0b560440e9a9ebac22e66c6054a0388243a37a4e
[libav.git] / doc / avconv.texi
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
14 The generic syntax is:
15
16 @example
17 @c man begin SYNOPSIS
18 avconv [[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
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.
28
29 The command line interface is designed to be intuitive, in the sense
30 that avconv tries to figure out all parameters that can possibly be
31 derived automatically. You usually only have to specify the target
32 bitrate you want.
33
34 As a general rule, options are applied to the next specified
35 file. Therefore, order is important, and you can have the same
36 option on the command line multiple times. Each occurrence is
37 then applied to the next input or output file.
38
39 @itemize
40 @item
41 To set the video bitrate of the output file to 64kbit/s:
42 @example
43 avconv -i input.avi -b 64k output.avi
44 @end example
45
46 @item
47 To force the frame rate of the output file to 24 fps:
48 @example
49 avconv -i input.avi -r 24 output.avi
50 @end example
51
52 @item
53 To force the frame rate of the input file (valid for raw formats only)
54 to 1 fps and the frame rate of the output file to 24 fps:
55 @example
56 avconv -r 1 -i input.m2v -r 24 output.avi
57 @end example
58 @end itemize
59
60 The format option may be needed for raw input files.
61
62 By default avconv tries to convert as losslessly as possible: It
63 uses the same audio and video parameters for the outputs as the one
64 specified for the inputs.
65
66 @c man end DESCRIPTION
67
68 @chapter Stream selection
69 @c man begin STREAM SELECTION
70
71 By default avconv tries to pick the "best" stream of each type present in input
72 files and add them to each output file. For video, this means the highest
73 resolution, for audio the highest channel count. For subtitle it's simply the
74 first subtitle stream.
75
76 You can disable some of those defaults by using @code{-vn/-an/-sn} options. For
77 full manual control, use the @code{-map} option, which disables the defaults just
78 described.
79
80 @c man end STREAM SELECTION
81
82 @chapter Options
83 @c man begin OPTIONS
84
85 @include fftools-common-opts.texi
86
87 @section Main options
88
89 @table @option
90
91 @item -f @var{fmt}
92 Force format.
93
94 @item -i @var{filename}
95 input file name
96
97 @item -y
98 Overwrite output files.
99
100 @item -c[:@var{stream_type}][:@var{stream_index}] @var{codec}
101 @item -codec[:@var{stream_type}][:@var{stream_index}] @var{codec}
102 Select an encoder (when used before an output file) or a decoder (when used
103 before an input file) for one or more streams. @var{codec} is the name of a
104 decoder/encoder or a special value @code{copy} (output only) to indicate that
105 the stream is not to be reencoded.
106
107 @var{stream_type} may be 'v' for video, 'a' for audio, 's' for subtitle and 'd'
108 for data streams. @var{stream_index} is a global zero-based stream index if
109 @var{stream_type} isn't given, otherwise it counts only streams of the given
110 type. If @var{stream_index} is omitted, this option applies to all streams of
111 the given type or all streams of any type if @var{stream_type} is missing as
112 well (note that this only makes sense when all streams are of the same type or
113 @var{codec} is @code{copy}).
114
115 For example
116 @example
117 avconv -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
118 @end example
119 encodes all video streams with libx264 and copies all audio streams.
120
121 For each stream, the last matching @code{c} option is applied, so
122 @example
123 avconv -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
124 @end example
125 will copy all the streams except the second video, which will be encoded with
126 libx264, and the 138th audio, which will be encoded with libvorbis.
127
128 @item -t @var{duration}
129 Restrict the transcoded/captured video sequence
130 to the duration specified in seconds.
131 @code{hh:mm:ss[.xxx]} syntax is also supported.
132
133 @item -fs @var{limit_size}
134 Set the file size limit.
135
136 @item -ss @var{position}
137 When used as an input option (before @code{-i}), seeks in this input file to
138 @var{position}. When used as an output option (before an output filename),
139 decodes but discards input until the timestamps reach @var{position}. This is
140 slower, but more accurate.
