1 \input texinfo @c -*- texinfo -*-
3 @settitle avconv Documentation
5 @center @titlefont{avconv Documentation}
14 The generic syntax is:
18 avconv [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
23 @c man begin DESCRIPTION
25 avconv 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 The command line interface is designed to be intuitive, in the sense
30 that avconv tries to figure out all parameters that can possibly be
31 derived automatically. You usually only have to specify the target
34 As a general rule, options are applied to the next specified
35 file. Therefore, order is important, and you can have the same
36 option on the command line multiple times. Each occurrence is
37 then applied to the next input or output file.
41 To set the video bitrate of the output file to 64kbit/s:
43 avconv -i input.avi -b 64k output.avi
47 To force the frame rate of the output file to 24 fps:
49 avconv -i input.avi -r 24 output.avi
53 To force the frame rate of the input file (valid for raw formats only)
54 to 1 fps and the frame rate of the output file to 24 fps:
56 avconv -r 1 -i input.m2v -r 24 output.avi
60 The format option may be needed for raw input files.
62 By default avconv tries to convert as losslessly as possible: It
63 uses the same audio and video parameters for the outputs as the one
64 specified for the inputs.
66 @c man end DESCRIPTION
68 @chapter Stream selection
69 @c man begin STREAM SELECTION
71 By default avconv tries to pick the "best" stream of each type present in input
72 files and add them to each output file. For video, this means the highest
73 resolution, for audio the highest channel count. For subtitle it's simply the
74 first subtitle stream.
76 You can disable some of those defaults by using @code{-vn/-an/-sn} options. For
77 full manual control, use the @code{-map} option, which disables the defaults just
80 @c man end STREAM SELECTION
85 @include fftools-common-opts.texi
94 @item -i @var{filename}
98 Overwrite output files.
100 @item -c[:@var{stream_type}][:@var{stream_index}] @var{codec}
101 @item -codec[:@var{stream_type}][:@var{stream_index}] @var{codec}
102 Select an encoder (when used before an output file) or a decoder (when used
103 before an input file) for one or more streams. @var{codec} is the name of a
104 decoder/encoder or a special value @code{copy} (output only) to indicate that
105 the stream is not to be reencoded.
107 @var{stream_type} may be 'v' for video, 'a' for audio, 's' for subtitle and 'd'
108 for data streams. @var{stream_index} is a global zero-based stream index if
109 @var{stream_type} isn't given, otherwise it counts only streams of the given
110 type. If @var{stream_index} is omitted, this option applies to all streams of
111 the given type or all streams of any type if @var{stream_type} is missing as
112 well (note that this only makes sense when all streams are of the same type or
113 @var{codec} is @code{copy}).
117 avconv -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
119 encodes all video streams with libx264 and copies all audio streams.
121 For each stream, the last matching @code{c} option is applied, so
123 avconv -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
125 will copy all the streams except the second video, which will be encoded with
126 libx264, and the 138th audio, which will be encoded with libvorbis.
128 @item -t @var{duration}
129 Restrict the transcoded/captured video sequence
130 to the duration specified in seconds.
131 @code{hh:mm:ss[.xxx]} syntax is also supported.
133 @item -fs @var{limit_size}
134 Set the file size limit.
136 @item -ss @var{position}
137 When used as an input option (before @code{-i}), seeks in this input file to
138 @var{position}. When used as an output option (before an output filename),
139 decodes but discards input until the timestamps reach @var{position}. This is
140 slower, but more accurate.
142 @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
144 @item -itsoffset @var{offset}
145 Set the input time offset in seconds.
146 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
147 The offset is added to the timestamps of the input files.
148 Specifying a positive offset means that the corresponding
149 streams are delayed by 'offset' seconds.
151 @item -timestamp @var{time}
152 Set the recording timestamp in the container.
153 The syntax for @var{time} is:
155 now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
157 If the value is "now" it takes the current time.
158 Time is local time unless 'Z' or 'z' is appended, in which case it is
160 If the year-month-day part is not specified it takes the current
163 @item -metadata[:metadata_specifier] @var{key}=@var{value}
164 Set a metadata key/value pair.
166 An optional @var{metadata_specifier} may be given to set metadata
167 on streams or chapters. See @code{-map_metadata} documentation for
170 This option overrides metadata set with @code{-map_metadata}. It is
171 also possible to delete metadata by using an empty value.
