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 avconv reads from an arbitrary number of input "files" (which can be regular
30 files, pipes, network streams, grabbing devices, etc.), specified by the
31 @code{-i} option, and writes to an arbitrary number of output "files", which are
32 specified by a plain output filename. Anything found on the command line which
33 cannot be interpreted as an option is considered to be an output filename.
35 Each input or output file can in principle contain any number of streams of
36 different types (video/audio/subtitle/attachment/data). Allowed number and/or
37 types of streams can be limited by the container format. Selecting, which
38 streams from which inputs go into output, is done either automatically or with
39 the @code{-map} option (see the Stream selection chapter).
41 To refer to input files in options, you must use their indices (0-based). E.g.
42 the first input file is @code{0}, the second is @code{1} etc. Similarly, streams
43 within a file are referred to by their indices. E.g. @code{2:3} refers to the
44 fourth stream in the third input file. See also the Stream specifiers chapter.
46 As a general rule, options are applied to the next specified
47 file. Therefore, order is important, and you can have the same
48 option on the command line multiple times. Each occurrence is
49 then applied to the next input or output file.
50 Exceptions from this rule are the global options (e.g. verbosity level),
51 which should be specified first.
53 Do not mix input and output files -- first specify all input files, then all
54 output files. Also do not mix options which belong to different files. All
55 options apply ONLY to the next input or output file and are reset between files.
59 To set the video bitrate of the output file to 64kbit/s:
61 avconv -i input.avi -b 64k output.avi
65 To force the frame rate of the output file to 24 fps:
67 avconv -i input.avi -r 24 output.avi
71 To force the frame rate of the input file (valid for raw formats only)
72 to 1 fps and the frame rate of the output file to 24 fps:
74 avconv -r 1 -i input.m2v -r 24 output.avi
78 The format option may be needed for raw input files.
80 @c man end DESCRIPTION
82 @chapter Stream selection
83 @c man begin STREAM SELECTION
85 By default avconv tries to pick the "best" stream of each type present in input
86 files and add them to each output file. For video, this means the highest
87 resolution, for audio the highest channel count. For subtitle it's simply the
88 first subtitle stream.
90 You can disable some of those defaults by using @code{-vn/-an/-sn} options. For
91 full manual control, use the @code{-map} option, which disables the defaults just
94 @c man end STREAM SELECTION
99 @include avtools-common-opts.texi
101 @section Main options
105 @item -f @var{fmt} (@emph{input/output})
106 Force input or output file format. The format is normally autodetected for input
107 files and guessed from file extension for output files, so this option is not
108 needed in most cases.
110 @item -i @var{filename} (@emph{input})
113 @item -y (@emph{global})
114 Overwrite output files without asking.
116 @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
117 @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream})
118 Select an encoder (when used before an output file) or a decoder (when used
119 before an input file) for one or more streams. @var{codec} is the name of a
120 decoder/encoder or a special value @code{copy} (output only) to indicate that
121 the stream is not to be reencoded.
125 avconv -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
127 encodes all video streams with libx264 and copies all audio streams.
129 For each stream, the last matching @code{c} option is applied, so
131 avconv -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
133 will copy all the streams except the second video, which will be encoded with
134 libx264, and the 138th audio, which will be encoded with libvorbis.
136 @item -t @var{duration} (@emph{output})
137 Stop writing the output after its duration reaches @var{duration}.
138 @var{duration} may be a number in seconds, or in @code{hh:mm:ss[.xxx]} form.
140 @item -fs @var{limit_size} (@emph{output})
141 Set the file size limit.
143 @item -ss @var{position} (@emph{input/output})
144 When used as an input option (before @code{-i}), seeks in this input file to
145 @var{position}. When used as an output option (before an output filename),
146 decodes but discards input until the timestamps reach @var{position}. This is
147 slower, but more accurate.
149 @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
151 @item -itsoffset @var{offset} (@emph{input})
152 Set the input time offset in seconds.
153 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
154 The offset is added to the timestamps of the input files.
155 Specifying a positive offset means that the corresponding
156 streams are delayed by @var{offset} seconds.
