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| 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 | |
| 15 | ffmpeg [@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 |
| 21 | a live audio/video source. It can also convert between arbitrary sample |
| 22 | rates 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 |
| 25 | files, pipes, network streams, grabbing devices, etc.), specified by the |
| 26 | @code{-i} option, and writes to an arbitrary number of output "files", which are |
| 27 | specified by a plain output url. Anything found on the command line which |
| 28 | cannot be interpreted as an option is considered to be an output url. |
| 29 | |
| 30 | Each input or output url can, in principle, contain any number of streams of |
| 31 | different types (video/audio/subtitle/attachment/data). The allowed number and/or |
| 32 | types of streams may be limited by the container format. Selecting which |
| 33 | streams from which inputs will go into which output is either done automatically |
| 34 | or with the @code{-map} option (see the Stream selection chapter). |
| 35 | |
| 36 | To refer to input files in options, you must use their indices (0-based). E.g. |
| 37 | the first input file is @code{0}, the second is @code{1}, etc. Similarly, streams |
| 38 | within a file are referred to by their indices. E.g. @code{2:3} refers to the |
| 39 | fourth stream in the third input file. Also see the Stream specifiers chapter. |
| 40 | |
| 41 | As a general rule, options are applied to the next specified |
| 42 | file. Therefore, order is important, and you can have the same |
| 43 | option on the command line multiple times. Each occurrence is |
| 44 | then applied to the next input or output file. |
| 45 | Exceptions from this rule are the global options (e.g. verbosity level), |
| 46 | which should be specified first. |
| 47 | |
| 48 | Do not mix input and output files -- first specify all input files, then all |
| 49 | output files. Also do not mix options which belong to different files. All |
| 50 | options apply ONLY to the next input or output file and are reset between files. |
| 51 | |
| 52 | @itemize |
| 53 | @item |
| 54 | To set the video bitrate of the output file to 64 kbit/s: |
| 55 | @example |
| 56 | ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi |
| 57 | @end example |
| 58 | |
| 59 | @item |
| 60 | To force the frame rate of the output file to 24 fps: |
| 61 | @example |
| 62 | ffmpeg -i input.avi -r 24 output.avi |
| 63 | @end example |
| 64 | |
| 65 | @item |
| 66 | To force the frame rate of the input file (valid for raw formats only) |
| 67 | to 1 fps and the frame rate of the output file to 24 fps: |
| 68 | @example |
| 69 | ffmpeg -r 1 -i input.m2v -r 24 output.avi |
| 70 | @end example |
| 71 | @end itemize |
| 72 | |
| 73 | The 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 | |
| 80 | The transcoding process in @command{ffmpeg} for each output can be described by |
| 81 | the 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 |
| 105 | input files and get packets containing encoded data from them. When there are |
| 106 | multiple input files, @command{ffmpeg} tries to keep them synchronized by |
| 107 | tracking lowest timestamp on any active input stream. |
| 108 | |
| 109 | Encoded packets are then passed to the decoder (unless streamcopy is selected |
| 110 | for the stream, see further for a description). The decoder produces |
| 111 | uncompressed frames (raw video/PCM audio/...) which can be processed further by |
| 112 | filtering (see next section). After filtering, the frames are passed to the |
| 113 | encoder, which encodes them and outputs encoded packets. Finally those are |
| 114 | passed to the muxer, which writes the encoded packets to the output file. |
| 115 | |
| 116 | @section Filtering |
| 117 | Before encoding, @command{ffmpeg} can process raw audio and video frames using |
| 118 | filters from the libavfilter library. Several chained filters form a filter |
| 119 | graph. @command{ffmpeg} distinguishes between two types of filtergraphs: |
| 120 | simple and complex. |
| 121 | |
| 122 | @subsection Simple filtergraphs |
| 123 | Simple filtergraphs are those that have exactly one input and output, both of |