141
142 @var{position} may be either in seconds or in @code{hh:mm:ss[.xxx]} form.
143
144 @item -itsoffset @var{offset}
145 Set the input time offset in seconds.
146 @code{[-]hh:mm:ss[.xxx]} syntax is also supported.
147 The offset is added to the timestamps of the input files.
148 Specifying a positive offset means that the corresponding
149 streams are delayed by 'offset' seconds.
150
151 @item -timestamp @var{time}
152 Set the recording timestamp in the container.
153 The syntax for @var{time} is:
154 @example
155 now|([(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH[:MM[:SS[.m...]]])|(HH[MM[SS[.m...]]]))[Z|z])
156 @end example
157 If the value is "now" it takes the current time.
158 Time is local time unless 'Z' or 'z' is appended, in which case it is
159 interpreted as UTC.
160 If the year-month-day part is not specified it takes the current
161 year-month-day.
162
163 @item -metadata[:metadata_specifier] @var{key}=@var{value}
164 Set a metadata key/value pair.
165
166 An optional @var{metadata_specifier} may be given to set metadata
167 on streams or chapters. See @code{-map_metadata} documentation for
168 details.
169
170 This option overrides metadata set with @code{-map_metadata}. It is
171 also possible to delete metadata by using an empty value.
172
173 For example, for setting the title in the output file:
174 @example
175 avconv -i in.avi -metadata title="my title" out.flv
176 @end example
177
178 To set the language of the second stream:
179 @example
180 avconv -i INPUT -metadata:s:1 language=eng OUTPUT
181 @end example
182
183 @item -v @var{number}
184 Set the logging verbosity level.
185
186 @item -target @var{type}
187 Specify target file type ("vcd", "svcd", "dvd", "dv", "dv50", "pal-vcd",
188 "ntsc-svcd", ... ). All the format options (bitrate, codecs,
189 buffer sizes) are then set automatically. You can just type:
190
191 @example
192 avconv -i myfile.avi -target vcd /tmp/vcd.mpg
193 @end example
194
195 Nevertheless you can specify additional options as long as you know
196 they do not conflict with the standard, as in:
197
198 @example
199 avconv -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
200 @end example
201
202 @item -dframes @var{number}
203 Set the number of data frames to record.
204
205 @item -slang @var{code}
206 Set the ISO 639 language code (3 letters) of the current subtitle stream.
207
208 @end table
209
210 @section Video Options
211
212 @table @option
213 @item -vframes @var{number}
214 Set the number of video frames to record.
215 @item -r @var{fps}
216 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
217 @item -s @var{size}
218 Set frame size. The format is @samp{wxh} (avserver default = 160x128, avconv default = same as source).
219 The following abbreviations are recognized:
220 @table @samp
221 @item sqcif
222 128x96
223 @item qcif
224 176x144
225 @item cif
226 352x288
227 @item 4cif
228 704x576
229 @item 16cif
230 1408x1152
231 @item qqvga
232 160x120
233 @item qvga
234 320x240
235 @item vga
236 640x480
237 @item svga
238 800x600
239 @item xga
240 1024x768
241 @item uxga
242 1600x1200
243 @item qxga
244 2048x1536
245 @item sxga
246 1280x1024
247 @item qsxga
248 2560x2048
249 @item hsxga
250 5120x4096
251 @item wvga
252 852x480
253 @item wxga
254 1366x768
255 @item wsxga
256 1600x1024
257 @item wuxga
258 1920x1200
259 @item woxga
260 2560x1600
261 @item wqsxga
262 3200x2048
263 @item wquxga
264 3840x2400
265 @item whsxga
266 6400x4096
267 @item whuxga
268 7680x4800
269 @item cga
270 320x200
271 @item ega
272 640x350
273 @item hd480
274 852x480
275 @item hd720
276 1280x720
277 @item hd1080
278 1920x1080
279 @end table
280
281 @item -aspect @var{aspect}
282 Set the video display aspect ratio specified by @var{aspect}.
283
284 @var{aspect} can be a floating point number string, or a string of the
285 form @var{num}:@var{den}, where @var{num} and @var{den} are the
286 numerator and denominator of the aspect ratio. For example "4:3",
287 "16:9", "1.3333", and "1.7777" are valid argument values.