158 @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata})
159 Set a metadata key/value pair.
161 An optional @var{metadata_specifier} may be given to set metadata
162 on streams or chapters. See @code{-map_metadata} documentation for
165 This option overrides metadata set with @code{-map_metadata}. It is
166 also possible to delete metadata by using an empty value.
168 For example, for setting the title in the output file:
170 avconv -i in.avi -metadata title="my title" out.flv
173 To set the language of the first audio stream:
175 avconv -i INPUT -metadata:s:a:0 language=eng OUTPUT
178 @item -target @var{type} (@emph{output})
179 Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv},
180 @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or
181 @code{film-} to use the corresponding standard. All the format options
182 (bitrate, codecs, buffer sizes) are then set automatically. You can just type:
185 avconv -i myfile.avi -target vcd /tmp/vcd.mpg
188 Nevertheless you can specify additional options as long as you know
189 they do not conflict with the standard, as in:
192 avconv -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
195 @item -dframes @var{number} (@emph{output})
196 Set the number of data frames to record. This is an alias for @code{-frames:d}.
198 @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream})
199 Stop writing to the stream after @var{framecount} frames.
201 @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
202 @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream})
203 Use fixed quality scale (VBR). The meaning of @var{q} is
206 @item -filter[:@var{stream_specifier}] @var{filter_graph} (@emph{output,per-stream})
207 @var{filter_graph} is a description of the filter graph to apply to
208 the stream. Use @code{-filters} to show all the available filters
209 (including also sources and sinks).
211 See also the @option{-filter_complex} option if you want to create filter graphs
212 with multiple inputs and/or outputs.
213 @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
214 Specify the preset for matching stream(s).
216 @item -stats (@emph{global})
217 Print encoding progress/statistics. On by default.
219 @item -attach @var{filename} (@emph{output})
220 Add an attachment to the output file. This is supported by a few formats
221 like Matroska for e.g. fonts used in rendering subtitles. Attachments
222 are implemented as a specific type of stream, so this option will add
223 a new stream to the file. It is then possible to use per-stream options
224 on this stream in the usual way. Attachment streams created with this
225 option will be created after all the other streams (i.e. those created
226 with @code{-map} or automatic mappings).
228 Note that for Matroska you also have to set the mimetype metadata tag:
230 avconv -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
232 (assuming that the attachment stream will be third in the output file).
234 @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream})
235 Extract the matching attachment stream into a file named @var{filename}. If
236 @var{filename} is empty, then the value of the @code{filename} metadata tag
239 E.g. to extract the first attachment to a file named 'out.ttf':
241 avconv -dump_attachment:t:0 out.ttf INPUT
243 To extract all attachments to files determined by the @code{filename} tag:
245 avconv -dump_attachment:t "" INPUT
248 Technical note -- attachments are implemented as codec extradata, so this
249 option can actually be used to extract extradata from any stream, not just
254 @section Video Options
257 @item -vframes @var{number} (@emph{output})
258 Set the number of video frames to record. This is an alias for @code{-frames:v}.
259 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
260 Set frame rate (Hz value, fraction or abbreviation), (default = 25). For output
261 streams implies @code{-vsync cfr}.
262 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
263 Set frame size. The format is @samp{wxh} (default - same as source).
264 The following abbreviations are recognized:
326 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
327 Set the video display aspect ratio specified by @var{aspect}.
329 @var{aspect} can be a floating point number string, or a string of the
330 form @var{num}:@var{den}, where @var{num} and @var{den} are the
331 numerator and denominator of the aspect ratio. For example "4:3",
332 "16:9", "1.3333", and "1.7777" are valid argument values.