| 124 | the same type. In the above diagram they can be represented by simply inserting |
| 125 | an 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 | |
| 141 | Simple filtergraphs are configured with the per-stream @option{-filter} option |
| 142 | (with @option{-vf} and @option{-af} aliases for video and audio respectively). |
| 143 | A 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 | |
| 153 | Note 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 |
| 155 | touch the frame contents. Another example is the @code{setpts} filter, which |
| 156 | only sets timestamps and otherwise passes the frames unchanged. |
| 157 | |
| 158 | @subsection Complex filtergraphs |
| 159 | Complex filtergraphs are those which cannot be described as simply a linear |
| 160 | processing chain applied to one stream. This is the case, for example, when the graph has |
| 161 | more than one input and/or output, or when output stream type is different from |
| 162 | input. 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 | |
| 184 | Complex filtergraphs are configured with the @option{-filter_complex} option. |
| 185 | Note that this option is global, since a complex filtergraph, by its nature, |
| 186 | cannot be unambiguously associated with a single stream or file. |
| 187 | |
| 188 | The @option{-lavfi} option is equivalent to @option{-filter_complex}. |
| 189 | |
| 190 | A trivial example of a complex filtergraph is the @code{overlay} filter, which |
| 191 | has two video inputs and one video output, containing one video overlaid on top |
| 192 | of the other. Its audio counterpart is the @code{amix} filter. |
| 193 | |
| 194 | @section Stream copy |
| 195 | Stream 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 |
| 197 | step for the specified stream, so it does only demuxing and muxing. It is useful |
| 198 | for changing the container format or modifying container-level metadata. The |
| 199 | diagram 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 | |
| 210 | Since there is no decoding or encoding, it is very fast and there is no quality |
| 211 | loss. However, it might not work in some cases because of many factors. Applying |
| 212 | filters 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 | By default, @command{ffmpeg} includes only one stream of each type (video, audio, subtitle) |
| 220 | present in the input files and adds them to each output file. It picks the |
| 221 | "best" of each based upon the following criteria: for video, it is the stream |
| 222 | with the highest resolution, for audio, it is the stream with the most channels, for |
| 223 | subtitles, it is the first subtitle stream. In the case where several streams of |
| 224 | the same type rate equally, the stream with the lowest index is chosen. |
| 225 | |
| 226 | You can disable some of those defaults by using the @code{-vn/-an/-sn/-dn} options. For |
| 227 | full manual control, use the @code{-map} option, which disables the defaults just |
| 228 | described. |
| 229 | |
| 230 | @c man end STREAM SELECTION |
| 231 | |
| 232 | @chapter Options |
| 233 | @c man begin OPTIONS |
| 234 | |
| 235 | @include fftools-common-opts.texi |
| 236 | |
| 237 | @section Main options |
| 238 | |
| 239 | @table @option |
| 240 | |
| 241 | @item -f @var{fmt} (@emph{input/output}) |
| 242 | Force input or output file format. The format is normally auto detected for input |
| 243 | files and guessed from the file extension for output files, so this option is not |
| 244 | needed in most cases. |
| 245 | |
| 246 | @item -i @var{url} (@emph{input}) |
| 247 | input file url |
| 248 | |
| 249 | @item -y (@emph{global}) |
| 250 | Overwrite output files without asking. |
| 251 | |
| 252 | @item -n (@emph{global}) |
| 253 | Do not overwrite output files, and exit immediately if a specified |
| 254 | output file already exists. |
| 255 | |
| 256 | @item -stream_loop @var{number} (@emph{input}) |
| 257 | Set number of times input stream shall be looped. Loop 0 means no loop, |
| 258 | loop -1 means infinite loop. |
| 259 | |
| 260 | @item -c[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream}) |
| 261 | @itemx -codec[:@var{stream_specifier}] @var{codec} (@emph{input/output,per-stream}) |
| 262 | Select an encoder (when used before an output file) or a decoder (when used |
