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 avtools-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 -metadata[:metadata_specifier] @var{key}=@var{value}
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 avconv -i in.avi -metadata title="my title" out.flv
166 To set the language of the second stream:
168 avconv -i INPUT -metadata:s:1 language=eng OUTPUT
171 @item -v @var{number}
172 Set the logging verbosity level.
174 @item -target @var{type}
175 Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
176 "ntsc-svcd", ... ). All the format options (bitrate, codecs,
177 buffer sizes) are then set automatically. You can just type:
180 avconv -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 avconv -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
190 @item -dframes @var{number}
191 Set the number of data frames to record. This is an alias for @code{-frames:d}.
193 @item -frames[:stream_specifier] @var{framecount}
194 Stop writing to the stream after @var{framecount} frames.
197 @item -qscale @var{q}
198 Use fixed quality scale (VBR). The meaning of @var{q} is
201 @item -filter[: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}
212 Set the number of video frames to record. This is an alias for @code{-frames:v}.
214 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
216 Set frame size. The format is @samp{wxh} (avserver default = 160x128, avconv default = same as source).
217 The following abbreviations are recognized:
279 @item -aspect @var{aspect}
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.
288 Disable video recording.
289 @item -bt @var{tolerance}
290 Set video bitrate tolerance (in bits, default 4000k).
291 Has a minimum value of: (target_bitrate/target_framerate).
292 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
293 willing to deviate from the target average bitrate value. This is
294 not related to min/max bitrate. Lowering tolerance too much has
295 an adverse effect on quality.
296 @item -maxrate @var{bitrate}
297 Set max video bitrate (in bit/s).
298 Requires -bufsize to be set.
299 @item -minrate @var{bitrate}
300 Set min video bitrate (in bit/s).
301 Most useful in setting up a CBR encode:
303 avconv -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
305 It is of little use elsewise.
306 @item -bufsize @var{size}
307 Set video buffer verifier buffer size (in bits).
308 @item -vcodec @var{codec}
309 Set the video codec. This is an alias for @code{-codec:v}.
311 Use same quantizer as source (implies VBR).
313 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
317 Select the pass number (1 or 2). It is used to do two-pass
318 video encoding. The statistics of the video are recorded in the first
319 pass into a log file (see also the option -passlogfile),
320 and in the second pass that log file is used to generate the video
321 at the exact requested bitrate.
322 On pass 1, you may just deactivate audio and set output to null,
323 examples for Windows and Unix:
325 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
326 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
329 @item -passlogfile @var{prefix}
330 Set two-pass log file name prefix to @var{prefix}, the default file name
331 prefix is ``av2pass''. The complete file name will be
332 @file{PREFIX-N.log}, where N is a number specific to the output
335 @item -vf @var{filter_graph}
336 @var{filter_graph} is a description of the filter graph to apply to
338 Use the option "-filters" to show all the available filters (including
339 also sources and sinks). This is an alias for @code{-filter:v}.
343 @section Advanced Video Options
346 @item -pix_fmt @var{format}
347 Set pixel format. Use @code{-pix_fmts} to show all the supported
349 @item -sws_flags @var{flags}
351 @item -g @var{gop_size}
352 Set the group of pictures size.
356 minimum video quantizer scale (VBR)
358 maximum video quantizer scale (VBR)
360 maximum difference between the quantizer scales (VBR)
361 @item -qblur @var{blur}
362 video quantizer scale blur (VBR) (range 0.0 - 1.0)
363 @item -qcomp @var{compression}
364 video quantizer scale compression (VBR) (default 0.5).
365 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
367 @item -lmin @var{lambda}
368 minimum video lagrange factor (VBR)
369 @item -lmax @var{lambda}
370 max video lagrange factor (VBR)
371 @item -mblmin @var{lambda}
372 minimum macroblock quantizer scale (VBR)
373 @item -mblmax @var{lambda}
374 maximum macroblock quantizer scale (VBR)
376 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
377 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
379 avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
382 @item -rc_init_cplx @var{complexity}
383 initial complexity for single pass encoding
384 @item -b_qfactor @var{factor}
385 qp factor between P- and B-frames
386 @item -i_qfactor @var{factor}
387 qp factor between P- and I-frames
388 @item -b_qoffset @var{offset}
389 qp offset between P- and B-frames
390 @item -i_qoffset @var{offset}
391 qp offset between P- and I-frames
392 @item -rc_eq @var{equation}
393 Set rate control equation (see section "Expression Evaluation")
394 (default = @code{tex^qComp}).
