1 \input texinfo @c -*- texinfo -*-
3 @settitle avconv Documentation
5 @center @titlefont{avconv Documentation}
14 The generic syntax is:
18 avconv [global options] [[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 As a general rule, options are applied to the next specified
30 file. Therefore, order is important, and you can have the same
31 option on the command line multiple times. Each occurrence is
32 then applied to the next input or output file.
33 Exceptions from this rule are the global options (e.g. verbosity level),
34 which should be specified first.
38 To set the video bitrate of the output file to 64kbit/s:
40 avconv -i input.avi -b 64k output.avi
44 To force the frame rate of the output file to 24 fps:
46 avconv -i input.avi -r 24 output.avi
50 To force the frame rate of the input file (valid for raw formats only)
51 to 1 fps and the frame rate of the output file to 24 fps:
53 avconv -r 1 -i input.m2v -r 24 output.avi
57 The format option may be needed for raw input files.
59 @c man end DESCRIPTION
61 @chapter Stream selection
62 @c man begin STREAM SELECTION
64 By default avconv tries to pick the "best" stream of each type present in input
65 files and add them to each output file. For video, this means the highest
66 resolution, for audio the highest channel count. For subtitle it's simply the
67 first subtitle stream.
69 You can disable some of those defaults by using @code{-vn/-an/-sn} options. For
70 full manual control, use the @code{-map} option, which disables the defaults just
73 @c man end STREAM SELECTION
78 @include avtools-common-opts.texi
84 @item -f @var{fmt} (@emph{input/output})
85 Force input or output file format. The format is normally autodetected for input
86 files and guessed from file extension for output files, so this option is not
89 @item -i @var{filename} (@emph{input})
92 @item -y (@emph{global})
93 Overwrite output files without asking.
95 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
96 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
97 Select an encoder (when used before an output file) or a decoder (when used
98 before an input file) for one or more streams. @var{codec} is the name of a
99 decoder/encoder or a special value @code{copy} (output only) to indicate that
100 the stream is not to be reencoded.
104 avconv -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
106 encodes all video streams with libx264 and copies all audio streams.
108 For each stream, the last matching @code{c} option is applied, so
110 avconv -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
112 will copy all the streams except the second video, which will be encoded with
113 libx264, and the 138th audio, which will be encoded with libvorbis.
115 @item -t @var{duration} (@emph{output})
116 Stop writing the output after its duration reaches @var{duration}.
117 @var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form.
119 @item -fs @var{limit_size} (@emph{output})
120 Set the file size limit.
122 @item -ss @var{position} (@emph{input/output})
123 When used as an input option (before @code{-i}), seeks in this input file to
124 @var{position}. When used as an output option (before an output filename),
125 decodes but discards input until the timestamps reach @var{position}. This is
126 slower, but more accurate.
128 @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
130 @item -itsoffset @var{offset} (@emph{input})
131 Set the input time offset in seconds.
132 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
133 The offset is added to the timestamps of the input files.
134 Specifying a positive offset means that the corresponding
135 streams are delayed by @var{offset} seconds.
137 @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata})
138 Set a metadata key/value pair.
140 An optional @var{metadata_specifier} may be given to set metadata
141 on streams or chapters. See @code{-map_metadata} documentation for
144 This option overrides metadata set with @code{-map_metadata}. It is
145 also possible to delete metadata by using an empty value.
