presets: rename presets directory
[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).
189 @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
190 Specify the preset for matching stream(s).
192 @item -stats (@emph{global})
193 Print encoding progress/statistics. On by default.
195 @end table
197 @section Video Options
199 @table @option
200 @item -vframes @var{number} (@emph{output})
201 Set the number of video frames to record. This is an alias for @code{-frames:v}.
202 @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream})
203 Set frame rate (Hz value, fraction or abbreviation), (default = 25).
204 @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream})
205 Set frame size. The format is @samp{wxh} (avserver default = 160x128, avconv default = same as source).
206 The following abbreviations are recognized:
207 @table @samp
208 @item sqcif
209 128x96
210 @item qcif
211 176x144
212 @item cif
213 352x288
214 @item 4cif
215 704x576
216 @item 16cif
217 1408x1152
218 @item qqvga
219 160x120
220 @item qvga
221 320x240
222 @item vga
223 640x480
224 @item svga
225 800x600
226 @item xga
227 1024x768
228 @item uxga
229 1600x1200
230 @item qxga
231 2048x1536
232 @item sxga
233 1280x1024
234 @item qsxga
235 2560x2048
236 @item hsxga
237 5120x4096
238 @item wvga
239 852x480
240 @item wxga
241 1366x768
242 @item wsxga
243 1600x1024
244 @item wuxga
245 1920x1200
246 @item woxga
247 2560x1600
248 @item wqsxga
249 3200x2048
250 @item wquxga
251 3840x2400
252 @item whsxga
253 6400x4096
254 @item whuxga
255 7680x4800
256 @item cga
257 320x200
258 @item ega
259 640x350
260 @item hd480
261 852x480
262 @item hd720
263 1280x720
264 @item hd1080
265 1920x1080
266 @end table
268 @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream})
269 Set the video display aspect ratio specified by @var{aspect}.
271 @var{aspect} can be a floating point number string, or a string of the
272 form @var{num}:@var{den}, where @var{num} and @var{den} are the
273 numerator and denominator of the aspect ratio. For example "4:3",
274 "16:9", "1.3333", and "1.7777" are valid argument values.
276 @item -vn (@emph{output})
277 Disable video recording.
278 @item -bt @var{tolerance}
279 Set video bitrate tolerance (in bits, default 4000k).
280 Has a minimum value of: (target_bitrate/target_framerate).
281 In 1-pass mode, bitrate tolerance specifies how far ratecontrol is
282 willing to deviate from the target average bitrate value. This is
283 not related to min/max bitrate. Lowering tolerance too much has
284 an adverse effect on quality.
285 @item -maxrate @var{bitrate}
286 Set max video bitrate (in bit/s).
287 Requires -bufsize to be set.
288 @item -minrate @var{bitrate}
289 Set min video bitrate (in bit/s).
290 Most useful in setting up a CBR encode:
291 @example
292 avconv -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
293 @end example
294 It is of little use elsewise.
295 @item -bufsize @var{size}
296 Set video buffer verifier buffer size (in bits).
297 @item -vcodec @var{codec} (@emph{output})
298 Set the video codec. This is an alias for @code{-codec:v}.
299 @item -same_quant
300 Use same quantizer as source (implies VBR).
302 Note that this is NOT SAME QUALITY. Do not use this option unless you know you
303 need it.
305 @item -pass @var{n}
306 Select the pass number (1 or 2). It is used to do two-pass
307 video encoding. The statistics of the video are recorded in the first
308 pass into a log file (see also the option -passlogfile),
309 and in the second pass that log file is used to generate the video
310 at the exact requested bitrate.
311 On pass 1, you may just deactivate audio and set output to null,
312 examples for Windows and Unix:
313 @example
314 avconv -i -c:v libxvid -pass 1 -an -f rawvideo -y NUL
315 avconv -i -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
316 @end example
318 @item -passlogfile @var{prefix} (@emph{global})
319 Set two-pass log file name prefix to @var{prefix}, the default file name
320 prefix is ``av2pass''. The complete file name will be
321 @file{PREFIX-N.log}, where N is a number specific to the output
322 stream.
324 @item -vf @var{filter_graph} (@emph{output})
325 @var{filter_graph} is a description of the filter graph to apply to
326 the input video.