396 When computing the rate control equation expression, besides the
397 standard functions defined in the section "Expression Evaluation", the
398 following functions are available:
404 and the following constants are available:
426 @item -rc_override @var{override}
427 rate control override for specific intervals
428 @item -me_method @var{method}
429 Set motion estimation method to @var{method}.
430 Available methods are (from lowest to best quality):
433 Try just the (0, 0) vector.
442 exhaustive search (slow and marginally better than epzs)
445 @item -dct_algo @var{algo}
446 Set DCT algorithm to @var{algo}. Available values are:
449 FF_DCT_AUTO (default)
462 @item -idct_algo @var{algo}
463 Set IDCT algorithm to @var{algo}. Available values are:
466 FF_IDCT_AUTO (default)
490 Set error resilience to @var{n}.
493 FF_ER_CAREFUL (default)
499 FF_ER_VERY_AGGRESSIVE
502 @item -ec @var{bit_mask}
503 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
504 the following values:
507 FF_EC_GUESS_MVS (default = enabled)
509 FF_EC_DEBLOCK (default = enabled)
512 @item -bf @var{frames}
513 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
514 @item -mbd @var{mode}
518 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in avconv).
520 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
522 FF_MB_DECISION_RD: rate distortion
526 Use four motion vector by macroblock (MPEG-4 only).
528 Use data partitioning (MPEG-4 only).
529 @item -bug @var{param}
530 Work around encoder bugs that are not auto-detected.
531 @item -strict @var{strictness}
532 How strictly to follow the standards.
534 Enable Advanced intra coding (h263+).
536 Enable Unlimited Motion Vector (h263+)
539 Deinterlace pictures.
541 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
542 Use this option if your input file is interlaced and you want
543 to keep the interlaced format for minimum losses.
544 The alternative is to deinterlace the input stream with
545 @option{-deinterlace}, but deinterlacing introduces losses.
547 Dump video coding statistics to @file{vstats_HHMMSS.log}.
548 @item -vstats_file @var{file}
549 Dump video coding statistics to @var{file}.
551 top=1/bottom=0/auto=-1 field first
552 @item -dc @var{precision}
554 @item -vtag @var{fourcc/tag}
555 Force video tag/fourcc. This is an alias for @code{-tag:v}.
558 @item -force_key_frames @var{time}[,@var{time}...]
559 Force key frames at the specified timestamps, more precisely at the first
560 frames after each specified time.
561 This option can be useful to ensure that a seek point is present at a
562 chapter mark or any other designated place in the output file.
563 The timestamps must be specified in ascending order.
566 @section Audio Options
569 @item -aframes @var{number}
570 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
572 Set the audio sampling frequency. For output streams it is set by
573 default to the frequency of the corresponding input stream. For input
574 streams this option only makes sense for audio grabbing devices and raw
575 demuxers and is mapped to the corresponding demuxer options.
577 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
578 @item -ac @var{channels}
579 Set the number of audio channels. For output streams it is set by
580 default to the number of input audio channels. For input streams
581 this option only makes sense for audio grabbing devices and raw demuxers
582 and is mapped to the corresponding demuxer options.
584 Disable audio recording.
585 @item -acodec @var{codec}
586 Set the audio codec. This is an alias for @code{-codec:a}.
587 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt}
588 Set the audio sample format. Use @code{-help sample_fmts} to get a list
589 of supported sample formats.
592 @section Advanced Audio options:
595 @item -atag @var{fourcc/tag}
596 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
597 @item -audio_service_type @var{type}
598 Set the type of service that the audio stream contains.
601 Main Audio Service (default)
621 @section Subtitle options:
624 @item -scodec @var{codec}
625 Set the subtitle codec. This is an alias for @code{-codec:s}.
627 Disable subtitle recording.
630 @section Audio/Video grab options
634 Synchronize read on input.
637 @section Advanced options
640 @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}]]
642 Designate one or more input streams as a source for the output file. Each input
643 stream is identified by the input file index @var{input_file_id} and
644 the input stream index @var{input_stream_id} within the input
645 file. Both indices start at 0. If specified,
646 @var{sync_file_id}:@var{sync_stream_id} sets which input stream
647 is used as a presentation sync reference.
649 If @var{input_stream_type} is specified -- 'v' for video, 'a' for audio, 's' for
650 subtitle and 'd' for data -- then @var{input_stream_id} counts only the streams
651 of this type. Same for @var{sync_stream_type}.
653 @var{input_stream_id} may be omitted, in which case all streams of the given
654 type are mapped (or all streams in the file, if no type is specified).
