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.
440 @section Advanced Audio options:
443 @item -atag @var{fourcc/tag} (@emph{output})
444 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
447 @section Subtitle options:
450 @item -scodec @var{codec} (@emph{input/output})
451 Set the subtitle codec. This is an alias for @code{-codec:s}.
452 @item -sn (@emph{output})
453 Disable subtitle recording.
456 @section Audio/Video grab options
459 @item -isync (@emph{global})
460 Synchronize read on input.
463 @section Advanced options
466 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output})
468 Designate one or more input streams as a source for the output file. Each input
469 stream is identified by the input file index @var{input_file_id} and
470 the input stream index @var{input_stream_id} within the input
471 file. Both indices start at 0. If specified,
472 @var{sync_file_id}:@var{stream_specifier} sets which input stream
473 is used as a presentation sync reference.
475 The first @code{-map} option on the command line specifies the
476 source for output stream 0, the second @code{-map} option specifies
477 the source for output stream 1, etc.
479 A @code{-} character before the stream identifier creates a "negative" mapping.
480 It disables matching streams from already created mappings.
482 An alternative @var{[linklabel]} form will map outputs from complex filter
483 graphs (see the @option{-filter_complex} option) to the output file.
484 @var{linklabel} must correspond to a defined output link label in the graph.
486 For example, to map ALL streams from the first input file to output
488 avconv -i INPUT -map 0 output
491 For example, if you have two audio streams in the first input file,
492 these streams are identified by "0:0" and "0:1". You can use
493 @code{-map} to select which streams to place in an output file. For
496 avconv -i INPUT -map 0:1 out.wav
498 will map the input stream in @file{INPUT} identified by "0:1" to
499 the (single) output stream in @file{out.wav}.
501 For example, to select the stream with index 2 from input file
502 @file{a.mov} (specified by the identifier "0:2"), and stream with
503 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
504 and copy them to the output file @file{out.mov}:
506 avconv -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
509 To select all video and the third audio stream from an input file:
511 avconv -i INPUT -map 0:v -map 0:a:2 OUTPUT
514 To map all the streams except the second audio, use negative mappings
516 avconv -i INPUT -map 0 -map -0:a:1 OUTPUT
519 Note that using this option disables the default mappings for this output file.
521 @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata})
522 Set metadata information of the next output file from @var{infile}. Note that
523 those are file indices (zero-based), not filenames.
524 Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy.
525 A metadata specifier can have the following forms:
528 global metadata, i.e. metadata that applies to the whole file
530 @item @var{s}[:@var{stream_spec}]
531 per-stream metadata. @var{stream_spec} is a stream specifier as described
532 in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first
533 matching stream is copied from. In an output metadata specifier, all matching
534 streams are copied to.
536 @item @var{c}:@var{chapter_index}
537 per-chapter metadata. @var{chapter_index} is the zero-based chapter index.
539 @item @var{p}:@var{program_index}
540 per-program metadata. @var{program_index} is the zero-based program index.
542 If metadata specifier is omitted, it defaults to global.
544 By default, global metadata is copied from the first input file,
545 per-stream and per-chapter metadata is copied along with streams/chapters. These
546 default mappings are disabled by creating any mapping of the relevant type. A negative
547 file index can be used to create a dummy mapping that just disables automatic copying.
549 For example to copy metadata from the first stream of the input file to global metadata
552 avconv -i in.ogg -map_metadata 0:s:0 out.mp3
555 To do the reverse, i.e. copy global metadata to all audio streams:
557 avconv -i in.mkv -map_metadata:s:a 0:g out.mkv
559 Note that simple @code{0} would work as well in this example, since global
560 metadata is assumed by default.
562 @item -map_chapters @var{input_file_index} (@emph{output})
563 Copy chapters from input file with index @var{input_file_index} to the next
564 output file. If no chapter mapping is specified, then chapters are copied from
565 the first input file with at least one chapter. Use a negative file index to
566 disable any chapter copying.
568 Print specific debug info.
569 @item -benchmark (@emph{global})
570 Show benchmarking information at the end of an encode.
571 Shows CPU time used and maximum memory consumption.
572 Maximum memory consumption is not supported on all systems,
573 it will usually display as 0 if not supported.