288
289 @item -vn
290 Disable video recording.
291 @item -bt @var{tolerance}
292 Set video bitrate tolerance (in bits, default 4000k).
293 Has a minimum value of: (target_bitrate/target_framerate).
294 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
295 willing to deviate from the target average bitrate value. This is
296 not related to min/max bitrate. Lowering tolerance too much has
297 an adverse effect on quality.
298 @item -maxrate @var{bitrate}
299 Set max video bitrate (in bit/s).
300 Requires -bufsize to be set.
301 @item -minrate @var{bitrate}
302 Set min video bitrate (in bit/s).
303 Most useful in setting up a CBR encode:
304 @example
305 avconv -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
306 @end example
307 It is of little use elsewise.
308 @item -bufsize @var{size}
309 Set video buffer verifier buffer size (in bits).
310 @item -vcodec @var{codec}
311 Set the video codec. This is an alias for @code{-codec:v}.
312 @item -same_quant
313 Use same quantizer as source (implies VBR).
314
315 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
316 need it.
317
318 @item -pass @var{n}
319 Select the pass number (1 or 2). It is used to do two-pass
320 video encoding. The statistics of the video are recorded in the first
321 pass into a log file (see also the option -passlogfile),
322 and in the second pass that log file is used to generate the video
323 at the exact requested bitrate.
324 On pass 1, you may just deactivate audio and set output to null,
325 examples for Windows and Unix:
326 @example
327 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
328 avconv -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
329 @end example
330
331 @item -passlogfile @var{prefix}
332 Set two-pass log file name prefix to @var{prefix}, the default file name
333 prefix is ``av2pass''. The complete file name will be
334 @file{PREFIX-N.log}, where N is a number specific to the output
335 stream.
336
337 @item -vlang @var{code}
338 Set the ISO 639 language code (3 letters) of the current video stream.
339
340 @item -vf @var{filter_graph}
341 @var{filter_graph} is a description of the filter graph to apply to
342 the input video.
343 Use the option "-filters" to show all the available filters (including
344 also sources and sinks).
345
346 @end table
347
348 @section Advanced Video Options
349
350 @table @option
351 @item -pix_fmt @var{format}
352 Set pixel format. Use 'list' as parameter to show all the supported
353 pixel formats.
354 @item -sws_flags @var{flags}
355 Set SwScaler flags.
356 @item -g @var{gop_size}
357 Set the group of pictures size.
358 @item -vdt @var{n}
359 Discard threshold.
360 @item -qscale @var{q}
361 Use fixed video quantizer scale (VBR).
362 @item -qmin @var{q}
363 minimum video quantizer scale (VBR)
364 @item -qmax @var{q}
365 maximum video quantizer scale (VBR)
366 @item -qdiff @var{q}
367 maximum difference between the quantizer scales (VBR)
368 @item -qblur @var{blur}
369 video quantizer scale blur (VBR) (range 0.0 - 1.0)
370 @item -qcomp @var{compression}
371 video quantizer scale compression (VBR) (default 0.5).
372 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
373
374 @item -lmin @var{lambda}
375 minimum video lagrange factor (VBR)
376 @item -lmax @var{lambda}
377 max video lagrange factor (VBR)
378 @item -mblmin @var{lambda}
379 minimum macroblock quantizer scale (VBR)
380 @item -mblmax @var{lambda}
381 maximum macroblock quantizer scale (VBR)
382
383 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
384 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
385 @example
386 avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
387 @end example
388
389 @item -rc_init_cplx @var{complexity}
390 initial complexity for single pass encoding
391 @item -b_qfactor @var{factor}
392 qp factor between P- and B-frames
393 @item -i_qfactor @var{factor}
394 qp factor between P- and I-frames
395 @item -b_qoffset @var{offset}
396 qp offset between P- and B-frames
397 @item -i_qoffset @var{offset}
398 qp offset between P- and I-frames
399 @item -rc_eq @var{equation}
400 Set rate control equation (see section "Expression Evaluation")
401 (default = @code{tex^qComp}).