334 @item -vn (@emph{output})
335 Disable video recording.
337 @item -vcodec @var{codec} (@emph{output})
338 Set the video codec. This is an alias for @code{-codec:v}.
340 Use same quantizer as source (implies VBR).
342 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
346 Select the pass number (1 or 2). It is used to do two-pass
347 video encoding. The statistics of the video are recorded in the first
348 pass into a log file (see also the option -passlogfile),
349 and in the second pass that log file is used to generate the video
350 at the exact requested bitrate.
351 On pass 1, you may just deactivate audio and set output to null,
352 examples for Windows and Unix:
354 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
355 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
358 @item -passlogfile @var{prefix} (@emph{global})
359 Set two-pass log file name prefix to @var{prefix}, the default file name
360 prefix is ``av2pass''. The complete file name will be
361 @file{PREFIX-N.log}, where N is a number specific to the output
364 @item -vf @var{filter_graph} (@emph{output})
365 @var{filter_graph} is a description of the filter graph to apply to
367 Use the option "-filters" to show all the available filters (including
368 also sources and sinks). This is an alias for @code{-filter:v}.
372 @section Advanced Video Options
375 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
376 Set pixel format. Use @code{-pix_fmts} to show all the supported
378 @item -sws_flags @var{flags} (@emph{input/output})
383 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
384 rate control override for specific intervals
387 Deinterlace pictures.
388 This option is deprecated since the deinterlacing is very low quality.
389 Use the yadif filter with @code{-filter:v yadif}.
391 Dump video coding statistics to @file{vstats_HHMMSS.log}.
392 @item -vstats_file @var{file}
393 Dump video coding statistics to @var{file}.
394 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
395 top=1/bottom=0/auto=-1 field first
396 @item -dc @var{precision}
398 @item -vtag @var{fourcc/tag} (@emph{output})
399 Force video tag/fourcc. This is an alias for @code{-tag:v}.
400 @item -qphist (@emph{global})
402 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
403 Force key frames at the specified timestamps, more precisely at the first
404 frames after each specified time.
405 This option can be useful to ensure that a seek point is present at a
406 chapter mark or any other designated place in the output file.
407 The timestamps must be specified in ascending order.
409 @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream})
410 When doing stream copy, copy also non-key frames found at the
414 @section Audio Options
417 @item -aframes @var{number} (@emph{output})
418 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
419 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
420 Set the audio sampling frequency. For output streams it is set by
421 default to the frequency of the corresponding input stream. For input
422 streams this option only makes sense for audio grabbing devices and raw
423 demuxers and is mapped to the corresponding demuxer options.
424 @item -aq @var{q} (@emph{output})
425 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
426 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
427 Set the number of audio channels. For output streams it is set by
428 default to the number of input audio channels. For input streams
429 this option only makes sense for audio grabbing devices and raw demuxers
430 and is mapped to the corresponding demuxer options.
431 @item -an (@emph{output})
432 Disable audio recording.
433 @item -acodec @var{codec} (@emph{input/output})
434 Set the audio codec. This is an alias for @code{-codec:a}.
435 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
436 Set the audio sample format. Use @code{-sample_fmts} to get a list
437 of supported sample formats.
438 @item -af @var{filter_graph} (@emph{output})
439 @var{filter_graph} is a description of the filter graph to apply to
441 Use the option "-filters" to show all the available filters (including
442 also sources and sinks). This is an alias for @code{-filter:a}.
445 @section Advanced Audio options:
448 @item -atag @var{fourcc/tag} (@emph{output})
449 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
452 @section Subtitle options:
455 @item -scodec @var{codec} (@emph{input/output})
456 Set the subtitle codec. This is an alias for @code{-codec:s}.
457 @item -sn (@emph{output})
458 Disable subtitle recording.
461 @section Audio/Video grab options
464 @item -isync (@emph{global})
465 Synchronize read on input.
468 @section Advanced options
471 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
473 Designate one or more input streams as a source for the output file. Each input
474 stream is identified by the input file index @var{input_file_id} and
475 the input stream index @var{input_stream_id} within the input
476 file. Both indices start at 0. If specified,
477 @var{sync_file_id}:@var{stream_specifier} sets which input stream
478 is used as a presentation sync reference.