327 Use the option "-filters" to show all the available filters (including
328 also sources and sinks). This is an alias for @code{-filter:v}.
330 @end table
332 @section Advanced Video Options
334 @table @option
335 @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
336 Set pixel format. Use @code{-pix_fmts} to show all the supported
337 pixel formats.
338 @item -sws_flags @var{flags} (@emph{input/output})
339 Set SwScaler flags.
340 @item -g @var{gop_size}
341 Set the group of pictures size.
342 @item -vdt @var{n}
343 Discard threshold.
344 @item -qmin @var{q}
345 minimum video quantizer scale (VBR)
346 @item -qmax @var{q}
347 maximum video quantizer scale (VBR)
348 @item -qdiff @var{q}
349 maximum difference between the quantizer scales (VBR)
350 @item -qblur @var{blur}
351 video quantizer scale blur (VBR) (range 0.0 - 1.0)
352 @item -qcomp @var{compression}
353 video quantizer scale compression (VBR) (default 0.5).
354 Constant of ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0
356 @item -lmin @var{lambda}
357 minimum video lagrange factor (VBR)
358 @item -lmax @var{lambda}
359 max video lagrange factor (VBR)
360 @item -mblmin @var{lambda}
361 minimum macroblock quantizer scale (VBR)
362 @item -mblmax @var{lambda}
363 maximum macroblock quantizer scale (VBR)
365 These four options (lmin, lmax, mblmin, mblmax) use 'lambda' units,
366 but you may use the QP2LAMBDA constant to easily convert from 'q' units:
367 @example
368 avconv -i src.ext -lmax 21*QP2LAMBDA dst.ext
369 @end example
371 @item -rc_init_cplx @var{complexity}
372 initial complexity for single pass encoding
373 @item -b_qfactor @var{factor}
374 qp factor between P- and B-frames
375 @item -i_qfactor @var{factor}
376 qp factor between P- and I-frames
377 @item -b_qoffset @var{offset}
378 qp offset between P- and B-frames
379 @item -i_qoffset @var{offset}
380 qp offset between P- and I-frames
381 @item -rc_eq @var{equation}
382 Set rate control equation (see section "Expression Evaluation")
383 (default = @code{tex^qComp}).
385 When computing the rate control equation expression, besides the
386 standard functions defined in the section "Expression Evaluation", the
387 following functions are available:
388 @table @var
389 @item bits2qp(bits)
390 @item qp2bits(qp)
391 @end table
393 and the following constants are available:
394 @table @var
395 @item iTex
396 @item pTex
397 @item tex
398 @item mv
399 @item fCode
400 @item iCount
401 @item mcVar
402 @item var
403 @item isI
404 @item isP
405 @item isB
406 @item avgQP
407 @item qComp
408 @item avgIITex
409 @item avgPITex
410 @item avgPPTex
411 @item avgBPTex
412 @item avgTex
413 @end table
415 @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream})
416 rate control override for specific intervals
417 @item -me_method @var{method}
418 Set motion estimation method to @var{method}.
419 Available methods are (from lowest to best quality):
420 @table @samp
421 @item zero
422 Try just the (0, 0) vector.
423 @item phods
424 @item log
425 @item x1
426 @item hex
427 @item umh
428 @item epzs
429 (default method)
430 @item full
431 exhaustive search (slow and marginally better than epzs)
432 @end table
434 @item -er @var{n}
435 Set error resilience to @var{n}.
436 @table @samp
437 @item 1
438 FF_ER_CAREFUL (default)
439 @item 2
441 @item 3
443 @item 4
445 @end table
447 @item -ec @var{bit_mask}
448 Set error concealment to @var{bit_mask}. @var{bit_mask} is a bit mask of
449 the following values:
450 @table @samp
451 @item 1
452 FF_EC_GUESS_MVS (default = enabled)
453 @item 2
454 FF_EC_DEBLOCK (default = enabled)
455 @end table
457 @item -bf @var{frames}
458 Use 'frames' B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).
459 @item -mbd @var{mode}
460 macroblock decision
461 @table @samp
462 @item 0
463 FF_MB_DECISION_SIMPLE: Use mb_cmp (cannot change it yet in avconv).
464 @item 1
465 FF_MB_DECISION_BITS: Choose the one which needs the fewest bits.
466 @item 2
467 FF_MB_DECISION_RD: rate distortion
468 @end table
470 @item -bug @var{param}
471 Work around encoder bugs that are not auto-detected.
472 @item -strict @var{strictness}
473 How strictly to follow the standards.
475 @item -deinterlace
476 Deinterlace pictures.
477 @item -vstats
478 Dump video coding statistics to @file{vstats_HHMMSS.log}.
479 @item -vstats_file @var{file}
480 Dump video coding statistics to @var{file}.
481 @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
482 top=1/bottom=0/auto=-1 field first
483 @item -dc @var{precision}
484 Intra_dc_precision.
485 @item -vtag @var{fourcc/tag} (@emph{output})
486 Force video tag/fourcc. This is an alias for @code{-tag:v}.
487 @item -qphist (@emph{global})
488 Show QP histogram.
489 @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream})
490 Force key frames at the specified timestamps, more precisely at the first
491 frames after each specified time.
492 This option can be useful to ensure that a seek point is present at a
493 chapter mark or any other designated place in the output file.
494 The timestamps must be specified in ascending order.
495 @end table
497 @section Audio Options
499 @table @option
500 @item -aframes @var{number} (@emph{output})
501 Set the number of audio frames to record. This is an alias for @code{-frames:a}.
502 @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream})
503 Set the audio sampling frequency. For output streams it is set by
504 default to the frequency of the corresponding input stream. For input
505 streams this option only makes sense for audio grabbing devices and raw
506 demuxers and is mapped to the corresponding demuxer options.
507 @item -aq @var{q} (@emph{output})
508 Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
509 @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream})
510 Set the number of audio channels. For output streams it is set by
511 default to the number of input audio channels. For input streams
512 this option only makes sense for audio grabbing devices and raw demuxers
513 and is mapped to the corresponding demuxer options.
514 @item -an (@emph{output})
515 Disable audio recording.
516 @item -acodec @var{codec} (@emph{input/output})
517 Set the audio codec. This is an alias for @code{-codec:a}.
518 @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream})
519 Set the audio sample format. Use @code{-help sample_fmts} to get a list
520 of supported sample formats.
521 @end table
523 @section Advanced Audio options:
525 @table @option
526 @item -atag @var{fourcc/tag} (@emph{output})
527 Force audio tag/fourcc. This is an alias for @code{-tag:a}.
528 @item -audio_service_type @var{type}
529 Set the type of service that the audio stream contains.
530 @table @option
531 @item ma
532 Main Audio Service (default)
533 @item ef
534 Effects
535 @item vi
536 Visually Impaired
537 @item hi
538 Hearing Impaired
539 @item di
540 Dialogue
541 @item co
542 Commentary
543 @item em
544 Emergency
545 @item vo
546 Voice Over
547 @item ka
548 Karaoke
549 @end table
550 @end table
552 @section Subtitle options:
554 @table @option
555 @item -scodec @var{codec} (@emph{input/output})
556 Set the subtitle codec. This is an alias for @code{-codec:s}.
557 @item -sn (@emph{output})
558 Disable subtitle recording.
559 @end table
561 @section Audio/Video grab options
563 @table @option
564 @item -isync (@emph{global})
565 Synchronize read on input.
566 @end table
568 @section Advanced options
570 @table @option
571 @item -map [-]@var{input_file_id}[:@var{stream_specifier}][,@var{sync_file_id}[:@var{stream_specifier}]] (@emph{output})
573 Designate one or more input streams as a source for the output file. Each input
574 stream is identified by the input file index @var{input_file_id} and
575 the input stream index @var{input_stream_id} within the input
576 file. Both indices start at 0. If specified,
577 @var{sync_file_id}:@var{stream_specifier} sets which input stream
578 is used as a presentation sync reference.
580 The first @code{-map} option on the command line specifies the
581 source for output stream 0, the second @code{-map} option specifies
582 the source for output stream 1, etc.