402
403 When computing the rate control equation expression, besides the
404 standard functions defined in the section "Expression Evaluation", the
405 following functions are available:
406 @table @var
407 @item bits2qp(bits)
408 @item qp2bits(qp)
409 @end table
410
411 and the following constants are available:
412 @table @var
413 @item iTex
414 @item pTex
415 @item tex
416 @item mv
417 @item fCode
418 @item iCount
419 @item mcVar
420 @item var
421 @item isI
422 @item isP
423 @item isB
424 @item avgQP
425 @item qComp
426 @item avgIITex
427 @item avgPITex
428 @item avgPPTex
429 @item avgBPTex
430 @item avgTex
431 @end table
432
433 @item -rc_override @var{override}
434 rate control override for specific intervals
435 @item -me_method @var{method}
436 Set motion estimation method to @var{method}.
437 Available methods are (from lowest to best quality):
438 @table @samp
439 @item zero
440 Try just the (0, 0) vector.
441 @item phods
442 @item log
443 @item x1
444 @item hex
445 @item umh
446 @item epzs
447 (default method)
448 @item full
449 exhaustive search (slow and marginally better than epzs)
450 @end table
451
452 @item -dct_algo @var{algo}
453 Set DCT algorithm to @var{algo}. Available values are:
454 @table @samp
455 @item 0
456 FF_DCT_AUTO (default)
457 @item 1
458 FF_DCT_FASTINT
459 @item 2
460 FF_DCT_INT
461 @item 3
462 FF_DCT_MMX
463 @item 4
464 FF_DCT_MLIB
465 @item 5
466 FF_DCT_ALTIVEC
467 @end table
468
469 @item -idct_algo @var{algo}
470 Set IDCT algorithm to @var{algo}. Available values are:
471 @table @samp
472 @item 0
473 FF_IDCT_AUTO (default)
474 @item 1
475 FF_IDCT_INT
476 @item 2
477 FF_IDCT_SIMPLE
478 @item 3
479 FF_IDCT_SIMPLEMMX
480 @item 4
481 FF_IDCT_LIBMPEG2MMX
482 @item 5
483 FF_IDCT_PS2
484 @item 6
485 FF_IDCT_MLIB
486 @item 7
487 FF_IDCT_ARM
488 @item 8
489 FF_IDCT_ALTIVEC
490 @item 9
491 FF_IDCT_SH4
492 @item 10
493 FF_IDCT_SIMPLEARM
494 @end table
495
496 @item -er @var{n}
497 Set error resilience to @var{n}.
498 @table @samp
499 @item 1
500 FF_ER_CAREFUL (default)
501 @item 2
502 FF_ER_COMPLIANT
503 @item 3
504 FF_ER_AGGRESSIVE
505 @item 4
506 FF_ER_VERY_AGGRESSIVE
507 @end table
508
509 @item -ec @var{bit_mask}
510 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
511 the following values:
512 @table @samp
513 @item 1
514 FF_EC_GUESS_MVS (default = enabled)
515 @item 2
516 FF_EC_DEBLOCK (default = enabled)
517 @end table
518
519 @item -bf @var{frames}
520 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
521 @item -mbd @var{mode}
522 macroblock decision
523 @table @samp
524 @item 0
525 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in avconv).
526 @item 1
527 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
528 @item 2
529 FF_MB_DECISION_RD: rate distortion
530 @end table
531
532 @item -4mv
533 Use four motion vector by macroblock (MPEG-4 only).
534 @item -part
535 Use data partitioning (MPEG-4 only).
536 @item -bug @var{param}
537 Work around encoder bugs that are not auto-detected.
538 @item -strict @var{strictness}
539 How strictly to follow the standards.
540 @item -aic
541 Enable Advanced intra coding (h263+).
542 @item -umv
543 Enable Unlimited Motion Vector (h263+)
544
545 @item -deinterlace
546 Deinterlace pictures.
547 @item -ilme
548 Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
549 Use this option if your input file is interlaced and you want
550 to keep the interlaced format for minimum losses.
