1\input texinfo @c -*- texinfo -*- 2@documentencoding UTF-8 3 4@settitle ffmpeg Documentation 5@titlepage 6@center @titlefont{ffmpeg Documentation} 7@end titlepage 8 9@top 10 11@contents 12 13@chapter Synopsis 14 15ffmpeg [@var{global_options}] @{[@var{input_file_options}] -i @file{input_url}@} ... @{[@var{output_file_options}] @file{output_url}@} ... 16 17@chapter Description 18@c man begin DESCRIPTION 19 20@command{ffmpeg} is a very fast video and audio converter that can also grab from 21a live audio/video source. It can also convert between arbitrary sample 22rates and resize video on the fly with a high quality polyphase filter. 23 24@command{ffmpeg} reads from an arbitrary number of input "files" (which can be regular 25files, pipes, network streams, grabbing devices, etc.), specified by the 26@code{-i} option, and writes to an arbitrary number of output "files", which are 27specified by a plain output url. Anything found on the command line which 28cannot be interpreted as an option is considered to be an output url. 29 30Each input or output url can, in principle, contain any number of streams of 31different types (video/audio/subtitle/attachment/data). The allowed number and/or 32types of streams may be limited by the container format. Selecting which 33streams from which inputs will go into which output is either done automatically 34or with the @code{-map} option (see the Stream selection chapter). 35 36To refer to input files in options, you must use their indices (0-based). E.g. 37the first input file is @code{0}, the second is @code{1}, etc. Similarly, streams 38within a file are referred to by their indices. E.g. @code{2:3} refers to the 39fourth stream in the third input file. Also see the Stream specifiers chapter. 40 41As a general rule, options are applied to the next specified 42file. Therefore, order is important, and you can have the same 43option on the command line multiple times. Each occurrence is 44then applied to the next input or output file. 45Exceptions from this rule are the global options (e.g. verbosity level), 46which should be specified first. 47 48Do not mix input and output files -- first specify all input files, then all 49output files. Also do not mix options which belong to different files. All 50options apply ONLY to the next input or output file and are reset between files. 51 52@itemize 53@item 54To set the video bitrate of the output file to 64 kbit/s: 55@example 56ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi 57@end example 58 59@item 60To force the frame rate of the output file to 24 fps: 61@example 62ffmpeg -i input.avi -r 24 output.avi 63@end example 64 65@item 66To force the frame rate of the input file (valid for raw formats only) 67to 1 fps and the frame rate of the output file to 24 fps: 68@example 69ffmpeg -r 1 -i input.m2v -r 24 output.avi 70@end example 71@end itemize 72 73The format option may be needed for raw input files. 74 75@c man end DESCRIPTION 76 77@chapter Detailed description 78@c man begin DETAILED DESCRIPTION 79 80The transcoding process in @command{ffmpeg} for each output can be described by 81the following diagram: 82 83@verbatim 84 _______ ______________ 85| | | | 86| input | demuxer | encoded data | decoder 87| file | ---------> | packets | -----+ 88|_______| |______________| | 89 v 90 _________ 91 | | 92 | decoded | 93 | frames | 94 |_________| 95 ________ ______________ | 96| | | | | 97| output | <-------- | encoded data | <----+ 98| file | muxer | packets | encoder 99|________| |______________| 100 101 102@end verbatim 103 104@command{ffmpeg} calls the libavformat library (containing demuxers) to read 105input files and get packets containing encoded data from them. When there are 106multiple input files, @command{ffmpeg} tries to keep them synchronized by 107tracking lowest timestamp on any active input stream. 108 109Encoded packets are then passed to the decoder (unless streamcopy is selected 110for the stream, see further for a description). The decoder produces 111uncompressed frames (raw video/PCM audio/...) which can be processed further by 112filtering (see next section). After filtering, the frames are passed to the 113encoder, which encodes them and outputs encoded packets. Finally those are 114passed to the muxer, which writes the encoded packets to the output file. 115 116@section Filtering 117Before encoding, @command{ffmpeg} can process raw audio and video frames using 118filters from the libavfilter library. Several chained filters form a filter 119graph. @command{ffmpeg} distinguishes between two types of filtergraphs: 120simple and complex. 121 122@subsection Simple filtergraphs 123Simple filtergraphs are those that have exactly one input and output, both of 124the same type. In the above diagram they can be represented by simply inserting 125an additional step between decoding and encoding: 126 127@verbatim 128 _________ ______________ 129| | | | 130| decoded | | encoded data | 131| frames |\ _ | packets | 132|_________| \ /||______________| 133 \ __________ / 134 simple _\|| | / encoder 135 filtergraph | filtered |/ 136 | frames | 137 |__________| 138 139@end verbatim 140 141Simple filtergraphs are configured with the per-stream @option{-filter} option 142(with @option{-vf} and @option{-af} aliases for video and audio respectively). 143A simple filtergraph for video can look for example like this: 144 145@verbatim 146 _______ _____________ _______ ________ 147| | | | | | | | 148| input | ---> | deinterlace | ---> | scale | ---> | output | 149|_______| |_____________| |_______| |________| 150 151@end verbatim 152 153Note that some filters change frame properties but not frame contents. E.g. the 154@code{fps} filter in the example above changes number of frames, but does not 155touch the frame contents. Another example is the @code{setpts} filter, which 156only sets timestamps and otherwise passes the frames unchanged. 157 158@subsection Complex filtergraphs 159Complex filtergraphs are those which cannot be described as simply a linear 160processing chain applied to one stream. This is the case, for example, when the graph has 161more than one input and/or output, or when output stream type is different from 162input. They can be represented with the following diagram: 163 164@verbatim 165 _________ 166| | 167| input 0 |\ __________ 168|_________| \ | | 169 \ _________ /| output 0 | 170 \ | | / |__________| 171 _________ \| complex | / 172| | | |/ 173| input 1 |---->| filter |\ 174|_________| | | \ __________ 175 /| graph | \ | | 176 / | | \| output 1 | 177 _________ / |_________| |__________| 178| | / 179| input 2 |/ 180|_________| 181 182@end verbatim 183 184Complex filtergraphs are configured with the @option{-filter_complex} option. 185Note that this option is global, since a complex filtergraph, by its nature, 186cannot be unambiguously associated with a single stream or file. 187 188The @option{-lavfi} option is equivalent to @option{-filter_complex}. 189 190A trivial example of a complex filtergraph is the @code{overlay} filter, which 191has two video inputs and one video output, containing one video overlaid on top 192of the other. Its audio counterpart is the @code{amix} filter. 193 194@section Stream copy 195Stream copy is a mode selected by supplying the @code{copy} parameter to the 196@option{-codec} option. It makes @command{ffmpeg} omit the decoding and encoding 197step for the specified stream, so it does only demuxing and muxing. It is useful 198for changing the container format or modifying container-level metadata. The 199diagram above will, in this case, simplify to this: 200 201@verbatim 202 _______ ______________ ________ 203| | | | | | 204| input | demuxer | encoded data | muxer | output | 205| file | ---------> | packets | -------> | file | 206|_______| |______________| |________| 207 208@end verbatim 209 210Since there is no decoding or encoding, it is very fast and there is no quality 211loss. However, it might not work in some cases because of many factors. Applying 212filters is obviously also impossible, since filters work on uncompressed data. 213 214@c man end DETAILED DESCRIPTION 215 216@chapter Stream selection 217@c man begin STREAM SELECTION 218 219@command{ffmpeg} provides the @code{-map} option for manual control of stream selection in each 220output file. Users can skip @code{-map} and let ffmpeg perform automatic stream selection as 221described below. The @code{-vn / -an / -sn / -dn} options can be used to skip inclusion of 222video, audio, subtitle and data streams respectively, whether manually mapped or automatically 223selected, except for those streams which are outputs of complex filtergraphs. 224 225@section Description 226The sub-sections that follow describe the various rules that are involved in stream selection. 227The examples that follow next show how these rules are applied in practice. 228 229While every effort is made to accurately reflect the behavior of the program, FFmpeg is under 230continuous development and the code may have changed since the time of this writing. 231 232@subsection Automatic stream selection 233 234In the absence of any map options for a particular output file, ffmpeg inspects the output 235format to check which type of streams can be included in it, viz. video, audio and/or 236subtitles. For each acceptable stream type, ffmpeg will pick one stream, when available, 237from among all the inputs. 238 239It will select that stream based upon the following criteria: 240@itemize 241@item 242for video, it is the stream with the highest resolution, 243@item 244for audio, it is the stream with the most channels, 245@item 246for subtitles, it is the first subtitle stream found but there's a caveat. 247The output format's default subtitle encoder can be either text-based or image-based, 248and only a subtitle stream of the same type will be chosen. 249@end itemize 250 251In the case where several streams of the same type rate equally, the stream with the lowest 252index is chosen. 253 254Data or attachment streams are not automatically selected and can only be included 255using @code{-map}. 256@subsection Manual stream selection 257 258When @code{-map} is used, only user-mapped streams are included in that output file, 259with one possible exception for filtergraph outputs described below. 260 261@subsection Complex filtergraphs 262 263If there are any complex filtergraph output streams with unlabeled pads, they will be added 264to the first output file. This will lead to a fatal error if the stream type is not supported 265by the output format. In the absence of the map option, the inclusion of these streams leads 266to the automatic stream selection of their types being skipped. If map options are present, 267these filtergraph streams are included in addition to the mapped streams. 268 269Complex filtergraph output streams with labeled pads must be mapped once and exactly once. 270 271@subsection Stream handling 272 273Stream handling is independent of stream selection, with an exception for subtitles described 274below. Stream handling is set via the @code{-codec} option addressed to streams within a 275specific @emph{output} file. In particular, codec options are applied by ffmpeg after the 276stream selection process and thus do not influence the latter. If no @code{-codec} option is 277specified for a stream type, ffmpeg will select the default encoder registered by the output 278file muxer. 