584 A @code{-} character before the stream identifier creates a "negative" mapping.
585 It disables matching streams from already created mappings.
587 For example, to map ALL streams from the first input file to output
588 @example
589 avconv -i INPUT -map 0 output
590 @end example
592 For example, if you have two audio streams in the first input file,
593 these streams are identified by "0:0" and "0:1". You can use
594 @code{-map} to select which streams to place in an output file. For
595 example:
596 @example
597 avconv -i INPUT -map 0:1 out.wav
598 @end example
599 will map the input stream in @file{INPUT} identified by "0:1" to
600 the (single) output stream in @file{out.wav}.
602 For example, to select the stream with index 2 from input file
603 @file{} (specified by the identifier "0:2"), and stream with
604 index 6 from input @file{} (specified by the identifier "1:6"),
605 and copy them to the output file @file{}:
606 @example
607 avconv -i -i -c copy -map 0:2 -map 1:6
608 @end example
610 To select all video and the third audio stream from an input file:
611 @example
612 avconv -i INPUT -map 0:v -map 0:a:2 OUTPUT
613 @end example
615 To map all the streams except the second audio, use negative mappings
616 @example
617 avconv -i INPUT -map 0 -map -0:a:1 OUTPUT
618 @end example
620 Note that using this option disables the default mappings for this output file.
622 @item -map_metadata[:@var{metadata_type}][:@var{index}] @var{infile}[:@var{metadata_type}][:@var{index}] (@emph{output,per-metadata})
623 Set metadata information of the next output file from @var{infile}. Note that
624 those are file indices (zero-based), not filenames.
625 Optional @var{metadata_type} parameters specify, which metadata to copy - (g)lobal
626 (i.e. metadata that applies to the whole file), per-(s)tream, per-(c)hapter or
627 per-(p)rogram. All metadata specifiers other than global must be followed by the
628 stream/chapter/program index. If metadata specifier is omitted, it defaults to
629 global.
631 By default, global metadata is copied from the first input file,
632 per-stream and per-chapter metadata is copied along with streams/chapters. These
633 default mappings are disabled by creating any mapping of the relevant type. A negative
634 file index can be used to create a dummy mapping that just disables automatic copying.
636 For example to copy metadata from the first stream of the input file to global metadata
637 of the output file:
638 @example
639 avconv -i in.ogg -map_metadata 0:s:0 out.mp3
640 @end example
641 @item -map_chapters @var{input_file_index} (@emph{output})
642 Copy chapters from input file with index @var{input_file_index} to the next
643 output file. If no chapter mapping is specified, then chapters are copied from
644 the first input file with at least one chapter. Use a negative file index to
645 disable any chapter copying.
646 @item -debug
647 Print specific debug info.
648 @item -benchmark (@emph{global})
649 Show benchmarking information at the end of an encode.
650 Shows CPU time used and maximum memory consumption.
651 Maximum memory consumption is not supported on all systems,
652 it will usually display as 0 if not supported.
653 @item -timelimit @var{duration} (@emph{global})
654 Exit after avconv has been running for @var{duration} seconds.
655 @item -dump (@emph{global})
656 Dump each input packet to stderr.
657 @item -hex (@emph{global})
658 When dumping packets, also dump the payload.
659 @item -ps @var{size}
660 Set RTP payload size in bytes.
661 @item -re (@emph{input})
662 Read input at native frame rate. Mainly used to simulate a grab device.
663 @item -threads @var{count}
664 Thread count.
665 @item -vsync @var{parameter}
666 Video sync method.
668 @table @option
669 @item 0
670 Each frame is passed with its timestamp from the demuxer to the muxer.
671 @item 1
672 Frames will be duplicated and dropped to achieve exactly the requested
673 constant framerate.
674 @item 2
675 Frames are passed through with their timestamp or dropped so as to
676 prevent 2 frames from having the same timestamp.
677 @item -1
678 Chooses between 1 and 2 depending on muxer capabilities. This is the
679 default method.
680 @end table
682 With -map you can select from which stream the timestamps should be
683 taken. You can leave either video or audio unchanged and sync the
684 remaining stream(s) to the unchanged one.
686 @item -async @var{samples_per_second}
687 Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
688 the parameter is the maximum samples per second by which the audio is changed.
689 -async 1 is a special case where only the start of the audio stream is corrected
690 without any later correction.