| 263 | before an input file) for one or more streams. @var{codec} is the name of a |
| 264 | decoder/encoder or a special value @code{copy} (output only) to indicate that |
| 265 | the stream is not to be re-encoded. |
| 266 | |
| 267 | For example |
| 268 | @example |
| 269 | ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT |
| 270 | @end example |
| 271 | encodes all video streams with libx264 and copies all audio streams. |
| 272 | |
| 273 | For each stream, the last matching @code{c} option is applied, so |
| 274 | @example |
| 275 | ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT |
| 276 | @end example |
| 277 | will copy all the streams except the second video, which will be encoded with |
| 278 | libx264, and the 138th audio, which will be encoded with libvorbis. |
| 279 | |
| 280 | @item -t @var{duration} (@emph{input/output}) |
| 281 | When used as an input option (before @code{-i}), limit the @var{duration} of |
| 282 | data read from the input file. |
| 283 | |
| 284 | When used as an output option (before an output url), stop writing the |
| 285 | output after its duration reaches @var{duration}. |
| 286 | |
| 287 | @var{duration} must be a time duration specification, |
| 288 | see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| 289 | |
| 290 | -to and -t are mutually exclusive and -t has priority. |
| 291 | |
| 292 | @item -to @var{position} (@emph{output}) |
| 293 | Stop writing the output at @var{position}. |
| 294 | @var{position} must be a time duration specification, |
| 295 | see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| 296 | |
| 297 | -to and -t are mutually exclusive and -t has priority. |
| 298 | |
| 299 | @item -fs @var{limit_size} (@emph{output}) |
| 300 | Set the file size limit, expressed in bytes. No further chunk of bytes is written |
| 301 | after the limit is exceeded. The size of the output file is slightly more than the |
| 302 | requested file size. |
| 303 | |
| 304 | @item -ss @var{position} (@emph{input/output}) |
| 305 | When used as an input option (before @code{-i}), seeks in this input file to |
| 306 | @var{position}. Note that in most formats it is not possible to seek exactly, |
| 307 | so @command{ffmpeg} will seek to the closest seek point before @var{position}. |
| 308 | When transcoding and @option{-accurate_seek} is enabled (the default), this |
| 309 | extra segment between the seek point and @var{position} will be decoded and |
| 310 | discarded. When doing stream copy or when @option{-noaccurate_seek} is used, it |
| 311 | will be preserved. |
| 312 | |
| 313 | When used as an output option (before an output url), decodes but discards |
| 314 | input until the timestamps reach @var{position}. |
| 315 | |
| 316 | @var{position} must be a time duration specification, |
| 317 | see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| 318 | |
| 319 | @item -sseof @var{position} (@emph{input/output}) |
| 320 | |
| 321 | Like the @code{-ss} option but relative to the "end of file". That is negative |
| 322 | values are earlier in the file, 0 is at EOF. |
| 323 | |
| 324 | @item -itsoffset @var{offset} (@emph{input}) |
| 325 | Set the input time offset. |
| 326 | |
| 327 | @var{offset} must be a time duration specification, |
| 328 | see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| 329 | |
| 330 | The offset is added to the timestamps of the input files. Specifying |
| 331 | a positive offset means that the corresponding streams are delayed by |
| 332 | the time duration specified in @var{offset}. |
| 333 | |
| 334 | @item -timestamp @var{date} (@emph{output}) |
| 335 | Set the recording timestamp in the container. |
| 336 | |
| 337 | @var{date} must be a date specification, |
| 338 | see @ref{date syntax,,the Date section in the ffmpeg-utils(1) manual,ffmpeg-utils}. |
| 339 | |
| 340 | @item -metadata[:metadata_specifier] @var{key}=@var{value} (@emph{output,per-metadata}) |
| 341 | Set a metadata key/value pair. |
| 342 | |
| 343 | An optional @var{metadata_specifier} may be given to set metadata |
| 344 | on streams, chapters or programs. See @code{-map_metadata} |
| 345 | documentation for details. |
| 346 | |
| 347 | This option overrides metadata set with @code{-map_metadata}. It is |
| 348 | also possible to delete metadata by using an empty value. |
| 349 | |
