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 tries to pick the "best" stream of each type present in input
65 files and add them to each output file. For video, this means the highest
66 resolution, for audio the highest channel count. For subtitle it's simply the
67 first subtitle stream.
69 You can disable some of those defaults by using @code{-vn/-an/-sn} options. For
70 full manual control, use the @code{-map} option, which disables the defaults just
73 @c man end STREAM SELECTION
78 @include avtools-common-opts.texi
84 @item -f @var{fmt} (@emph{input/output})
85 Force input or output file format. The format is normally autodetected for input
86 files and guessed from file extension for output files, so this option is not
89 @item -i @var{filename} (@emph{input})
92 @item -y (@emph{global})
93 Overwrite output files without asking.
95 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
96 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
97 Select an encoder (when used before an output file) or a decoder (when used
98 before an input file) for one or more streams. @var{codec} is the name of a
99 decoder/encoder or a special value @code{copy} (output only) to indicate that
100 the stream is not to be reencoded.
104 ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
106 encodes all video streams with libx264 and copies all audio streams.
108 For each stream, the last matching @code{c} option is applied, so
110 ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
112 will copy all the streams except the second video, which will be encoded with
113 libx264, and the 138th audio, which will be encoded with libvorbis.
115 @item -t @var{duration} (@emph{output})
116 Stop writing the output after its duration reaches @var{duration}.
117 @var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form.
119 @item -fs @var{limit_size} (@emph{output})
120 Set the file size limit.
122 @item -ss @var{position} (@emph{input/output})
123 When used as an input option (before @code{-i}), seeks in this input file to
124 @var{position}. When used as an output option (before an output filename),
125 decodes but discards input until the timestamps reach @var{position}. This is
126 slower, but more accurate.
128 @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
130 @item -itsoffset @var{offset} (@emph{input})
131 Set the input time offset in seconds.
132 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
133 The offset is added to the timestamps of the input files.
134 Specifying a positive offset means that the corresponding
135 streams are delayed by @var{offset} seconds.
137 @item -timestamp @var{time} (@emph{output})
138 Set the recording timestamp in the container.
139 The syntax for @var{time} is:
141 now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
143 If the value is "now" it takes the current time.
144 Time is local time unless 'Z' or 'z' is appended, in which case it is
146 If the year-month-day part is not specified it takes the current
149 @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata})
150 Set a metadata key/value pair.
152 An optional @var{metadata_specifier} may be given to set metadata
153 on streams or chapters. See @code{-map_metadata} documentation for
156 This option overrides metadata set with @code{-map_metadata}. It is
157 also possible to delete metadata by using an empty value.
159 For example, for setting the title in the output file:
161 ffmpeg -i in.avi -metadata title="my title" out.flv
164 To set the language of the second stream:
166 ffmpeg -i INPUT -metadata:s:1 language=eng OUTPUT
169 @item -v @var{number} (@emph{global})
170 This option is deprecated and has no effect, use -loglevel
171 to set verbosity level.
173 @item -target @var{type} (@emph{output})
174 Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
175 @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or
176 @code{film-} to use the corresponding standard. All the format options
177 (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
180 ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
183 Nevertheless you can specify additional options as long as you know
184 they do not conflict with the standard, as in:
187 ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
190 @item -dframes @var{number} (@emph{output})
191 Set the number of data frames to record. This is an alias for @code{-frames:d}.
193 @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream})
194 Stop writing to the stream after @var{framecount} frames.
196 @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
197 @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
198 Use fixed quality scale (VBR). The meaning of @var{q} is
201 @item -filter[:@var{stream_specifier}] @var{filter_graph}
202 @var{filter_graph} is a description of the filter graph to apply to
203 the stream. Use @code{-filters} to show all the available filters
204 (including also sources and sinks).
208 @section Video Options
211 @item -vframes @var{number} (@emph{output})
212 Set the number of video frames to record. This is an alias for @code{-frames:v}.
213 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
214 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
215 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
216 Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
217 The following abbreviations are recognized:
279 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
280 Set the video display aspect ratio specified by @var{aspect}.
282 @var{aspect} can be a floating point number string, or a string of the
283 form @var{num}:@var{den}, where @var{num} and @var{den} are the
284 numerator and denominator of the aspect ratio. For example "4:3",
285 "16:9", "1.3333", and "1.7777" are valid argument values.