480 The first @code{-map} option on the command line specifies the
481 source for output stream 0, the second @code{-map} option specifies
482 the source for output stream 1, etc.
484 A @code{-} character before the stream identifier creates a "negative" mapping.
485 It disables matching streams from already created mappings.
487 An alternative @var{[linklabel]} form will map outputs from complex filter
488 graphs (see the @option{-filter_complex} option) to the output file.
489 @var{linklabel} must correspond to a defined output link label in the graph.
491 For example, to map ALL streams from the first input file to output
493 avconv -i INPUT -map 0 output
496 For example, if you have two audio streams in the first input file,
497 these streams are identified by "0:0" and "0:1". You can use
498 @code{-map} to select which streams to place in an output file. For
501 avconv -i INPUT -map 0:1 out.wav
503 will map the input stream in @file{INPUT} identified by "0:1" to
504 the (single) output stream in @file{out.wav}.
506 For example, to select the stream with index 2 from input file
507 @file{a.mov} (specified by the identifier "0:2"), and stream with
508 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
509 and copy them to the output file @file{out.mov}:
511 avconv -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
514 To select all video and the third audio stream from an input file:
516 avconv -i INPUT -map 0:v -map 0:a:2 OUTPUT
519 To map all the streams except the second audio, use negative mappings
521 avconv -i INPUT -map 0 -map -0:a:1 OUTPUT
524 Note that using this option disables the default mappings for this output file.
526 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
527 Set metadata information of the next output file from @var{infile}. Note that
528 those are file indices (zero-based), not filenames.
529 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
530 A metadata specifier can have the following forms:
533 global metadata, i.e. metadata that applies to the whole file
535 @item @var{s}[:@var{stream_spec}]
536 per-stream metadata. @var{stream_spec} is a stream specifier as described
537 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
538 matching stream is copied from. In an output metadata specifier, all matching
539 streams are copied to.
541 @item @var{c}:@var{chapter_index}
542 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
544 @item @var{p}:@var{program_index}
545 per-program metadata. @var{program_index} is the zero-based program index.
547 If metadata specifier is omitted, it defaults to global.
549 By default, global metadata is copied from the first input file,
550 per-stream and per-chapter metadata is copied along with streams/chapters. These
551 default mappings are disabled by creating any mapping of the relevant type. A negative
552 file index can be used to create a dummy mapping that just disables automatic copying.
554 For example to copy metadata from the first stream of the input file to global metadata
557 avconv -i in.ogg -map_metadata 0:s:0 out.mp3
560 To do the reverse, i.e. copy global metadata to all audio streams:
562 avconv -i in.mkv -map_metadata:s:a 0:g out.mkv
564 Note that simple @code{0} would work as well in this example, since global
565 metadata is assumed by default.
567 @item -map_chapters @var{input_file_index} (@emph{output})
568 Copy chapters from input file with index @var{input_file_index} to the next
569 output file. If no chapter mapping is specified, then chapters are copied from
570 the first input file with at least one chapter. Use a negative file index to
571 disable any chapter copying.
573 Print specific debug info.
574 @item -benchmark (@emph{global})
575 Show benchmarking information at the end of an encode.
576 Shows CPU time used and maximum memory consumption.
577 Maximum memory consumption is not supported on all systems,
578 it will usually display as 0 if not supported.
579 @item -timelimit @var{duration} (@emph{global})
580 Exit after avconv has been running for @var{duration} seconds.
581 @item -dump (@emph{global})
582 Dump each input packet to stderr.
583 @item -hex (@emph{global})
584 When dumping packets, also dump the payload.
585 @item -re (@emph{input})
586 Read input at native frame rate. Mainly used to simulate a grab device.
587 @item -vsync @var{parameter}
592 Each frame is passed with its timestamp from the demuxer to the muxer.
594 Frames will be duplicated and dropped to achieve exactly the requested
597 Frames are passed through with their timestamp or dropped so as to
598 prevent 2 frames from having the same timestamp.