279 280An exception exists for subtitles. If a subtitle encoder is specified for an output file, the 281first subtitle stream found of any type, text or image, will be included. ffmpeg does not validate 282if the specified encoder can convert the selected stream or if the converted stream is acceptable 283within the output format. This applies generally as well: when the user sets an encoder manually, 284the stream selection process cannot check if the encoded stream can be muxed into the output file. 285If it cannot, ffmpeg will abort and @emph{all} output files will fail to be processed. 286 287@section Examples 288 289The following examples illustrate the behavior, quirks and limitations of ffmpeg's stream 290selection methods. 291 292They assume the following three input files. 293 294@verbatim 295 296input file 'A.avi' 297 stream 0: video 640x360 298 stream 1: audio 2 channels 299 300input file 'B.mp4' 301 stream 0: video 1920x1080 302 stream 1: audio 2 channels 303 stream 2: subtitles (text) 304 stream 3: audio 5.1 channels 305 stream 4: subtitles (text) 306 307input file 'C.mkv' 308 stream 0: video 1280x720 309 stream 1: audio 2 channels 310 stream 2: subtitles (image) 311@end verbatim 312 313@subsubheading Example: automatic stream selection 314@example 315ffmpeg -i A.avi -i B.mp4 out1.mkv out2.wav -map 1:a -c:a copy out3.mov 316@end example 317There are three output files specified, and for the first two, no @code{-map} options 318are set, so ffmpeg will select streams for these two files automatically. 319 320@file{out1.mkv} is a Matroska container file and accepts video, audio and subtitle streams, 321so ffmpeg will try to select one of each type.@* 322For video, it will select @code{stream 0} from @file{B.mp4}, which has the highest 323resolution among all the input video streams.@* 324For audio, it will select @code{stream 3} from @file{B.mp4}, since it has the greatest 325number of channels.@* 326For subtitles, it will select @code{stream 2} from @file{B.mp4}, which is the first subtitle 327stream from among @file{A.avi} and @file{B.mp4}. 328 329@file{out2.wav} accepts only audio streams, so only @code{stream 3} from @file{B.mp4} is 330selected. 331 332For @file{out3.mov}, since a @code{-map} option is set, no automatic stream selection will 333occur. The @code{-map 1:a} option will select all audio streams from the second input 334@file{B.mp4}. No other streams will be included in this output file. 335 336For the first two outputs, all included streams will be transcoded. The encoders chosen will 337be the default ones registered by each output format, which may not match the codec of the 338selected input streams. 339 340For the third output, codec option for audio streams has been set 341to @code{copy}, so no decoding-filtering-encoding operations will occur, or @emph{can} occur. 342Packets of selected streams shall be conveyed from the input file and muxed within the output 343file. 344 345@subsubheading Example: automatic subtitles selection 346@example 347ffmpeg -i C.mkv out1.mkv -c:s dvdsub -an out2.mkv 348@end example 349Although @file{out1.mkv} is a Matroska container file which accepts subtitle streams, only a 350video and audio stream shall be selected. The subtitle stream of @file{C.mkv} is image-based 351and the default subtitle encoder of the Matroska muxer is text-based, so a transcode operation 352for the subtitles is expected to fail and hence the stream isn't selected. However, in 353@file{out2.mkv}, a subtitle encoder is specified in the command and so, the subtitle stream is 354selected, in addition to the video stream. The presence of @code{-an} disables audio stream 355selection for @file{out2.mkv}. 356 357@subsubheading Example: unlabeled filtergraph outputs 358@example 359ffmpeg -i A.avi -i C.mkv -i B.mp4 -filter_complex "overlay" out1.mp4 out2.srt 360@end example 361A filtergraph is setup here using the @code{-filter_complex} option and consists of a single 362video filter. The @code{overlay} filter requires exactly two video inputs, but none are 363specified, so the first two available video streams are used, those of @file{A.avi} and 364@file{C.mkv}. The output pad of the filter has no label and so is sent to the first output file 365@file{out1.mp4}. Due to this, automatic selection of the video stream is skipped, which would 366have selected the stream in @file{B.mp4}. The audio stream with most channels viz. @code{stream 3} 367in @file{B.mp4}, is chosen automatically. No subtitle stream is chosen however, since the MP4 368format has no default subtitle encoder registered, and the user hasn't specified a subtitle encoder. 369 370The 2nd output file, @file{out2.srt}, only accepts text-based subtitle streams. So, even though 371the first subtitle stream available belongs to @file{C.mkv}, it is image-based and hence skipped. 372The selected stream, @code{stream 2} in @file{B.mp4}, is the first text-based subtitle stream. 373 374@subsubheading Example: labeled filtergraph outputs 375@example 376ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0[outv];overlay;aresample" \ 377 -map '[outv]' -an out1.mp4 \ 378 out2.mkv \ 379 -map '[outv]' -map 1:a:0 out3.mkv 380@end example 381 382The above command will fail, as the output pad labelled @code{[outv]} has been mapped twice. 383None of the output files shall be processed. 384 385@example 386ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0[outv];overlay;aresample" \ 387 -an out1.mp4 \ 388 out2.mkv \ 389 -map 1:a:0 out3.mkv 390@end example 391 392This command above will also fail as the hue filter output has a label, @code{[outv]}, 393and hasn't been mapped anywhere. 394 395The command should be modified as follows, 396@example 397ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex "[1:v]hue=s=0,split=2[outv1][outv2];overlay;aresample" \ 398 -map '[outv1]' -an out1.mp4 \ 399 out2.mkv \ 400 -map '[outv2]' -map 1:a:0 out3.mkv 401@end example 402The video stream from @file{B.mp4} is sent to the hue filter, whose output is cloned once using 403the split filter, and both outputs labelled. Then a copy each is mapped to the first and third 404output files. 405 406The overlay filter, requiring two video inputs, uses the first two unused video streams. Those 407are the streams from @file{A.avi} and @file{C.mkv}. The overlay output isn't labelled, so it is 408sent to the first output file @file{out1.mp4}, regardless of the presence of the @code{-map} option. 409 410The aresample filter is sent the first unused audio stream, that of @file{A.avi}. Since this filter 411output is also unlabelled, it too is mapped to the first output file. The presence of @code{-an} 412only suppresses automatic or manual stream selection of audio streams, not outputs sent from 413filtergraphs. Both these mapped streams shall be ordered before the mapped stream in @file{out1.mp4}. 414 415The video, audio and subtitle streams mapped to @code{out2.mkv} are entirely determined by 416automatic stream selection. 417 418@file{out3.mkv} consists of the cloned video output from the hue filter and the first audio 419stream from @file{B.mp4}. 420@* 421 422@c man end STREAM SELECTION 423 424@chapter Options 425@c man begin OPTIONS 426 427@include fftools-common-opts.texi 428 429@section Main options 430 431@table @option 432 433@item -f @var{fmt} (@emph{input/output}) 434Force input or output file format. The format is normally auto detected for input 435files and guessed from the file extension for output files, so this option is not 436needed in most cases. 437 438@item -i @var{url} (@emph{input}) 439input file url 440 441@item -y (@emph{global}) 442Overwrite output files without asking. 443 444@item -n (@emph{global}) 445Do not overwrite output files, and exit immediately if a specified 446output file already exists. 447 448@item -stream_loop @var{number} (@emph{input}) 449Set number of times input stream shall be looped. Loop 0 means no loop, 450loop -1 means infinite loop. 451 452@item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream}) 453@itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream}) 454Select an encoder (when used before an output file) or a decoder (when used 455before an input file) for one or more streams. @var{codec} is the name of a 456decoder/encoder or a special value @code{copy} (output only) to indicate that 457the stream is not to be re-encoded. 458 459For example 460@example 461ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT 462@end example 463encodes all video streams with libx264 and copies all audio streams. 464 465For each stream, the last matching @code{c} option is applied, so 466@example 467ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT 468@end example 469will copy all the streams except the second video, which will be encoded with 470libx264, and the 138th audio, which will be encoded with libvorbis. 471 472@item -t @var{duration} (@emph{input/output}) 473When used as an input option (before @code{-i}), limit the @var{duration} of 474data read from the input file. 475 476When used as an output option (before an output url), stop writing the 477output after its duration reaches @var{duration}. 478 479@var{duration} must be a time duration specification, 480see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. 481 482-to and -t are mutually exclusive and -t has priority. 483 484@item -to @var{position} (@emph{input/output}) 485Stop writing the output or reading the input at @var{position}. 486@var{position} must be a time duration specification, 487see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. 488 489-to and -t are mutually exclusive and -t has priority. 490 491@item -fs @var{limit_size} (@emph{output}) 492Set the file size limit, expressed in bytes. No further chunk of bytes is written 493after the limit is exceeded. The size of the output file is slightly more than the 494requested file size. 495 496@item -ss @var{position} (@emph{input/output}) 497When used as an input option (before @code{-i}), seeks in this input file to 498@var{position}. Note that in most formats it is not possible to seek exactly, 499so @command{ffmpeg} will seek to the closest seek point before @var{position}. 500When transcoding and @option{-accurate_seek} is enabled (the default), this 501extra segment between the seek point and @var{position} will be decoded and 502discarded. When doing stream copy or when @option{-noaccurate_seek} is used, it 503will be preserved. 504 505When used as an output option (before an output url), decodes but discards 506input until the timestamps reach @var{position}. 507 508@var{position} must be a time duration specification, 509see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. 510 511@item -sseof @var{position} (@emph{input}) 512 513Like the @code{-ss} option but relative to the "end of file". That is negative 514values are earlier in the file, 0 is at EOF. 515 516@item -itsoffset @var{offset} (@emph{input}) 517Set the input time offset. 518 519@var{offset} must be a time duration specification, 520see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. 521 522The offset is added to the timestamps of the input files. Specifying 523a positive offset means that the corresponding streams are delayed by 524the time duration specified in @var{offset}. 525 526@item -itsscale @var{scale} (@emph{input,per-stream}) 527Rescale input timestamps. @var{scale} should be a floating point number. 528 529@item -timestamp @var{date} (@emph{output}) 530Set the recording timestamp in the container. 