287 @item -croptop @var{size}
288 @item -cropbottom @var{size}
289 @item -cropleft @var{size}
290 @item -cropright @var{size}
291 All the crop options have been removed. Use -vf
292 crop=width:height:x:y instead.
294 @item -padtop @var{size}
295 @item -padbottom @var{size}
296 @item -padleft @var{size}
297 @item -padright @var{size}
298 @item -padcolor @var{hex_color}
299 All the pad options have been removed. Use -vf
300 pad=width:height:x:y:color instead.
302 @item -vn (@emph{output})
303 Disable video recording.
304 @item -bt @var{tolerance}
305 Set video bitrate tolerance (in bits, default 4000k).
306 Has a minimum value of: (target_bitrate/target_framerate).
307 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
308 willing to deviate from the target average bitrate value. This is
309 not related to min/max bitrate. Lowering tolerance too much has
310 an adverse effect on quality.
311 @item -maxrate @var{bitrate}
312 Set max video bitrate (in bit/s).
313 Requires -bufsize to be set.
314 @item -minrate @var{bitrate}
315 Set min video bitrate (in bit/s).
316 Most useful in setting up a CBR encode:
318 ffmpeg -i myfile.avi -b:v 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
320 It is of little use elsewise.
321 @item -bufsize @var{size}
322 Set video buffer verifier buffer size (in bits).
323 @item -vcodec @var{codec} (@emph{output})
324 Set the video codec. This is an alias for @code{-codec:v}.
326 Use same quantizer as source (implies VBR).
328 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
332 Select the pass number (1 or 2). It is used to do two-pass
333 video encoding. The statistics of the video are recorded in the first
334 pass into a log file (see also the option -passlogfile),
335 and in the second pass that log file is used to generate the video
336 at the exact requested bitrate.
337 On pass 1, you may just deactivate audio and set output to null,
338 examples for Windows and Unix:
340 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
341 ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
344 @item -passlogfile @var{prefix} (@emph{global})
345 Set two-pass log file name prefix to @var{prefix}, the default file name
346 prefix is ``ffmpeg2pass''. The complete file name will be
347 @file{PREFIX-N.log}, where N is a number specific to the output
350 @item -vlang @var{code}
351 Set the ISO 639 language code (3 letters) of the current video stream.
353 @item -vf @var{filter_graph} (@emph{output})
354 @var{filter_graph} is a description of the filter graph to apply to
356 Use the option "-filters" to show all the available filters (including
357 also sources and sinks). This is an alias for @code{-filter:v}.
361 @section Advanced Video Options
364 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
365 Set pixel format. Use @code{-pix_fmts} to show all the supported
367 @item -sws_flags @var{flags} (@emph{input/output})
369 @item -g @var{gop_size}
370 Set the group of pictures size.
376 minimum video quantizer scale (VBR)
378 maximum video quantizer scale (VBR)
380 maximum difference between the quantizer scales (VBR)
381 @item -qblur @var{blur}
382 video quantizer scale blur (VBR) (range 0.0 - 1.0)
383 @item -qcomp @var{compression}
384 video quantizer scale compression (VBR) (default 0.5).
385 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
387 @item -lmin @var{lambda}
388 minimum video lagrange factor (VBR)
389 @item -lmax @var{lambda}
390 max video lagrange factor (VBR)
391 @item -mblmin @var{lambda}
392 minimum macroblock quantizer scale (VBR)
393 @item -mblmax @var{lambda}
394 maximum macroblock quantizer scale (VBR)
396 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
397 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
399 ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
402 @item -rc_init_cplx @var{complexity}
403 initial complexity for single pass encoding
404 @item -b_qfactor @var{factor}
405 qp factor between P- and B-frames
406 @item -i_qfactor @var{factor}
407 qp factor between P- and I-frames
408 @item -b_qoffset @var{offset}
409 qp offset between P- and B-frames
410 @item -i_qoffset @var{offset}
411 qp offset between P- and I-frames
412 @item -rc_eq @var{equation}
413 Set rate control equation (see section "Expression Evaluation")
414 (default = @code{tex^qComp}).