600 Chooses between 1 and 2 depending on muxer capabilities. This is the
604 With -map you can select from which stream the timestamps should be
605 taken. You can leave either video or audio unchanged and sync the
606 remaining stream(s) to the unchanged one.
608 @item -async @var{samples_per_second}
609 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
610 the parameter is the maximum samples per second by which the audio is changed.
611 -async 1 is a special case where only the start of the audio stream is corrected
612 without any later correction.
613 This option has been deprecated. Use the @code{asyncts} audio filter instead.
615 Copy timestamps from input to output.
617 Copy input stream time base from input to output when stream copying.
619 Finish encoding when the shortest input stream ends.
620 @item -dts_delta_threshold
621 Timestamp discontinuity delta threshold.
622 @item -muxdelay @var{seconds} (@emph{input})
623 Set the maximum demux-decode delay.
624 @item -muxpreload @var{seconds} (@emph{input})
625 Set the initial demux-decode delay.
626 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
627 Assign a new stream-id value to an output stream. This option should be
628 specified prior to the output filename to which it applies.
629 For the situation where multiple output files exist, a streamid
630 may be reassigned to a different value.
632 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
633 an output mpegts file:
635 avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
638 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
639 Set bitstream filters for matching streams. @var{bistream_filters} is
640 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
641 to get the list of bitstream filters.
643 avconv -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
646 avconv -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
649 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{output,per-stream})
650 Force a tag/fourcc for matching streams.
652 @item -cpuflags mask (@emph{global})
653 Set a mask that's applied to autodetected CPU flags. This option is intended
654 for testing. Do not use it unless you know what you're doing.
656 @item -filter_complex @var{filtergraph} (@emph{global})
657 Define a complex filter graph, i.e. one with arbitrary number of inputs and/or
658 outputs. For simple graphs -- those with one input and one output of the same
659 type -- see the @option{-filter} options. @var{filtergraph} is a description of
660 the filter graph, as described in @ref{Filtergraph syntax}.
662 Input link labels must refer to input streams using the
663 @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map}
664 uses). If @var{stream_specifier} matches multiple streams, the first one will be
665 used. An unlabeled input will be connected to the first unused input stream of
668 Output link labels are referred to with @option{-map}. Unlabeled outputs are
669 added to the first output file.
671 For example, to overlay an image over video
673 avconv -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
676 Here @code{[0:v]} refers to the first video stream in the first input file,
677 which is linked to the first (main) input of the overlay filter. Similarly the
678 first video stream in the second input is linked to the second (overlay) input
681 Assuming there is only one video stream in each input file, we can omit input
682 labels, so the above is equivalent to
684 avconv -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
688 Furthermore we can omit the output label and the single output from the filter
689 graph will be added to the output file automatically, so we can simply write
691 avconv -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
701 For streaming at very low bitrate application, use a low frame rate
702 and a small GOP size. This is especially true for RealVideo where
703 the Linux player does not seem to be very fast, so it can miss
704 frames. An example is:
707 avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
711 The parameter 'q' which is displayed while encoding is the current
712 quantizer. The value 1 indicates that a very good quality could
713 be achieved. The value 31 indicates the worst quality. If q=31 appears
714 too often, it means that the encoder cannot compress enough to meet
715 your bitrate. You must either increase the bitrate, decrease the
716 frame rate or decrease the frame size.
719 If your computer is not fast enough, you can speed up the
720 compression at the expense of the compression ratio. You can use
721 '-me zero' to speed up motion estimation, and '-g 0' to disable
722 motion estimation completely (you have only I-frames, which means it
723 is about as good as JPEG compression).
726 To have very low audio bitrates, reduce the sampling frequency
727 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
730 To have a constant quality (but a variable bitrate), use the option
731 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
738 @c man begin EXAMPLES
740 @section Preset files
742 A preset file contains a sequence of @var{option=value} pairs, one for
743 each line, specifying a sequence of options which can be specified also on
744 the command line. Lines starting with the hash ('#') character are ignored and
745 are used to provide comments. Empty lines are also ignored. Check the
746 @file{presets} directory in the Libav source tree for examples.