531 532@var{date} must be a date specification, 533see @ref{date syntax,,the Date section in the ffmpeg-utils(1) manual,ffmpeg-utils}. 534 535@item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata}) 536Set a metadata key/value pair. 537 538An optional @var{metadata_specifier} may be given to set metadata 539on streams, chapters or programs. See @code{-map_metadata} 540documentation for details. 541 542This option overrides metadata set with @code{-map_metadata}. It is 543also possible to delete metadata by using an empty value. 544 545For example, for setting the title in the output file: 546@example 547ffmpeg -i in.avi -metadata title="my title" out.flv 548@end example 549 550To set the language of the first audio stream: 551@example 552ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT 553@end example 554 555@item -disposition[:stream_specifier] @var{value} (@emph{output,per-stream}) 556Sets the disposition for a stream. 557 558This option overrides the disposition copied from the input stream. It is also 559possible to delete the disposition by setting it to 0. 560 561The following dispositions are recognized: 562@table @option 563@item default 564@item dub 565@item original 566@item comment 567@item lyrics 568@item karaoke 569@item forced 570@item hearing_impaired 571@item visual_impaired 572@item clean_effects 573@item attached_pic 574@item captions 575@item descriptions 576@item dependent 577@item metadata 578@end table 579 580For example, to make the second audio stream the default stream: 581@example 582ffmpeg -i in.mkv -c copy -disposition:a:1 default out.mkv 583@end example 584 585To make the second subtitle stream the default stream and remove the default 586disposition from the first subtitle stream: 587@example 588ffmpeg -i in.mkv -c copy -disposition:s:0 0 -disposition:s:1 default out.mkv 589@end example 590 591To add an embedded cover/thumbnail: 592@example 593ffmpeg -i in.mp4 -i IMAGE -map 0 -map 1 -c copy -c:v:1 png -disposition:v:1 attached_pic out.mp4 594@end example 595 596Not all muxers support embedded thumbnails, and those who do, only support a few formats, like JPEG or PNG. 597 598@item -program [title=@var{title}:][program_num=@var{program_num}:]st=@var{stream}[:st=@var{stream}...] (@emph{output}) 599 600Creates a program with the specified @var{title}, @var{program_num} and adds the specified 601@var{stream}(s) to it. 602 603@item -target @var{type} (@emph{output}) 604Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv}, 605@code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or 606@code{film-} to use the corresponding standard. All the format options 607(bitrate, codecs, buffer sizes) are then set automatically. You can just type: 608 609@example 610ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg 611@end example 612 613Nevertheless you can specify additional options as long as you know 614they do not conflict with the standard, as in: 615 616@example 617ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg 618@end example 619 620The parameters set for each target are as follows. 621 622@strong{VCD} 623@example 624@var{pal}: 625-f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324 626-s 352x288 -r 25 627-codec:v mpeg1video -g 15 -b:v 1150k -maxrate:v 1150v -minrate:v 1150k -bufsize:v 327680 628-ar 44100 -ac 2 629-codec:a mp2 -b:a 224k 630 631@var{ntsc}: 632-f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324 633-s 352x240 -r 30000/1001 634-codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150v -minrate:v 1150k -bufsize:v 327680 635-ar 44100 -ac 2 636-codec:a mp2 -b:a 224k 637 638@var{film}: 639-f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324 640-s 352x240 -r 24000/1001 641-codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150v -minrate:v 1150k -bufsize:v 327680 642-ar 44100 -ac 2 643-codec:a mp2 -b:a 224k 644@end example 645 646@strong{SVCD} 647@example 648@var{pal}: 649-f svcd -packetsize 2324 650-s 480x576 -pix_fmt yuv420p -r 25 651-codec:v mpeg2video -g 15 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1 652-ar 44100 653-codec:a mp2 -b:a 224k 654 655@var{ntsc}: 656-f svcd -packetsize 2324 657-s 480x480 -pix_fmt yuv420p -r 30000/1001 658-codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1 659-ar 44100 660-codec:a mp2 -b:a 224k 661 662@var{film}: 663-f svcd -packetsize 2324 664-s 480x480 -pix_fmt yuv420p -r 24000/1001 665-codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1 666-ar 44100 667-codec:a mp2 -b:a 224k 668@end example 669 670@strong{DVD} 671@example 672@var{pal}: 673-f dvd -muxrate 10080k -packetsize 2048 674-s 720x576 -pix_fmt yuv420p -r 25 675-codec:v mpeg2video -g 15 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008 676-ar 48000 677-codec:a ac3 -b:a 448k 678 679@var{ntsc}: 680-f dvd -muxrate 10080k -packetsize 2048 681-s 720x480 -pix_fmt yuv420p -r 30000/1001 682-codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008 683-ar 48000 684-codec:a ac3 -b:a 448k 685 686@var{film}: 687-f dvd -muxrate 10080k -packetsize 2048 688-s 720x480 -pix_fmt yuv420p -r 24000/1001 689-codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008 690-ar 48000 691-codec:a ac3 -b:a 448k 692@end example 693 694@strong{DV} 695@example 696@var{pal}: 697-f dv 698-s 720x576 -pix_fmt yuv420p -r 25 699-ar 48000 -ac 2 700 701@var{ntsc}: 702-f dv 703-s 720x480 -pix_fmt yuv411p -r 30000/1001 704-ar 48000 -ac 2 705 706@var{film}: 707-f dv 708-s 720x480 -pix_fmt yuv411p -r 24000/1001 709-ar 48000 -ac 2 710@end example 711The @code{dv50} target is identical to the @code{dv} target except that the pixel format set is @code{yuv422p} for all three standards. 712 713Any user-set value for a parameter above will override the target preset value. In that case, the output may 714not comply with the target standard. 715 716@item -dn (@emph{input/output}) 717As an input option, blocks all data streams of a file from being filtered or 718being automatically selected or mapped for any output. See @code{-discard} 719option to disable streams individually. 720 721As an output option, disables data recording i.e. automatic selection or 722mapping of any data stream. For full manual control see the @code{-map} 723option. 724 725@item -dframes @var{number} (@emph{output}) 726Set the number of data frames to output. This is an obsolete alias for 727@code{-frames:d}, which you should use instead. 728 729@item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream}) 730Stop writing to the stream after @var{framecount} frames. 731 732@item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream}) 733@itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream}) 734Use fixed quality scale (VBR). The meaning of @var{q}/@var{qscale} is 735codec-dependent. 736If @var{qscale} is used without a @var{stream_specifier} then it applies only 737to the video stream, this is to maintain compatibility with previous behavior 738and as specifying the same codec specific value to 2 different codecs that is 739audio and video generally is not what is intended when no stream_specifier is 740used. 741 742@anchor{filter_option} 743@item -filter[:@var{stream_specifier}] @var{filtergraph} (@emph{output,per-stream}) 744Create the filtergraph specified by @var{filtergraph} and use it to 745filter the stream. 746 747@var{filtergraph} is a description of the filtergraph to apply to 748the stream, and must have a single input and a single output of the 749same type of the stream. In the filtergraph, the input is associated 750to the label @code{in}, and the output to the label @code{out}. See 751the ffmpeg-filters manual for more information about the filtergraph 752syntax. 753 754See the @ref{filter_complex_option,,-filter_complex option} if you 755want to create filtergraphs with multiple inputs and/or outputs. 756 757@item -filter_script[:@var{stream_specifier}] @var{filename} (@emph{output,per-stream}) 758This option is similar to @option{-filter}, the only difference is that its 759argument is the name of the file from which a filtergraph description is to be 760read. 761 762@item -filter_threads @var{nb_threads} (@emph{global}) 763Defines how many threads are used to process a filter pipeline. Each pipeline 764will produce a thread pool with this many threads available for parallel processing. 765The default is the number of available CPUs. 766 767@item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream}) 768Specify the preset for matching stream(s). 769 770@item -stats (@emph{global}) 771Print encoding progress/statistics. It is on by default, to explicitly 772disable it you need to specify @code{-nostats}. 773 774@item -stats_period @var{time} (@emph{global}) 775Set period at which encoding progress/statistics are updated. Default is 0.5 seconds. 776 777@item -progress @var{url} (@emph{global}) 778Send program-friendly progress information to @var{url}. 779 780Progress information is written periodically and at the end of 781the encoding process. It is made of "@var{key}=@var{value}" lines. @var{key} 782consists of only alphanumeric characters. The last key of a sequence of 783progress information is always "progress". 784 785The update period is set using @code{-stats_period}. 786 787@anchor{stdin option} 788@item -stdin 789Enable interaction on standard input. On by default unless standard input is 790used as an input. To explicitly disable interaction you need to specify 791@code{-nostdin}. 792 793Disabling interaction on standard input is useful, for example, if 794ffmpeg is in the background process group. Roughly the same result can 795be achieved with @code{ffmpeg ... < /dev/null} but it requires a 796shell. 797 798@item -debug_ts (@emph{global}) 799Print timestamp information. It is off by default. This option is 800mostly useful for testing and debugging purposes, and the output 801format may change from one version to another, so it should not be 802employed by portable scripts. 803 804See also the option @code{-fdebug ts}. 805 806@item -attach @var{filename} (@emph{output}) 807Add an attachment to the output file. This is supported by a few formats 808like Matroska for e.g. fonts used in rendering subtitles. Attachments 809are implemented as a specific type of stream, so this option will add 810a new stream to the file. It is then possible to use per-stream options 811on this stream in the usual way. Attachment streams created with this 812option will be created after all the other streams (i.e. those created 813with @code{-map} or automatic mappings). 814 815Note that for Matroska you also have to set the mimetype metadata tag: 816@example 817ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv 818@end example 819(assuming that the attachment stream will be third in the output file). 820 821@item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream}) 822Extract the matching attachment stream into a file named @var{filename}. If 823@var{filename} is empty, then the value of the @code{filename} metadata tag 824will be used. 825 826E.g. to extract the first attachment to a file named 'out.ttf': 827@example 828ffmpeg -dump_attachment:t:0 out.ttf -i INPUT 829@end example 830To extract all attachments to files determined by the @code{filename} tag: 831@example 832ffmpeg -dump_attachment:t "" -i INPUT 833@end example 834 835Technical note -- attachments are implemented as codec extradata, so this 836option can actually be used to extract extradata from any stream, not just 837attachments. 