416 When computing the rate control equation expression, besides the
417 standard functions defined in the section "Expression Evaluation", the
418 following functions are available:
424 and the following constants are available:
446 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
447 Rate control override for specific intervals, formated as "int,int,int"
448 list separated with slashes. Two first values are the beginning and
449 end frame numbers, last one is quantizer to use if positive, or quality
451 @item -me_method @var{method}
452 Set motion estimation method to @var{method}.
453 Available methods are (from lowest to best quality):
456 Try just the (0, 0) vector.
465 exhaustive search (slow and marginally better than epzs)
468 @item -dct_algo @var{algo}
469 Set DCT algorithm to @var{algo}. Available values are:
472 FF_DCT_AUTO (default)
485 @item -idct_algo @var{algo}
486 Set IDCT algorithm to @var{algo}. Available values are:
489 FF_IDCT_AUTO (default)
513 Set error resilience to @var{n}.
516 FF_ER_CAREFUL (default)
522 FF_ER_VERY_AGGRESSIVE
525 @item -ec @var{bit_mask}
526 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
527 the following values:
530 FF_EC_GUESS_MVS (default = enabled)
532 FF_EC_DEBLOCK (default = enabled)
535 @item -bf @var{frames}
536 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
537 @item -mbd @var{mode}
541 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in ffmpeg).
543 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
545 FF_MB_DECISION_RD: rate distortion
549 Use four motion vector by macroblock (MPEG-4 only).
551 Use data partitioning (MPEG-4 only).
552 @item -bug @var{param}
553 Work around encoder bugs that are not auto-detected.
554 @item -strict @var{strictness}
555 How strictly to follow the standards.
557 Enable Advanced intra coding (h263+).
559 Enable Unlimited Motion Vector (h263+)
562 Deinterlace pictures.
564 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
565 Use this option if your input file is interlaced and you want
566 to keep the interlaced format for minimum losses.
567 The alternative is to deinterlace the input stream with
568 @option{-deinterlace}, but deinterlacing introduces losses.
570 Calculate PSNR of compressed frames.
572 Dump video coding statistics to @file{vstats_HHMMSS.log}.
573 @item -vstats_file @var{file}
574 Dump video coding statistics to @var{file}.
575 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
576 top=1/bottom=0/auto=-1 field first
577 @item -dc @var{precision}
579 @item -vtag @var{fourcc/tag} (@emph{output})
580 Force video tag/fourcc. This is an alias for @code{-tag:v}.
581 @item -qphist (@emph{global})
583 @item -vbsf @var{bitstream_filter}
585 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
586 Force key frames at the specified timestamps, more precisely at the first
587 frames after each specified time.
588 This option can be useful to ensure that a seek point is present at a
589 chapter mark or any other designated place in the output file.
590 The timestamps must be specified in ascending order.
593 @section Audio Options
596 @item -aframes @var{number} (@emph{output})
597 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
598 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
599 Set the audio sampling frequency. For output streams it is set by
600 default to the frequency of the corresponding input stream. For input
601 streams this option only makes sense for audio grabbing devices and raw
602 demuxers and is mapped to the corresponding demuxer options.
603 @item -aq @var{q} (@emph{output})
604 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
605 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
606 Set the number of audio channels. For output streams it is set by
607 default to the number of input audio channels. For input streams
608 this option only makes sense for audio grabbing devices and raw demuxers
609 and is mapped to the corresponding demuxer options.
610 @item -an (@emph{output})
611 Disable audio recording.
612 @item -acodec @var{codec} (@emph{input/output})
613 Set the audio codec. This is an alias for @code{-codec:a}.
614 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
615 Set the audio sample format. Use @code{-help sample_fmts} to get a list
616 of supported sample formats.
619 @section Advanced Audio options:
622 @item -atag @var{fourcc/tag} (@emph{output})
623 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
624 @item -audio_service_type @var{type}
625 Set the type of service that the audio stream contains.
628 Main Audio Service (default)
646 @item -absf @var{bitstream_filter}
650 @section Subtitle options:
653 @item -slang @var{code}
654 Set the ISO 639 language code (3 letters) of the current subtitle stream.
655 @item -scodec @var{codec} (@emph{input/output})
656 Set the subtitle codec. This is an alias for @code{-codec:s}.
657 @item -sn (@emph{output})
658 Disable subtitle recording.
659 @item -sbsf @var{bitstream_filter}
663 @section Audio/Video grab options
666 @item -isync (@emph{global})
667 Synchronize read on input.
670 @section Advanced options
673 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] (@emph{output})
675 Designate one or more input streams as a source for the output file. Each input
676 stream is identified by the input file index @var{input_file_id} and
677 the input stream index @var{input_stream_id} within the input
678 file. Both indices start at 0. If specified,
679 @var{sync_file_id}:@var{stream_specifier} sets which input stream
680 is used as a presentation sync reference.