147 For example, for setting the title in the output file:
149 avconv -i in.avi -metadata title="my title" out.flv
152 To set the language of the second stream:
154 avconv -i INPUT -metadata:s:1 language=eng OUTPUT
157 @item -target @var{type} (@emph{output})
158 Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
159 @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or
160 @code{film-} to use the corresponding standard. All the format options
161 (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
164 avconv -i myfile.avi -target vcd /tmp/vcd.mpg
167 Nevertheless you can specify additional options as long as you know
168 they do not conflict with the standard, as in:
171 avconv -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
174 @item -dframes @var{number} (@emph{output})
175 Set the number of data frames to record. This is an alias for @code{-frames:d}.
177 @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream})
178 Stop writing to the stream after @var{framecount} frames.
180 @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
181 @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
182 Use fixed quality scale (VBR). The meaning of @var{q} is
185 @item -filter[:@var{stream_specifier}] @var{filter_graph} (@emph{output,per-stream})
186 @var{filter_graph} is a description of the filter graph to apply to
187 the stream. Use @code{-filters} to show all the available filters
188 (including also sources and sinks).
189 @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
190 Specify the preset for matching stream(s).
192 @item -stats (@emph{global})
193 Print encoding progress/statistics. On by default.
195 @item -attach @var{filename} (@emph{output})
196 Add an attachment to the output file. This is supported by a few formats
197 like Matroska for e.g. fonts used in rendering subtitles. Attachments
198 are implemented as a specific type of stream, so this option will add
199 a new stream to the file. It is then possible to use per-stream options
200 on this stream in the usual way. Attachment streams created with this
201 option will be created after all the other streams (i.e. those created
202 with @code{-map} or automatic mappings).
204 Note that for Matroska you also have to set the mimetype metadata tag:
206 avconv -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
208 (assuming that the attachment stream will be third in the output file).
210 @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream})
211 Extract the matching attachment stream into a file named @var{filename}. If
212 @var{filename} is empty, then the value of the @code{filename} metadata tag
215 E.g. to extract the first attachment to a file named 'out.ttf':
217 avconv -dump_attachment:t:0 out.ttf INPUT
219 To extract all attachments to files determined by the @code{filename} tag:
221 avconv -dump_attachment:t "" INPUT
224 Technical note -- attachments are implemented as codec extradata, so this
225 option can actually be used to extract extradata from any stream, not just
230 @section Video Options
233 @item -vframes @var{number} (@emph{output})
234 Set the number of video frames to record. This is an alias for @code{-frames:v}.
235 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
236 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
237 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
238 Set frame size. The format is @samp{wxh} (ffserver default = 160x128, avconv default = same as source).
239 The following abbreviations are recognized:
301 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
302 Set the video display aspect ratio specified by @var{aspect}.
304 @var{aspect} can be a floating point number string, or a string of the
305 form @var{num}:@var{den}, where @var{num} and @var{den} are the
306 numerator and denominator of the aspect ratio. For example "4:3",
307 "16:9", "1.3333", and "1.7777" are valid argument values.
309 @item -vn (@emph{output})
310 Disable video recording.
311 @item -bt @var{tolerance}
312 Set video bitrate tolerance (in bits, default 4000k).
313 Has a minimum value of: (target_bitrate/target_framerate).
314 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
315 willing to deviate from the target average bitrate value. This is
316 not related to min/max bitrate. Lowering tolerance too much has
317 an adverse effect on quality.
318 @item -maxrate @var{bitrate}
319 Set max video bitrate (in bit/s).
320 Requires -bufsize to be set.
321 @item -minrate @var{bitrate}
322 Set min video bitrate (in bit/s).
323 Most useful in setting up a CBR encode:
325 avconv -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
327 It is of little use elsewise.
328 @item -bufsize @var{size}
329 Set video buffer verifier buffer size (in bits).
330 @item -vcodec @var{codec} (@emph{output})
331 Set the video codec. This is an alias for @code{-codec:v}.
333 Use same quantizer as source (implies VBR).
335 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
339 Select the pass number (1 or 2). It is used to do two-pass
340 video encoding. The statistics of the video are recorded in the first
341 pass into a log file (see also the option -passlogfile),
342 and in the second pass that log file is used to generate the video
343 at the exact requested bitrate.