838@end table 839 840@section Video Options 841 842@table @option 843@item -vframes @var{number} (@emph{output}) 844Set the number of video frames to output. This is an obsolete alias for 845@code{-frames:v}, which you should use instead. 846@item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream}) 847Set frame rate (Hz value, fraction or abbreviation). 848 849As an input option, ignore any timestamps stored in the file and instead 850generate timestamps assuming constant frame rate @var{fps}. 851This is not the same as the @option{-framerate} option used for some input formats 852like image2 or v4l2 (it used to be the same in older versions of FFmpeg). 853If in doubt use @option{-framerate} instead of the input option @option{-r}. 854 855As an output option, duplicate or drop input frames to achieve constant output 856frame rate @var{fps}. 857 858@item -fpsmax[:@var{stream_specifier}] @var{fps} (@emph{output,per-stream}) 859Set maximum frame rate (Hz value, fraction or abbreviation). 860 861Clamps output frame rate when output framerate is auto-set and is higher than this value. 862Useful in batch processing or when input framerate is wrongly detected as very high. 863It cannot be set together with @code{-r}. It is ignored during streamcopy. 864 865@item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream}) 866Set frame size. 867 868As an input option, this is a shortcut for the @option{video_size} private 869option, recognized by some demuxers for which the frame size is either not 870stored in the file or is configurable -- e.g. raw video or video grabbers. 871 872As an output option, this inserts the @code{scale} video filter to the 873@emph{end} of the corresponding filtergraph. Please use the @code{scale} filter 874directly to insert it at the beginning or some other place. 875 876The format is @samp{wxh} (default - same as source). 877 878@item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream}) 879Set the video display aspect ratio specified by @var{aspect}. 880 881@var{aspect} can be a floating point number string, or a string of the 882form @var{num}:@var{den}, where @var{num} and @var{den} are the 883numerator and denominator of the aspect ratio. For example "4:3", 884"16:9", "1.3333", and "1.7777" are valid argument values. 885 886If used together with @option{-vcodec copy}, it will affect the aspect ratio 887stored at container level, but not the aspect ratio stored in encoded 888frames, if it exists. 889 890@item -vn (@emph{input/output}) 891As an input option, blocks all video streams of a file from being filtered or 892being automatically selected or mapped for any output. See @code{-discard} 893option to disable streams individually. 894 895As an output option, disables video recording i.e. automatic selection or 896mapping of any video stream. For full manual control see the @code{-map} 897option. 898 899@item -vcodec @var{codec} (@emph{output}) 900Set the video codec. This is an alias for @code{-codec:v}. 901 902@item -pass[:@var{stream_specifier}] @var{n} (@emph{output,per-stream}) 903Select the pass number (1 or 2). It is used to do two-pass 904video encoding. The statistics of the video are recorded in the first 905pass into a log file (see also the option -passlogfile), 906and in the second pass that log file is used to generate the video 907at the exact requested bitrate. 908On pass 1, you may just deactivate audio and set output to null, 909examples for Windows and Unix: 910@example 911ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL 912ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null 913@end example 914 915@item -passlogfile[:@var{stream_specifier}] @var{prefix} (@emph{output,per-stream}) 916Set two-pass log file name prefix to @var{prefix}, the default file name 917prefix is ``ffmpeg2pass''. The complete file name will be 918@file{PREFIX-N.log}, where N is a number specific to the output 919stream 920 921@item -vf @var{filtergraph} (@emph{output}) 922Create the filtergraph specified by @var{filtergraph} and use it to 923filter the stream. 924 925This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter option}. 926 927@item -autorotate 928Automatically rotate the video according to file metadata. Enabled by 929default, use @option{-noautorotate} to disable it. 930 931@item -autoscale 932Automatically scale the video according to the resolution of first frame. 933Enabled by default, use @option{-noautoscale} to disable it. When autoscale is 934disabled, all output frames of filter graph might not be in the same resolution 935and may be inadequate for some encoder/muxer. Therefore, it is not recommended 936to disable it unless you really know what you are doing. 937Disable autoscale at your own risk. 938@end table 939 940@section Advanced Video options 941 942@table @option 943@item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream}) 944Set pixel format. Use @code{-pix_fmts} to show all the supported 945pixel formats. 946If the selected pixel format can not be selected, ffmpeg will print a 947warning and select the best pixel format supported by the encoder. 948If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error 949if the requested pixel format can not be selected, and automatic conversions 950inside filtergraphs are disabled. 951If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format 952as the input (or graph output) and automatic conversions are disabled. 953 954@item -sws_flags @var{flags} (@emph{input/output}) 955Set SwScaler flags. 956 957@item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream}) 958Rate control override for specific intervals, formatted as "int,int,int" 959list separated with slashes. Two first values are the beginning and 960end frame numbers, last one is quantizer to use if positive, or quality 961factor if negative. 962 963@item -ilme 964Force interlacing support in encoder (MPEG-2 and MPEG-4 only). 965Use this option if your input file is interlaced and you want 966to keep the interlaced format for minimum losses. 967The alternative is to deinterlace the input stream by use of a filter 968such as @code{yadif} or @code{bwdif}, but deinterlacing introduces losses. 969@item -psnr 970Calculate PSNR of compressed frames. 971@item -vstats 972Dump video coding statistics to @file{vstats_HHMMSS.log}. 973@item -vstats_file @var{file} 974Dump video coding statistics to @var{file}. 975@item -vstats_version @var{file} 976Specifies which version of the vstats format to use. Default is 2. 977 978version = 1 : 979 980@code{frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s} 981 982version > 1: 983 984@code{out= %2d st= %2d frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s} 985@item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream}) 986top=1/bottom=0/auto=-1 field first 987@item -dc @var{precision} 988Intra_dc_precision. 989@item -vtag @var{fourcc/tag} (@emph{output}) 990Force video tag/fourcc. This is an alias for @code{-tag:v}. 991@item -qphist (@emph{global}) 992Show QP histogram 993@item -vbsf @var{bitstream_filter} 994Deprecated see -bsf 995 996@item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream}) 997@item -force_key_frames[:@var{stream_specifier}] expr:@var{expr} (@emph{output,per-stream}) 998@item -force_key_frames[:@var{stream_specifier}] source (@emph{output,per-stream}) 999 1000@var{force_key_frames} can take arguments of the following form: 1001 1002@table @option 1003 1004@item @var{time}[,@var{time}...] 1005If the argument consists of timestamps, ffmpeg will round the specified times to the nearest 1006output timestamp as per the encoder time base and force a keyframe at the first frame having 1007timestamp equal or greater than the computed timestamp. Note that if the encoder time base is too 1008coarse, then the keyframes may be forced on frames with timestamps lower than the specified time. 1009The default encoder time base is the inverse of the output framerate but may be set otherwise 1010via @code{-enc_time_base}. 1011 1012If one of the times is "@code{chapters}[@var{delta}]", it is expanded into 1013the time of the beginning of all chapters in the file, shifted by 1014@var{delta}, expressed as a time in seconds. 1015This option can be useful to ensure that a seek point is present at a 1016chapter mark or any other designated place in the output file. 1017 1018For example, to insert a key frame at 5 minutes, plus key frames 0.1 second 1019before the beginning of every chapter: 1020@example 1021-force_key_frames 0:05:00,chapters-0.1 1022@end example 1023 1024@item expr:@var{expr} 1025If the argument is prefixed with @code{expr:}, the string @var{expr} 1026is interpreted like an expression and is evaluated for each frame. A 1027key frame is forced in case the evaluation is non-zero. 1028 1029The expression in @var{expr} can contain the following constants: 1030@table @option 1031@item n 1032the number of current processed frame, starting from 0 1033@item n_forced 1034the number of forced frames 1035@item prev_forced_n 1036the number of the previous forced frame, it is @code{NAN} when no 1037keyframe was forced yet 1038@item prev_forced_t 1039the time of the previous forced frame, it is @code{NAN} when no 1040keyframe was forced yet 1041@item t 1042the time of the current processed frame 1043@end table 1044 1045For example to force a key frame every 5 seconds, you can specify: 1046@example 1047-force_key_frames expr:gte(t,n_forced*5) 1048@end example 1049 1050To force a key frame 5 seconds after the time of the last forced one, 1051starting from second 13: 1052@example 1053-force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5)) 1054@end example 1055 1056@item source 1057If the argument is @code{source}, ffmpeg will force a key frame if 1058the current frame being encoded is marked as a key frame in its source. 1059 1060@end table 1061 1062Note that forcing too many keyframes is very harmful for the lookahead 1063algorithms of certain encoders: using fixed-GOP options or similar 1064would be more efficient. 1065 1066@item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream}) 1067When doing stream copy, copy also non-key frames found at the 1068beginning. 1069 1070@item -init_hw_device @var{type}[=@var{name}][:@var{device}[,@var{key=value}...]] 1071Initialise a new hardware device of type @var{type} called @var{name}, using the 1072given device parameters. 1073If no name is specified it will receive a default name of the form "@var{type}%d". 1074 1075The meaning of @var{device} and the following arguments depends on the 1076device type: 1077@table @option 1078 1079@item cuda 1080@var{device} is the number of the CUDA device. 1081 1082@item dxva2 1083@var{device} is the number of the Direct3D 9 display adapter. 1084 1085@item vaapi 1086@var{device} is either an X11 display name or a DRM render node. 1087If not specified, it will attempt to open the default X11 display (@emph{$DISPLAY}) 1088and then the first DRM render node (@emph{/dev/dri/renderD128}). 1089 1090@item vdpau 1091@var{device} is an X11 display name. 1092If not specified, it will attempt to open the default X11 display (@emph{$DISPLAY}). 1093 1094@item qsv 1095@var{device} selects a value in @samp{MFX_IMPL_*}. Allowed values are: 1096@table @option 1097@item auto 1098@item sw 1099@item hw 1100@item auto_any 1101@item hw_any 1102@item hw2 1103@item hw3 1104@item hw4 1105@end table 1106If not specified, @samp{auto_any} is used. 1107(Note that it may be easier to achieve the desired result for QSV by creating the 1108platform-appropriate subdevice (@samp{dxva2} or @samp{vaapi}) and then deriving a 1109QSV device from that.) 1110 1111@item opencl 1112@var{device} selects the platform and device as @emph{platform_index.device_index}. 