682 The first @code{-map} option on the command line specifies the
683 source for output stream 0, the second @code{-map} option specifies
684 the source for output stream 1, etc.
686 A @code{-} character before the stream identifier creates a "negative" mapping.
687 It disables matching streams from already created mappings.
689 For example, to map ALL streams from the first input file to output
691 ffmpeg -i INPUT -map 0 output
694 For example, if you have two audio streams in the first input file,
695 these streams are identified by "0:0" and "0:1". You can use
696 @code{-map} to select which streams to place in an output file. For
699 ffmpeg -i INPUT -map 0:1 out.wav
701 will map the input stream in @file{INPUT} identified by "0:1" to
702 the (single) output stream in @file{out.wav}.
704 For example, to select the stream with index 2 from input file
705 @file{a.mov} (specified by the identifier "0:2"), and stream with
706 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
707 and copy them to the output file @file{out.mov}:
709 ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
712 To select all video and the third audio stream from an input file:
714 ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
717 To map all the streams except the second audio, use negative mappings
719 ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
722 Note that using this option disables the default mappings for this output file.
724 @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}]
725 Map an audio channel from a given input to an output. If
726 @var{output_file_id}.@var{stream_specifier} are not set, the audio channel will
727 be mapped on all the audio streams.
729 Using "-1" instead of
730 @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted
733 For example, assuming @var{INPUT} is a stereo audio file, you can switch the
734 two audio channels with the following command:
736 ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
739 If you want to mute the first channel and keep the second:
741 ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
744 The order of the "-map_channel" option specifies the order of the channels in
745 the output stream. The output channel layout is guessed from the number of
746 channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
747 in combination of "-map_channel" makes the channel gain levels to be updated if
748 channel layouts don't match (for instance two "-map_channel" options and "-ac
751 You can also extract each channel of an @var{INPUT} to specific outputs; the
752 following command extract each channel of the audio stream (file 0, stream 0)
753 to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1}:
755 ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
758 Note that "-map_channel" is currently limited to the scope of one input for
759 each output; you can't for example use it to pick multiple input audio files
760 and mix them into one single output.
762 @item -map_metadata[:@var{metadata_type}][:@var{index}] @var{infile}[:@var{metadata_type}][:@var{index}] (@emph{output,per-metadata})
763 Set metadata information of the next output file from @var{infile}. Note that
764 those are file indices (zero-based), not filenames.
765 Optional @var{metadata_type} parameters specify, which metadata to copy - (g)lobal
766 (i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
767 per-(p)rogram. All metadata specifiers other than global must be followed by the
768 stream/chapter/program index. If metadata specifier is omitted, it defaults to
771 By default, global metadata is copied from the first input file,
772 per-stream and per-chapter metadata is copied along with streams/chapters. These
773 default mappings are disabled by creating any mapping of the relevant type. A negative
774 file index can be used to create a dummy mapping that just disables automatic copying.
776 For example to copy metadata from the first stream of the input file to global metadata
779 ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
781 @item -map_chapters @var{input_file_index} (@emph{output})
782 Copy chapters from input file with index @var{input_file_index} to the next
783 output file. If no chapter mapping is specified, then chapters are copied from
784 the first input file with at least one chapter. Use a negative file index to
785 disable any chapter copying.
786 @item -debug @var{category}
787 Print specific debug info.
788 @var{category} is a number or a string containing one of the following values:
792 picture buffer allocations
800 memory management control operations (H.264)
807 per-block quantization parameter (QP)
815 visualize block types
817 visualize quantization parameter (QP), lower QP are tinted greener
819 @item -benchmark (@emph{global})
820 Show benchmarking information at the end of an encode.
821 Shows CPU time used and maximum memory consumption.
822 Maximum memory consumption is not supported on all systems,
823 it will usually display as 0 if not supported.