| 350 | For example, for setting the title in the output file: |
| 351 | @example |
| 352 | ffmpeg -i in.avi -metadata title="my title" out.flv |
| 353 | @end example |
| 354 | |
| 355 | To set the language of the first audio stream: |
| 356 | @example |
| 357 | ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT |
| 358 | @end example |
| 359 | |
| 360 | @item -disposition[:stream_specifier] @var{value} (@emph{output,per-stream}) |
| 361 | Sets the disposition for a stream. |
| 362 | |
| 363 | This option overrides the disposition copied from the input stream. It is also |
| 364 | possible to delete the disposition by setting it to 0. |
| 365 | |
| 366 | The following dispositions are recognized: |
| 367 | @table @option |
| 368 | @item default |
| 369 | @item dub |
| 370 | @item original |
| 371 | @item comment |
| 372 | @item lyrics |
| 373 | @item karaoke |
| 374 | @item forced |
| 375 | @item hearing_impaired |
| 376 | @item visual_impaired |
| 377 | @item clean_effects |
| 378 | @item captions |
| 379 | @item descriptions |
| 380 | @item metadata |
| 381 | @end table |
| 382 | |
| 383 | For example, to make the second audio stream the default stream: |
| 384 | @example |
| 385 | ffmpeg -i in.mkv -disposition:a:1 default out.mkv |
| 386 | @end example |
| 387 | |
| 388 | To make the second subtitle stream the default stream and remove the default |
| 389 | disposition from the first subtitle stream: |
| 390 | @example |
| 391 | ffmpeg -i INPUT -disposition:s:0 0 -disposition:s:1 default OUTPUT |
| 392 | @end example |
| 393 | |
| 394 | @item -program [title=@var{title}:][program_num=@var{program_num}:]st=@var{stream}[:st=@var{stream}...] (@emph{output}) |
| 395 | |
| 396 | Creates a program with the specified @var{title}, @var{program_num} and adds the specified |
| 397 | @var{stream}(s) to it. |
| 398 | |
| 399 | @item -target @var{type} (@emph{output}) |
| 400 | Specify target file type (@code{vcd}, @code{svcd}, @code{dvd}, @code{dv}, |
| 401 | @code{dv50}). @var{type} may be prefixed with @code{pal-}, @code{ntsc-} or |
| 402 | @code{film-} to use the corresponding standard. All the format options |
| 403 | (bitrate, codecs, buffer sizes) are then set automatically. You can just type: |
| 404 | |
| 405 | @example |
| 406 | ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg |
| 407 | @end example |
| 408 | |
| 409 | Nevertheless you can specify additional options as long as you know |
| 410 | they do not conflict with the standard, as in: |
| 411 | |
| 412 | @example |
| 413 | ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg |
| 414 | @end example |
| 415 | |
| 416 | @item -dframes @var{number} (@emph{output}) |
| 417 | Set the number of data frames to output. This is an obsolete alias for |
| 418 | @code{-frames:d}, which you should use instead. |
| 419 | |
| 420 | @item -frames[:@var{stream_specifier}] @var{framecount} (@emph{output,per-stream}) |
| 421 | Stop writing to the stream after @var{framecount} frames. |
| 422 | |
| 423 | @item -q[:@var{stream_specifier}] @var{q} (@emph{output,per-stream}) |
| 424 | @itemx -qscale[:@var{stream_specifier}] @var{q} (@emph{output,per-stream}) |
| 425 | Use fixed quality scale (VBR). The meaning of @var{q}/@var{qscale} is |
| 426 | codec-dependent. |
| 427 | If @var{qscale} is used without a @var{stream_specifier} then it applies only |
| 428 | to the video stream, this is to maintain compatibility with previous behavior |
| 429 | and as specifying the same codec specific value to 2 different codecs that is |
| 430 | audio and video generally is not what is intended when no stream_specifier is |
| 431 | used. |
| 432 | |
| 433 | @anchor{filter_option} |
| 434 | @item -filter[:@var{stream_specifier}] @var{filtergraph} (@emph{output,per-stream}) |
| 435 | Create the filtergraph specified by @var{filtergraph} and use it to |
| 436 | filter the stream. |
| 437 | |
| 438 | @var{filtergraph} is a description of the filtergraph to apply to |
| 439 | the stream, and must have a single input and a single output of the |
| 440 | same type of the stream. In the filtergraph, the input is associated |
| 441 | to the label @code{in}, and the output to the label @code{out}. See |
| 442 | the ffmpeg-filters manual for more information about the filtergraph |
| 443 | syntax. |
| 444 | |