1113 1114The set of devices can also be filtered using the key-value pairs to find only 1115devices matching particular platform or device strings. 1116 1117The strings usable as filters are: 1118@table @option 1119@item platform_profile 1120@item platform_version 1121@item platform_name 1122@item platform_vendor 1123@item platform_extensions 1124@item device_name 1125@item device_vendor 1126@item driver_version 1127@item device_version 1128@item device_profile 1129@item device_extensions 1130@item device_type 1131@end table 1132 1133The indices and filters must together uniquely select a device. 1134 1135Examples: 1136@table @emph 1137@item -init_hw_device opencl:0.1 1138Choose the second device on the first platform. 1139 1140@item -init_hw_device opencl:,device_name=Foo9000 1141Choose the device with a name containing the string @emph{Foo9000}. 1142 1143@item -init_hw_device opencl:1,device_type=gpu,device_extensions=cl_khr_fp16 1144Choose the GPU device on the second platform supporting the @emph{cl_khr_fp16} 1145extension. 1146@end table 1147 1148@item vulkan 1149If @var{device} is an integer, it selects the device by its index in a 1150system-dependent list of devices. If @var{device} is any other string, it 1151selects the first device with a name containing that string as a substring. 1152 1153The following options are recognized: 1154@table @option 1155@item debug 1156If set to 1, enables the validation layer, if installed. 1157@item linear_images 1158If set to 1, images allocated by the hwcontext will be linear and locally mappable. 1159@item instance_extensions 1160A plus separated list of additional instance extensions to enable. 1161@item device_extensions 1162A plus separated list of additional device extensions to enable. 1163@end table 1164 1165Examples: 1166@table @emph 1167@item -init_hw_device vulkan:1 1168Choose the second device on the system. 1169 1170@item -init_hw_device vulkan:RADV 1171Choose the first device with a name containing the string @emph{RADV}. 1172 1173@item -init_hw_device vulkan:0,instance_extensions=VK_KHR_wayland_surface+VK_KHR_xcb_surface 1174Choose the first device and enable the Wayland and XCB instance extensions. 1175@end table 1176 1177@end table 1178 1179@item -init_hw_device @var{type}[=@var{name}]@@@var{source} 1180Initialise a new hardware device of type @var{type} called @var{name}, 1181deriving it from the existing device with the name @var{source}. 1182 1183@item -init_hw_device list 1184List all hardware device types supported in this build of ffmpeg. 1185 1186@item -filter_hw_device @var{name} 1187Pass the hardware device called @var{name} to all filters in any filter graph. 1188This can be used to set the device to upload to with the @code{hwupload} filter, 1189or the device to map to with the @code{hwmap} filter. Other filters may also 1190make use of this parameter when they require a hardware device. Note that this 1191is typically only required when the input is not already in hardware frames - 1192when it is, filters will derive the device they require from the context of the 1193frames they receive as input. 1194 1195This is a global setting, so all filters will receive the same device. 1196 1197@item -hwaccel[:@var{stream_specifier}] @var{hwaccel} (@emph{input,per-stream}) 1198Use hardware acceleration to decode the matching stream(s). The allowed values 1199of @var{hwaccel} are: 1200@table @option 1201@item none 1202Do not use any hardware acceleration (the default). 1203 1204@item auto 1205Automatically select the hardware acceleration method. 1206 1207@item vdpau 1208Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration. 1209 1210@item dxva2 1211Use DXVA2 (DirectX Video Acceleration) hardware acceleration. 1212 1213@item vaapi 1214Use VAAPI (Video Acceleration API) hardware acceleration. 1215 1216@item qsv 1217Use the Intel QuickSync Video acceleration for video transcoding. 1218 1219Unlike most other values, this option does not enable accelerated decoding (that 1220is used automatically whenever a qsv decoder is selected), but accelerated 1221transcoding, without copying the frames into the system memory. 1222 1223For it to work, both the decoder and the encoder must support QSV acceleration 1224and no filters must be used. 1225@end table 1226 1227This option has no effect if the selected hwaccel is not available or not 1228supported by the chosen decoder. 1229 1230Note that most acceleration methods are intended for playback and will not be 1231faster than software decoding on modern CPUs. Additionally, @command{ffmpeg} 1232will usually need to copy the decoded frames from the GPU memory into the system 1233memory, resulting in further performance loss. This option is thus mainly 1234useful for testing. 1235 1236@item -hwaccel_device[:@var{stream_specifier}] @var{hwaccel_device} (@emph{input,per-stream}) 1237Select a device to use for hardware acceleration. 1238 1239This option only makes sense when the @option{-hwaccel} option is also specified. 1240It can either refer to an existing device created with @option{-init_hw_device} 1241by name, or it can create a new device as if 1242@samp{-init_hw_device} @var{type}:@var{hwaccel_device} 1243were called immediately before. 1244 1245@item -hwaccels 1246List all hardware acceleration methods supported in this build of ffmpeg. 1247 1248@end table 1249 1250@section Audio Options 1251 1252@table @option 1253@item -aframes @var{number} (@emph{output}) 1254Set the number of audio frames to output. This is an obsolete alias for 1255@code{-frames:a}, which you should use instead. 1256@item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream}) 1257Set the audio sampling frequency. For output streams it is set by 1258default to the frequency of the corresponding input stream. For input 1259streams this option only makes sense for audio grabbing devices and raw 1260demuxers and is mapped to the corresponding demuxer options. 1261@item -aq @var{q} (@emph{output}) 1262Set the audio quality (codec-specific, VBR). This is an alias for -q:a. 1263@item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream}) 1264Set the number of audio channels. For output streams it is set by 1265default to the number of input audio channels. For input streams 1266this option only makes sense for audio grabbing devices and raw demuxers 1267and is mapped to the corresponding demuxer options. 1268@item -an (@emph{input/output}) 1269As an input option, blocks all audio streams of a file from being filtered or 1270being automatically selected or mapped for any output. See @code{-discard} 1271option to disable streams individually. 1272 1273As an output option, disables audio recording i.e. automatic selection or 1274mapping of any audio stream. For full manual control see the @code{-map} 1275option. 1276@item -acodec @var{codec} (@emph{input/output}) 1277Set the audio codec. This is an alias for @code{-codec:a}. 1278@item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream}) 1279Set the audio sample format. Use @code{-sample_fmts} to get a list 1280of supported sample formats. 1281 1282@item -af @var{filtergraph} (@emph{output}) 1283Create the filtergraph specified by @var{filtergraph} and use it to 1284filter the stream. 1285 1286This is an alias for @code{-filter:a}, see the @ref{filter_option,,-filter option}. 1287@end table 1288 1289@section Advanced Audio options 1290 1291@table @option 1292@item -atag @var{fourcc/tag} (@emph{output}) 1293Force audio tag/fourcc. This is an alias for @code{-tag:a}. 1294@item -absf @var{bitstream_filter} 1295Deprecated, see -bsf 1296@item -guess_layout_max @var{channels} (@emph{input,per-stream}) 1297If some input channel layout is not known, try to guess only if it 1298corresponds to at most the specified number of channels. For example, 2 1299tells to @command{ffmpeg} to recognize 1 channel as mono and 2 channels as 1300stereo but not 6 channels as 5.1. The default is to always try to guess. Use 13010 to disable all guessing. 1302@end table 1303 1304@section Subtitle options 1305 1306@table @option 1307@item -scodec @var{codec} (@emph{input/output}) 1308Set the subtitle codec. This is an alias for @code{-codec:s}. 1309@item -sn (@emph{input/output}) 1310As an input option, blocks all subtitle streams of a file from being filtered or 1311being automatically selected or mapped for any output. See @code{-discard} 1312option to disable streams individually. 1313 1314As an output option, disables subtitle recording i.e. automatic selection or 1315mapping of any subtitle stream. For full manual control see the @code{-map} 1316option. 1317@item -sbsf @var{bitstream_filter} 1318Deprecated, see -bsf 1319@end table 1320 1321@section Advanced Subtitle options 1322 1323@table @option 1324 1325@item -fix_sub_duration 1326Fix subtitles durations. For each subtitle, wait for the next packet in the 1327same stream and adjust the duration of the first to avoid overlap. This is 1328necessary with some subtitles codecs, especially DVB subtitles, because the 1329duration in the original packet is only a rough estimate and the end is 1330actually marked by an empty subtitle frame. Failing to use this option when 1331necessary can result in exaggerated durations or muxing failures due to 1332non-monotonic timestamps. 1333 1334Note that this option will delay the output of all data until the next 1335subtitle packet is decoded: it may increase memory consumption and latency a 1336lot. 1337 1338@item -canvas_size @var{size} 1339Set the size of the canvas used to render subtitles. 1340 1341@end table 1342 1343@section Advanced options 1344 1345@table @option 1346@item -map [-]@var{input_file_id}[:@var{stream_specifier}][?][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output}) 1347 1348Designate one or more input streams as a source for the output file. Each input 1349stream is identified by the input file index @var{input_file_id} and 1350the input stream index @var{input_stream_id} within the input 1351file. Both indices start at 0. If specified, 1352@var{sync_file_id}:@var{stream_specifier} sets which input stream 1353is used as a presentation sync reference. 1354 1355The first @code{-map} option on the command line specifies the 1356source for output stream 0, the second @code{-map} option specifies 1357the source for output stream 1, etc. 1358 1359A @code{-} character before the stream identifier creates a "negative" mapping. 1360It disables matching streams from already created mappings. 1361 1362A trailing @code{?} after the stream index will allow the map to be 1363optional: if the map matches no streams the map will be ignored instead 1364of failing. Note the map will still fail if an invalid input file index 1365is used; such as if the map refers to a non-existent input. 1366 1367An alternative @var{[linklabel]} form will map outputs from complex filter 1368graphs (see the @option{-filter_complex} option) to the output file. 1369@var{linklabel} must correspond to a defined output link label in the graph. 1370 1371For example, to map ALL streams from the first input file to output 1372@example 1373ffmpeg -i INPUT -map 0 output 1374@end example 1375 1376For example, if you have two audio streams in the first input file, 1377these streams are identified by "0:0" and "0:1". You can use 1378@code{-map} to select which streams to place in an output file. For 1379example: 1380@example 1381ffmpeg -i INPUT -map 0:1 out.wav 1382@end example 1383will map the input stream in @file{INPUT} identified by "0:1" to 1384the (single) output stream in @file{out.wav}. 