691 @item -copyts
692 Copy timestamps from input to output.
693 @item -copytb
694 Copy input stream time base from input to output when stream copying.
695 @item -shortest
696 Finish encoding when the shortest input stream ends.
697 @item -dts_delta_threshold
698 Timestamp discontinuity delta threshold.
699 @item -muxdelay @var{seconds} (@emph{input})
700 Set the maximum demux-decode delay.
701 @item -muxpreload @var{seconds} (@emph{input})
702 Set the initial demux-decode delay.
703 @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output})
704 Assign a new stream-id value to an output stream. This option should be
705 specified prior to the output filename to which it applies.
706 For the situation where multiple output files exist, a streamid
707 may be reassigned to a different value.
709 For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
710 an output mpegts file:
711 @example
712 avconv -i infile -streamid 0:33 -streamid 1:36 out.ts
713 @end example
715 @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream})
716 Set bitstream filters for matching streams. @var{bistream_filters} is
717 a comma-separated list of bitstream filters. Use the @code{-bsfs} option
718 to get the list of bitstream filters.
719 @example
720 avconv -i h264.mp4 -c:v copy -vbsf h264_mp4toannexb -an out.h264
721 @end example
722 @example
723 avconv -i -an -vn -sbsf mov2textsub -c:s copy -f rawvideo sub.txt
724 @end example
726 @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{output,per-stream})
727 Force a tag/fourcc for matching streams.
728 @end table
729 @c man end OPTIONS
731 @chapter Tips
732 @c man begin TIPS
734 @itemize
735 @item
736 For streaming at very low bitrate application, use a low frame rate
737 and a small GOP size. This is especially true for RealVideo where
738 the Linux player does not seem to be very fast, so it can miss
739 frames. An example is:
741 @example
742 avconv -g 3 -r 3 -t 10 -b 50k -s qcif -f rv10 /tmp/b.rm
743 @end example
745 @item
746 The parameter 'q' which is displayed while encoding is the current
747 quantizer. The value 1 indicates that a very good quality could
748 be achieved. The value 31 indicates the worst quality. If q=31 appears
749 too often, it means that the encoder cannot compress enough to meet
750 your bitrate. You must either increase the bitrate, decrease the
751 frame rate or decrease the frame size.
753 @item
754 If your computer is not fast enough, you can speed up the
755 compression at the expense of the compression ratio. You can use
756 '-me zero' to speed up motion estimation, and '-intra' to disable
757 motion estimation completely (you have only I-frames, which means it
758 is about as good as JPEG compression).
760 @item
761 To have very low audio bitrates, reduce the sampling frequency
762 (down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
764 @item
765 To have a constant quality (but a variable bitrate), use the option
766 '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
767 quality).
769 @end itemize
770 @c man end TIPS
772 @chapter Examples
773 @c man begin EXAMPLES
775 @section Preset files
777 A preset file contains a sequence of @var{option=value} pairs, one for
778 each line, specifying a sequence of options which can be specified also on
779 the command line. Lines starting with the hash ('#') character are ignored and
780 are used to provide comments. Empty lines are also ignored. Check the
781 @file{presets} directory in the Libav source tree for examples.
783 Preset files are specified with the @code{pre} option, this option takes a
784 preset name as input. Avconv searches for a file named @var{preset_name}.avpreset in
785 the directories @file{$AVCONV_DATADIR} (if set), and @file{$HOME/.avconv}, and in
786 the data directory defined at configuration time (usually @file{$PREFIX/share/avconv})
787 in that order. For example, if the argument is @code{libx264-max}, it will
788 search for the file @file{libx264-max.avpreset}.
790 @section Video and Audio grabbing
792 If you specify the input format and device then avconv can grab video
793 and audio directly.
795 @example
796 avconv -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
797 @end example
799 Note that you must activate the right video source and channel before
800 launching avconv with any TV viewer such as
801 @uref{, xawtv} by Gerd Knorr. You also
802 have to set the audio recording levels correctly with a
803 standard mixer.
805 @section X11 grabbing
807 Grab the X11 display with avconv via
809 @example
810 avconv -f x11grab -s cif -r 25 -i :0.0 /tmp/out.mpg
811 @end example
813 0.0 is display.screen number of your X11 server, same as
814 the DISPLAY environment variable.
816 @example
817 avconv -f x11grab -s cif -r 25 -i :0.0+10,20 /tmp/out.mpg
818 @end example
820 0.0 is display.screen number of your X11 server, same as the DISPLAY environment
821 variable. 10 is the x-offset and 20 the y-offset for the grabbing.