| 445 | See the @ref{filter_complex_option,,-filter_complex option} if you |
| 446 | want to create filtergraphs with multiple inputs and/or outputs. |
| 447 | |
| 448 | @item -filter_script[:@var{stream_specifier}] @var{filename} (@emph{output,per-stream}) |
| 449 | This option is similar to @option{-filter}, the only difference is that its |
| 450 | argument is the name of the file from which a filtergraph description is to be |
| 451 | read. |
| 452 | |
| 453 | @item -filter_threads @var{nb_threads} (@emph{global}) |
| 454 | Defines how many threads are used to process a filter pipeline. Each pipeline |
| 455 | will produce a thread pool with this many threads available for parallel processing. |
| 456 | The default is the number of available CPUs. |
| 457 | |
| 458 | @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream}) |
| 459 | Specify the preset for matching stream(s). |
| 460 | |
| 461 | @item -stats (@emph{global}) |
| 462 | Print encoding progress/statistics. It is on by default, to explicitly |
| 463 | disable it you need to specify @code{-nostats}. |
| 464 | |
| 465 | @item -progress @var{url} (@emph{global}) |
| 466 | Send program-friendly progress information to @var{url}. |
| 467 | |
| 468 | Progress information is written approximately every second and at the end of |
| 469 | the encoding process. It is made of "@var{key}=@var{value}" lines. @var{key} |
| 470 | consists of only alphanumeric characters. The last key of a sequence of |
| 471 | progress information is always "progress". |
| 472 | |
| 473 | @item -stdin |
| 474 | Enable interaction on standard input. On by default unless standard input is |
| 475 | used as an input. To explicitly disable interaction you need to specify |
| 476 | @code{-nostdin}. |
| 477 | |
| 478 | Disabling interaction on standard input is useful, for example, if |
| 479 | ffmpeg is in the background process group. Roughly the same result can |
| 480 | be achieved with @code{ffmpeg ... < /dev/null} but it requires a |
| 481 | shell. |
| 482 | |
| 483 | @item -debug_ts (@emph{global}) |
| 484 | Print timestamp information. It is off by default. This option is |
| 485 | mostly useful for testing and debugging purposes, and the output |
| 486 | format may change from one version to another, so it should not be |
| 487 | employed by portable scripts. |
| 488 | |
| 489 | See also the option @code{-fdebug ts}. |
| 490 | |
| 491 | @item -attach @var{filename} (@emph{output}) |
| 492 | Add an attachment to the output file. This is supported by a few formats |
| 493 | like Matroska for e.g. fonts used in rendering subtitles. Attachments |
| 494 | are implemented as a specific type of stream, so this option will add |
| 495 | a new stream to the file. It is then possible to use per-stream options |
| 496 | on this stream in the usual way. Attachment streams created with this |
| 497 | option will be created after all the other streams (i.e. those created |
| 498 | with @code{-map} or automatic mappings). |
| 499 | |
| 500 | Note that for Matroska you also have to set the mimetype metadata tag: |
| 501 | @example |
| 502 | ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv |
| 503 | @end example |
| 504 | (assuming that the attachment stream will be third in the output file). |
| 505 | |
| 506 | @item -dump_attachment[:@var{stream_specifier}] @var{filename} (@emph{input,per-stream}) |
| 507 | Extract the matching attachment stream into a file named @var{filename}. If |
| 508 | @var{filename} is empty, then the value of the @code{filename} metadata tag |
| 509 | will be used. |
| 510 | |
| 511 | E.g. to extract the first attachment to a file named 'out.ttf': |
| 512 | @example |
| 513 | ffmpeg -dump_attachment:t:0 out.ttf -i INPUT |
| 514 | @end example |
| 515 | To extract all attachments to files determined by the @code{filename} tag: |
| 516 | @example |
| 517 | ffmpeg -dump_attachment:t "" -i INPUT |
| 518 | @end example |
| 519 | |
| 520 | Technical note -- attachments are implemented as codec extradata, so this |
| 521 | option can actually be used to extract extradata from any stream, not just |
| 522 | attachments. |
| 523 | |
| 524 | @item -noautorotate |
| 525 | Disable automatically rotating video based on file metadata. |
| 526 | |
| 527 | @end table |
| 528 | |