824 @item -timelimit @var{duration} (@emph{global})
825 Exit after ffmpeg has been running for @var{duration} seconds.
826 @item -dump (@emph{global})
827 Dump each input packet to stderr.
828 @item -hex (@emph{global})
829 When dumping packets, also dump the payload.
831 Set RTP payload size in bytes.
832 @item -re (@emph{input})
833 Read input at native frame rate. Mainly used to simulate a grab device.
835 Loop over the input stream. Currently it works only for image
836 streams. This option is used for automatic FFserver testing.
837 This option is deprecated, use -loop 1.
838 @item -loop_output @var{number_of_times}
839 Repeatedly loop output for formats that support looping such as animated GIF
840 (0 will loop the output infinitely).
841 This option is deprecated, use -loop.
842 @item -threads @var{count}
844 @item -vsync @var{parameter}
849 Each frame is passed with its timestamp from the demuxer to the muxer.
851 Frames will be duplicated and dropped to achieve exactly the requested
854 Frames are passed through with their timestamp or dropped so as to
855 prevent 2 frames from having the same timestamp.
857 Chooses between 1 and 2 depending on muxer capabilities. This is the
861 With -map you can select from which stream the timestamps should be
862 taken. You can leave either video or audio unchanged and sync the
863 remaining stream(s) to the unchanged one.
865 @item -async @var{samples_per_second}
866 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
867 the parameter is the maximum samples per second by which the audio is changed.
868 -async 1 is a special case where only the start of the audio stream is corrected
869 without any later correction.
871 Copy timestamps from input to output.
873 Copy input stream time base from input to output when stream copying.
875 Finish encoding when the shortest input stream ends.
876 @item -dts_delta_threshold
877 Timestamp discontinuity delta threshold.
878 @item -muxdelay @var{seconds} (@emph{input})
879 Set the maximum demux-decode delay.
880 @item -muxpreload @var{seconds} (@emph{input})
881 Set the initial demux-decode delay.
882 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
883 Assign a new stream-id value to an output stream. This option should be
884 specified prior to the output filename to which it applies.
885 For the situation where multiple output files exist, a streamid
886 may be reassigned to a different value.
888 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
889 an output mpegts file:
891 ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
894 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
895 Set bitstream filters for matching streams. @var{bistream_filters} is
896 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
897 to get the list of bitstream filters.
899 ffmpeg -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
902 ffmpeg -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
905 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{per-stream})
906 Force a tag/fourcc for matching streams.
909 @section Preset files
910 A preset file contains a sequence of @var{option}=@var{value} pairs,
911 one for each line, specifying a sequence of options which would be
912 awkward to specify on the command line. Lines starting with the hash
913 ('#') character are ignored and are used to provide comments. Check
914 the @file{presets} directory in the FFmpeg source tree for examples.
916 Preset files are specified with the @code{vpre}, @code{apre},
917 @code{spre}, and @code{fpre} options. The @code{fpre} option takes the
918 filename of the preset instead of a preset name as input and can be
919 used for any kind of codec. For the @code{vpre}, @code{apre}, and
920 @code{spre} options, the options specified in a preset file are
921 applied to the currently selected codec of the same type as the preset
924 The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
925 preset options identifies the preset file to use according to the
928 First ffmpeg searches for a file named @var{arg}.ffpreset in the
929 directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in
930 the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg})
931 or in a @file{ffpresets} folder along the executable on win32,
932 in that order. For example, if the argument is @code{libx264-max}, it will
933 search for the file @file{libx264-max.ffpreset}.
935 If no such file is found, then ffmpeg will search for a file named
936 @var{codec_name}-@var{arg}.ffpreset in the above-mentioned
937 directories, where @var{codec_name} is the name of the codec to which
938 the preset file options will be applied. For example, if you select
939 the video codec with @code{-vcodec libx264} and use @code{-vpre max},
940 then it will search for the file @file{libx264-max.ffpreset}.