1385 1386For example, to select the stream with index 2 from input file 1387@file{a.mov} (specified by the identifier "0:2"), and stream with 1388index 6 from input @file{b.mov} (specified by the identifier "1:6"), 1389and copy them to the output file @file{out.mov}: 1390@example 1391ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov 1392@end example 1393 1394To select all video and the third audio stream from an input file: 1395@example 1396ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT 1397@end example 1398 1399To map all the streams except the second audio, use negative mappings 1400@example 1401ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT 1402@end example 1403 1404To map the video and audio streams from the first input, and using the 1405trailing @code{?}, ignore the audio mapping if no audio streams exist in 1406the first input: 1407@example 1408ffmpeg -i INPUT -map 0:v -map 0:a? OUTPUT 1409@end example 1410 1411To pick the English audio stream: 1412@example 1413ffmpeg -i INPUT -map 0:m:language:eng OUTPUT 1414@end example 1415 1416Note that using this option disables the default mappings for this output file. 1417 1418@item -ignore_unknown 1419Ignore input streams with unknown type instead of failing if copying 1420such streams is attempted. 1421 1422@item -copy_unknown 1423Allow input streams with unknown type to be copied instead of failing if copying 1424such streams is attempted. 1425 1426@item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][?][:@var{output_file_id}.@var{stream_specifier}] 1427Map an audio channel from a given input to an output. If 1428@var{output_file_id}.@var{stream_specifier} is not set, the audio channel will 1429be mapped on all the audio streams. 1430 1431Using "-1" instead of 1432@var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted 1433channel. 1434 1435A trailing @code{?} will allow the map_channel to be 1436optional: if the map_channel matches no channel the map_channel will be ignored instead 1437of failing. 1438 1439For example, assuming @var{INPUT} is a stereo audio file, you can switch the 1440two audio channels with the following command: 1441@example 1442ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT 1443@end example 1444 1445If you want to mute the first channel and keep the second: 1446@example 1447ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT 1448@end example 1449 1450The order of the "-map_channel" option specifies the order of the channels in 1451the output stream. The output channel layout is guessed from the number of 1452channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac" 1453in combination of "-map_channel" makes the channel gain levels to be updated if 1454input and output channel layouts don't match (for instance two "-map_channel" 1455options and "-ac 6"). 1456 1457You can also extract each channel of an input to specific outputs; the following 1458command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0) 1459to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs: 1460@example 1461ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1 1462@end example 1463 1464The following example splits the channels of a stereo input into two separate 1465streams, which are put into the same output file: 1466@example 1467ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg 1468@end example 1469 1470Note that currently each output stream can only contain channels from a single 1471input stream; you can't for example use "-map_channel" to pick multiple input 1472audio channels contained in different streams (from the same or different files) 1473and merge them into a single output stream. It is therefore not currently 1474possible, for example, to turn two separate mono streams into a single stereo 1475stream. However splitting a stereo stream into two single channel mono streams 1476is possible. 1477 1478If you need this feature, a possible workaround is to use the @emph{amerge} 1479filter. For example, if you need to merge a media (here @file{input.mkv}) with 2 1480mono audio streams into one single stereo channel audio stream (and keep the 1481video stream), you can use the following command: 1482@example 1483ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv 1484@end example 1485 1486To map the first two audio channels from the first input, and using the 1487trailing @code{?}, ignore the audio channel mapping if the first input is 1488mono instead of stereo: 1489@example 1490ffmpeg -i INPUT -map_channel 0.0.0 -map_channel 0.0.1? OUTPUT 1491@end example 1492 1493@item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata}) 1494Set metadata information of the next output file from @var{infile}. Note that 1495those are file indices (zero-based), not filenames. 1496Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy. 1497A metadata specifier can have the following forms: 1498@table @option 1499@item @var{g} 1500global metadata, i.e. metadata that applies to the whole file 1501 1502@item @var{s}[:@var{stream_spec}] 1503per-stream metadata. @var{stream_spec} is a stream specifier as described 1504in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first 1505matching stream is copied from. In an output metadata specifier, all matching 1506streams are copied to. 1507 1508@item @var{c}:@var{chapter_index} 1509per-chapter metadata. @var{chapter_index} is the zero-based chapter index. 1510 1511@item @var{p}:@var{program_index} 1512per-program metadata. @var{program_index} is the zero-based program index. 1513@end table 1514If metadata specifier is omitted, it defaults to global. 1515 1516By default, global metadata is copied from the first input file, 1517per-stream and per-chapter metadata is copied along with streams/chapters. These 1518default mappings are disabled by creating any mapping of the relevant type. A negative 1519file index can be used to create a dummy mapping that just disables automatic copying. 1520 1521For example to copy metadata from the first stream of the input file to global metadata 1522of the output file: 1523@example 1524ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3 1525@end example 1526 1527To do the reverse, i.e. copy global metadata to all audio streams: 1528@example 1529ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv 1530@end example 1531Note that simple @code{0} would work as well in this example, since global 1532metadata is assumed by default. 1533 1534@item -map_chapters @var{input_file_index} (@emph{output}) 1535Copy chapters from input file with index @var{input_file_index} to the next 1536output file. If no chapter mapping is specified, then chapters are copied from 1537the first input file with at least one chapter. Use a negative file index to 1538disable any chapter copying. 1539 1540@item -benchmark (@emph{global}) 1541Show benchmarking information at the end of an encode. 1542Shows real, system and user time used and maximum memory consumption. 1543Maximum memory consumption is not supported on all systems, 1544it will usually display as 0 if not supported. 1545@item -benchmark_all (@emph{global}) 1546Show benchmarking information during the encode. 1547Shows real, system and user time used in various steps (audio/video encode/decode). 1548@item -timelimit @var{duration} (@emph{global}) 1549Exit after ffmpeg has been running for @var{duration} seconds in CPU user time. 1550@item -dump (@emph{global}) 1551Dump each input packet to stderr. 1552@item -hex (@emph{global}) 1553When dumping packets, also dump the payload. 1554@item -re (@emph{input}) 1555Read input at native frame rate. Mainly used to simulate a grab device, 1556or live input stream (e.g. when reading from a file). Should not be used 1557with actual grab devices or live input streams (where it can cause packet 1558loss). 1559By default @command{ffmpeg} attempts to read the input(s) as fast as possible. 1560This option will slow down the reading of the input(s) to the native frame rate 1561of the input(s). It is useful for real-time output (e.g. live streaming). 1562@item -vsync @var{parameter} 1563Video sync method. 1564For compatibility reasons old values can be specified as numbers. 1565Newly added values will have to be specified as strings always. 1566 1567@table @option 1568@item 0, passthrough 1569Each frame is passed with its timestamp from the demuxer to the muxer. 1570@item 1, cfr 1571Frames will be duplicated and dropped to achieve exactly the requested 1572constant frame rate. 1573@item 2, vfr 1574Frames are passed through with their timestamp or dropped so as to 1575prevent 2 frames from having the same timestamp. 1576@item drop 1577As passthrough but destroys all timestamps, making the muxer generate 1578fresh timestamps based on frame-rate. 1579@item -1, auto 1580Chooses between 1 and 2 depending on muxer capabilities. This is the 1581default method. 1582@end table 1583 1584Note that the timestamps may be further modified by the muxer, after this. 1585For example, in the case that the format option @option{avoid_negative_ts} 1586is enabled. 1587 1588With -map you can select from which stream the timestamps should be 1589taken. You can leave either video or audio unchanged and sync the 1590remaining stream(s) to the unchanged one. 1591 1592@item -frame_drop_threshold @var{parameter} 1593Frame drop threshold, which specifies how much behind video frames can 1594be before they are dropped. In frame rate units, so 1.0 is one frame. 1595The default is -1.1. One possible usecase is to avoid framedrops in case 1596of noisy timestamps or to increase frame drop precision in case of exact 1597timestamps. 1598 1599@item -async @var{samples_per_second} 1600Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps, 1601the parameter is the maximum samples per second by which the audio is changed. 1602-async 1 is a special case where only the start of the audio stream is corrected 1603without any later correction. 1604 1605Note that the timestamps may be further modified by the muxer, after this. 1606For example, in the case that the format option @option{avoid_negative_ts} 1607is enabled. 1608 1609This option has been deprecated. Use the @code{aresample} audio filter instead. 1610 1611@item -adrift_threshold @var{time} 1612Set the minimum difference between timestamps and audio data (in seconds) to trigger 1613adding/dropping samples to make it match the timestamps. This option effectively is 1614a threshold to select between hard (add/drop) and soft (squeeze/stretch) compensation. 1615@code{-async} must be set to a positive value. 1616 1617@item -apad @var{parameters} (@emph{output,per-stream}) 1618Pad the output audio stream(s). This is the same as applying @code{-af apad}. 1619Argument is a string of filter parameters composed the same as with the @code{apad} filter. 1620@code{-shortest} must be set for this output for the option to take effect. 1621 1622@item -copyts 1623Do not process input timestamps, but keep their values without trying 1624to sanitize them. In particular, do not remove the initial start time 1625offset value. 1626 1627Note that, depending on the @option{vsync} option or on specific muxer 1628processing (e.g. in case the format option @option{avoid_negative_ts} 1629is enabled) the output timestamps may mismatch with the input 1630timestamps even when this option is selected. 