551 The alternative is to deinterlace the input stream with
552 @option{-deinterlace}, but deinterlacing introduces losses.
553 @item -psnr
554 Calculate PSNR of compressed frames.
555 @item -vstats
556 Dump video coding statistics to @file{vstats_HHMMSS.log}.
557 @item -vstats_file @var{file}
558 Dump video coding statistics to @var{file}.
559 @item -top @var{n}
560 top=1/bottom=0/auto=-1 field first
561 @item -dc @var{precision}
562 Intra_dc_precision.
563 @item -vtag @var{fourcc/tag}
564 Force video tag/fourcc.
565 @item -qphist
566 Show QP histogram.
567 @item -vbsf @var{bitstream_filter}
568 Bitstream filters available are "dump_extra", "remove_extra", "noise", "h264_mp4toannexb", "imxdump", "mjpegadump", "mjpeg2jpeg".
569 @example
570 avconv -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
571 @end example
572 @item -force_key_frames @var{time}[,@var{time}...]
573 Force key frames at the specified timestamps, more precisely at the first
574 frames after each specified time.
575 This option can be useful to ensure that a seek point is present at a
576 chapter mark or any other designated place in the output file.
577 The timestamps must be specified in ascending order.
578 @end table
579
580 @section Audio Options
581
582 @table @option
583 @item -aframes @var{number}
584 Set the number of audio frames to record.
585 @item -ar @var{freq}
586 Set the audio sampling frequency. For output streams it is set by
587 default to the frequency of the corresponding input stream. For input
588 streams this option only makes sense for audio grabbing devices and raw
589 demuxers and is mapped to the corresponding demuxer options.
590 @item -aq @var{q}
591 Set the audio quality (codec-specific, VBR).
592 @item -ac @var{channels}
593 Set the number of audio channels. For output streams it is set by
594 default to the number of input audio channels. For input streams
595 this option only makes sense for audio grabbing devices and raw demuxers
596 and is mapped to the corresponding demuxer options.
597 @item -an
598 Disable audio recording.
599 @item -acodec @var{codec}
600 Set the audio codec. This is an alias for @code{-codec:a}.
601 @item -alang @var{code}
602 Set the ISO 639 language code (3 letters) of the current audio stream.
603 @end table
604
605 @section Advanced Audio options:
606
607 @table @option
608 @item -atag @var{fourcc/tag}
609 Force audio tag/fourcc.
610 @item -audio_service_type @var{type}
611 Set the type of service that the audio stream contains.
612 @table @option
613 @item ma
614 Main Audio Service (default)
615 @item ef
616 Effects
617 @item vi
618 Visually Impaired
619 @item hi
620 Hearing Impaired
621 @item di
622 Dialogue
623 @item co
624 Commentary
625 @item em
626 Emergency
627 @item vo
628 Voice Over
629 @item ka
630 Karaoke
631 @end table
632 @item -absf @var{bitstream_filter}
633 Bitstream filters available are "dump_extra", "remove_extra", "noise", "mp3comp", "mp3decomp".
634 @end table
635
636 @section Subtitle options:
637
638 @table @option
639 @item -scodec @var{codec}
640 Set the subtitle codec. This is an alias for @code{-codec:s}.
641 @item -slang @var{code}
642 Set the ISO 639 language code (3 letters) of the current subtitle stream.
643 @item -sn
644 Disable subtitle recording.
645 @item -sbsf @var{bitstream_filter}
646 Bitstream filters available are "mov2textsub", "text2movsub".
647 @example
648 avconv -i file.mov -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
649 @end example
650 @end table
651
652 @section Audio/Video grab options
653
654 @table @option
655 @item -isync
656 Synchronize read on input.
657 @end table
658
659 @section Advanced options
660
661 @table @option
662 @item -map [-]@var{input_file_id}[:@var{input_stream_type}][:@var{input_stream_id}][,@var{sync_file_id}[:@var{sync_stream_type}][:@var{sync_stream_id}]]
663
664 Designate one or more input streams as a source for the output file. Each input
665 stream is identified by the input file index @var{input_file_id} and
666 the input stream index @var{input_stream_id} within the input
667 file. Both indices start at 0. If specified,
668 @var{sync_file_id}:@var{sync_stream_id} sets which input stream
669 is used as a presentation sync reference.