173 For example, for setting the title in the output file:
175 avconv -i in.avi -metadata title="my title" out.flv
178 To set the language of the second stream:
180 avconv -i INPUT -metadata:s:1 language=eng OUTPUT
183 @item -v @var{number}
184 Set the logging verbosity level.
186 @item -target @var{type}
187 Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
188 "ntsc-svcd", ... ). All the format options (bitrate, codecs,
189 buffer sizes) are then set automatically. You can just type:
192 avconv -i myfile.avi -target vcd /tmp/vcd.mpg
195 Nevertheless you can specify additional options as long as you know
196 they do not conflict with the standard, as in:
199 avconv -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
202 @item -dframes @var{number}
203 Set the number of data frames to record. This is an alias for @code{-frames:d}.
205 @item -frames[:stream_specifier] @var{framecount}
206 Stop writing to the stream after @var{framecount} frames.
210 @section Video Options
213 @item -vframes @var{number}
214 Set the number of video frames to record. This is an alias for @code{-frames:v}.
216 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
218 Set frame size. The format is @samp{wxh} (avserver default = 160x128, avconv default = same as source).
219 The following abbreviations are recognized:
281 @item -aspect @var{aspect}
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.
290 Disable video recording.
291 @item -bt @var{tolerance}
292 Set video bitrate tolerance (in bits, default 4000k).
293 Has a minimum value of: (target_bitrate/target_framerate).
294 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
295 willing to deviate from the target average bitrate value. This is
296 not related to min/max bitrate. Lowering tolerance too much has
297 an adverse effect on quality.
298 @item -maxrate @var{bitrate}
299 Set max video bitrate (in bit/s).
300 Requires -bufsize to be set.
301 @item -minrate @var{bitrate}
302 Set min video bitrate (in bit/s).
303 Most useful in setting up a CBR encode:
305 avconv -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
307 It is of little use elsewise.
308 @item -bufsize @var{size}
309 Set video buffer verifier buffer size (in bits).
310 @item -vcodec @var{codec}
311 Set the video codec. This is an alias for @code{-codec:v}.
313 Use same quantizer as source (implies VBR).
315 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
319 Select the pass number (1 or 2). It is used to do two-pass
320 video encoding. The statistics of the video are recorded in the first
321 pass into a log file (see also the option -passlogfile),
322 and in the second pass that log file is used to generate the video
323 at the exact requested bitrate.
324 On pass 1, you may just deactivate audio and set output to null,
325 examples for Windows and Unix:
327 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
328 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
331 @item -passlogfile @var{prefix}
332 Set two-pass log file name prefix to @var{prefix}, the default file name
333 prefix is ``av2pass''. The complete file name will be
334 @file{PREFIX-N.log}, where N is a number specific to the output
337 @item -vf @var{filter_graph}
338 @var{filter_graph} is a description of the filter graph to apply to
340 Use the option "-filters" to show all the available filters (including
341 also sources and sinks).
345 @section Advanced Video Options
348 @item -pix_fmt @var{format}
349 Set pixel format. Use 'list' as parameter to show all the supported
351 @item -sws_flags @var{flags}
353 @item -g @var{gop_size}
354 Set the group of pictures size.
357 @item -qscale @var{q}
358 Use fixed video quantizer scale (VBR).
360 minimum video quantizer scale (VBR)
362 maximum video quantizer scale (VBR)
364 maximum difference between the quantizer scales (VBR)
365 @item -qblur @var{blur}
366 video quantizer scale blur (VBR) (range 0.0 - 1.0)
367 @item -qcomp @var{compression}
368 video quantizer scale compression (VBR) (default 0.5).
369 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
371 @item -lmin @var{lambda}
372 minimum video lagrange factor (VBR)
373 @item -lmax @var{lambda}
374 max video lagrange factor (VBR)
375 @item -mblmin @var{lambda}
376 minimum macroblock quantizer scale (VBR)
377 @item -mblmax @var{lambda}
378 maximum macroblock quantizer scale (VBR)
380 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
381 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
383 avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
386 @item -rc_init_cplx @var{complexity}
387 initial complexity for single pass encoding
388 @item -b_qfactor @var{factor}
389 qp factor between P- and B-frames
390 @item -i_qfactor @var{factor}
391 qp factor between P- and I-frames
392 @item -b_qoffset @var{offset}
393 qp offset between P- and B-frames
394 @item -i_qoffset @var{offset}
395 qp offset between P- and I-frames
396 @item -rc_eq @var{equation}
397 Set rate control equation (see section "Expression Evaluation")
398 (default = @code{tex^qComp}).