656 The first @code{-map} option on the command line specifies the
657 source for output stream 0, the second @code{-map} option specifies
658 the source for output stream 1, etc.
660 A @code{-} character before the stream identifier creates a "negative" mapping.
661 It disables matching streams from already created mappings.
663 For example, to map ALL streams from the first input file to output
665 avconv -i INPUT -map 0 output
668 For example, if you have two audio streams in the first input file,
669 these streams are identified by "0:0" and "0:1". You can use
670 @code{-map} to select which streams to place in an output file. For
673 avconv -i INPUT -map 0:1 out.wav
675 will map the input stream in @file{INPUT} identified by "0:1" to
676 the (single) output stream in @file{out.wav}.
678 For example, to select the stream with index 2 from input file
679 @file{a.mov} (specified by the identifier "0:2"), and stream with
680 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
681 and copy them to the output file @file{out.mov}:
683 avconv -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
686 To select all video and the third audio stream from an input file:
688 avconv -i INPUT -map 0:v -map 0:a:2 OUTPUT
691 To map all the streams except the second audio, use negative mappings
693 avconv -i INPUT -map 0 -map -0:a:1 OUTPUT
696 Note that using this option disables the default mappings for this output file.
698 @item -map_metadata[:@var{metadata_type}][:@var{index}] @var{infile}[:@var{metadata_type}][:@var{index}]
699 Set metadata information of the next output file from @var{infile}. Note that
700 those are file indices (zero-based), not filenames.
701 Optional @var{metadata_type} parameters specify, which metadata to copy - (g)lobal
702 (i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
703 per-(p)rogram. All metadata specifiers other than global must be followed by the
704 stream/chapter/program index. If metadata specifier is omitted, it defaults to
707 By default, global metadata is copied from the first input file,
708 per-stream and per-chapter metadata is copied along with streams/chapters. These
709 default mappings are disabled by creating any mapping of the relevant type. A negative
710 file index can be used to create a dummy mapping that just disables automatic copying.
712 For example to copy metadata from the first stream of the input file to global metadata
715 avconv -i in.ogg -map_metadata 0:s:0 out.mp3
717 @item -map_chapters @var{input_file_index}
718 Copy chapters from input file with index @var{input_file_index} to the next
719 output file. If no chapter mapping is specified, then chapters are copied from
720 the first input file with at least one chapter. Use a negative file index to
721 disable any chapter copying.
723 Print specific debug info.
725 Show benchmarking information at the end of an encode.
726 Shows CPU time used and maximum memory consumption.
727 Maximum memory consumption is not supported on all systems,
728 it will usually display as 0 if not supported.
730 Dump each input packet.
732 When dumping packets, also dump the payload.
734 Only use bit exact algorithms (for codec testing).
736 Set RTP payload size in bytes.
738 Read input at native frame rate. Mainly used to simulate a grab device.
739 @item -threads @var{count}
741 @item -vsync @var{parameter}
746 Each frame is passed with its timestamp from the demuxer to the muxer.
748 Frames will be duplicated and dropped to achieve exactly the requested
751 Frames are passed through with their timestamp or dropped so as to
752 prevent 2 frames from having the same timestamp.
754 Chooses between 1 and 2 depending on muxer capabilities. This is the
758 With -map you can select from which stream the timestamps should be
759 taken. You can leave either video or audio unchanged and sync the
760 remaining stream(s) to the unchanged one.
762 @item -async @var{samples_per_second}
763 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
764 the parameter is the maximum samples per second by which the audio is changed.
765 -async 1 is a special case where only the start of the audio stream is corrected
766 without any later correction.
768 Copy timestamps from input to output.
770 Copy input stream time base from input to output when stream copying.
772 Finish encoding when the shortest input stream ends.
773 @item -dts_delta_threshold
774 Timestamp discontinuity delta threshold.
775 @item -muxdelay @var{seconds}
776 Set the maximum demux-decode delay.
777 @item -muxpreload @var{seconds}
778 Set the initial demux-decode delay.
779 @item -streamid @var{output-stream-index}:@var{new-value}
780 Assign a new stream-id value to an output stream. This option should be
781 specified prior to the output filename to which it applies.
782 For the situation where multiple output files exist, a streamid
783 may be reassigned to a different value.
785 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
786 an output mpegts file:
788 avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
791 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters}
792 Set bitstream filters for matching streams. @var{bistream_filters} is
793 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
794 to get the list of bitstream filters.