670
671 If @var{input_stream_type} is specified -- 'v' for video, 'a' for audio, 's' for
672 subtitle and 'd' for data -- then @var{input_stream_id} counts only the streams
673 of this type. Same for @var{sync_stream_type}.
674
675 @var{input_stream_id} may be omitted, in which case all streams of the given
676 type are mapped (or all streams in the file, if no type is specified).
677
678 The first @code{-map} option on the command line specifies the
679 source for output stream 0, the second @code{-map} option specifies
680 the source for output stream 1, etc.
681
682 A @code{-} character before the stream identifier creates a "negative" mapping.
683 It disables matching streams from already created mappings.
684
685 For example, to map ALL streams from the first input file to output
686 @example
687 avconv -i INPUT -map 0 output
688 @end example
689
690 For example, if you have two audio streams in the first input file,
691 these streams are identified by "0:0" and "0:1". You can use
692 @code{-map} to select which streams to place in an output file. For
693 example:
694 @example
695 avconv -i INPUT -map 0:1 out.wav
696 @end example
697 will map the input stream in @file{INPUT} identified by "0:1" to
698 the (single) output stream in @file{out.wav}.
699
700 For example, to select the stream with index 2 from input file
701 @file{a.mov} (specified by the identifier "0:2"), and stream with
702 index 6 from input @file{b.mov} (specified by the identifier "1:6"),
703 and copy them to the output file @file{out.mov}:
704 @example
705 avconv -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
706 @end example
707
708 To select all video and the third audio stream from an input file:
709 @example
710 avconv -i INPUT -map 0:v -map 0:a:2 OUTPUT
711 @end example
712
713 To map all the streams except the second audio, use negative mappings
714 @example
715 avconv -i INPUT -map 0 -map -0:a:1 OUTPUT
716 @end example
717
718 Note that using this option disables the default mappings for this output file.
719
720 @item -map_metadata[:@var{metadata_type}][:@var{index}] @var{infile}[:@var{metadata_type}][:@var{index}]
721 Set metadata information of the next output file from @var{infile}. Note that
722 those are file indices (zero-based), not filenames.
723 Optional @var{metadata_type} parameters specify, which metadata to copy - (g)lobal
724 (i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
725 per-(p)rogram. All metadata specifiers other than global must be followed by the
726 stream/chapter/program index. If metadata specifier is omitted, it defaults to
727 global.
728
729 By default, global metadata is copied from the first input file,
730 per-stream and per-chapter metadata is copied along with streams/chapters. These
731 default mappings are disabled by creating any mapping of the relevant type. A negative
732 file index can be used to create a dummy mapping that just disables automatic copying.
733
734 For example to copy metadata from the first stream of the input file to global metadata
735 of the output file:
736 @example
737 avconv -i in.ogg -map_metadata 0:s:0 out.mp3
738 @end example
739 @item -map_chapters @var{input_file_index}
740 Copy chapters from input file with index @var{input_file_index} to the next
741 output file. If no chapter mapping is specified, then chapters are copied from
742 the first input file with at least one chapter. Use a negative file index to
743 disable any chapter copying.
744 @item -debug
745 Print specific debug info.
746 @item -benchmark
747 Show benchmarking information at the end of an encode.
748 Shows CPU time used and maximum memory consumption.
749 Maximum memory consumption is not supported on all systems,
750 it will usually display as 0 if not supported.
