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