1631 1632@item -start_at_zero 1633When used with @option{copyts}, shift input timestamps so they start at zero. 1634 1635This means that using e.g. @code{-ss 50} will make output timestamps start at 163650 seconds, regardless of what timestamp the input file started at. 1637 1638@item -copytb @var{mode} 1639Specify how to set the encoder timebase when stream copying. @var{mode} is an 1640integer numeric value, and can assume one of the following values: 1641 1642@table @option 1643@item 1 1644Use the demuxer timebase. 1645 1646The time base is copied to the output encoder from the corresponding input 1647demuxer. This is sometimes required to avoid non monotonically increasing 1648timestamps when copying video streams with variable frame rate. 1649 1650@item 0 1651Use the decoder timebase. 1652 1653The time base is copied to the output encoder from the corresponding input 1654decoder. 1655 1656@item -1 1657Try to make the choice automatically, in order to generate a sane output. 1658@end table 1659 1660Default value is -1. 1661 1662@item -enc_time_base[:@var{stream_specifier}] @var{timebase} (@emph{output,per-stream}) 1663Set the encoder timebase. @var{timebase} is a floating point number, 1664and can assume one of the following values: 1665 1666@table @option 1667@item 0 1668Assign a default value according to the media type. 1669 1670For video - use 1/framerate, for audio - use 1/samplerate. 1671 1672@item -1 1673Use the input stream timebase when possible. 1674 1675If an input stream is not available, the default timebase will be used. 1676 1677@item >0 1678Use the provided number as the timebase. 1679 1680This field can be provided as a ratio of two integers (e.g. 1:24, 1:48000) 1681or as a floating point number (e.g. 0.04166, 2.0833e-5) 1682@end table 1683 1684Default value is 0. 1685 1686@item -bitexact (@emph{input/output}) 1687Enable bitexact mode for (de)muxer and (de/en)coder 1688@item -shortest (@emph{output}) 1689Finish encoding when the shortest input stream ends. 1690@item -dts_delta_threshold 1691Timestamp discontinuity delta threshold. 1692@item -dts_error_threshold @var{seconds} 1693Timestamp error delta threshold. This threshold use to discard crazy/damaged 1694timestamps and the default is 30 hours which is arbitrarily picked and quite 1695conservative. 1696@item -muxdelay @var{seconds} (@emph{output}) 1697Set the maximum demux-decode delay. 1698@item -muxpreload @var{seconds} (@emph{output}) 1699Set the initial demux-decode delay. 1700@item -streamid @var{output-stream-index}:@var{new-value} (@emph{output}) 1701Assign a new stream-id value to an output stream. This option should be 1702specified prior to the output filename to which it applies. 1703For the situation where multiple output files exist, a streamid 1704may be reassigned to a different value. 1705 1706For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for 1707an output mpegts file: 1708@example 1709ffmpeg -i inurl -streamid 0:33 -streamid 1:36 out.ts 1710@end example 1711 1712@item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream}) 1713Set bitstream filters for matching streams. @var{bitstream_filters} is 1714a comma-separated list of bitstream filters. Use the @code{-bsfs} option 1715to get the list of bitstream filters. 1716@example 1717ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264 1718@end example 1719@example 1720ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt 1721@end example 1722 1723@item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{input/output,per-stream}) 1724Force a tag/fourcc for matching streams. 1725 1726@item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff} 1727Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';' 1728(or '.') for drop. 1729@example 1730ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg 1731@end example 1732 1733@anchor{filter_complex_option} 1734@item -filter_complex @var{filtergraph} (@emph{global}) 1735Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or 1736outputs. For simple graphs -- those with one input and one output of the same 1737type -- see the @option{-filter} options. @var{filtergraph} is a description of 1738the filtergraph, as described in the ``Filtergraph syntax'' section of the 1739ffmpeg-filters manual. 1740 1741Input link labels must refer to input streams using the 1742@code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map} 1743uses). If @var{stream_specifier} matches multiple streams, the first one will be 1744used. An unlabeled input will be connected to the first unused input stream of 1745the matching type. 1746 1747Output link labels are referred to with @option{-map}. Unlabeled outputs are 1748added to the first output file. 1749 1750Note that with this option it is possible to use only lavfi sources without 1751normal input files. 1752 1753For example, to overlay an image over video 1754@example 1755ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map 1756'[out]' out.mkv 1757@end example 1758Here @code{[0:v]} refers to the first video stream in the first input file, 1759which is linked to the first (main) input of the overlay filter. Similarly the 1760first video stream in the second input is linked to the second (overlay) input 1761of overlay. 1762 1763Assuming there is only one video stream in each input file, we can omit input 1764labels, so the above is equivalent to 1765@example 1766ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map 1767'[out]' out.mkv 1768@end example 1769 1770Furthermore we can omit the output label and the single output from the filter 1771graph will be added to the output file automatically, so we can simply write 1772@example 1773ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv 1774@end example 1775 1776As a special exception, you can use a bitmap subtitle stream as input: it 1777will be converted into a video with the same size as the largest video in 1778the file, or 720x576 if no video is present. Note that this is an 1779experimental and temporary solution. It will be removed once libavfilter has 1780proper support for subtitles. 1781 1782For example, to hardcode subtitles on top of a DVB-T recording stored in 1783MPEG-TS format, delaying the subtitles by 1 second: 1784@example 1785ffmpeg -i input.ts -filter_complex \ 1786 '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \ 1787 -sn -map '#0x2dc' output.mkv 1788@end example 1789(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video, 1790audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too) 1791 1792To generate 5 seconds of pure red video using lavfi @code{color} source: 1793@example 1794ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv 1795@end example 1796 1797@item -filter_complex_threads @var{nb_threads} (@emph{global}) 1798Defines how many threads are used to process a filter_complex graph. 1799Similar to filter_threads but used for @code{-filter_complex} graphs only. 1800The default is the number of available CPUs. 1801 1802@item -lavfi @var{filtergraph} (@emph{global}) 1803Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or 1804outputs. Equivalent to @option{-filter_complex}. 1805 1806@item -filter_complex_script @var{filename} (@emph{global}) 1807This option is similar to @option{-filter_complex}, the only difference is that 1808its argument is the name of the file from which a complex filtergraph 1809description is to be read. 1810 1811@item -accurate_seek (@emph{input}) 1812This option enables or disables accurate seeking in input files with the 1813@option{-ss} option. It is enabled by default, so seeking is accurate when 1814transcoding. Use @option{-noaccurate_seek} to disable it, which may be useful 1815e.g. when copying some streams and transcoding the others. 1816 1817@item -seek_timestamp (@emph{input}) 1818This option enables or disables seeking by timestamp in input files with the 1819@option{-ss} option. It is disabled by default. If enabled, the argument 1820to the @option{-ss} option is considered an actual timestamp, and is not 1821offset by the start time of the file. This matters only for files which do 1822not start from timestamp 0, such as transport streams. 1823 1824@item -thread_queue_size @var{size} (@emph{input}) 1825This option sets the maximum number of queued packets when reading from the 1826file or device. With low latency / high rate live streams, packets may be 1827discarded if they are not read in a timely manner; setting this value can 1828force ffmpeg to use a separate input thread and read packets as soon as they 1829arrive. By default ffmpeg only do this if multiple inputs are specified. 1830 1831@item -sdp_file @var{file} (@emph{global}) 1832Print sdp information for an output stream to @var{file}. 1833This allows dumping sdp information when at least one output isn't an 1834rtp stream. (Requires at least one of the output formats to be rtp). 1835 1836@item -discard (@emph{input}) 1837Allows discarding specific streams or frames from streams. 1838Any input stream can be fully discarded, using value @code{all} whereas 1839selective discarding of frames from a stream occurs at the demuxer 1840and is not supported by all demuxers. 1841 1842@table @option 1843@item none 1844Discard no frame. 1845 1846@item default 1847Default, which discards no frames. 1848 1849@item noref 1850Discard all non-reference frames. 1851 1852@item bidir 1853Discard all bidirectional frames. 1854 1855@item nokey 1856Discard all frames excepts keyframes. 1857 1858@item all 1859Discard all frames. 1860@end table 1861 1862@item -abort_on @var{flags} (@emph{global}) 1863Stop and abort on various conditions. The following flags are available: 1864 1865@table @option 1866@item empty_output 1867No packets were passed to the muxer, the output is empty. 1868@item empty_output_stream 1869No packets were passed to the muxer in some of the output streams. 1870@end table 1871 1872@item -max_error_rate (@emph{global}) 1873Set fraction of decoding frame failures across all inputs which when crossed 1874ffmpeg will return exit code 69. Crossing this threshold does not terminate 1875processing. Range is a floating-point number between 0 to 1. Default is 2/3. 1876 1877@item -xerror (@emph{global}) 1878Stop and exit on error 1879 1880@item -max_muxing_queue_size @var{packets} (@emph{output,per-stream}) 1881When transcoding audio and/or video streams, ffmpeg will not begin writing into 1882the output until it has one packet for each such stream. While waiting for that 1883to happen, packets for other streams are buffered. This option sets the size of 1884this buffer, in packets, for the matching output stream. 1885 1886The default value of this option should be high enough for most uses, so only 1887touch this option if you are sure that you need it. 1888 1889@item -muxing_queue_data_threshold @var{bytes} (@emph{output,per-stream}) 1890This is a minimum threshold until which the muxing queue size is not taken into 1891account. Defaults to 50 megabytes per stream, and is based on the overall size 1892of packets passed to the muxer. 1893 1894@item -auto_conversion_filters (@emph{global}) 1895Enable automatically inserting format conversion filters in all filter 1896graphs, including those defined by @option{-vf}, @option{-af}, 1897@option{-filter_complex} and @option{-lavfi}. If filter format negotiation 1898requires a conversion, the initialization of the filters will fail. 1899Conversions can still be performed by inserting the relevant conversion 1900filter (scale, aresample) in the graph. 