Make a copy of ffmpeg under a new name -- avconv.
[libav.git] / doc / avconv.texi
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1\input texinfo @c -*- texinfo -*-
2
3@settitle avconv Documentation
4@titlepage
5@center @titlefont{avconv Documentation}
6@end titlepage
7
8@top
9
10@contents
11
12@chapter Synopsis
13
14The generic syntax is:
15
16@example
17@c man begin SYNOPSIS
18avconv [[infile options][@option{-i} @var{infile}]]... @{[outfile options] @var{outfile}@}...
19@c man end
20@end example
21
22@chapter Description
23@c man begin DESCRIPTION
24
25avconv is a very fast video and audio converter that can also grab from
26a live audio/video source. It can also convert between arbitrary sample
27rates and resize video on the fly with a high quality polyphase filter.
28
29The command line interface is designed to be intuitive, in the sense
30that avconv tries to figure out all parameters that can possibly be
31derived automatically. You usually only have to specify the target
32bitrate you want.
33
34As a general rule, options are applied to the next specified
35file. Therefore, order is important, and you can have the same
36option on the command line multiple times. Each occurrence is
37then applied to the next input or output file.
38
39@itemize
40@item
41To set the video bitrate of the output file to 64kbit/s:
42@example
43avconv -i input.avi -b 64k output.avi
44@end example
45
46@item
47To force the frame rate of the output file to 24 fps:
48@example
49avconv -i input.avi -r 24 output.avi
50@end example
51
52@item
53To force the frame rate of the input file (valid for raw formats only)
54to 1 fps and the frame rate of the output file to 24 fps:
55@example
56avconv -r 1 -i input.m2v -r 24 output.avi
57@end example
58@end itemize
59
60The format option may be needed for raw input files.
61
62By default avconv tries to convert as losslessly as possible: It
63uses the same audio and video parameters for the outputs as the one
64specified for the inputs.
65
66@c man end DESCRIPTION
67
68@chapter Options
69@c man begin OPTIONS
70
71@include fftools-common-opts.texi
72
73@section Main options
74
75@table @option
76
77@item -f @var{fmt}
78Force format.
79
80@item -i @var{filename}
81input file name
82
83@item -y
84Overwrite output files.
85
86@item -t @var{duration}
87Restrict the transcoded/captured video sequence
88to the duration specified in seconds.
89@code{hh:mm:ss[.xxx]} syntax is also supported.
90
91@item -fs @var{limit_size}
92Set the file size limit.
93
94@item -ss @var{position}
95Seek to given time position in seconds.
96@code{hh:mm:ss[.xxx]} syntax is also supported.
97
98@item -itsoffset @var{offset}
99Set the input time offset in seconds.
100@code{[-]hh:mm:ss[.xxx]} syntax is also supported.
101This option affects all the input files that follow it.
102The offset is added to the timestamps of the input files.
103Specifying a positive offset means that the corresponding
104streams are delayed by 'offset' seconds.
105
106@item -timestamp @var{time}
107Set the recording timestamp in the container.
108The syntax for @var{time} is:
109@example
110now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
111@end example
112If the value is "now" it takes the current time.
113Time is local time unless 'Z' or 'z' is appended, in which case it is
114interpreted as UTC.
115If the year-month-day part is not specified it takes the current
116year-month-day.
117
118@item -metadata @var{key}=@var{value}
119Set a metadata key/value pair.
120
121For example, for setting the title in the output file:
122@example
123avconv -i in.avi -metadata title="my title" out.flv
124@end example
125
126@item -v @var{number}
127Set the logging verbosity level.
128
129@item -target @var{type}
130Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
131"ntsc-svcd", ... ). All the format options (bitrate, codecs,
132buffer sizes) are then set automatically. You can just type:
133
134@example
135avconv -i myfile.avi -target vcd /tmp/vcd.mpg
136@end example
137
138Nevertheless you can specify additional options as long as you know
139they do not conflict with the standard, as in:
140
141@example
142avconv -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
143@end example
144
145@item -dframes @var{number}
146Set the number of data frames to record.