751 @item -dump
752 Dump each input packet.
753 @item -hex
754 When dumping packets, also dump the payload.
755 @item -bitexact
756 Only use bit exact algorithms (for codec testing).
757 @item -ps @var{size}
758 Set RTP payload size in bytes.
759 @item -re
760 Read input at native frame rate. Mainly used to simulate a grab device.
761 @item -threads @var{count}
762 Thread count.
763 @item -vsync @var{parameter}
764 Video sync method.
765
766 @table @option
767 @item 0
768 Each frame is passed with its timestamp from the demuxer to the muxer.
769 @item 1
770 Frames will be duplicated and dropped to achieve exactly the requested
771 constant framerate.
772 @item 2
773 Frames are passed through with their timestamp or dropped so as to
774 prevent 2 frames from having the same timestamp.
775 @item -1
776 Chooses between 1 and 2 depending on muxer capabilities. This is the
777 default method.
778 @end table
779
780 With -map you can select from which stream the timestamps should be
781 taken. You can leave either video or audio unchanged and sync the
782 remaining stream(s) to the unchanged one.
783
784 @item -async @var{samples_per_second}
785 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
786 the parameter is the maximum samples per second by which the audio is changed.
787 -async 1 is a special case where only the start of the audio stream is corrected
788 without any later correction.
789 @item -copyts
790 Copy timestamps from input to output.
791 @item -copytb
792 Copy input stream time base from input to output when stream copying.
793 @item -shortest
794 Finish encoding when the shortest input stream ends.
795 @item -dts_delta_threshold
796 Timestamp discontinuity delta threshold.
797 @item -muxdelay @var{seconds}
798 Set the maximum demux-decode delay.
799 @item -muxpreload @var{seconds}
800 Set the initial demux-decode delay.
801 @item -streamid @var{output-stream-index}:@var{new-value}
802 Assign a new stream-id value to an output stream. This option should be
803 specified prior to the output filename to which it applies.
804 For the situation where multiple output files exist, a streamid
805 may be reassigned to a different value.
806
807 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
808 an output mpegts file:
809 @example
810 avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
811 @end example
812 @end table
813 @c man end OPTIONS
814
815 @chapter Tips
816 @c man begin TIPS
817
818 @itemize
819 @item
820 For streaming at very low bitrate application, use a low frame rate
821 and a small GOP size. This is especially true for RealVideo where
822 the Linux player does not seem to be very fast, so it can miss
823 frames. An example is:
824
825 @example
826 avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
827 @end example
828
829 @item
830 The parameter 'q' which is displayed while encoding is the current
831 quantizer. The value 1 indicates that a very good quality could
832 be achieved. The value 31 indicates the worst quality. If q=31 appears
833 too often, it means that the encoder cannot compress enough to meet
834 your bitrate. You must either increase the bitrate, decrease the
835 frame rate or decrease the frame size.
836
837 @item
838 If your computer is not fast enough, you can speed up the
839 compression at the expense of the compression ratio. You can use
840 '-me zero' to speed up motion estimation, and '-intra' to disable
841 motion estimation completely (you have only I-frames, which means it
842 is about as good as JPEG compression).
843
844 @item
845 To have very low audio bitrates, reduce the sampling frequency
846 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
847
848 @item
849 To have a constant quality (but a variable bitrate), use the option
850 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
851 quality).
852
853 @end itemize
854 @c man end TIPS
855
856 @chapter Examples
857 @c man begin EXAMPLES
858
859 @section Video and Audio grabbing
860
861 If you specify the input format and device then avconv can grab video
862 and audio directly.
863
864 @example
865 avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
866 @end example
867
868 Note that you must activate the right video source and channel before
869 launching avconv with any TV viewer such as
870 @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also
871 have to set the audio recording levels correctly with a
872 standard mixer.
873
874 @section X11 grabbing
875
876 Grab the X11 display with avconv via
877
878 @example
879 avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
880 @end example
881
882 0.0 is display.screen number of your X11 server, same as
883 the DISPLAY environment variable.