1901On by default, to explicitly disable it you need to specify 1902@code{-noauto_conversion_filters}. 1903 1904@end table 1905 1906@section Preset files 1907A preset file contains a sequence of @var{option}=@var{value} pairs, 1908one for each line, specifying a sequence of options which would be 1909awkward to specify on the command line. Lines starting with the hash 1910('#') character are ignored and are used to provide comments. Check 1911the @file{presets} directory in the FFmpeg source tree for examples. 1912 1913There are two types of preset files: ffpreset and avpreset files. 1914 1915@subsection ffpreset files 1916ffpreset files are specified with the @code{vpre}, @code{apre}, 1917@code{spre}, and @code{fpre} options. The @code{fpre} option takes the 1918filename of the preset instead of a preset name as input and can be 1919used for any kind of codec. For the @code{vpre}, @code{apre}, and 1920@code{spre} options, the options specified in a preset file are 1921applied to the currently selected codec of the same type as the preset 1922option. 1923 1924The argument passed to the @code{vpre}, @code{apre}, and @code{spre} 1925preset options identifies the preset file to use according to the 1926following rules: 1927 1928First ffmpeg searches for a file named @var{arg}.ffpreset in the 1929directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in 1930the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg}) 1931or in a @file{ffpresets} folder along the executable on win32, 1932in that order. For example, if the argument is @code{libvpx-1080p}, it will 1933search for the file @file{libvpx-1080p.ffpreset}. 1934 1935If no such file is found, then ffmpeg will search for a file named 1936@var{codec_name}-@var{arg}.ffpreset in the above-mentioned 1937directories, where @var{codec_name} is the name of the codec to which 1938the preset file options will be applied. For example, if you select 1939the video codec with @code{-vcodec libvpx} and use @code{-vpre 1080p}, 1940then it will search for the file @file{libvpx-1080p.ffpreset}. 1941 1942@subsection avpreset files 1943avpreset files are specified with the @code{pre} option. They work similar to 1944ffpreset files, but they only allow encoder- specific options. Therefore, an 1945@var{option}=@var{value} pair specifying an encoder cannot be used. 1946 1947When the @code{pre} option is specified, ffmpeg will look for files with the 1948suffix .avpreset in the directories @file{$AVCONV_DATADIR} (if set), and 1949@file{$HOME/.avconv}, and in the datadir defined at configuration time (usually 1950@file{PREFIX/share/ffmpeg}), in that order. 1951 1952First ffmpeg searches for a file named @var{codec_name}-@var{arg}.avpreset in 1953the above-mentioned directories, where @var{codec_name} is the name of the codec 1954to which the preset file options will be applied. For example, if you select the 1955video codec with @code{-vcodec libvpx} and use @code{-pre 1080p}, then it will 1956search for the file @file{libvpx-1080p.avpreset}. 1957 1958If no such file is found, then ffmpeg will search for a file named 1959@var{arg}.avpreset in the same directories. 1960 1961@c man end OPTIONS 1962 1963@chapter Examples 1964@c man begin EXAMPLES 1965 1966@section Video and Audio grabbing 1967 1968If you specify the input format and device then ffmpeg can grab video 1969and audio directly. 1970 1971@example 1972ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg 1973@end example 1974 1975Or with an ALSA audio source (mono input, card id 1) instead of OSS: 1976@example 1977ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg 1978@end example 1979 1980Note that you must activate the right video source and channel before 1981launching ffmpeg with any TV viewer such as 1982@uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also 1983have to set the audio recording levels correctly with a 1984standard mixer. 1985 1986@section X11 grabbing 1987 1988Grab the X11 display with ffmpeg via 1989 1990@example 1991ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg 1992@end example 1993 19940.0 is display.screen number of your X11 server, same as 1995the DISPLAY environment variable. 1996 1997@example 1998ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg 1999@end example 2000 20010.0 is display.screen number of your X11 server, same as the DISPLAY environment 2002variable. 10 is the x-offset and 20 the y-offset for the grabbing. 2003 2004@section Video and Audio file format conversion 2005 2006Any supported file format and protocol can serve as input to ffmpeg: 2007 2008Examples: 2009@itemize 2010@item 2011You can use YUV files as input: 2012 2013@example 2014ffmpeg -i /tmp/test%d.Y /tmp/out.mpg 2015@end example 2016 2017It will use the files: 2018@example 2019/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V, 2020/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc... 2021@end example 2022 2023The Y files use twice the resolution of the U and V files. They are 2024raw files, without header. They can be generated by all decent video 2025decoders. You must specify the size of the image with the @option{-s} option 2026if ffmpeg cannot guess it. 2027 2028@item 2029You can input from a raw YUV420P file: 2030 2031@example 2032ffmpeg -i /tmp/test.yuv /tmp/out.avi 2033@end example 2034 2035test.yuv is a file containing raw YUV planar data. Each frame is composed 2036of the Y plane followed by the U and V planes at half vertical and 2037horizontal resolution. 2038 2039@item 2040You can output to a raw YUV420P file: 2041 2042@example 2043ffmpeg -i mydivx.avi hugefile.yuv 2044@end example 2045 2046@item 2047You can set several input files and output files: 2048 2049@example 2050ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg 2051@end example 2052 2053Converts the audio file a.wav and the raw YUV video file a.yuv 2054to MPEG file a.mpg. 2055 2056@item 2057You can also do audio and video conversions at the same time: 2058 2059@example 2060ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2 2061@end example 2062 2063Converts a.wav to MPEG audio at 22050 Hz sample rate. 2064 2065@item 2066You can encode to several formats at the same time and define a 2067mapping from input stream to output streams: 2068 2069@example 2070ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2 2071@end example 2072 2073Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map 2074file:index' specifies which input stream is used for each output 2075stream, in the order of the definition of output streams. 2076 2077@item 2078You can transcode decrypted VOBs: 2079 2080@example 2081ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi 2082@end example 2083 2084This is a typical DVD ripping example; the input is a VOB file, the 2085output an AVI file with MPEG-4 video and MP3 audio. Note that in this 2086command we use B-frames so the MPEG-4 stream is DivX5 compatible, and 2087GOP size is 300 which means one intra frame every 10 seconds for 29.97fps 2088input video. Furthermore, the audio stream is MP3-encoded so you need 2089to enable LAME support by passing @code{--enable-libmp3lame} to configure. 2090The mapping is particularly useful for DVD transcoding 2091to get the desired audio language. 2092 2093NOTE: To see the supported input formats, use @code{ffmpeg -demuxers}. 2094 2095@item 2096You can extract images from a video, or create a video from many images: 2097 2098For extracting images from a video: 2099@example 2100ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg 2101@end example 2102 2103This will extract one video frame per second from the video and will 2104output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg}, 2105etc. Images will be rescaled to fit the new WxH values. 2106 2107If you want to extract just a limited number of frames, you can use the 2108above command in combination with the @code{-frames:v} or @code{-t} option, 2109or in combination with -ss to start extracting from a certain point in time. 2110 2111For creating a video from many images: 2112@example 2113ffmpeg -f image2 -framerate 12 -i foo-%03d.jpeg -s WxH foo.avi 2114@end example 2115 2116The syntax @code{foo-%03d.jpeg} specifies to use a decimal number 2117composed of three digits padded with zeroes to express the sequence 2118number. It is the same syntax supported by the C printf function, but 2119only formats accepting a normal integer are suitable. 2120 2121When importing an image sequence, -i also supports expanding 2122shell-like wildcard patterns (globbing) internally, by selecting the 2123image2-specific @code{-pattern_type glob} option. 2124 2125For example, for creating a video from filenames matching the glob pattern 2126@code{foo-*.jpeg}: 2127@example 2128ffmpeg -f image2 -pattern_type glob -framerate 12 -i 'foo-*.jpeg' -s WxH foo.avi 2129@end example 2130 2131@item 2132You can put many streams of the same type in the output: 2133 2134@example 2135ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut 2136@end example 2137 2138The resulting output file @file{test12.nut} will contain the first four streams 2139from the input files in reverse order. 2140 2141@item 2142To force CBR video output: 2143@example 2144ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v 2145@end example 2146 2147@item 2148The four options lmin, lmax, mblmin and mblmax use 'lambda' units, 2149but you may use the QP2LAMBDA constant to easily convert from 'q' units: 2150@example 2151ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext 2152@end example 2153 2154@end itemize 2155@c man end EXAMPLES 2156 2157@include config.texi 2158@ifset config-all 2159@ifset config-avutil 2160@include utils.texi 2161@end ifset 2162@ifset config-avcodec 2163@include codecs.texi 2164@include bitstream_filters.texi 2165@end ifset 2166@ifset config-avformat 2167@include formats.texi 2168@include protocols.texi 2169@end ifset 2170@ifset config-avdevice 2171@include devices.texi 2172@end ifset 2173@ifset config-swresample 2174@include resampler.texi 2175@end ifset 2176@ifset config-swscale 2177@include scaler.texi 2178@end ifset 2179@ifset config-avfilter 2180@include filters.texi 2181@end ifset 2182@include general_contents.texi 2183@end ifset 2184 2185@chapter See Also 2186 2187@ifhtml 2188@ifset config-all 2189@url{ffmpeg.html,ffmpeg} 2190@end ifset 2191@ifset config-not-all 2192@url{ffmpeg-all.html,ffmpeg-all}, 2193@end ifset 2194@url{ffplay.html,ffplay}, @url{ffprobe.html,ffprobe}, 2195@url{ffmpeg-utils.html,ffmpeg-utils}, 2196@url{ffmpeg-scaler.html,ffmpeg-scaler}, 2197@url{ffmpeg-resampler.html,ffmpeg-resampler}, 2198@url{ffmpeg-codecs.html,ffmpeg-codecs}, 2199@url{ffmpeg-bitstream-filters.html,ffmpeg-bitstream-filters}, 2200@url{ffmpeg-formats.html,ffmpeg-formats}, 2201@url{ffmpeg-devices.html,ffmpeg-devices}, 2202@url{ffmpeg-protocols.html,ffmpeg-protocols}, 2203@url{ffmpeg-filters.html,ffmpeg-filters} 2204@end ifhtml 2205 2206@ifnothtml 2207@ifset config-all 2208ffmpeg(1), 2209@end ifset 2210@ifset config-not-all 2211ffmpeg-all(1), 2212@end ifset 2213ffplay(1), ffprobe(1), 2214ffmpeg-utils(1), ffmpeg-scaler(1), ffmpeg-resampler(1), 2215ffmpeg-codecs(1), ffmpeg-bitstream-filters(1), ffmpeg-formats(1), 2216ffmpeg-devices(1), ffmpeg-protocols(1), ffmpeg-filters(1) 2217@end ifnothtml 2218 2219@include authors.texi 2220 2221@ignore 2222 2223@setfilename ffmpeg 2224@settitle ffmpeg video converter 2225 2226@end ignore 2227 2228@bye 2229