147
148@item -scodec @var{codec}
149Force subtitle codec ('copy' to copy stream).
150
151@item -newsubtitle
152Add a new subtitle stream to the current output stream.
153
154@item -slang @var{code}
155Set the ISO 639 language code (3 letters) of the current subtitle stream.
156
157@end table
158
159@section Video Options
160
161@table @option
162@item -vframes @var{number}
163Set the number of video frames to record.
164@item -r @var{fps}
165Set frame rate (Hz value, fraction or abbreviation), (default = 25).
166@item -s @var{size}
167Set frame size. The format is @samp{wxh} (avserver default = 160x128, avconv default = same as source).
168The following abbreviations are recognized:
169@table @samp
170@item sqcif
171128x96
172@item qcif
173176x144
174@item cif
175352x288
176@item 4cif
177704x576
178@item 16cif
1791408x1152
180@item qqvga
181160x120
182@item qvga
183320x240
184@item vga
185640x480
186@item svga
187800x600
188@item xga
1891024x768
190@item uxga
1911600x1200
192@item qxga
1932048x1536
194@item sxga
1951280x1024
196@item qsxga
1972560x2048
198@item hsxga
1995120x4096
200@item wvga
201852x480
202@item wxga
2031366x768
204@item wsxga
2051600x1024
206@item wuxga
2071920x1200
208@item woxga
2092560x1600
210@item wqsxga
2113200x2048
212@item wquxga
2133840x2400
214@item whsxga
2156400x4096
216@item whuxga
2177680x4800
218@item cga
219320x200
220@item ega
221640x350
222@item hd480
223852x480
224@item hd720
2251280x720
226@item hd1080
2271920x1080
228@end table
229
230@item -aspect @var{aspect}
231Set the video display aspect ratio specified by @var{aspect}.
232
233@var{aspect} can be a floating point number string, or a string of the
234form @var{num}:@var{den}, where @var{num} and @var{den} are the
235numerator and denominator of the aspect ratio. For example "4:3",
236"16:9", "1.3333", and "1.7777" are valid argument values.
237
238@item -croptop @var{size}
239@item -cropbottom @var{size}
240@item -cropleft @var{size}
241@item -cropright @var{size}
242All the crop options have been removed. Use -vf
243crop=width:height:x:y instead.
244
245@item -padtop @var{size}
246@item -padbottom @var{size}
247@item -padleft @var{size}
248@item -padright @var{size}
249@item -padcolor @var{hex_color}
250All the pad options have been removed. Use -vf
251pad=width:height:x:y:color instead.
252@item -vn
253Disable video recording.
254@item -bt @var{tolerance}
255Set video bitrate tolerance (in bits, default 4000k).
256Has a minimum value of: (target_bitrate/target_framerate).
257In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
258willing to deviate from the target average bitrate value. This is
259not related to min/max bitrate. Lowering tolerance too much has
260an adverse effect on quality.
261@item -maxrate @var{bitrate}
262Set max video bitrate (in bit/s).
263Requires -bufsize to be set.
264@item -minrate @var{bitrate}
265Set min video bitrate (in bit/s).
266Most useful in setting up a CBR encode:
267@example
268avconv -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
269@end example
270It is of little use elsewise.
271@item -bufsize @var{size}
272Set video buffer verifier buffer size (in bits).
273@item -vcodec @var{codec}
274Force video codec to @var{codec}. Use the @code{copy} special value to
275tell that the raw codec data must be copied as is.
276@item -sameq
277Use same quantizer as source (implies VBR).
278
279@item -pass @var{n}
280Select the pass number (1 or 2). It is used to do two-pass
281video encoding. The statistics of the video are recorded in the first
282pass into a log file (see also the option -passlogfile),
283and in the second pass that log file is used to generate the video
284at the exact requested bitrate.
