first @code{-map} option on the command line specifies the
685 source for output stream 0, the second @code{-map} option specifies
686 the source for output stream 1, etc.
688 A @code{-} character before the stream identifier creates a "negative" mapping.
689 It disables matching streams from already created mappings.
691 For example, to map ALL streams from the first input file to output
693 ffmpeg -i INPUT -map 0 output
696 For example, if you have two audio streams in the first input file,
697 these streams are identified by "0:0" and "0:1". You can use
698 @code{-map} to select which streams to place in an output file. For
701 ffmpeg -i INPUT -map 0:1 out.wav
703 will map the input stream in @file{INPUT} identified by "0:1" to
704 the (single) output stream in @file{out.wav}.
706 For example, to select the stream with index 2 from input file
707 @file{a.mov} (specified by the identifier "0:2"), and stream with
708 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
709 and copy them to the output file @file{out.mov}:
711 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
714 To select all video and the third audio stream from an input file:
716 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
719 To map all the streams except the second audio, use negative mappings
721 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
724 Note that using this option disables the default mappings for this output file.
726 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
727 Map an audio channel from a given input to an output. If
728 @var{output_file_id}.@var{stream_specifier} are not set, the audio channel will
729 be mapped on all the audio streams.
731 Using "-1" instead of
732 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
735 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
736 two audio channels with the following command:
738 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
741 If you want to mute the first channel and keep the second:
743 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
746 The order of the "-map_channel" option specifies the order of the channels in
747 the output stream. The output channel layout is guessed from the number of
748 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
749 in combination of "-map_channel" makes the channel gain levels to be updated if
750 channel layouts don't match (for instance two "-map_channel" options and "-ac
753 You can also extract each channel of an @var{INPUT} to specific outputs; the
754 following command extract each channel of the audio stream (file 0, stream 0)
755 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1}:
757 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
760 The following example split the channels of a stereo input into streams:
763 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
766 Note that "-map_channel" is currently limited to the scope of one input for
767 each output; you can't for example use it to pick multiple input audio files
768 and mix them into one single output.
770 @item -map_metadata[:@var{metadata_type}][:@var{index}] @var{infile}[:@var{metadata_type}][:@var{index}] (@emph{output,per-metadata})
771 Set metadata information of the next output file from @var{infile}. Note that
772 those are file indices (zero-based), not filenames.
773 Optional @var{metadata_type} parameters specify, which metadata to copy - (g)lobal
774 (i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
775 per-(p)rogram. All metadata specifiers other than global must be followed by the
776 stream/chapter/program index. If metadata specifier is omitted, it defaults to
779 By default, global metadata is copied from the first input file,
780 per-stream and per-chapter metadata is copied along with streams/chapters. These
781 default mappings are disabled by creating any mapping of the relevant type. A negative
782 file index can be used to create a dummy mapping that just disables automatic copying.
784 For example to copy metadata from the first stream of the input file to global metadata
787 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
789 @item -map_chapters @var{input_file_index} (@emph{output})
790 Copy chapters from input file with index @var{input_file_index} to the next
791 output file. If no chapter mapping is specified, then chapters are copied from
792 the first input file with at least one chapter. Use a negative file index to
793 disable any chapter copying.
794 @item -debug @var{category}
795 Print specific debug info.
796 @var{category} is a number or a string containing one of the following values:
800 picture buffer allocations
808 memory management control operations (H.264)
815 per-block quantization parameter (QP)
823 visualize block types
825 visualize quantization parameter (QP), lower QP are tinted greener
827 @item -benchmark (@emph{global})
828 Show benchmarking information at the end of an encode.
829 Shows CPU time used and maximum memory consumption.
830 Maximum memory consumption is not supported on all systems,
831 it will usually display as 0 if not supported.