823 @section Video and Audio file format conversion
825 Any supported file format and protocol can serve as input to avconv:
827 Examples:
828 @itemize
829 @item
830 You can use YUV files as input:
832 @example
833 avconv -i /tmp/test%d.Y /tmp/out.mpg
834 @end example
836 It will use the files:
837 @example
838 /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
839 /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
840 @end example
842 The Y files use twice the resolution of the U and V files. They are
843 raw files, without header. They can be generated by all decent video
844 decoders. You must specify the size of the image with the @option{-s} option
845 if avconv cannot guess it.
847 @item
848 You can input from a raw YUV420P file:
850 @example
851 avconv -i /tmp/test.yuv /tmp/out.avi
852 @end example
854 test.yuv is a file containing raw YUV planar data. Each frame is composed
855 of the Y plane followed by the U and V planes at half vertical and
856 horizontal resolution.
858 @item
859 You can output to a raw YUV420P file:
861 @example
862 avconv -i mydivx.avi hugefile.yuv
863 @end example
865 @item
866 You can set several input files and output files:
868 @example
869 avconv -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
870 @end example
872 Converts the audio file a.wav and the raw YUV video file a.yuv
873 to MPEG file a.mpg.
875 @item
876 You can also do audio and video conversions at the same time:
878 @example
879 avconv -i /tmp/a.wav -ar 22050 /tmp/a.mp2
880 @end example
882 Converts a.wav to MPEG audio at 22050 Hz sample rate.
884 @item
885 You can encode to several formats at the same time and define a
886 mapping from input stream to output streams:
888 @example
889 avconv -i /tmp/a.wav -map 0:a -b 64k /tmp/a.mp2 -map 0:a -b 128k /tmp/b.mp2
890 @end example
892 Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
893 file:index' specifies which input stream is used for each output
894 stream, in the order of the definition of output streams.
896 @item
897 You can transcode decrypted VOBs:
899 @example
900 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
901 @end example
903 This is a typical DVD ripping example; the input is a VOB file, the
904 output an AVI file with MPEG-4 video and MP3 audio. Note that in this
905 command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
906 GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
907 input video. Furthermore, the audio stream is MP3-encoded so you need
908 to enable LAME support by passing @code{--enable-libmp3lame} to configure.
909 The mapping is particularly useful for DVD transcoding
910 to get the desired audio language.
912 NOTE: To see the supported input formats, use @code{avconv -formats}.
914 @item
915 You can extract images from a video, or create a video from many images:
917 For extracting images from a video:
918 @example
919 avconv -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
920 @end example
922 This will extract one video frame per second from the video and will
923 output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg},
924 etc. Images will be rescaled to fit the new WxH values.
926 If you want to extract just a limited number of frames, you can use the
927 above command in combination with the -vframes or -t option, or in
928 combination with -ss to start extracting from a certain point in time.
930 For creating a video from many images:
931 @example
932 avconv -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
933 @end example
935 The syntax @code{foo-%03d.jpeg} specifies to use a decimal number
936 composed of three digits padded with zeroes to express the sequence
937 number. It is the same syntax supported by the C printf function, but
938 only formats accepting a normal integer are suitable.
940 @item
941 You can put many streams of the same type in the output:
943 @example
944 avconv -i test1.avi -i test2.avi -map 0.3 -map 0.2 -map 0.1 -map 0.0 -c copy test12.nut
945 @end example
947 The resulting output file @file{test12.avi} will contain first four streams from
948 the input file in reverse order.
950 @end itemize
951 @c man end EXAMPLES
953 @include eval.texi
954 @include encoders.texi
955 @include demuxers.texi
956 @include muxers.texi
957 @include indevs.texi
958 @include outdevs.texi
959 @include protocols.texi
960 @include bitstream_filters.texi
961 @include filters.texi
962 @include metadata.texi
964 @ignore
966 @setfilename avconv
967 @settitle avconv video converter
969 @c man begin SEEALSO
970 avplay(1), avprobe(1), avserver(1) and the Libav HTML documentation
971 @c man end
973 @c man begin AUTHORS
974 The Libav developers
975 @c man end
977 @end ignore
979 @bye