| 529 | @section Video Options |
| 530 | |
| 531 | @table @option |
| 532 | @item -vframes @var{number} (@emph{output}) |
| 533 | Set the number of video frames to output. This is an obsolete alias for |
| 534 | @code{-frames:v}, which you should use instead. |
| 535 | @item -r[:@var{stream_specifier}] @var{fps} (@emph{input/output,per-stream}) |
| 536 | Set frame rate (Hz value, fraction or abbreviation). |
| 537 | |
| 538 | As an input option, ignore any timestamps stored in the file and instead |
| 539 | generate timestamps assuming constant frame rate @var{fps}. |
| 540 | This is not the same as the @option{-framerate} option used for some input formats |
| 541 | like image2 or v4l2 (it used to be the same in older versions of FFmpeg). |
| 542 | If in doubt use @option{-framerate} instead of the input option @option{-r}. |
| 543 | |
| 544 | As an output option, duplicate or drop input frames to achieve constant output |
| 545 | frame rate @var{fps}. |
| 546 | |
| 547 | @item -s[:@var{stream_specifier}] @var{size} (@emph{input/output,per-stream}) |
| 548 | Set frame size. |
| 549 | |
| 550 | As an input option, this is a shortcut for the @option{video_size} private |
| 551 | option, recognized by some demuxers for which the frame size is either not |
| 552 | stored in the file or is configurable -- e.g. raw video or video grabbers. |
| 553 | |
| 554 | As an output option, this inserts the @code{scale} video filter to the |
| 555 | @emph{end} of the corresponding filtergraph. Please use the @code{scale} filter |
| 556 | directly to insert it at the beginning or some other place. |
| 557 | |
| 558 | The format is @samp{wxh} (default - same as source). |
| 559 | |
| 560 | @item -aspect[:@var{stream_specifier}] @var{aspect} (@emph{output,per-stream}) |
| 561 | Set the video display aspect ratio specified by @var{aspect}. |
| 562 | |
| 563 | @var{aspect} can be a floating point number string, or a string of the |
| 564 | form @var{num}:@var{den}, where @var{num} and @var{den} are the |
| 565 | numerator and denominator of the aspect ratio. For example "4:3", |
| 566 | "16:9", "1.3333", and "1.7777" are valid argument values. |
| 567 | |
| 568 | If used together with @option{-vcodec copy}, it will affect the aspect ratio |
| 569 | stored at container level, but not the aspect ratio stored in encoded |
| 570 | frames, if it exists. |
| 571 | |
| 572 | @item -vn (@emph{output}) |
| 573 | Disable video recording. |
| 574 | |
| 575 | @item -vcodec @var{codec} (@emph{output}) |
| 576 | Set the video codec. This is an alias for @code{-codec:v}. |
| 577 | |
| 578 | @item -pass[:@var{stream_specifier}] @var{n} (@emph{output,per-stream}) |
| 579 | Select the pass number (1 or 2). It is used to do two-pass |
| 580 | video encoding. The statistics of the video are recorded in the first |
| 581 | pass into a log file (see also the option -passlogfile), |
| 582 | and in the second pass that log file is used to generate the video |
| 583 | at the exact requested bitrate. |
| 584 | On pass 1, you may just deactivate audio and set output to null, |
| 585 | examples for Windows and Unix: |
| 586 | @example |
| 587 | ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL |
| 588 | ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null |
| 589 | @end example |
| 590 | |
| 591 | @item -passlogfile[:@var{stream_specifier}] @var{prefix} (@emph{output,per-stream}) |
| 592 | Set two-pass log file name prefix to @var{prefix}, the default file name |
| 593 | prefix is ``ffmpeg2pass''. The complete file name will be |
| 594 | @file{PREFIX-N.log}, where N is a number specific to the output |
| 595 | stream |
| 596 | |
| 597 | @item -vf @var{filtergraph} (@emph{output}) |
| 598 | Create the filtergraph specified by @var{filtergraph} and use it to |
| 599 | filter the stream. |
| 600 | |
| 601 | This is an alias for @code{-filter:v}, see the @ref{filter_option,,-filter option}. |
| 602 | @end table |
| 603 | |
| 604 | @section Advanced Video options |
| 605 | |
| 606 | @table @option |
| 607 | @item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream}) |
| 608 | Set pixel format. Use @code{-pix_fmts} to show all the supported |
| 609 | pixel formats. |
| 610 | If the selected pixel format can not be selected, ffmpeg will print a |
