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 -slang @var{code}
206 Set the ISO 639 language code (3 letters) of the current subtitle stream.
208 @item -frames[:stream_specifier] @var{framecount}
209 Stop writing to the stream after @var{framecount} frames.
213 @section Video Options
216 @item -vframes @var{number}
217 Set the number of video frames to record. This is an alias for @code{-frames:v}.
219 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
221 Set frame size. The format is @samp{wxh} (avserver default = 160x128, avconv default = same as source).
222 The following abbreviations are recognized:
284 @item -aspect @var{aspect}
285 Set the video display aspect ratio specified by @var{aspect}.
287 @var{aspect} can be a floating point number string, or a string of the
288 form @var{num}:@var{den}, where @var{num} and @var{den} are the
289 numerator and denominator of the aspect ratio. For example "4:3",
290 "16:9", "1.3333", and "1.7777" are valid argument values.
293 Disable video recording.
294 @item -bt @var{tolerance}
295 Set video bitrate tolerance (in bits, default 4000k).
296 Has a minimum value of: (target_bitrate/target_framerate).
297 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
298 willing to deviate from the target average bitrate value. This is
299 not related to min/max bitrate. Lowering tolerance too much has
300 an adverse effect on quality.
301 @item -maxrate @var{bitrate}
302 Set max video bitrate (in bit/s).
303 Requires -bufsize to be set.
304 @item -minrate @var{bitrate}
305 Set min video bitrate (in bit/s).
306 Most useful in setting up a CBR encode:
308 avconv -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
310 It is of little use elsewise.
311 @item -bufsize @var{size}
312 Set video buffer verifier buffer size (in bits).
313 @item -vcodec @var{codec}
314 Set the video codec. This is an alias for @code{-codec:v}.
316 Use same quantizer as source (implies VBR).
318 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
322 Select the pass number (1 or 2). It is used to do two-pass
323 video encoding. The statistics of the video are recorded in the first
324 pass into a log file (see also the option -passlogfile),
325 and in the second pass that log file is used to generate the video
326 at the exact requested bitrate.
327 On pass 1, you may just deactivate audio and set output to null,
328 examples for Windows and Unix:
330 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
331 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
334 @item -passlogfile @var{prefix}
335 Set two-pass log file name prefix to @var{prefix}, the default file name
336 prefix is ``av2pass''. The complete file name will be
337 @file{PREFIX-N.log}, where N is a number specific to the output
340 @item -vlang @var{code}
341 Set the ISO 639 language code (3 letters) of the current video stream.
343 @item -vf @var{filter_graph}
344 @var{filter_graph} is a description of the filter graph to apply to
346 Use the option "-filters" to show all the available filters (including
347 also sources and sinks).
351 @section Advanced Video Options
354 @item -pix_fmt @var{format}
355 Set pixel format. Use 'list' as parameter to show all the supported
357 @item -sws_flags @var{flags}
359 @item -g @var{gop_size}
360 Set the group of pictures size.
363 @item -qscale @var{q}
364 Use fixed video quantizer scale (VBR).
366 minimum video quantizer scale (VBR)
368 maximum video quantizer scale (VBR)
370 maximum difference between the quantizer scales (VBR)
371 @item -qblur @var{blur}
372 video quantizer scale blur (VBR) (range 0.0 - 1.0)
373 @item -qcomp @var{compression}
374 video quantizer scale compression (VBR) (default 0.5).
375 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
377 @item -lmin @var{lambda}
378 minimum video lagrange factor (VBR)
379 @item -lmax @var{lambda}
380 max video lagrange factor (VBR)
381 @item -mblmin @var{lambda}
382 minimum macroblock quantizer scale (VBR)
383 @item -mblmax @var{lambda}
384 maximum macroblock quantizer scale (VBR)
386 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
387 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
389 avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
392 @item -rc_init_cplx @var{complexity}
393 initial complexity for single pass encoding
394 @item -b_qfactor @var{factor}
395 qp factor between P- and B-frames
396 @item -i_qfactor @var{factor}
397 qp factor between P- and I-frames
398 @item -b_qoffset @var{offset}
399 qp offset between P- and B-frames
400 @item -i_qoffset @var{offset}
401 qp offset between P- and I-frames
402 @item -rc_eq @var{equation}
403 Set rate control equation (see section "Expression Evaluation")
404 (default = @code{tex^qComp}).