574 @item -timelimit @var{duration} (@emph{global})
575 Exit after avconv has been running for @var{duration} seconds.
576 @item -dump (@emph{global})
577 Dump each input packet to stderr.
578 @item -hex (@emph{global})
579 When dumping packets, also dump the payload.
580 @item -re (@emph{input})
581 Read input at native frame rate. Mainly used to simulate a grab device.
582 @item -vsync @var{parameter}
587 Each frame is passed with its timestamp from the demuxer to the muxer.
589 Frames will be duplicated and dropped to achieve exactly the requested
592 Frames are passed through with their timestamp or dropped so as to
593 prevent 2 frames from having the same timestamp.
595 Chooses between 1 and 2 depending on muxer capabilities. This is the
599 With -map you can select from which stream the timestamps should be
600 taken. You can leave either video or audio unchanged and sync the
601 remaining stream(s) to the unchanged one.
603 @item -async @var{samples_per_second}
604 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
605 the parameter is the maximum samples per second by which the audio is changed.
606 -async 1 is a special case where only the start of the audio stream is corrected
607 without any later correction.
609 Copy timestamps from input to output.
611 Copy input stream time base from input to output when stream copying.
613 Finish encoding when the shortest input stream ends.
614 @item -dts_delta_threshold
615 Timestamp discontinuity delta threshold.
616 @item -muxdelay @var{seconds} (@emph{input})
617 Set the maximum demux-decode delay.
618 @item -muxpreload @var{seconds} (@emph{input})
619 Set the initial demux-decode delay.
620 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
621 Assign a new stream-id value to an output stream. This option should be
622 specified prior to the output filename to which it applies.
623 For the situation where multiple output files exist, a streamid
624 may be reassigned to a different value.
626 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
627 an output mpegts file:
629 avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
632 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
633 Set bitstream filters for matching streams. @var{bistream_filters} is
634 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
635 to get the list of bitstream filters.
637 avconv -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
640 avconv -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
643 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{output,per-stream})
644 Force a tag/fourcc for matching streams.
646 @item -cpuflags mask (@emph{global})
647 Set a mask that's applied to autodetected CPU flags. This option is intended
648 for testing. Do not use it unless you know what you're doing.
650 @item -filter_complex @var{filtergraph} (@emph{global})
651 Define a complex filter graph, i.e. one with arbitrary number of inputs and/or
652 outputs. For simple graphs -- those with one input and one output of the same
653 type -- see the @option{-filter} options. @var{filtergraph} is a description of
654 the filter graph, as described in @ref{Filtergraph syntax}.
656 Input link labels must refer to input streams using the
657 @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map}
658 uses). If @var{stream_specifier} matches multiple streams, the first one will be
659 used. An unlabeled input will be connected to the first unused input stream of
662 Output link labels are referred to with @option{-map}. Unlabeled outputs are
663 added to the first output file.
665 For example, to overlay an image over video
667 avconv -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
670 Here @code{[0:v]} refers to the first video stream in the first input file,
671 which is linked to the first (main) input of the overlay filter. Similarly the
672 first video stream in the second input is linked to the second (overlay) input
675 Assuming there is only one video stream in each input file, we can omit input
676 labels, so the above is equivalent to
678 avconv -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
682 Furthermore we can omit the output label and the single output from the filter
683 graph will be added to the output file automatically, so we can simply write
685 avconv -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
695 For streaming at very low bitrate application, use a low frame rate
696 and a small GOP size. This is especially true for RealVideo where
697 the Linux player does not seem to be very fast, so it can miss
698 frames. An example is:
701 avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
705 The parameter 'q' which is displayed while encoding is the current
706 quantizer. The value 1 indicates that a very good quality could
707 be achieved. The value 31 indicates the worst quality. If q=31 appears
708 too often, it means that the encoder cannot compress enough to meet
709 your bitrate. You must either increase the bitrate, decrease the
710 frame rate or decrease the frame size.
713 If your computer is not fast enough, you can speed up the
714 compression at the expense of the compression ratio. You can use
715 '-me zero' to speed up motion estimation, and '-g 0' to disable
716 motion estimation completely (you have only I-frames, which means it
717 is about as good as JPEG compression).
