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.
205 @item -slang @var{code}
206 Set the ISO 639 language code (3 letters) of the current subtitle stream.
210 @section Video Options
213 @item -vframes @var{number}
214 Set the number of video frames to record.
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 -vlang @var{code}
338 Set the ISO 639 language code (3 letters) of the current video stream.
340 @item -vf @var{filter_graph}
341 @var{filter_graph} is a description of the filter graph to apply to
343 Use the option "-filters" to show all the available filters (including
344 also sources and sinks).
348 @section Advanced Video Options
351 @item -pix_fmt @var{format}
352 Set pixel format. Use 'list' as parameter to show all the supported
354 @item -sws_flags @var{flags}
356 @item -g @var{gop_size}
357 Set the group of pictures size.
360 @item -qscale @var{q}
361 Use fixed video quantizer scale (VBR).
363 minimum video quantizer scale (VBR)
365 maximum video quantizer scale (VBR)
367 maximum difference between the quantizer scales (VBR)
368 @item -qblur @var{blur}
369 video quantizer scale blur (VBR) (range 0.0 - 1.0)
370 @item -qcomp @var{compression}
371 video quantizer scale compression (VBR) (default 0.5).
372 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
374 @item -lmin @var{lambda}
375 minimum video lagrange factor (VBR)
376 @item -lmax @var{lambda}
377 max video lagrange factor (VBR)
378 @item -mblmin @var{lambda}
379 minimum macroblock quantizer scale (VBR)
380 @item -mblmax @var{lambda}
381 maximum macroblock quantizer scale (VBR)
383 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
384 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
386 avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
389 @item -rc_init_cplx @var{complexity}
390 initial complexity for single pass encoding
391 @item -b_qfactor @var{factor}
392 qp factor between P- and B-frames
393 @item -i_qfactor @var{factor}
394 qp factor between P- and I-frames
395 @item -b_qoffset @var{offset}
396 qp offset between P- and B-frames
397 @item -i_qoffset @var{offset}
398 qp offset between P- and I-frames
399 @item -rc_eq @var{equation}
400 Set rate control equation (see section "Expression Evaluation")
401 (default = @code{tex^qComp}).
403 When computing the rate control equation expression, besides the
404 standard functions defined in the section "Expression Evaluation", the
405 following functions are available:
411 and the following constants are available:
433 @item -rc_override @var{override}
434 rate control override for specific intervals
435 @item -me_method @var{method}
436 Set motion estimation method to @var{method}.
437 Available methods are (from lowest to best quality):
440 Try just the (0, 0) vector.
449 exhaustive search (slow and marginally better than epzs)
452 @item -dct_algo @var{algo}
453 Set DCT algorithm to @var{algo}. Available values are:
456 FF_DCT_AUTO (default)
469 @item -idct_algo @var{algo}
470 Set IDCT algorithm to @var{algo}. Available values are:
473 FF_IDCT_AUTO (default)
497 Set error resilience to @var{n}.
500 FF_ER_CAREFUL (default)
506 FF_ER_VERY_AGGRESSIVE
509 @item -ec @var{bit_mask}
510 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
511 the following values:
514 FF_EC_GUESS_MVS (default = enabled)
516 FF_EC_DEBLOCK (default = enabled)
519 @item -bf @var{frames}
520 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
521 @item -mbd @var{mode}
525 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in avconv).
527 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
529 FF_MB_DECISION_RD: rate distortion
533 Use four motion vector by macroblock (MPEG-4 only).
535 Use data partitioning (MPEG-4 only).
536 @item -bug @var{param}
537 Work around encoder bugs that are not auto-detected.
538 @item -strict @var{strictness}
539 How strictly to follow the standards.
541 Enable Advanced intra coding (h263+).
543 Enable Unlimited Motion Vector (h263+)
546 Deinterlace pictures.
548 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
549 Use this option if your input file is interlaced and you want
550 to keep the interlaced format for minimum losses.
551 The alternative is to deinterlace the input stream with
552 @option{-deinterlace}, but deinterlacing introduces losses.