285On pass 1, you may just deactivate audio and set output to null,
286examples for Windows and Unix:
287@example
288avconv -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y NUL
289avconv -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y /dev/null
290@end example
291
292@item -passlogfile @var{prefix}
293Set two-pass log file name prefix to @var{prefix}, the default file name
294prefix is ``av2pass''. The complete file name will be
295@file{PREFIX-N.log}, where N is a number specific to the output
296stream.
297
298@item -newvideo
299Add a new video stream to the current output stream.
300
301@item -vlang @var{code}
302Set the ISO 639 language code (3 letters) of the current video stream.
303
304@item -vf @var{filter_graph}
305@var{filter_graph} is a description of the filter graph to apply to
306the input video.
307Use the option "-filters" to show all the available filters (including
308also sources and sinks).
309
310@end table
311
312@section Advanced Video Options
313
314@table @option
315@item -pix_fmt @var{format}
316Set pixel format. Use 'list' as parameter to show all the supported
317pixel formats.
318@item -sws_flags @var{flags}
319Set SwScaler flags.
320@item -g @var{gop_size}
321Set the group of pictures size.
322@item -intra
323Use only intra frames.
324@item -vdt @var{n}
325Discard threshold.
326@item -qscale @var{q}
327Use fixed video quantizer scale (VBR).
328@item -qmin @var{q}
329minimum video quantizer scale (VBR)
330@item -qmax @var{q}
331maximum video quantizer scale (VBR)
332@item -qdiff @var{q}
333maximum difference between the quantizer scales (VBR)
334@item -qblur @var{blur}
335video quantizer scale blur (VBR) (range 0.0 - 1.0)
336@item -qcomp @var{compression}
337video quantizer scale compression (VBR) (default 0.5).
338Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
339
340@item -lmin @var{lambda}
341minimum video lagrange factor (VBR)
342@item -lmax @var{lambda}
343max video lagrange factor (VBR)
344@item -mblmin @var{lambda}
345minimum macroblock quantizer scale (VBR)
346@item -mblmax @var{lambda}
347maximum macroblock quantizer scale (VBR)
348
349These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
350but you may use the QP2LAMBDA constant to easily convert from 'q' units:
351@example
352avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
353@end example
354
355@item -rc_init_cplx @var{complexity}
356initial complexity for single pass encoding
357@item -b_qfactor @var{factor}
358qp factor between P- and B-frames
359@item -i_qfactor @var{factor}
360qp factor between P- and I-frames
361@item -b_qoffset @var{offset}
362qp offset between P- and B-frames
363@item -i_qoffset @var{offset}
364qp offset between P- and I-frames
365@item -rc_eq @var{equation}
366Set rate control equation (see section "Expression Evaluation")
367(default = @code{tex^qComp}).
368
369When computing the rate control equation expression, besides the
370standard functions defined in the section "Expression Evaluation", the
371following functions are available:
372@table @var
373@item bits2qp(bits)
374@item qp2bits(qp)
375@end table
376
377and the following constants are available:
378@table @var
379@item iTex
380@item pTex
381@item tex
382@item mv
383@item fCode
384@item iCount
385@item mcVar
386@item var
387@item isI
388@item isP
389@item isB
390@item avgQP
391@item qComp
392@item avgIITex
393@item avgPITex
394@item avgPPTex
395@item avgBPTex
396@item avgTex
397@end table
398
399@item -rc_override @var{override}
400rate control override for specific intervals
401@item -me_method @var{method}
402Set motion estimation method to @var{method}.
403Available methods are (from lowest to best quality):
404@table @samp
405@item zero
406Try just the (0, 0) vector.