832 @item -timelimit @var{duration} (@emph{global})
833 Exit after ffmpeg has been running for @var{duration} seconds.
834 @item -dump (@emph{global})
835 Dump each input packet to stderr.
836 @item -hex (@emph{global})
837 When dumping packets, also dump the payload.
839 Set RTP payload size in bytes.
840 @item -re (@emph{input})
841 Read input at native frame rate. Mainly used to simulate a grab device.
843 Loop over the input stream. Currently it works only for image
844 streams. This option is used for automatic FFserver testing.
845 This option is deprecated, use -loop 1.
846 @item -loop_output @var{number_of_times}
847 Repeatedly loop output for formats that support looping such as animated GIF
848 (0 will loop the output infinitely).
849 This option is deprecated, use -loop.
850 @item -threads @var{count}
852 @item -vsync @var{parameter}
857 Each frame is passed with its timestamp from the demuxer to the muxer.
859 Frames will be duplicated and dropped to achieve exactly the requested
862 Frames are passed through with their timestamp or dropped so as to
863 prevent 2 frames from having the same timestamp.
865 Chooses between 1 and 2 depending on muxer capabilities. This is the
869 With -map you can select from which stream the timestamps should be
870 taken. You can leave either video or audio unchanged and sync the
871 remaining stream(s) to the unchanged one.
873 @item -async @var{samples_per_second}
874 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
875 the parameter is the maximum samples per second by which the audio is changed.
876 -async 1 is a special case where only the start of the audio stream is corrected
877 without any later correction.
879 Copy timestamps from input to output.
881 Copy input stream time base from input to output when stream copying.
883 Finish encoding when the shortest input stream ends.
884 @item -dts_delta_threshold
885 Timestamp discontinuity delta threshold.
886 @item -muxdelay @var{seconds} (@emph{input})
887 Set the maximum demux-decode delay.
888 @item -muxpreload @var{seconds} (@emph{input})
889 Set the initial demux-decode delay.
890 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
891 Assign a new stream-id value to an output stream. This option should be
892 specified prior to the output filename to which it applies.
893 For the situation where multiple output files exist, a streamid
894 may be reassigned to a different value.
896 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
897 an output mpegts file:
899 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
902 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
903 Set bitstream filters for matching streams. @var{bistream_filters} is
904 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
905 to get the list of bitstream filters.
907 ffmpeg -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
910 ffmpeg -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
913 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
914 Force a tag/fourcc for matching streams.
917 @section Preset files
918 A preset file contains a sequence of @var{option}=@var{value} pairs,
919 one for each line, specifying a sequence of options which would be
920 awkward to specify on the command line. Lines starting with the hash
921 ('#') character are ignored and are used to provide comments. Check
922 the @file{presets} directory in the FFmpeg source tree for examples.
924 Preset files are specified with the @code{vpre}, @code{apre},
925 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
926 filename of the preset instead of a preset name as input and can be
927 used for any kind of codec. For the @code{vpre}, @code{apre}, and
928 @code{spre} options, the options specified in a preset file are
929 applied to the currently selected codec of the same type as the preset
932 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
933 preset options identifies the preset file to use according to the
936 First ffmpeg searches for a file named @var{arg}.ffpreset in the
937 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
938 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
939 or in a @file{ffpresets} folder along the executable on win32,
940 in that order. For example, if the argument is @code{libx264-max}, it will
941 search for the file @file{libx264-max.ffpreset}.
943 If no such file is found, then ffmpeg will search for a file named
944 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
945 directories, where @var{codec_name} is the name of the codec to which
946 the preset file options will be applied. For example, if you select
947 the video codec with @code{-vcodec libx264} and use @code{-vpre max},
948 then it will search for the file @file{libx264-max.ffpreset}.
956 For streaming at very low bitrate application, use a low frame rate
957 and a small GOP size. This is especially true for RealVideo where
958 the Linux player does not seem to be very fast, so it can miss
959 frames. An example is:
962 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
966 The parameter 'q' which is displayed while encoding is the current
967 quantizer. The value 1 indicates that a very good quality could
968 be achieved. The value 31 indicates the worst quality. If q=31 appears
969 too often, it means that the encoder cannot compress enough to meet
970 your bitrate. You must either increase the bitrate, decrease the
971 frame rate or decrease the frame size.