554 Calculate PSNR of compressed frames.
556 Dump video coding statistics to @file{vstats_HHMMSS.log}.
557 @item -vstats_file @var{file}
558 Dump video coding statistics to @var{file}.
560 top=1/bottom=0/auto=-1 field first
561 @item -dc @var{precision}
563 @item -vtag @var{fourcc/tag}
564 Force video tag/fourcc.
567 @item -vbsf @var{bitstream_filter}
568 Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump", "mjpeg2jpeg".
570 avconv -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
572 @item -force_key_frames @var{time}[,@var{time}...]
573 Force key frames at the specified timestamps, more precisely at the first
574 frames after each specified time.
575 This option can be useful to ensure that a seek point is present at a
576 chapter mark or any other designated place in the output file.
577 The timestamps must be specified in ascending order.
580 @section Audio Options
583 @item -aframes @var{number}
584 Set the number of audio frames to record.
586 Set the audio sampling frequency. For output streams it is set by
587 default to the frequency of the corresponding input stream. For input
588 streams this option only makes sense for audio grabbing devices and raw
589 demuxers and is mapped to the corresponding demuxer options.
591 Set the audio quality (codec-specific, VBR).
592 @item -ac @var{channels}
593 Set the number of audio channels. For output streams it is set by
594 default to the number of input audio channels. For input streams
595 this option only makes sense for audio grabbing devices and raw demuxers
596 and is mapped to the corresponding demuxer options.
598 Disable audio recording.
599 @item -acodec @var{codec}
600 Set the audio codec. This is an alias for @code{-codec:a}.
601 @item -alang @var{code}
602 Set the ISO 639 language code (3 letters) of the current audio stream.
605 @section Advanced Audio options:
608 @item -atag @var{fourcc/tag}
609 Force audio tag/fourcc.
610 @item -audio_service_type @var{type}
611 Set the type of service that the audio stream contains.
614 Main Audio Service (default)
632 @item -absf @var{bitstream_filter}
633 Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
636 @section Subtitle options:
639 @item -scodec @var{codec}
640 Set the subtitle codec. This is an alias for @code{-codec:s}.
641 @item -slang @var{code}
642 Set the ISO 639 language code (3 letters) of the current subtitle stream.
644 Disable subtitle recording.
645 @item -sbsf @var{bitstream_filter}
646 Bitstream filters available are "mov2textsub", "text2movsub".
648 avconv -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
652 @section Audio/Video grab options
656 Synchronize read on input.
659 @section Advanced options
662 @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}]]
664 Designate one or more input streams as a source for the output file. Each input
665 stream is identified by the input file index @var{input_file_id} and
666 the input stream index @var{input_stream_id} within the input
667 file. Both indices start at 0. If specified,
668 @var{sync_file_id}:@var{sync_stream_id} sets which input stream
669 is used as a presentation sync reference.
671 If @var{input_stream_type} is specified -- 'v' for video, 'a' for audio, 's' for
672 subtitle and 'd' for data -- then @var{input_stream_id} counts only the streams
673 of this type. Same for @var{sync_stream_type}.
675 @var{input_stream_id} may be omitted, in which case all streams of the given
676 type are mapped (or all streams in the file, if no type is specified).
678 The first @code{-map} option on the command line specifies the
679 source for output stream 0, the second @code{-map} option specifies
680 the source for output stream 1, etc.
682 A @code{-} character before the stream identifier creates a "negative" mapping.
683 It disables matching streams from already created mappings.
685 For example, to map ALL streams from the first input file to output
687 avconv -i INPUT -map 0 output
690 For example, if you have two audio streams in the first input file,
691 these streams are identified by "0:0" and "0:1". You can use
692 @code{-map} to select which streams to place in an output file. For
695 avconv -i INPUT -map 0:1 out.wav
697 will map the input stream in @file{INPUT} identified by "0:1" to
698 the (single) output stream in @file{out.wav}.