407@item phods
408@item log
409@item x1
410@item hex
411@item umh
412@item epzs
413(default method)
414@item full
415exhaustive search (slow and marginally better than epzs)
416@end table
417
418@item -dct_algo @var{algo}
419Set DCT algorithm to @var{algo}. Available values are:
420@table @samp
421@item 0
422FF_DCT_AUTO (default)
423@item 1
424FF_DCT_FASTINT
425@item 2
426FF_DCT_INT
427@item 3
428FF_DCT_MMX
429@item 4
430FF_DCT_MLIB
431@item 5
432FF_DCT_ALTIVEC
433@end table
434
435@item -idct_algo @var{algo}
436Set IDCT algorithm to @var{algo}. Available values are:
437@table @samp
438@item 0
439FF_IDCT_AUTO (default)
440@item 1
441FF_IDCT_INT
442@item 2
443FF_IDCT_SIMPLE
444@item 3
445FF_IDCT_SIMPLEMMX
446@item 4
447FF_IDCT_LIBMPEG2MMX
448@item 5
449FF_IDCT_PS2
450@item 6
451FF_IDCT_MLIB
452@item 7
453FF_IDCT_ARM
454@item 8
455FF_IDCT_ALTIVEC
456@item 9
457FF_IDCT_SH4
458@item 10
459FF_IDCT_SIMPLEARM
460@end table
461
462@item -er @var{n}
463Set error resilience to @var{n}.
464@table @samp
465@item 1
466FF_ER_CAREFUL (default)
467@item 2
468FF_ER_COMPLIANT
469@item 3
470FF_ER_AGGRESSIVE
471@item 4
472FF_ER_VERY_AGGRESSIVE
473@end table
474
475@item -ec @var{bit_mask}
476Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
477the following values:
478@table @samp
479@item 1
480FF_EC_GUESS_MVS (default = enabled)
481@item 2
482FF_EC_DEBLOCK (default = enabled)
483@end table
484
485@item -bf @var{frames}
486Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
487@item -mbd @var{mode}
488macroblock decision
489@table @samp
490@item 0
491FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in avconv).
492@item 1
493FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
494@item 2
495FF_MB_DECISION_RD: rate distortion
496@end table
497
498@item -4mv
499Use four motion vector by macroblock (MPEG-4 only).
500@item -part
501Use data partitioning (MPEG-4 only).
502@item -bug @var{param}
503Work around encoder bugs that are not auto-detected.
504@item -strict @var{strictness}
505How strictly to follow the standards.
506@item -aic
507Enable Advanced intra coding (h263+).
508@item -umv
509Enable Unlimited Motion Vector (h263+)
510
511@item -deinterlace
512Deinterlace pictures.
513@item -ilme
514Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
515Use this option if your input file is interlaced and you want
516to keep the interlaced format for minimum losses.
517The alternative is to deinterlace the input stream with
518@option{-deinterlace}, but deinterlacing introduces losses.
519@item -psnr
520Calculate PSNR of compressed frames.
521@item -vstats
522Dump video coding statistics to @file{vstats_HHMMSS.log}.
523@item -vstats_file @var{file}
524Dump video coding statistics to @var{file}.
525@item -top @var{n}
526top=1/bottom=0/auto=-1 field first
527@item -dc @var{precision}
528Intra_dc_precision.
529@item -vtag @var{fourcc/tag}
530Force video tag/fourcc.
531@item -qphist
532Show QP histogram.
533@item -vbsf @var{bitstream_filter}
534Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump", "mjpeg2jpeg".
535@example
536avconv -i h264.mp4 -vcodec copy -vbsf h264_mp4toannexb -an out.h264
537@end example
538@item -force_key_frames @var{time}[,@var{time}...]
539Force key frames at the specified timestamps, more precisely at the first
540frames after each specified time.
541This option can be useful to ensure that a seek point is present at a
542chapter mark or any other designated place in the output file.
543The timestamps must be specified in ascending order.
544@end table
545
546@section Audio Options
547
548@table @option
549@item -aframes @var{number}
550Set the number of audio frames to record.
551@item -ar @var{freq}
552Set the audio sampling frequency. For output streams it is set by
553default to the frequency of the corresponding input stream. For input
554streams this option only makes sense for audio grabbing devices and raw
555demuxers and is mapped to the corresponding demuxer options.
556@item -aq @var{q}
557Set the audio quality (codec-specific, VBR).