948 For streaming at very low bitrate application, use a low frame rate
949 and a small GOP size. This is especially true for RealVideo where
950 the Linux player does not seem to be very fast, so it can miss
951 frames. An example is:
954 ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
958 The parameter 'q' which is displayed while encoding is the current
959 quantizer. The value 1 indicates that a very good quality could
960 be achieved. The value 31 indicates the worst quality. If q=31 appears
961 too often, it means that the encoder cannot compress enough to meet
962 your bitrate. You must either increase the bitrate, decrease the
963 frame rate or decrease the frame size.
966 If your computer is not fast enough, you can speed up the
967 compression at the expense of the compression ratio. You can use
968 '-me zero' to speed up motion estimation, and '-intra' to disable
969 motion estimation completely (you have only I-frames, which means it
970 is about as good as JPEG compression).
973 To have very low audio bitrates, reduce the sampling frequency
974 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
977 To have a constant quality (but a variable bitrate), use the option
978 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
985 @c man begin EXAMPLES
987 @section Video and Audio grabbing
989 If you specify the input format and device then ffmpeg can grab video
993 ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
996 Or with an ALSA audio source (mono input, card id 1) instead of OSS:
998 ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
1001 Note that you must activate the right video source and channel before
1002 launching ffmpeg with any TV viewer such as
1003 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
1004 have to set the audio recording levels correctly with a
1007 @section X11 grabbing
1009 Grab the X11 display with ffmpeg via
1012 ffmpeg -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
1015 0.0 is display.screen number of your X11 server, same as
1016 the DISPLAY environment variable.
1019 ffmpeg -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
1022 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
1023 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
1025 @section Video and Audio file format conversion
1027 Any supported file format and protocol can serve as input to ffmpeg:
1032 You can use YUV files as input:
1035 ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
1038 It will use the files:
1040 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
1041 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
1044 The Y files use twice the resolution of the U and V files. They are
1045 raw files, without header. They can be generated by all decent video
1046 decoders. You must specify the size of the image with the @option{-s} option
1047 if ffmpeg cannot guess it.
1050 You can input from a raw YUV420P file:
1053 ffmpeg -i /tmp/test.yuv /tmp/out.avi
1056 test.yuv is a file containing raw YUV planar data. Each frame is composed
1057 of the Y plane followed by the U and V planes at half vertical and
1058 horizontal resolution.
1061 You can output to a raw YUV420P file:
1064 ffmpeg -i mydivx.avi hugefile.yuv
1068 You can set several input files and output files:
1071 ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
1074 Converts the audio file a.wav and the raw YUV video file a.yuv
1078 You can also do audio and video conversions at the same time:
1081 ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
1084 Converts a.wav to MPEG audio at 22050 Hz sample rate.
1087 You can encode to several formats at the same time and define a
1088 mapping from input stream to output streams:
1091 ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
1094 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
1095 file:index' specifies which input stream is used for each output
1096 stream, in the order of the definition of output streams.
1099 You can transcode decrypted VOBs:
1102 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
1105 This is a typical DVD ripping example; the input is a VOB file, the
1106 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
1107 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
1108 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
1109 input video. Furthermore, the audio stream is MP3-encoded so you need
1110 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
1111 The mapping is particularly useful for DVD transcoding
1112 to get the desired audio language.
1114 NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
1117 You can extract images from a video, or create a video from many images:
1119 For extracting images from a video:
1121 ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1124 This will extract one video frame per second from the video and will
1125 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1126 etc. Images will be rescaled to fit the new WxH values.
1128 If you want to extract just a limited number of frames, you can use the
1129 above command in combination with the -vframes or -t option, or in
1130 combination with -ss to start extracting from a certain point in time.
1132 For creating a video from many images:
1134 ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1137 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1138 composed of three digits padded with zeroes to express the sequence
1139 number. It is the same syntax supported by the C printf function, but
1140 only formats accepting a normal integer are suitable.
1143 You can put many streams of the same type in the output:
1146 ffmpeg -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1149 The resulting output file @file{test12.avi} will contain first four streams from
1150 the input file in reverse order.
1156 @include decoders.texi
1157 @include encoders.texi
1158 @include demuxers.texi
1159 @include muxers.texi
1160 @include indevs.texi
1161 @include outdevs.texi
1162 @include protocols.texi
1163 @include bitstream_filters.texi
1164 @include filters.texi
1165 @include metadata.texi
1170 @settitle ffmpeg video converter
1172 @c man begin SEEALSO
1173 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1176 @c man begin AUTHORS