748 Preset files are specified with the @code{pre} option, this option takes a
749 preset name as input. Avconv searches for a file named @var{preset_name}.avpreset in
750 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.avconv}, and in
751 the data directory defined at configuration time (usually @file{$PREFIX/share/avconv})
752 in that order. For example, if the argument is @code{libx264-max}, it will
753 search for the file @file{libx264-max.avpreset}.
755 @section Video and Audio grabbing
757 If you specify the input format and device then avconv can grab video
761 avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
764 Note that you must activate the right video source and channel before
765 launching avconv with any TV viewer such as
766 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
767 have to set the audio recording levels correctly with a
770 @section X11 grabbing
772 Grab the X11 display with avconv via
775 avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
778 0.0 is display.screen number of your X11 server, same as
779 the DISPLAY environment variable.
782 avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
785 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
786 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
788 @section Video and Audio file format conversion
790 Any supported file format and protocol can serve as input to avconv:
795 You can use YUV files as input:
798 avconv -i /tmp/test%d.Y /tmp/out.mpg
801 It will use the files:
803 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
804 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
807 The Y files use twice the resolution of the U and V files. They are
808 raw files, without header. They can be generated by all decent video
809 decoders. You must specify the size of the image with the @option{-s} option
810 if avconv cannot guess it.
813 You can input from a raw YUV420P file:
816 avconv -i /tmp/test.yuv /tmp/out.avi
819 test.yuv is a file containing raw YUV planar data. Each frame is composed
820 of the Y plane followed by the U and V planes at half vertical and
821 horizontal resolution.
824 You can output to a raw YUV420P file:
827 avconv -i mydivx.avi hugefile.yuv
831 You can set several input files and output files:
834 avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
837 Converts the audio file a.wav and the raw YUV video file a.yuv
841 You can also do audio and video conversions at the same time:
844 avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
847 Converts a.wav to MPEG audio at 22050 Hz sample rate.
850 You can encode to several formats at the same time and define a
851 mapping from input stream to output streams:
854 avconv -i /tmp/a.wav -map 0:a -b 64k /tmp/a.mp2 -map 0:a -b 128k /tmp/b.mp2
857 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
858 file:index' specifies which input stream is used for each output
859 stream, in the order of the definition of output streams.
862 You can transcode decrypted VOBs:
865 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
868 This is a typical DVD ripping example; the input is a VOB file, the
869 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
870 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
871 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
872 input video. Furthermore, the audio stream is MP3-encoded so you need
873 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
874 The mapping is particularly useful for DVD transcoding
875 to get the desired audio language.
877 NOTE: To see the supported input formats, use @code{avconv -formats}.
880 You can extract images from a video, or create a video from many images:
882 For extracting images from a video:
884 avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
887 This will extract one video frame per second from the video and will
888 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
889 etc. Images will be rescaled to fit the new WxH values.
891 If you want to extract just a limited number of frames, you can use the
892 above command in combination with the -vframes or -t option, or in
893 combination with -ss to start extracting from a certain point in time.
895 For creating a video from many images:
897 avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
900 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
901 composed of three digits padded with zeroes to express the sequence
902 number. It is the same syntax supported by the C printf function, but
903 only formats accepting a normal integer are suitable.
906 You can put many streams of the same type in the output:
909 avconv -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
912 The resulting output file @file{test12.avi} will contain first four streams from
913 the input file in reverse order.
916 To force CBR video output:
918 avconv -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
922 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
923 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
925 avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
932 @include encoders.texi
933 @include demuxers.texi
936 @include outdevs.texi
937 @include protocols.texi
938 @include bitstream_filters.texi
939 @include filters.texi
940 @include metadata.texi
945 @settitle avconv video converter
948 avplay(1), avprobe(1) and the Libav HTML documentation