558@item -ac @var{channels}
559Set the number of audio channels. For output streams it is set by
560default to the number of input audio channels. For input streams
561this option only makes sense for audio grabbing devices and raw demuxers
562and is mapped to the corresponding demuxer options.
563@item -an
564Disable audio recording.
565@item -acodec @var{codec}
566Force audio codec to @var{codec}. Use the @code{copy} special value to
567specify that the raw codec data must be copied as is.
568@item -newaudio
569Add a new audio track to the output file. If you want to specify parameters,
570do so before @code{-newaudio} (@code{-acodec}, @code{-ab}, etc..).
571
572Mapping will be done automatically, if the number of output streams is equal to
573the number of input streams, else it will pick the first one that matches. You
574can override the mapping using @code{-map} as usual.
575
576Example:
577@example
578avconv -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
579@end example
580@item -alang @var{code}
581Set the ISO 639 language code (3 letters) of the current audio stream.
582@end table
583
584@section Advanced Audio options:
585
586@table @option
587@item -atag @var{fourcc/tag}
588Force audio tag/fourcc.
589@item -audio_service_type @var{type}
590Set the type of service that the audio stream contains.
591@table @option
592@item ma
593Main Audio Service (default)
594@item ef
595Effects
596@item vi
597Visually Impaired
598@item hi
599Hearing Impaired
600@item di
601Dialogue
602@item co
603Commentary
604@item em
605Emergency
606@item vo
607Voice Over
608@item ka
609Karaoke
610@end table
611@item -absf @var{bitstream_filter}
612Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
613@end table
614
615@section Subtitle options:
616
617@table @option
618@item -scodec @var{codec}
619Force subtitle codec ('copy' to copy stream).
620@item -newsubtitle
621Add a new subtitle stream to the current output stream.
622@item -slang @var{code}
623Set the ISO 639 language code (3 letters) of the current subtitle stream.
624@item -sn
625Disable subtitle recording.
626@item -sbsf @var{bitstream_filter}
627Bitstream filters available are "mov2textsub", "text2movsub".
628@example
629avconv -i file.mov -an -vn -sbsf mov2textsub -scodec copy -f rawvideo sub.txt
630@end example
631@end table
632
633@section Audio/Video grab options
634
635@table @option
636@item -vc @var{channel}
637Set video grab channel (DV1394 only).
638@item -tvstd @var{standard}
639Set television standard (NTSC, PAL (SECAM)).
640@item -isync
641Synchronize read on input.
642@end table
643
644@section Advanced options
645
646@table @option
647@item -map @var{input_file_id}.@var{input_stream_id}[:@var{sync_file_id}.@var{sync_stream_id}]
648
649Designate an input stream as a source for the output file. Each input
650stream is identified by the input file index @var{input_file_id} and
651the input stream index @var{input_stream_id} within the input
652file. Both indexes start at 0. If specified,
653@var{sync_file_id}.@var{sync_stream_id} sets which input stream
654is used as a presentation sync reference.
655
656The @code{-map} options must be specified just after the output file.
657If any @code{-map} options are used, the number of @code{-map} options
658on the command line must match the number of streams in the output
659file. The first @code{-map} option on the command line specifies the
660source for output stream 0, the second @code{-map} option specifies
661the source for output stream 1, etc.
662
663For example, if you have two audio streams in the first input file,
664these streams are identified by "0.0" and "0.1". You can use
665@code{-map} to select which stream to place in an output file. For
666example:
667@example
668avconv -i INPUT out.wav -map 0.1
669@end example
670will map the input stream in @file{INPUT} identified by "0.1" to
671the (single) output stream in @file{out.wav}.
672
673For example, to select the stream with index 2 from input file
674@file{a.mov} (specified by the identifier "0.2"), and stream with
675index 6 from input @file{b.mov} (specified by the identifier "1.6"),
676and copy them to the output file @file{out.mov}:
677@example
678avconv -i a.mov -i b.mov -vcodec copy -acodec copy out.mov -map 0.2 -map 1.6
679@end example
680
681To add more streams to the output file, you can use the
682@code{-newaudio}, @code{-newvideo}, @code{-newsubtitle} options.