400 When computing the rate control equation expression, besides the
401 standard functions defined in the section "Expression Evaluation", the
402 following functions are available:
408 and the following constants are available:
430 @item -rc_override @var{override}
431 rate control override for specific intervals
432 @item -me_method @var{method}
433 Set motion estimation method to @var{method}.
434 Available methods are (from lowest to best quality):
437 Try just the (0, 0) vector.
446 exhaustive search (slow and marginally better than epzs)
449 @item -dct_algo @var{algo}
450 Set DCT algorithm to @var{algo}. Available values are:
453 FF_DCT_AUTO (default)
466 @item -idct_algo @var{algo}
467 Set IDCT algorithm to @var{algo}. Available values are:
470 FF_IDCT_AUTO (default)
494 Set error resilience to @var{n}.
497 FF_ER_CAREFUL (default)
503 FF_ER_VERY_AGGRESSIVE
506 @item -ec @var{bit_mask}
507 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
508 the following values:
511 FF_EC_GUESS_MVS (default = enabled)
513 FF_EC_DEBLOCK (default = enabled)
516 @item -bf @var{frames}
517 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
518 @item -mbd @var{mode}
522 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in avconv).
524 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
526 FF_MB_DECISION_RD: rate distortion
530 Use four motion vector by macroblock (MPEG-4 only).
532 Use data partitioning (MPEG-4 only).
533 @item -bug @var{param}
534 Work around encoder bugs that are not auto-detected.
535 @item -strict @var{strictness}
536 How strictly to follow the standards.
538 Enable Advanced intra coding (h263+).
540 Enable Unlimited Motion Vector (h263+)
543 Deinterlace pictures.
545 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
546 Use this option if your input file is interlaced and you want
547 to keep the interlaced format for minimum losses.
548 The alternative is to deinterlace the input stream with
549 @option{-deinterlace}, but deinterlacing introduces losses.
551 Calculate PSNR of compressed frames.
553 Dump video coding statistics to @file{vstats_HHMMSS.log}.
554 @item -vstats_file @var{file}
555 Dump video coding statistics to @var{file}.
557 top=1/bottom=0/auto=-1 field first
558 @item -dc @var{precision}
560 @item -vtag @var{fourcc/tag}
561 Force video tag/fourcc. This is an alias for @code{-tag:v}.
564 @item -force_key_frames @var{time}[,@var{time}...]
565 Force key frames at the specified timestamps, more precisely at the first
566 frames after each specified time.
567 This option can be useful to ensure that a seek point is present at a
568 chapter mark or any other designated place in the output file.
569 The timestamps must be specified in ascending order.
572 @section Audio Options
575 @item -aframes @var{number}
576 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
578 Set the audio sampling frequency. For output streams it is set by
579 default to the frequency of the corresponding input stream. For input
580 streams this option only makes sense for audio grabbing devices and raw
581 demuxers and is mapped to the corresponding demuxer options.
583 Set the audio quality (codec-specific, VBR).
584 @item -ac @var{channels}
585 Set the number of audio channels. For output streams it is set by
586 default to the number of input audio channels. For input streams
587 this option only makes sense for audio grabbing devices and raw demuxers
588 and is mapped to the corresponding demuxer options.
590 Disable audio recording.
591 @item -acodec @var{codec}
592 Set the audio codec. This is an alias for @code{-codec:a}.
595 @section Advanced Audio options:
598 @item -atag @var{fourcc/tag}
599 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
600 @item -audio_service_type @var{type}
601 Set the type of service that the audio stream contains.
604 Main Audio Service (default)
624 @section Subtitle options:
627 @item -scodec @var{codec}
628 Set the subtitle codec. This is an alias for @code{-codec:s}.
630 Disable subtitle recording.
633 @section Audio/Video grab options
637 Synchronize read on input.
640 @section Advanced options
643 @item -map [-]@var{input_file_id}[:@var{input_stream_type}][:@var{input_stream_id}][,@var{sync_file_id}[:@var{sync_stream_type}][:@var{sync_stream_id}]]
645 Designate one or more input streams as a source for the output file. Each input
646 stream is identified by the input file index @var{input_file_id} and
647 the input stream index @var{input_stream_id} within the input
648 file. Both indices start at 0. If specified,
649 @var{sync_file_id}:@var{sync_stream_id} sets which input stream
650 is used as a presentation sync reference.
652 If @var{input_stream_type} is specified -- 'v' for video, 'a' for audio, 's' for
653 subtitle and 'd' for data -- then @var{input_stream_id} counts only the streams
654 of this type. Same for @var{sync_stream_type}.
656 @var{input_stream_id} may be omitted, in which case all streams of the given
657 type are mapped (or all streams in the file, if no type is specified).