974 If your computer is not fast enough, you can speed up the
975 compression at the expense of the compression ratio. You can use
976 '-me zero' to speed up motion estimation, and '-intra' to disable
977 motion estimation completely (you have only I-frames, which means it
978 is about as good as JPEG compression).
981 To have very low audio bitrates, reduce the sampling frequency
982 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
985 To have a constant quality (but a variable bitrate), use the option
986 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
993 @c man begin EXAMPLES
995 @section Video and Audio grabbing
997 If you specify the input format and device then ffmpeg can grab video
1001 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
1004 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
1006 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1009 Note that you must activate the right video source and channel before
1010 launching ffmpeg with any TV viewer such as
1011 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1012 have to set the audio recording levels correctly with a
1015 @section X11 grabbing
1017 Grab the X11 display with ffmpeg via
1020 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
1023 0.0 is display.screen number of your X11 server, same as
1024 the DISPLAY environment variable.
1027 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
1030 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1031 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1033 @section Video and Audio file format conversion
1035 Any supported file format and protocol can serve as input to ffmpeg:
1040 You can use YUV files as input:
1043 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1046 It will use the files:
1048 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1049 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1052 The Y files use twice the resolution of the U and V files. They are
1053 raw files, without header. They can be generated by all decent video
1054 decoders. You must specify the size of the image with the @option{-s} option
1055 if ffmpeg cannot guess it.
1058 You can input from a raw YUV420P file:
1061 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1064 test.yuv is a file containing raw YUV planar data. Each frame is composed
1065 of the Y plane followed by the U and V planes at half vertical and
1066 horizontal resolution.
1069 You can output to a raw YUV420P file:
1072 ffmpeg -i mydivx.avi hugefile.yuv
1076 You can set several input files and output files:
1079 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1082 Converts the audio file a.wav and the raw YUV video file a.yuv
1086 You can also do audio and video conversions at the same time:
1089 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1092 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1095 You can encode to several formats at the same time and define a
1096 mapping from input stream to output streams:
1099 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1102 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1103 file:index' specifies which input stream is used for each output
1104 stream, in the order of the definition of output streams.
1107 You can transcode decrypted VOBs:
1110 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
1113 This is a typical DVD ripping example; the input is a VOB file, the
1114 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1115 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1116 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1117 input video. Furthermore, the audio stream is MP3-encoded so you need
1118 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1119 The mapping is particularly useful for DVD transcoding
1120 to get the desired audio language.
1122 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1125 You can extract images from a video, or create a video from many images:
1127 For extracting images from a video:
1129 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1132 This will extract one video frame per second from the video and will
1133 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1134 etc. Images will be rescaled to fit the new WxH values.
1136 If you want to extract just a limited number of frames, you can use the
1137 above command in combination with the -vframes or -t option, or in
1138 combination with -ss to start extracting from a certain point in time.
1140 For creating a video from many images:
1142 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1145 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1146 composed of three digits padded with zeroes to express the sequence
1147 number. It is the same syntax supported by the C printf function, but
1148 only formats accepting a normal integer are suitable.
1151 You can put many streams of the same type in the output:
1154 ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1157 The resulting output file @file{test12.avi} will contain first four streams from
1158 the input file in reverse order.
1164 @include decoders.texi
1165 @include encoders.texi
1166 @include demuxers.texi
1167 @include muxers.texi
1168 @include indevs.texi
1169 @include outdevs.texi
1170 @include protocols.texi
1171 @include bitstream_filters.texi
1172 @include filters.texi
1173 @include metadata.texi
1178 @settitle ffmpeg video converter
1180 @c man begin SEEALSO
1181 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1184 @c man begin AUTHORS