683
684@item -map_meta_data @var{outfile}[,@var{metadata}]:@var{infile}[,@var{metadata}]
685Deprecated, use @var{-map_metadata} instead.
686
687@item -map_metadata @var{outfile}[,@var{metadata}]:@var{infile}[,@var{metadata}]
688Set metadata information of @var{outfile} from @var{infile}. Note that those
689are file indices (zero-based), not filenames.
690Optional @var{metadata} parameters specify, which metadata to copy - (g)lobal
691(i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
692per-(p)rogram. All metadata specifiers other than global must be followed by the
693stream/chapter/program number. If metadata specifier is omitted, it defaults to
694global.
695
696By default, global metadata is copied from the first input file to all output files,
697per-stream and per-chapter metadata is copied along with streams/chapters. These
698default mappings are disabled by creating any mapping of the relevant type. A negative
699file index can be used to create a dummy mapping that just disables automatic copying.
700
701For example to copy metadata from the first stream of the input file to global metadata
702of the output file:
703@example
704avconv -i in.ogg -map_metadata 0:0,s0 out.mp3
705@end example
706@item -map_chapters @var{outfile}:@var{infile}
707Copy chapters from @var{infile} to @var{outfile}. If no chapter mapping is specified,
708then chapters are copied from the first input file with at least one chapter to all
709output files. Use a negative file index to disable any chapter copying.
710@item -debug
711Print specific debug info.
712@item -benchmark
713Show benchmarking information at the end of an encode.
714Shows CPU time used and maximum memory consumption.
715Maximum memory consumption is not supported on all systems,
716it will usually display as 0 if not supported.
717@item -dump
718Dump each input packet.
719@item -hex
720When dumping packets, also dump the payload.
721@item -bitexact
722Only use bit exact algorithms (for codec testing).
723@item -ps @var{size}
724Set RTP payload size in bytes.
725@item -re
726Read input at native frame rate. Mainly used to simulate a grab device.
727@item -loop_input
728Loop over the input stream. Currently it works only for image
729streams. This option is used for automatic AVserver testing.
730This option is deprecated, use -loop.
731@item -loop_output @var{number_of_times}
732Repeatedly loop output for formats that support looping such as animated GIF
733(0 will loop the output infinitely).
734This option is deprecated, use -loop.
735@item -threads @var{count}
736Thread count.
737@item -vsync @var{parameter}
738Video sync method.
739
740@table @option
741@item 0
742Each frame is passed with its timestamp from the demuxer to the muxer.
743@item 1
744Frames will be duplicated and dropped to achieve exactly the requested
745constant framerate.
746@item 2
747Frames are passed through with their timestamp or dropped so as to
748prevent 2 frames from having the same timestamp.
749@item -1
750Chooses between 1 and 2 depending on muxer capabilities. This is the
751default method.
752@end table
753
754With -map you can select from which stream the timestamps should be
755taken. You can leave either video or audio unchanged and sync the
756remaining stream(s) to the unchanged one.
757
758@item -async @var{samples_per_second}
759Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
760the parameter is the maximum samples per second by which the audio is changed.
761-async 1 is a special case where only the start of the audio stream is corrected
762without any later correction.
763@item -copyts
764Copy timestamps from input to output.
765@item -copytb
766Copy input stream time base from input to output when stream copying.
767@item -shortest
768Finish encoding when the shortest input stream ends.
769@item -dts_delta_threshold
770Timestamp discontinuity delta threshold.
771@item -muxdelay @var{seconds}
772Set the maximum demux-decode delay.
773@item -muxpreload @var{seconds}
774Set the initial demux-decode delay.
775@item -streamid @var{output-stream-index}:@var{new-value}
776Assign a new stream-id value to an output stream. This option should be
777specified prior to the output filename to which it applies.
778For the situation where multiple output files exist, a streamid
779may be reassigned to a different value.