659 The first @code{-map} option on the command line specifies the
660 source for output stream 0, the second @code{-map} option specifies
661 the source for output stream 1, etc.
663 A @code{-} character before the stream identifier creates a "negative" mapping.
664 It disables matching streams from already created mappings.
666 For example, to map ALL streams from the first input file to output
668 avconv -i INPUT -map 0 output
671 For example, if you have two audio streams in the first input file,
672 these streams are identified by "0:0" and "0:1". You can use
673 @code{-map} to select which streams to place in an output file. For
676 avconv -i INPUT -map 0:1 out.wav
678 will map the input stream in @file{INPUT} identified by "0:1" to
679 the (single) output stream in @file{out.wav}.
681 For example, to select the stream with index 2 from input file
682 @file{a.mov} (specified by the identifier "0:2"), and stream with
683 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
684 and copy them to the output file @file{out.mov}:
686 avconv -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
689 To select all video and the third audio stream from an input file:
691 avconv -i INPUT -map 0:v -map 0:a:2 OUTPUT
694 To map all the streams except the second audio, use negative mappings
696 avconv -i INPUT -map 0 -map -0:a:1 OUTPUT
699 Note that using this option disables the default mappings for this output file.
701 @item -map_metadata[:@var{metadata_type}][:@var{index}] @var{infile}[:@var{metadata_type}][:@var{index}]
702 Set metadata information of the next output file from @var{infile}. Note that
703 those are file indices (zero-based), not filenames.
704 Optional @var{metadata_type} parameters specify, which metadata to copy - (g)lobal
705 (i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
706 per-(p)rogram. All metadata specifiers other than global must be followed by the
707 stream/chapter/program index. If metadata specifier is omitted, it defaults to
710 By default, global metadata is copied from the first input file,
711 per-stream and per-chapter metadata is copied along with streams/chapters. These
712 default mappings are disabled by creating any mapping of the relevant type. A negative
713 file index can be used to create a dummy mapping that just disables automatic copying.
715 For example to copy metadata from the first stream of the input file to global metadata
718 avconv -i in.ogg -map_metadata 0:s:0 out.mp3
720 @item -map_chapters @var{input_file_index}
721 Copy chapters from input file with index @var{input_file_index} to the next
722 output file. If no chapter mapping is specified, then chapters are copied from
723 the first input file with at least one chapter. Use a negative file index to
724 disable any chapter copying.
726 Print specific debug info.
728 Show benchmarking information at the end of an encode.
729 Shows CPU time used and maximum memory consumption.
730 Maximum memory consumption is not supported on all systems,
731 it will usually display as 0 if not supported.
733 Dump each input packet.
735 When dumping packets, also dump the payload.
737 Only use bit exact algorithms (for codec testing).
739 Set RTP payload size in bytes.
741 Read input at native frame rate. Mainly used to simulate a grab device.
742 @item -threads @var{count}
744 @item -vsync @var{parameter}
749 Each frame is passed with its timestamp from the demuxer to the muxer.
751 Frames will be duplicated and dropped to achieve exactly the requested
754 Frames are passed through with their timestamp or dropped so as to
755 prevent 2 frames from having the same timestamp.
757 Chooses between 1 and 2 depending on muxer capabilities. This is the
761 With -map you can select from which stream the timestamps should be
762 taken. You can leave either video or audio unchanged and sync the
763 remaining stream(s) to the unchanged one.
765 @item -async @var{samples_per_second}
766 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
767 the parameter is the maximum samples per second by which the audio is changed.
768 -async 1 is a special case where only the start of the audio stream is corrected
769 without any later correction.
771 Copy timestamps from input to output.
773 Copy input stream time base from input to output when stream copying.
775 Finish encoding when the shortest input stream ends.
776 @item -dts_delta_threshold
777 Timestamp discontinuity delta threshold.
778 @item -muxdelay @var{seconds}
779 Set the maximum demux-decode delay.
780 @item -muxpreload @var{seconds}
781 Set the initial demux-decode delay.
782 @item -streamid @var{output-stream-index}:@var{new-value}
783 Assign a new stream-id value to an output stream. This option should be
784 specified prior to the output filename to which it applies.
785 For the situation where multiple output files exist, a streamid
786 may be reassigned to a different value.
788 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
789 an output mpegts file:
791 avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
794 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters}
795 Set bitstream filters for matching streams. @var{bistream_filters} is
796 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
797 to get the list of bitstream filters.