344 On pass 1, you may just deactivate audio and set output to null,
345 examples for Windows and Unix:
347 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
348 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
351 @item -passlogfile @var{prefix} (@emph{global})
352 Set two-pass log file name prefix to @var{prefix}, the default file name
353 prefix is ``av2pass''. The complete file name will be
354 @file{PREFIX-N.log}, where N is a number specific to the output
357 @item -vf @var{filter_graph} (@emph{output})
358 @var{filter_graph} is a description of the filter graph to apply to
360 Use the option "-filters" to show all the available filters (including
361 also sources and sinks). This is an alias for @code{-filter:v}.
365 @section Advanced Video Options
368 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
369 Set pixel format. Use @code{-pix_fmts} to show all the supported
371 @item -sws_flags @var{flags} (@emph{input/output})
373 @item -g @var{gop_size}
374 Set the group of pictures size.
378 minimum video quantizer scale (VBR)
380 maximum video quantizer scale (VBR)
382 maximum difference between the quantizer scales (VBR)
383 @item -qblur @var{blur}
384 video quantizer scale blur (VBR) (range 0.0 - 1.0)
385 @item -qcomp @var{compression}
386 video quantizer scale compression (VBR) (default 0.5).
387 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
389 @item -lmin @var{lambda}
390 minimum video lagrange factor (VBR)
391 @item -lmax @var{lambda}
392 max video lagrange factor (VBR)
393 @item -mblmin @var{lambda}
394 minimum macroblock quantizer scale (VBR)
395 @item -mblmax @var{lambda}
396 maximum macroblock quantizer scale (VBR)
398 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
399 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
401 avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
404 @item -rc_init_cplx @var{complexity}
405 initial complexity for single pass encoding
406 @item -b_qfactor @var{factor}
407 qp factor between P- and B-frames
408 @item -i_qfactor @var{factor}
409 qp factor between P- and I-frames
410 @item -b_qoffset @var{offset}
411 qp offset between P- and B-frames
412 @item -i_qoffset @var{offset}
413 qp offset between P- and I-frames
414 @item -rc_eq @var{equation}
415 Set rate control equation (see section "Expression Evaluation")
416 (default = @code{tex^qComp}).
418 When computing the rate control equation expression, besides the
419 standard functions defined in the section "Expression Evaluation", the
420 following functions are available:
426 and the following constants are available:
448 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
449 rate control override for specific intervals
450 @item -me_method @var{method}
451 Set motion estimation method to @var{method}.
452 Available methods are (from lowest to best quality):
455 Try just the (0, 0) vector.
464 exhaustive search (slow and marginally better than epzs)
468 Set error resilience to @var{n}.
471 FF_ER_CAREFUL (default)
477 FF_ER_VERY_AGGRESSIVE
480 @item -ec @var{bit_mask}
481 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
482 the following values:
485 FF_EC_GUESS_MVS (default = enabled)
487 FF_EC_DEBLOCK (default = enabled)
490 @item -bf @var{frames}
491 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
492 @item -mbd @var{mode}
496 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in avconv).
498 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
500 FF_MB_DECISION_RD: rate distortion
503 @item -bug @var{param}
504 Work around encoder bugs that are not auto-detected.
505 @item -strict @var{strictness}
506 How strictly to follow the standards.
509 Deinterlace pictures.
511 Dump video coding statistics to @file{vstats_HHMMSS.log}.
512 @item -vstats_file @var{file}
513 Dump video coding statistics to @var{file}.
514 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
515 top=1/bottom=0/auto=-1 field first
516 @item -dc @var{precision}
518 @item -vtag @var{fourcc/tag} (@emph{output})
519 Force video tag/fourcc. This is an alias for @code{-tag:v}.
520 @item -qphist (@emph{global})
522 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
523 Force key frames at the specified timestamps, more precisely at the first
524 frames after each specified time.
525 This option can be useful to ensure that a seek point is present at a
526 chapter mark or any other designated place in the output file.