780
781For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
782an output mpegts file:
783@example
784avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
785@end example
786@end table
787
788@section Preset files
789
790A preset file contains a sequence of @var{option}=@var{value} pairs,
791one for each line, specifying a sequence of options which would be
792awkward to specify on the command line. Lines starting with the hash
793('#') character are ignored and are used to provide comments. Check
794the @file{ffpresets} directory in the Libav source tree for examples.
795
796Preset files are specified with the @code{vpre}, @code{apre},
797@code{spre}, and @code{fpre} options. The @code{fpre} option takes the
798filename of the preset instead of a preset name as input and can be
799used for any kind of codec. For the @code{vpre}, @code{apre}, and
800@code{spre} options, the options specified in a preset file are
801applied to the currently selected codec of the same type as the preset
802option.
803
804The argument passed to the @code{vpre}, @code{apre}, and @code{spre}
805preset options identifies the preset file to use according to the
806following rules:
807
808First avconv searches for a file named @var{arg}.ffpreset in the
809directories @file{$av_DATADIR} (if set), and @file{$HOME/.avconv}, and in
810the datadir defined at configuration time (usually @file{PREFIX/share/avconv})
811in that order. For example, if the argument is @code{libx264-max}, it will
812search for the file @file{libx264-max.ffpreset}.
813
814If no such file is found, then avconv will search for a file named
815@var{codec_name}-@var{arg}.ffpreset in the above-mentioned
816directories, where @var{codec_name} is the name of the codec to which
817the preset file options will be applied. For example, if you select
818the video codec with @code{-vcodec libx264} and use @code{-vpre max},
819then it will search for the file @file{libx264-max.ffpreset}.
820@c man end
821
822@chapter Tips
823@c man begin TIPS
824
825@itemize
826@item
827For streaming at very low bitrate application, use a low frame rate
828and a small GOP size. This is especially true for RealVideo where
829the Linux player does not seem to be very fast, so it can miss
830frames. An example is:
831
832@example
833avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
834@end example
835
836@item
837The parameter 'q' which is displayed while encoding is the current
838quantizer. The value 1 indicates that a very good quality could
839be achieved. The value 31 indicates the worst quality. If q=31 appears
840too often, it means that the encoder cannot compress enough to meet
841your bitrate. You must either increase the bitrate, decrease the
842frame rate or decrease the frame size.
843
844@item
845If your computer is not fast enough, you can speed up the
846compression at the expense of the compression ratio. You can use
847'-me zero' to speed up motion estimation, and '-intra' to disable
848motion estimation completely (you have only I-frames, which means it
849is about as good as JPEG compression).
850
851@item
852To have very low audio bitrates, reduce the sampling frequency
853(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
854
855@item
856To have a constant quality (but a variable bitrate), use the option
857'-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
858quality).
859
860@item
861When converting video files, you can use the '-sameq' option which
862uses the same quality factor in the encoder as in the decoder.
863It allows almost lossless encoding.
864
865@end itemize
866@c man end TIPS
867
868@chapter Examples
869@c man begin EXAMPLES
870
871@section Video and Audio grabbing
872
873If you specify the input format and device then avconv can grab video
874and audio directly.
875
876@example
877avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
878@end example
879
880Note that you must activate the right video source and channel before
881launching avconv with any TV viewer such as
882@uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
883have to set the audio recording levels correctly with a
884standard mixer.
885
886@section X11 grabbing
887
888Grab the X11 display with avconv via
889
890@example
891avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
892@end example
893
8940.0 is display.screen number of your X11 server, same as
895the DISPLAY environment variable.
896
897@example
898avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
899@end example
900
9010.0 is display.screen number of your X11 server, same as the DISPLAY environment
902variable. 10 is the x-offset and 20 the y-offset for the grabbing.