884
885 @example
886 avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
887 @end example
888
889 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
890 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
891
892 @section Video and Audio file format conversion
893
894 Any supported file format and protocol can serve as input to avconv:
895
896 Examples:
897 @itemize
898 @item
899 You can use YUV files as input:
900
901 @example
902 avconv -i /tmp/test%d.Y /tmp/out.mpg
903 @end example
904
905 It will use the files:
906 @example
907 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
908 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
909 @end example
910
911 The Y files use twice the resolution of the U and V files. They are
912 raw files, without header. They can be generated by all decent video
913 decoders. You must specify the size of the image with the @option{-s} option
914 if avconv cannot guess it.
915
916 @item
917 You can input from a raw YUV420P file:
918
919 @example
920 avconv -i /tmp/test.yuv /tmp/out.avi
921 @end example
922
923 test.yuv is a file containing raw YUV planar data. Each frame is composed
924 of the Y plane followed by the U and V planes at half vertical and
925 horizontal resolution.
926
927 @item
928 You can output to a raw YUV420P file:
929
930 @example
931 avconv -i mydivx.avi hugefile.yuv
932 @end example
933
934 @item
935 You can set several input files and output files:
936
937 @example
938 avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
939 @end example
940
941 Converts the audio file a.wav and the raw YUV video file a.yuv
942 to MPEG file a.mpg.
943
944 @item
945 You can also do audio and video conversions at the same time:
946
947 @example
948 avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
949 @end example
950
951 Converts a.wav to MPEG audio at 22050 Hz sample rate.
952
953 @item
954 You can encode to several formats at the same time and define a
955 mapping from input stream to output streams:
956
957 @example
958 avconv -i /tmp/a.wav -map 0:a -b 64k /tmp/a.mp2 -map 0:a -b 128k /tmp/b.mp2
959 @end example
960
961 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
962 file:index' specifies which input stream is used for each output
963 stream, in the order of the definition of output streams.
964
965 @item
966 You can transcode decrypted VOBs:
967
968 @example
969 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
970 @end example
971
972 This is a typical DVD ripping example; the input is a VOB file, the
973 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
974 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
975 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
976 input video. Furthermore, the audio stream is MP3-encoded so you need
977 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
978 The mapping is particularly useful for DVD transcoding
979 to get the desired audio language.
980
981 NOTE: To see the supported input formats, use @code{avconv -formats}.
982
983 @item
984 You can extract images from a video, or create a video from many images:
985
986 For extracting images from a video:
987 @example
988 avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
989 @end example
990
991 This will extract one video frame per second from the video and will
992 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
993 etc. Images will be rescaled to fit the new WxH values.
994
995 If you want to extract just a limited number of frames, you can use the
996 above command in combination with the -vframes or -t option, or in
997 combination with -ss to start extracting from a certain point in time.
998
999 For creating a video from many images:
1000 @example
1001 avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
1002 @end example
1003
1004 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
1005 composed of three digits padded with zeroes to express the sequence
1006 number. It is the same syntax supported by the C printf function, but
1007 only formats accepting a normal integer are suitable.
1008
1009 @item
1010 You can put many streams of the same type in the output:
1011
1012 @example
1013 avconv -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
1014 @end example
1015
1016 The resulting output file @file{test12.avi} will contain first four streams from
1017 the input file in reverse order.
1018
1019 @end itemize
1020 @c man end EXAMPLES
1021
1022 @include eval.texi
1023 @include encoders.texi
1024 @include demuxers.texi
1025 @include muxers.texi
1026 @include indevs.texi
1027 @include outdevs.texi
1028 @include protocols.texi
1029 @include bitstream_filters.texi
1030 @include filters.texi
1031 @include metadata.texi
1032
1033 @ignore
1034
1035 @setfilename avconv
1036 @settitle avconv video converter
1037
1038 @c man begin SEEALSO
1039 avplay(1), avprobe(1), avserver(1) and the Libav HTML documentation
1040 @c man end
1041
1042 @c man begin AUTHORS
1043 The Libav developers
1044 @c man end
1045
1046 @end ignore
1047
1048 @bye