406 When computing the rate control equation expression, besides the
407 standard functions defined in the section "Expression Evaluation", the
408 following functions are available:
414 and the following constants are available:
436 @item -rc_override @var{override}
437 rate control override for specific intervals
438 @item -me_method @var{method}
439 Set motion estimation method to @var{method}.
440 Available methods are (from lowest to best quality):
443 Try just the (0, 0) vector.
452 exhaustive search (slow and marginally better than epzs)
455 @item -dct_algo @var{algo}
456 Set DCT algorithm to @var{algo}. Available values are:
459 FF_DCT_AUTO (default)
472 @item -idct_algo @var{algo}
473 Set IDCT algorithm to @var{algo}. Available values are:
476 FF_IDCT_AUTO (default)
500 Set error resilience to @var{n}.
503 FF_ER_CAREFUL (default)
509 FF_ER_VERY_AGGRESSIVE
512 @item -ec @var{bit_mask}
513 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
514 the following values:
517 FF_EC_GUESS_MVS (default = enabled)
519 FF_EC_DEBLOCK (default = enabled)
522 @item -bf @var{frames}
523 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
524 @item -mbd @var{mode}
528 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in avconv).
530 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
532 FF_MB_DECISION_RD: rate distortion
536 Use four motion vector by macroblock (MPEG-4 only).
538 Use data partitioning (MPEG-4 only).
539 @item -bug @var{param}
540 Work around encoder bugs that are not auto-detected.
541 @item -strict @var{strictness}
542 How strictly to follow the standards.
544 Enable Advanced intra coding (h263+).
546 Enable Unlimited Motion Vector (h263+)
549 Deinterlace pictures.
551 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
552 Use this option if your input file is interlaced and you want
553 to keep the interlaced format for minimum losses.
554 The alternative is to deinterlace the input stream with
555 @option{-deinterlace}, but deinterlacing introduces losses.
557 Calculate PSNR of compressed frames.
559 Dump video coding statistics to @file{vstats_HHMMSS.log}.
560 @item -vstats_file @var{file}
561 Dump video coding statistics to @var{file}.
563 top=1/bottom=0/auto=-1 field first
564 @item -dc @var{precision}
566 @item -vtag @var{fourcc/tag}
567 Force video tag/fourcc.
570 @item -vbsf @var{bitstream_filter}
571 Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump", "mjpeg2jpeg".
573 avconv -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
575 @item -force_key_frames @var{time}[,@var{time}...]
576 Force key frames at the specified timestamps, more precisely at the first
577 frames after each specified time.
578 This option can be useful to ensure that a seek point is present at a
579 chapter mark or any other designated place in the output file.
580 The timestamps must be specified in ascending order.
583 @section Audio Options
586 @item -aframes @var{number}
587 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
589 Set the audio sampling frequency. For output streams it is set by
590 default to the frequency of the corresponding input stream. For input
591 streams this option only makes sense for audio grabbing devices and raw
592 demuxers and is mapped to the corresponding demuxer options.
594 Set the audio quality (codec-specific, VBR).
595 @item -ac @var{channels}
596 Set the number of audio channels. For output streams it is set by
597 default to the number of input audio channels. For input streams
598 this option only makes sense for audio grabbing devices and raw demuxers
599 and is mapped to the corresponding demuxer options.
601 Disable audio recording.
602 @item -acodec @var{codec}
603 Set the audio codec. This is an alias for @code{-codec:a}.
604 @item -alang @var{code}
605 Set the ISO 639 language code (3 letters) of the current audio stream.
608 @section Advanced Audio options:
611 @item -atag @var{fourcc/tag}
612 Force audio tag/fourcc.
613 @item -audio_service_type @var{type}
614 Set the type of service that the audio stream contains.
617 Main Audio Service (default)
635 @item -absf @var{bitstream_filter}
636 Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
639 @section Subtitle options:
642 @item -scodec @var{codec}
643 Set the subtitle codec. This is an alias for @code{-codec:s}.
644 @item -slang @var{code}
645 Set the ISO 639 language code (3 letters) of the current subtitle stream.
647 Disable subtitle recording.
648 @item -sbsf @var{bitstream_filter}
649 Bitstream filters available are "mov2textsub", "text2movsub".
651 avconv -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
655 @section Audio/Video grab options
659 Synchronize read on input.
662 @section Advanced options
665 @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}]]
667 Designate one or more input streams as a source for the output file. Each input
668 stream is identified by the input file index @var{input_file_id} and
669 the input stream index @var{input_stream_id} within the input
670 file. Both indices start at 0. If specified,
671 @var{sync_file_id}:@var{sync_stream_id} sets which input stream
672 is used as a presentation sync reference.