796 avconv -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
799 avconv -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
802 @item -tag[:@var{stream_specifier}] @var{codec_tag}
803 Force a tag/fourcc for matching streams.
812 For streaming at very low bitrate application, use a low frame rate
813 and a small GOP size. This is especially true for RealVideo where
814 the Linux player does not seem to be very fast, so it can miss
815 frames. An example is:
818 avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
822 The parameter 'q' which is displayed while encoding is the current
823 quantizer. The value 1 indicates that a very good quality could
824 be achieved. The value 31 indicates the worst quality. If q=31 appears
825 too often, it means that the encoder cannot compress enough to meet
826 your bitrate. You must either increase the bitrate, decrease the
827 frame rate or decrease the frame size.
830 If your computer is not fast enough, you can speed up the
831 compression at the expense of the compression ratio. You can use
832 '-me zero' to speed up motion estimation, and '-intra' to disable
833 motion estimation completely (you have only I-frames, which means it
834 is about as good as JPEG compression).
837 To have very low audio bitrates, reduce the sampling frequency
838 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
841 To have a constant quality (but a variable bitrate), use the option
842 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
849 @c man begin EXAMPLES
851 @section Video and Audio grabbing
853 If you specify the input format and device then avconv can grab video
857 avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
860 Note that you must activate the right video source and channel before
861 launching avconv with any TV viewer such as
862 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
863 have to set the audio recording levels correctly with a
866 @section X11 grabbing
868 Grab the X11 display with avconv via
871 avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
874 0.0 is display.screen number of your X11 server, same as
875 the DISPLAY environment variable.
878 avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
881 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
882 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
884 @section Video and Audio file format conversion
886 Any supported file format and protocol can serve as input to avconv:
891 You can use YUV files as input:
894 avconv -i /tmp/test%d.Y /tmp/out.mpg
897 It will use the files:
899 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
900 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
903 The Y files use twice the resolution of the U and V files. They are
904 raw files, without header. They can be generated by all decent video
905 decoders. You must specify the size of the image with the @option{-s} option
906 if avconv cannot guess it.
909 You can input from a raw YUV420P file:
912 avconv -i /tmp/test.yuv /tmp/out.avi
915 test.yuv is a file containing raw YUV planar data. Each frame is composed
916 of the Y plane followed by the U and V planes at half vertical and
917 horizontal resolution.
920 You can output to a raw YUV420P file:
923 avconv -i mydivx.avi hugefile.yuv
927 You can set several input files and output files:
930 avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
933 Converts the audio file a.wav and the raw YUV video file a.yuv
937 You can also do audio and video conversions at the same time:
940 avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
943 Converts a.wav to MPEG audio at 22050 Hz sample rate.
946 You can encode to several formats at the same time and define a
947 mapping from input stream to output streams:
950 avconv -i /tmp/a.wav -map 0:a -b 64k /tmp/a.mp2 -map 0:a -b 128k /tmp/b.mp2
953 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
954 file:index' specifies which input stream is used for each output
955 stream, in the order of the definition of output streams.
958 You can transcode decrypted VOBs:
961 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
964 This is a typical DVD ripping example; the input is a VOB file, the
965 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
966 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
967 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
968 input video. Furthermore, the audio stream is MP3-encoded so you need
969 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
970 The mapping is particularly useful for DVD transcoding
971 to get the desired audio language.
973 NOTE: To see the supported input formats, use @code{avconv -formats}.
976 You can extract images from a video, or create a video from many images:
978 For extracting images from a video:
980 avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
983 This will extract one video frame per second from the video and will
984 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
985 etc. Images will be rescaled to fit the new WxH values.
987 If you want to extract just a limited number of frames, you can use the
988 above command in combination with the -vframes or -t option, or in
989 combination with -ss to start extracting from a certain point in time.
991 For creating a video from many images:
993 avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
996 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
997 composed of three digits padded with zeroes to express the sequence
998 number. It is the same syntax supported by the C printf function, but
999 only formats accepting a normal integer are suitable.
1002 You can put many streams of the same type in the output:
1005 avconv -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1008 The resulting output file @file{test12.avi} will contain first four streams from
1009 the input file in reverse order.
1015 @include encoders.texi
1016 @include demuxers.texi
1017 @include muxers.texi
1018 @include indevs.texi
1019 @include outdevs.texi
1020 @include protocols.texi
1021 @include bitstream_filters.texi
1022 @include filters.texi
1023 @include metadata.texi
1028 @settitle avconv video converter
1030 @c man begin SEEALSO
1031 avplay(1), avprobe(1), avserver(1) and the Libav HTML documentation
1034 @c man begin AUTHORS
1035 The Libav developers