903
904@section Video and Audio file format conversion
905
906Any supported file format and protocol can serve as input to avconv:
907
908Examples:
909@itemize
910@item
911You can use YUV files as input:
912
913@example
914avconv -i /tmp/test%d.Y /tmp/out.mpg
915@end example
916
917It will use the files:
918@example
919/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
920/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
921@end example
922
923The Y files use twice the resolution of the U and V files. They are
924raw files, without header. They can be generated by all decent video
925decoders. You must specify the size of the image with the @option{-s} option
926if avconv cannot guess it.
927
928@item
929You can input from a raw YUV420P file:
930
931@example
932avconv -i /tmp/test.yuv /tmp/out.avi
933@end example
934
935test.yuv is a file containing raw YUV planar data. Each frame is composed
936of the Y plane followed by the U and V planes at half vertical and
937horizontal resolution.
938
939@item
940You can output to a raw YUV420P file:
941
942@example
943avconv -i mydivx.avi hugefile.yuv
944@end example
945
946@item
947You can set several input files and output files:
948
949@example
950avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
951@end example
952
953Converts the audio file a.wav and the raw YUV video file a.yuv
954to MPEG file a.mpg.
955
956@item
957You can also do audio and video conversions at the same time:
958
959@example
960avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
961@end example
962
963Converts a.wav to MPEG audio at 22050 Hz sample rate.
964
965@item
966You can encode to several formats at the same time and define a
967mapping from input stream to output streams:
968
969@example
970avconv -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
971@end example
972
973Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
974file:index' specifies which input stream is used for each output
975stream, in the order of the definition of output streams.
976
977@item
978You can transcode decrypted VOBs:
979
980@example
981avconv -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
982@end example
983
984This is a typical DVD ripping example; the input is a VOB file, the
985output an AVI file with MPEG-4 video and MP3 audio. Note that in this
986command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
987GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
988input video. Furthermore, the audio stream is MP3-encoded so you need
989to enable LAME support by passing @code{--enable-libmp3lame} to configure.
990The mapping is particularly useful for DVD transcoding
991to get the desired audio language.
992
993NOTE: To see the supported input formats, use @code{avconv -formats}.
994
995@item
996You can extract images from a video, or create a video from many images:
997
998For extracting images from a video:
999@example
1000avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
1001@end example
1002
1003This will extract one video frame per second from the video and will
1004output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
1005etc. Images will be rescaled to fit the new WxH values.
1006
1007If you want to extract just a limited number of frames, you can use the
1008above command in combination with the -vframes or -t option, or in
1009combination with -ss to start extracting from a certain point in time.
1010
1011For creating a video from many images:
1012@example
1013avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1014@end example
1015
1016The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1017composed of three digits padded with zeroes to express the sequence
1018number. It is the same syntax supported by the C printf function, but
1019only formats accepting a normal integer are suitable.
1020
1021@item
1022You can put many streams of the same type in the output:
1023
1024@example
1025avconv -i test1.avi -i test2.avi -vcodec copy -acodec copy -vcodec copy -acodec copy test12.avi -newvideo -newaudio
1026@end example
1027
1028In addition to the first video and audio streams, the resulting
1029output file @file{test12.avi} will contain the second video
1030and the second audio stream found in the input streams list.
1031
1032The @code{-newvideo}, @code{-newaudio} and @code{-newsubtitle}
1033options have to be specified immediately after the name of the output
1034file to which you want to add them.
1035
1036@end itemize
1037@c man end EXAMPLES
1038
1039@include eval.texi
1040@include encoders.texi
1041@include demuxers.texi
1042@include muxers.texi
1043@include indevs.texi
1044@include outdevs.texi
1045@include protocols.texi
1046@include bitstream_filters.texi
1047@include filters.texi
1048@include metadata.texi
1049
1050@ignore
1051
1052@setfilename avconv
1053@settitle avconv video converter
1054
1055@c man begin SEEALSO
1056avplay(1), avprobe(1), avserver(1) and the Libav HTML documentation
1057@c man end
1058
1059@c man begin AUTHORS
1060The Libav developers
1061@c man end
1062
1063@end ignore
1064
1065@bye