674 If @var{input_stream_type} is specified -- 'v' for video, 'a' for audio, 's' for
675 subtitle and 'd' for data -- then @var{input_stream_id} counts only the streams
676 of this type. Same for @var{sync_stream_type}.
678 @var{input_stream_id} may be omitted, in which case all streams of the given
679 type are mapped (or all streams in the file, if no type is specified).
681 The first @code{-map} option on the command line specifies the
682 source for output stream 0, the second @code{-map} option specifies
683 the source for output stream 1, etc.
685 A @code{-} character before the stream identifier creates a "negative" mapping.
686 It disables matching streams from already created mappings.
688 For example, to map ALL streams from the first input file to output
690 avconv -i INPUT -map 0 output
693 For example, if you have two audio streams in the first input file,
694 these streams are identified by "0:0" and "0:1". You can use
695 @code{-map} to select which streams to place in an output file. For
698 avconv -i INPUT -map 0:1 out.wav
700 will map the input stream in @file{INPUT} identified by "0:1" to
701 the (single) output stream in @file{out.wav}.
703 For example, to select the stream with index 2 from input file
704 @file{a.mov} (specified by the identifier "0:2"), and stream with
705 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
706 and copy them to the output file @file{out.mov}:
708 avconv -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
711 To select all video and the third audio stream from an input file:
713 avconv -i INPUT -map 0:v -map 0:a:2 OUTPUT
716 To map all the streams except the second audio, use negative mappings
718 avconv -i INPUT -map 0 -map -0:a:1 OUTPUT
721 Note that using this option disables the default mappings for this output file.
723 @item -map_metadata[:@var{metadata_type}][:@var{index}] @var{infile}[:@var{metadata_type}][:@var{index}]
724 Set metadata information of the next output file from @var{infile}. Note that
725 those are file indices (zero-based), not filenames.
726 Optional @var{metadata_type} parameters specify, which metadata to copy - (g)lobal
727 (i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
728 per-(p)rogram. All metadata specifiers other than global must be followed by the
729 stream/chapter/program index. If metadata specifier is omitted, it defaults to
732 By default, global metadata is copied from the first input file,
733 per-stream and per-chapter metadata is copied along with streams/chapters. These
734 default mappings are disabled by creating any mapping of the relevant type. A negative
735 file index can be used to create a dummy mapping that just disables automatic copying.
737 For example to copy metadata from the first stream of the input file to global metadata
740 avconv -i in.ogg -map_metadata 0:s:0 out.mp3
742 @item -map_chapters @var{input_file_index}
743 Copy chapters from input file with index @var{input_file_index} to the next
744 output file. If no chapter mapping is specified, then chapters are copied from
745 the first input file with at least one chapter. Use a negative file index to
746 disable any chapter copying.
748 Print specific debug info.
750 Show benchmarking information at the end of an encode.
751 Shows CPU time used and maximum memory consumption.
752 Maximum memory consumption is not supported on all systems,
753 it will usually display as 0 if not supported.
755 Dump each input packet.
757 When dumping packets, also dump the payload.
759 Only use bit exact algorithms (for codec testing).
761 Set RTP payload size in bytes.
763 Read input at native frame rate. Mainly used to simulate a grab device.
764 @item -threads @var{count}
766 @item -vsync @var{parameter}
771 Each frame is passed with its timestamp from the demuxer to the muxer.
773 Frames will be duplicated and dropped to achieve exactly the requested
776 Frames are passed through with their timestamp or dropped so as to
777 prevent 2 frames from having the same timestamp.
779 Chooses between 1 and 2 depending on muxer capabilities. This is the
783 With -map you can select from which stream the timestamps should be
784 taken. You can leave either video or audio unchanged and sync the
785 remaining stream(s) to the unchanged one.
787 @item -async @var{samples_per_second}
788 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
789 the parameter is the maximum samples per second by which the audio is changed.
790 -async 1 is a special case where only the start of the audio stream is corrected
791 without any later correction.
793 Copy timestamps from input to output.
795 Copy input stream time base from input to output when stream copying.
797 Finish encoding when the shortest input stream ends.
798 @item -dts_delta_threshold
799 Timestamp discontinuity delta threshold.
800 @item -muxdelay @var{seconds}
801 Set the maximum demux-decode delay.
802 @item -muxpreload @var{seconds}
803 Set the initial demux-decode delay.
804 @item -streamid @var{output-stream-index}:@var{new-value}
805 Assign a new stream-id value to an output stream. This option should be
806 specified prior to the output filename to which it applies.
807 For the situation where multiple output files exist, a streamid
808 may be reassigned to a different value.