720 To have very low audio bitrates, reduce the sampling frequency
721 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
724 To have a constant quality (but a variable bitrate), use the option
725 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
732 @c man begin EXAMPLES
734 @section Preset files
736 A preset file contains a sequence of @var{option=value} pairs, one for
737 each line, specifying a sequence of options which can be specified also on
738 the command line. Lines starting with the hash ('#') character are ignored and
739 are used to provide comments. Empty lines are also ignored. Check the
740 @file{presets} directory in the Libav source tree for examples.
742 Preset files are specified with the @code{pre} option, this option takes a
743 preset name as input. Avconv searches for a file named @var{preset_name}.avpreset in
744 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.avconv}, and in
745 the data directory defined at configuration time (usually @file{$PREFIX/share/avconv})
746 in that order. For example, if the argument is @code{libx264-max}, it will
747 search for the file @file{libx264-max.avpreset}.
749 @section Video and Audio grabbing
751 If you specify the input format and device then avconv can grab video
755 avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
758 Note that you must activate the right video source and channel before
759 launching avconv with any TV viewer such as
760 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
761 have to set the audio recording levels correctly with a
764 @section X11 grabbing
766 Grab the X11 display with avconv via
769 avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
772 0.0 is display.screen number of your X11 server, same as
773 the DISPLAY environment variable.
776 avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
779 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
780 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
782 @section Video and Audio file format conversion
784 Any supported file format and protocol can serve as input to avconv:
789 You can use YUV files as input:
792 avconv -i /tmp/test%d.Y /tmp/out.mpg
795 It will use the files:
797 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
798 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
801 The Y files use twice the resolution of the U and V files. They are
802 raw files, without header. They can be generated by all decent video
803 decoders. You must specify the size of the image with the @option{-s} option
804 if avconv cannot guess it.
807 You can input from a raw YUV420P file:
810 avconv -i /tmp/test.yuv /tmp/out.avi
813 test.yuv is a file containing raw YUV planar data. Each frame is composed
814 of the Y plane followed by the U and V planes at half vertical and
815 horizontal resolution.
818 You can output to a raw YUV420P file:
821 avconv -i mydivx.avi hugefile.yuv
825 You can set several input files and output files:
828 avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
831 Converts the audio file a.wav and the raw YUV video file a.yuv
835 You can also do audio and video conversions at the same time:
838 avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
841 Converts a.wav to MPEG audio at 22050 Hz sample rate.
844 You can encode to several formats at the same time and define a
845 mapping from input stream to output streams:
848 avconv -i /tmp/a.wav -map 0:a -b 64k /tmp/a.mp2 -map 0:a -b 128k /tmp/b.mp2
851 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
852 file:index' specifies which input stream is used for each output
853 stream, in the order of the definition of output streams.
856 You can transcode decrypted VOBs:
859 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
862 This is a typical DVD ripping example; the input is a VOB file, the
863 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
864 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
865 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
866 input video. Furthermore, the audio stream is MP3-encoded so you need
867 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
868 The mapping is particularly useful for DVD transcoding
869 to get the desired audio language.
871 NOTE: To see the supported input formats, use @code{avconv -formats}.
874 You can extract images from a video, or create a video from many images:
876 For extracting images from a video:
878 avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
881 This will extract one video frame per second from the video and will
882 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
883 etc. Images will be rescaled to fit the new WxH values.
885 If you want to extract just a limited number of frames, you can use the
886 above command in combination with the -vframes or -t option, or in
887 combination with -ss to start extracting from a certain point in time.
889 For creating a video from many images:
891 avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
894 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
895 composed of three digits padded with zeroes to express the sequence
896 number. It is the same syntax supported by the C printf function, but
897 only formats accepting a normal integer are suitable.
900 You can put many streams of the same type in the output:
903 avconv -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
906 The resulting output file @file{test12.avi} will contain first four streams from
907 the input file in reverse order.
910 To force CBR video output:
912 avconv -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
916 The four options lmin, lmax, mblmin and mblmax use 'lambda' units,
917 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
919 avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
926 @include encoders.texi
927 @include demuxers.texi
930 @include outdevs.texi
931 @include protocols.texi
932 @include bitstream_filters.texi
933 @include filters.texi
934 @include metadata.texi
939 @settitle avconv video converter
942 avplay(1), avprobe(1) and the Libav HTML documentation