527 The timestamps must be specified in ascending order.
530 @section Audio Options
533 @item -aframes @var{number} (@emph{output})
534 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
535 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
536 Set the audio sampling frequency. For output streams it is set by
537 default to the frequency of the corresponding input stream. For input
538 streams this option only makes sense for audio grabbing devices and raw
539 demuxers and is mapped to the corresponding demuxer options.
540 @item -aq @var{q} (@emph{output})
541 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
542 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
543 Set the number of audio channels. For output streams it is set by
544 default to the number of input audio channels. For input streams
545 this option only makes sense for audio grabbing devices and raw demuxers
546 and is mapped to the corresponding demuxer options.
547 @item -an (@emph{output})
548 Disable audio recording.
549 @item -acodec @var{codec} (@emph{input/output})
550 Set the audio codec. This is an alias for @code{-codec:a}.
551 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
552 Set the audio sample format. Use @code{-help sample_fmts} to get a list
553 of supported sample formats.
556 @section Advanced Audio options:
559 @item -atag @var{fourcc/tag} (@emph{output})
560 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
561 @item -audio_service_type @var{type}
562 Set the type of service that the audio stream contains.
565 Main Audio Service (default)
585 @section Subtitle options:
588 @item -scodec @var{codec} (@emph{input/output})
589 Set the subtitle codec. This is an alias for @code{-codec:s}.
590 @item -sn (@emph{output})
591 Disable subtitle recording.
594 @section Audio/Video grab options
597 @item -isync (@emph{global})
598 Synchronize read on input.
601 @section Advanced options
604 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] (@emph{output})
606 Designate one or more input streams as a source for the output file. Each input
607 stream is identified by the input file index @var{input_file_id} and
608 the input stream index @var{input_stream_id} within the input
609 file. Both indices start at 0. If specified,
610 @var{sync_file_id}:@var{stream_specifier} sets which input stream
611 is used as a presentation sync reference.
613 The first @code{-map} option on the command line specifies the
614 source for output stream 0, the second @code{-map} option specifies
615 the source for output stream 1, etc.
617 A @code{-} character before the stream identifier creates a "negative" mapping.
618 It disables matching streams from already created mappings.
620 For example, to map ALL streams from the first input file to output
622 avconv -i INPUT -map 0 output
625 For example, if you have two audio streams in the first input file,
626 these streams are identified by "0:0" and "0:1". You can use
627 @code{-map} to select which streams to place in an output file. For
630 avconv -i INPUT -map 0:1 out.wav
632 will map the input stream in @file{INPUT} identified by "0:1" to
633 the (single) output stream in @file{out.wav}.
635 For example, to select the stream with index 2 from input file
636 @file{a.mov} (specified by the identifier "0:2"), and stream with
637 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
638 and copy them to the output file @file{out.mov}:
640 avconv -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
643 To select all video and the third audio stream from an input file:
645 avconv -i INPUT -map 0:v -map 0:a:2 OUTPUT
648 To map all the streams except the second audio, use negative mappings
650 avconv -i INPUT -map 0 -map -0:a:1 OUTPUT
653 Note that using this option disables the default mappings for this output file.
655 @item -map_metadata[:@var{metadata_type}][:@var{index}] @var{infile}[:@var{metadata_type}][:@var{index}] (@emph{output,per-metadata})
656 Set metadata information of the next output file from @var{infile}. Note that
657 those are file indices (zero-based), not filenames.
658 Optional @var{metadata_type} parameters specify, which metadata to copy - (g)lobal
659 (i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
660 per-(p)rogram. All metadata specifiers other than global must be followed by the
661 stream/chapter/program index. If metadata specifier is omitted, it defaults to
664 By default, global metadata is copied from the first input file,
665 per-stream and per-chapter metadata is copied along with streams/chapters. These
666 default mappings are disabled by creating any mapping of the relevant type. A negative
667 file index can be used to create a dummy mapping that just disables automatic copying.