700 For example, to select the stream with index 2 from input file
701 @file{a.mov} (specified by the identifier "0:2"), and stream with
702 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
703 and copy them to the output file @file{out.mov}:
705 avconv -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
708 To select all video and the third audio stream from an input file:
710 avconv -i INPUT -map 0:v -map 0:a:2 OUTPUT
713 To map all the streams except the second audio, use negative mappings
715 avconv -i INPUT -map 0 -map -0:a:1 OUTPUT
718 Note that using this option disables the default mappings for this output file.
720 @item -map_metadata[:@var{metadata_type}][:@var{index}] @var{infile}[:@var{metadata_type}][:@var{index}]
721 Set metadata information of the next output file from @var{infile}. Note that
722 those are file indices (zero-based), not filenames.
723 Optional @var{metadata_type} parameters specify, which metadata to copy - (g)lobal
724 (i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
725 per-(p)rogram. All metadata specifiers other than global must be followed by the
726 stream/chapter/program index. If metadata specifier is omitted, it defaults to
729 By default, global metadata is copied from the first input file,
730 per-stream and per-chapter metadata is copied along with streams/chapters. These
731 default mappings are disabled by creating any mapping of the relevant type. A negative
732 file index can be used to create a dummy mapping that just disables automatic copying.
734 For example to copy metadata from the first stream of the input file to global metadata
737 avconv -i in.ogg -map_metadata 0:s:0 out.mp3
739 @item -map_chapters @var{input_file_index}
740 Copy chapters from input file with index @var{input_file_index} to the next
741 output file. If no chapter mapping is specified, then chapters are copied from
742 the first input file with at least one chapter. Use a negative file index to
743 disable any chapter copying.
745 Print specific debug info.
747 Show benchmarking information at the end of an encode.
748 Shows CPU time used and maximum memory consumption.
749 Maximum memory consumption is not supported on all systems,
750 it will usually display as 0 if not supported.
752 Dump each input packet.
754 When dumping packets, also dump the payload.
756 Only use bit exact algorithms (for codec testing).
758 Set RTP payload size in bytes.
760 Read input at native frame rate. Mainly used to simulate a grab device.
761 @item -threads @var{count}
763 @item -vsync @var{parameter}
768 Each frame is passed with its timestamp from the demuxer to the muxer.
770 Frames will be duplicated and dropped to achieve exactly the requested
773 Frames are passed through with their timestamp or dropped so as to
774 prevent 2 frames from having the same timestamp.
776 Chooses between 1 and 2 depending on muxer capabilities. This is the
780 With -map you can select from which stream the timestamps should be
781 taken. You can leave either video or audio unchanged and sync the
782 remaining stream(s) to the unchanged one.
784 @item -async @var{samples_per_second}
785 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
786 the parameter is the maximum samples per second by which the audio is changed.
787 -async 1 is a special case where only the start of the audio stream is corrected
788 without any later correction.
790 Copy timestamps from input to output.
792 Copy input stream time base from input to output when stream copying.
794 Finish encoding when the shortest input stream ends.
795 @item -dts_delta_threshold
796 Timestamp discontinuity delta threshold.
797 @item -muxdelay @var{seconds}
798 Set the maximum demux-decode delay.
799 @item -muxpreload @var{seconds}
800 Set the initial demux-decode delay.
801 @item -streamid @var{output-stream-index}:@var{new-value}
802 Assign a new stream-id value to an output stream. This option should be
803 specified prior to the output filename to which it applies.
804 For the situation where multiple output files exist, a streamid
805 may be reassigned to a different value.
807 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
808 an output mpegts file:
810 avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
820 For streaming at very low bitrate application, use a low frame rate
821 and a small GOP size. This is especially true for RealVideo where
822 the Linux player does not seem to be very fast, so it can miss
823 frames. An example is:
826 avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
830 The parameter 'q' which is displayed while encoding is the current
831 quantizer. The value 1 indicates that a very good quality could
832 be achieved. The value 31 indicates the worst quality. If q=31 appears
833 too often, it means that the encoder cannot compress enough to meet
834 your bitrate. You must either increase the bitrate, decrease the
835 frame rate or decrease the frame size.