799 avconv -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
802 avconv -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
805 @item -tag[:@var{stream_specifier}] @var{codec_tag}
806 Force a tag/fourcc for matching streams.
815 For streaming at very low bitrate application, use a low frame rate
816 and a small GOP size. This is especially true for RealVideo where
817 the Linux player does not seem to be very fast, so it can miss
818 frames. An example is:
821 avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
825 The parameter 'q' which is displayed while encoding is the current
826 quantizer. The value 1 indicates that a very good quality could
827 be achieved. The value 31 indicates the worst quality. If q=31 appears
828 too often, it means that the encoder cannot compress enough to meet
829 your bitrate. You must either increase the bitrate, decrease the
830 frame rate or decrease the frame size.
833 If your computer is not fast enough, you can speed up the
834 compression at the expense of the compression ratio. You can use
835 '-me zero' to speed up motion estimation, and '-intra' to disable
836 motion estimation completely (you have only I-frames, which means it
837 is about as good as JPEG compression).
840 To have very low audio bitrates, reduce the sampling frequency
841 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
844 To have a constant quality (but a variable bitrate), use the option
845 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
852 @c man begin EXAMPLES
854 @section Video and Audio grabbing
856 If you specify the input format and device then avconv can grab video
860 avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
863 Note that you must activate the right video source and channel before
864 launching avconv with any TV viewer such as
865 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
866 have to set the audio recording levels correctly with a
869 @section X11 grabbing
871 Grab the X11 display with avconv via
874 avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
877 0.0 is display.screen number of your X11 server, same as
878 the DISPLAY environment variable.
881 avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
884 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
885 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
887 @section Video and Audio file format conversion
889 Any supported file format and protocol can serve as input to avconv:
894 You can use YUV files as input:
897 avconv -i /tmp/test%d.Y /tmp/out.mpg
900 It will use the files:
902 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
903 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
906 The Y files use twice the resolution of the U and V files. They are
907 raw files, without header. They can be generated by all decent video
908 decoders. You must specify the size of the image with the @option{-s} option
909 if avconv cannot guess it.
912 You can input from a raw YUV420P file:
915 avconv -i /tmp/test.yuv /tmp/out.avi
918 test.yuv is a file containing raw YUV planar data. Each frame is composed
919 of the Y plane followed by the U and V planes at half vertical and
920 horizontal resolution.
923 You can output to a raw YUV420P file:
926 avconv -i mydivx.avi hugefile.yuv
930 You can set several input files and output files:
933 avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
936 Converts the audio file a.wav and the raw YUV video file a.yuv
940 You can also do audio and video conversions at the same time:
943 avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
946 Converts a.wav to MPEG audio at 22050 Hz sample rate.
949 You can encode to several formats at the same time and define a
950 mapping from input stream to output streams:
953 avconv -i /tmp/a.wav -map 0:a -b 64k /tmp/a.mp2 -map 0:a -b 128k /tmp/b.mp2
956 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
957 file:index' specifies which input stream is used for each output
958 stream, in the order of the definition of output streams.
961 You can transcode decrypted VOBs:
964 avconv -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
967 This is a typical DVD ripping example; the input is a VOB file, the
968 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
969 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
970 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
971 input video. Furthermore, the audio stream is MP3-encoded so you need
972 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
973 The mapping is particularly useful for DVD transcoding
974 to get the desired audio language.
976 NOTE: To see the supported input formats, use @code{avconv -formats}.
979 You can extract images from a video, or create a video from many images:
981 For extracting images from a video:
983 avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
986 This will extract one video frame per second from the video and will
987 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
988 etc. Images will be rescaled to fit the new WxH values.
990 If you want to extract just a limited number of frames, you can use the
991 above command in combination with the -vframes or -t option, or in
992 combination with -ss to start extracting from a certain point in time.
994 For creating a video from many images:
996 avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
999 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1000 composed of three digits padded with zeroes to express the sequence
1001 number. It is the same syntax supported by the C printf function, but
1002 only formats accepting a normal integer are suitable.
1005 You can put many streams of the same type in the output:
1008 avconv -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1011 The resulting output file @file{test12.avi} will contain first four streams from
1012 the input file in reverse order.
1018 @include encoders.texi
1019 @include demuxers.texi
1020 @include muxers.texi
1021 @include indevs.texi
1022 @include outdevs.texi
1023 @include protocols.texi
1024 @include bitstream_filters.texi
1025 @include filters.texi
1026 @include metadata.texi
1031 @settitle avconv video converter
1033 @c man begin SEEALSO
1034 avplay(1), avprobe(1), avserver(1) and the Libav HTML documentation
1037 @c man begin AUTHORS
1038 The Libav developers