669 For example to copy metadata from the first stream of the input file to global metadata
672 avconv -i in.ogg -map_metadata 0:s:0 out.mp3
674 @item -map_chapters @var{input_file_index} (@emph{output})
675 Copy chapters from input file with index @var{input_file_index} to the next
676 output file. If no chapter mapping is specified, then chapters are copied from
677 the first input file with at least one chapter. Use a negative file index to
678 disable any chapter copying.
680 Print specific debug info.
681 @item -benchmark (@emph{global})
682 Show benchmarking information at the end of an encode.
683 Shows CPU time used and maximum memory consumption.
684 Maximum memory consumption is not supported on all systems,
685 it will usually display as 0 if not supported.
686 @item -timelimit @var{duration} (@emph{global})
687 Exit after avconv has been running for @var{duration} seconds.
688 @item -dump (@emph{global})
689 Dump each input packet to stderr.
690 @item -hex (@emph{global})
691 When dumping packets, also dump the payload.
693 Set RTP payload size in bytes.
694 @item -re (@emph{input})
695 Read input at native frame rate. Mainly used to simulate a grab device.
696 @item -threads @var{count}
698 @item -vsync @var{parameter}
703 Each frame is passed with its timestamp from the demuxer to the muxer.
705 Frames will be duplicated and dropped to achieve exactly the requested
708 Frames are passed through with their timestamp or dropped so as to
709 prevent 2 frames from having the same timestamp.
711 Chooses between 1 and 2 depending on muxer capabilities. This is the
715 With -map you can select from which stream the timestamps should be
716 taken. You can leave either video or audio unchanged and sync the
717 remaining stream(s) to the unchanged one.
719 @item -async @var{samples_per_second}
720 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
721 the parameter is the maximum samples per second by which the audio is changed.
722 -async 1 is a special case where only the start of the audio stream is corrected
723 without any later correction.
725 Copy timestamps from input to output.
727 Copy input stream time base from input to output when stream copying.
729 Finish encoding when the shortest input stream ends.
730 @item -dts_delta_threshold
731 Timestamp discontinuity delta threshold.
732 @item -muxdelay @var{seconds} (@emph{input})
733 Set the maximum demux-decode delay.
734 @item -muxpreload @var{seconds} (@emph{input})
735 Set the initial demux-decode delay.
736 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
737 Assign a new stream-id value to an output stream. This option should be
738 specified prior to the output filename to which it applies.
739 For the situation where multiple output files exist, a streamid
740 may be reassigned to a different value.
742 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
743 an output mpegts file:
745 avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
748 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
749 Set bitstream filters for matching streams. @var{bistream_filters} is
750 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
751 to get the list of bitstream filters.
753 avconv -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
756 avconv -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
759 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{output,per-stream})
760 Force a tag/fourcc for matching streams.
769 For streaming at very low bitrate application, use a low frame rate
770 and a small GOP size. This is especially true for RealVideo where
771 the Linux player does not seem to be very fast, so it can miss
772 frames. An example is:
775 avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
779 The parameter 'q' which is displayed while encoding is the current
780 quantizer. The value 1 indicates that a very good quality could
781 be achieved. The value 31 indicates the worst quality. If q=31 appears
782 too often, it means that the encoder cannot compress enough to meet
783 your bitrate. You must either increase the bitrate, decrease the
784 frame rate or decrease the frame size.
787 If your computer is not fast enough, you can speed up the
788 compression at the expense of the compression ratio. You can use
789 '-me zero' to speed up motion estimation, and '-intra' to disable
790 motion estimation completely (you have only I-frames, which means it
791 is about as good as JPEG compression).
794 To have very low audio bitrates, reduce the sampling frequency
795 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
798 To have a constant quality (but a variable bitrate), use the option
799 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
806 @c man begin EXAMPLES
808 @section Preset files
810 A preset file contains a sequence of @var{option=value} pairs, one for
811 each line, specifying a sequence of options which can be specified also on
812 the command line. Lines starting with the hash ('#') character are ignored and
813 are used to provide comments. Empty lines are also ignored. Check the
814 @file{presets} directory in the Libav source tree for examples.