838 If your computer is not fast enough, you can speed up the
839 compression at the expense of the compression ratio. You can use
840 '-me zero' to speed up motion estimation, and '-intra' to disable
841 motion estimation completely (you have only I-frames, which means it
842 is about as good as JPEG compression).
845 To have very low audio bitrates, reduce the sampling frequency
846 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
849 To have a constant quality (but a variable bitrate), use the option
850 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
857 @c man begin EXAMPLES
859 @section Video and Audio grabbing
861 If you specify the input format and device then avconv can grab video
865 avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
868 Note that you must activate the right video source and channel before
869 launching avconv with any TV viewer such as
870 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
871 have to set the audio recording levels correctly with a
874 @section X11 grabbing
876 Grab the X11 display with avconv via
879 avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
882 0.0 is display.screen number of your X11 server, same as
883 the DISPLAY environment variable.
886 avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
889 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
890 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
892 @section Video and Audio file format conversion
894 Any supported file format and protocol can serve as input to avconv:
899 You can use YUV files as input:
902 avconv -i /tmp/test%d.Y /tmp/out.mpg
905 It will use the files:
907 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
908 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
911 The Y files use twice the resolution of the U and V files. They are
912 raw files, without header. They can be generated by all decent video
913 decoders. You must specify the size of the image with the @option{-s} option
914 if avconv cannot guess it.
917 You can input from a raw YUV420P file:
920 avconv -i /tmp/test.yuv /tmp/out.avi
923 test.yuv is a file containing raw YUV planar data. Each frame is composed
924 of the Y plane followed by the U and V planes at half vertical and
925 horizontal resolution.
928 You can output to a raw YUV420P file:
931 avconv -i mydivx.avi hugefile.yuv
935 You can set several input files and output files:
938 avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
941 Converts the audio file a.wav and the raw YUV video file a.yuv
945 You can also do audio and video conversions at the same time:
948 avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
951 Converts a.wav to MPEG audio at 22050 Hz sample rate.
954 You can encode to several formats at the same time and define a
955 mapping from input stream to output streams:
958 avconv -i /tmp/a.wav -map 0:a -b 64k /tmp/a.mp2 -map 0:a -b 128k /tmp/b.mp2
961 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
962 file:index' specifies which input stream is used for each output
963 stream, in the order of the definition of output streams.
966 You can transcode decrypted VOBs:
969 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
972 This is a typical DVD ripping example; the input is a VOB file, the
973 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
974 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
975 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
976 input video. Furthermore, the audio stream is MP3-encoded so you need
977 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
978 The mapping is particularly useful for DVD transcoding
979 to get the desired audio language.
981 NOTE: To see the supported input formats, use @code{avconv -formats}.
984 You can extract images from a video, or create a video from many images:
986 For extracting images from a video:
988 avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
991 This will extract one video frame per second from the video and will
992 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
993 etc. Images will be rescaled to fit the new WxH values.
995 If you want to extract just a limited number of frames, you can use the
996 above command in combination with the -vframes or -t option, or in
997 combination with -ss to start extracting from a certain point in time.
999 For creating a video from many images:
1001 avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1004 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1005 composed of three digits padded with zeroes to express the sequence
1006 number. It is the same syntax supported by the C printf function, but
1007 only formats accepting a normal integer are suitable.
1010 You can put many streams of the same type in the output:
1013 avconv -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1016 The resulting output file @file{test12.avi} will contain first four streams from
1017 the input file in reverse order.
1023 @include encoders.texi
1024 @include demuxers.texi
1025 @include muxers.texi
1026 @include indevs.texi
1027 @include outdevs.texi
1028 @include protocols.texi
1029 @include bitstream_filters.texi
1030 @include filters.texi
1031 @include metadata.texi
1036 @settitle avconv video converter
1038 @c man begin SEEALSO
1039 avplay(1), avprobe(1), avserver(1) and the Libav HTML documentation
1042 @c man begin AUTHORS
1043 The Libav developers