810 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
811 an output mpegts file:
813 avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
823 For streaming at very low bitrate application, use a low frame rate
824 and a small GOP size. This is especially true for RealVideo where
825 the Linux player does not seem to be very fast, so it can miss
826 frames. An example is:
829 avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
833 The parameter 'q' which is displayed while encoding is the current
834 quantizer. The value 1 indicates that a very good quality could
835 be achieved. The value 31 indicates the worst quality. If q=31 appears
836 too often, it means that the encoder cannot compress enough to meet
837 your bitrate. You must either increase the bitrate, decrease the
838 frame rate or decrease the frame size.
841 If your computer is not fast enough, you can speed up the
842 compression at the expense of the compression ratio. You can use
843 '-me zero' to speed up motion estimation, and '-intra' to disable
844 motion estimation completely (you have only I-frames, which means it
845 is about as good as JPEG compression).
848 To have very low audio bitrates, reduce the sampling frequency
849 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
852 To have a constant quality (but a variable bitrate), use the option
853 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
860 @c man begin EXAMPLES
862 @section Video and Audio grabbing
864 If you specify the input format and device then avconv can grab video
868 avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
871 Note that you must activate the right video source and channel before
872 launching avconv with any TV viewer such as
873 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
874 have to set the audio recording levels correctly with a
877 @section X11 grabbing
879 Grab the X11 display with avconv via
882 avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
885 0.0 is display.screen number of your X11 server, same as
886 the DISPLAY environment variable.
889 avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
892 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
893 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
895 @section Video and Audio file format conversion
897 Any supported file format and protocol can serve as input to avconv:
902 You can use YUV files as input:
905 avconv -i /tmp/test%d.Y /tmp/out.mpg
908 It will use the files:
910 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
911 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
914 The Y files use twice the resolution of the U and V files. They are
915 raw files, without header. They can be generated by all decent video
916 decoders. You must specify the size of the image with the @option{-s} option
917 if avconv cannot guess it.
920 You can input from a raw YUV420P file:
923 avconv -i /tmp/test.yuv /tmp/out.avi
926 test.yuv is a file containing raw YUV planar data. Each frame is composed
927 of the Y plane followed by the U and V planes at half vertical and
928 horizontal resolution.
931 You can output to a raw YUV420P file:
934 avconv -i mydivx.avi hugefile.yuv
938 You can set several input files and output files:
941 avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
944 Converts the audio file a.wav and the raw YUV video file a.yuv
948 You can also do audio and video conversions at the same time:
951 avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
954 Converts a.wav to MPEG audio at 22050 Hz sample rate.
957 You can encode to several formats at the same time and define a
958 mapping from input stream to output streams:
961 avconv -i /tmp/a.wav -map 0:a -b 64k /tmp/a.mp2 -map 0:a -b 128k /tmp/b.mp2
964 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
965 file:index' specifies which input stream is used for each output
966 stream, in the order of the definition of output streams.
969 You can transcode decrypted VOBs:
972 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
975 This is a typical DVD ripping example; the input is a VOB file, the
976 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
977 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
978 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
979 input video. Furthermore, the audio stream is MP3-encoded so you need
980 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
981 The mapping is particularly useful for DVD transcoding
982 to get the desired audio language.
984 NOTE: To see the supported input formats, use @code{avconv -formats}.
987 You can extract images from a video, or create a video from many images:
989 For extracting images from a video:
991 avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
994 This will extract one video frame per second from the video and will
995 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
996 etc. Images will be rescaled to fit the new WxH values.
998 If you want to extract just a limited number of frames, you can use the
999 above command in combination with the -vframes or -t option, or in
1000 combination with -ss to start extracting from a certain point in time.
1002 For creating a video from many images:
1004 avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1007 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1008 composed of three digits padded with zeroes to express the sequence
1009 number. It is the same syntax supported by the C printf function, but
1010 only formats accepting a normal integer are suitable.
1013 You can put many streams of the same type in the output:
1016 avconv -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1019 The resulting output file @file{test12.avi} will contain first four streams from
1020 the input file in reverse order.
1026 @include encoders.texi
1027 @include demuxers.texi
1028 @include muxers.texi
1029 @include indevs.texi
1030 @include outdevs.texi
1031 @include protocols.texi
1032 @include bitstream_filters.texi
1033 @include filters.texi
1034 @include metadata.texi
1039 @settitle avconv video converter
1041 @c man begin SEEALSO
1042 avplay(1), avprobe(1), avserver(1) and the Libav HTML documentation
1045 @c man begin AUTHORS
1046 The Libav developers