816 Preset files are specified with the @code{pre} option, this option takes a
817 preset name as input. Avconv searches for a file named @var{preset_name}.avpreset in
818 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.avconv}, and in
819 the data directory defined at configuration time (usually @file{$PREFIX/share/avconv})
820 in that order. For example, if the argument is @code{libx264-max}, it will
821 search for the file @file{libx264-max.avpreset}.
823 @section Video and Audio grabbing
825 If you specify the input format and device then avconv can grab video
829 avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
832 Note that you must activate the right video source and channel before
833 launching avconv with any TV viewer such as
834 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
835 have to set the audio recording levels correctly with a
838 @section X11 grabbing
840 Grab the X11 display with avconv via
843 avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
846 0.0 is display.screen number of your X11 server, same as
847 the DISPLAY environment variable.
850 avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
853 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
854 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
856 @section Video and Audio file format conversion
858 Any supported file format and protocol can serve as input to avconv:
863 You can use YUV files as input:
866 avconv -i /tmp/test%d.Y /tmp/out.mpg
869 It will use the files:
871 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
872 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
875 The Y files use twice the resolution of the U and V files. They are
876 raw files, without header. They can be generated by all decent video
877 decoders. You must specify the size of the image with the @option{-s} option
878 if avconv cannot guess it.
881 You can input from a raw YUV420P file:
884 avconv -i /tmp/test.yuv /tmp/out.avi
887 test.yuv is a file containing raw YUV planar data. Each frame is composed
888 of the Y plane followed by the U and V planes at half vertical and
889 horizontal resolution.
892 You can output to a raw YUV420P file:
895 avconv -i mydivx.avi hugefile.yuv
899 You can set several input files and output files:
902 avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
905 Converts the audio file a.wav and the raw YUV video file a.yuv
909 You can also do audio and video conversions at the same time:
912 avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
915 Converts a.wav to MPEG audio at 22050 Hz sample rate.
918 You can encode to several formats at the same time and define a
919 mapping from input stream to output streams:
922 avconv -i /tmp/a.wav -map 0:a -b 64k /tmp/a.mp2 -map 0:a -b 128k /tmp/b.mp2
925 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
926 file:index' specifies which input stream is used for each output
927 stream, in the order of the definition of output streams.
930 You can transcode decrypted VOBs:
933 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
936 This is a typical DVD ripping example; the input is a VOB file, the
937 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
938 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
939 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
940 input video. Furthermore, the audio stream is MP3-encoded so you need
941 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
942 The mapping is particularly useful for DVD transcoding
943 to get the desired audio language.
945 NOTE: To see the supported input formats, use @code{avconv -formats}.
948 You can extract images from a video, or create a video from many images:
950 For extracting images from a video:
952 avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
955 This will extract one video frame per second from the video and will
956 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
957 etc. Images will be rescaled to fit the new WxH values.
959 If you want to extract just a limited number of frames, you can use the
960 above command in combination with the -vframes or -t option, or in
961 combination with -ss to start extracting from a certain point in time.
963 For creating a video from many images:
965 avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
968 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
969 composed of three digits padded with zeroes to express the sequence
970 number. It is the same syntax supported by the C printf function, but
971 only formats accepting a normal integer are suitable.
974 You can put many streams of the same type in the output:
977 avconv -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
980 The resulting output file @file{test12.avi} will contain first four streams from
981 the input file in reverse order.
987 @include encoders.texi
988 @include demuxers.texi
991 @include outdevs.texi
992 @include protocols.texi
993 @include bitstream_filters.texi
994 @include filters.texi
995 @include metadata.texi
1000 @settitle avconv video converter
1002 @c man begin SEEALSO
1003 ffplay(1), ffprobe(1), ffserver(1) and the FFmpeg HTML documentation
1006 @c man begin AUTHORS
1007 The Libav developers