| 611 | warning and select the best pixel format supported by the encoder. |
| 612 | If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error |
| 613 | if the requested pixel format can not be selected, and automatic conversions |
| 614 | inside filtergraphs are disabled. |
| 615 | If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format |
| 616 | as the input (or graph output) and automatic conversions are disabled. |
| 617 | |
| 618 | @item -sws_flags @var{flags} (@emph{input/output}) |
| 619 | Set SwScaler flags. |
| 620 | @item -vdt @var{n} |
| 621 | Discard threshold. |
| 622 | |
| 623 | @item -rc_override[:@var{stream_specifier}] @var{override} (@emph{output,per-stream}) |
| 624 | Rate control override for specific intervals, formatted as "int,int,int" |
| 625 | list separated with slashes. Two first values are the beginning and |
| 626 | end frame numbers, last one is quantizer to use if positive, or quality |
| 627 | factor if negative. |
| 628 | |
| 629 | @item -ilme |
| 630 | Force interlacing support in encoder (MPEG-2 and MPEG-4 only). |
| 631 | Use this option if your input file is interlaced and you want |
| 632 | to keep the interlaced format for minimum losses. |
| 633 | The alternative is to deinterlace the input stream with |
| 634 | @option{-deinterlace}, but deinterlacing introduces losses. |
| 635 | @item -psnr |
| 636 | Calculate PSNR of compressed frames. |
| 637 | @item -vstats |
| 638 | Dump video coding statistics to @file{vstats_HHMMSS.log}. |
| 639 | @item -vstats_file @var{file} |
| 640 | Dump video coding statistics to @var{file}. |
| 641 | @item -vstats_version @var{file} |
| 642 | Specifies which version of the vstats format to use. Default is 2. |
| 643 | |
| 644 | version = 1 : |
| 645 | |
| 646 | @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} |
| 647 | |
| 648 | version > 1: |
| 649 | |
| 650 | @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} |
| 651 | @item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream}) |
| 652 | top=1/bottom=0/auto=-1 field first |
| 653 | @item -dc @var{precision} |
| 654 | Intra_dc_precision. |
| 655 | @item -vtag @var{fourcc/tag} (@emph{output}) |
| 656 | Force video tag/fourcc. This is an alias for @code{-tag:v}. |
| 657 | @item -qphist (@emph{global}) |
| 658 | Show QP histogram |
| 659 | @item -vbsf @var{bitstream_filter} |
| 660 | Deprecated see -bsf |
| 661 | |
| 662 | @item -force_key_frames[:@var{stream_specifier}] @var{time}[,@var{time}...] (@emph{output,per-stream}) |
| 663 | @item -force_key_frames[:@var{stream_specifier}] expr:@var{expr} (@emph{output,per-stream}) |
| 664 | Force key frames at the specified timestamps, more precisely at the first |
| 665 | frames after each specified time. |
| 666 | |
| 667 | If the argument is prefixed with @code{expr:}, the string @var{expr} |
| 668 | is interpreted like an expression and is evaluated for each frame. A |
| 669 | key frame is forced in case the evaluation is non-zero. |
| 670 | |
| 671 | If one of the times is "@code{chapters}[@var{delta}]", it is expanded into |
| 672 | the time of the beginning of all chapters in the file, shifted by |
| 673 | @var{delta}, expressed as a time in seconds. |
| 674 | This option can be useful to ensure that a seek point is present at a |
| 675 | chapter mark or any other designated place in the output file. |
| 676 | |
| 677 | For example, to insert a key frame at 5 minutes, plus key frames 0.1 second |
| 678 | before the beginning of every chapter: |
| 679 | @example |
| 680 | -force_key_frames 0:05:00,chapters-0.1 |
| 681 | @end example |
| 682 | |
| 683 | The expression in @var{expr} can contain the following constants: |
| 684 | @table @option |
| 685 | @item n |
| 686 | the number of current processed frame, starting from 0 |
| 687 | @item n_forced |
| 688 | the number of forced frames |
| 689 | @item prev_forced_n |
| 690 | the number of the previous forced frame, it is @code{NAN} when no |
| 691 | keyframe was forced yet |
| 692 | @item prev_forced_t |
| 693 | the time of the previous forced frame, it is @code{NAN} when no |
| 694 | keyframe was forced yet |
| 695 | @item t |
| 696 | the time of the current processed frame |
| 697 | @end table |
| 698 | |
| 699 | For example to force a key frame every 5 seconds, you can specify: |
| 700 | @example |
| 701 | -force_key_frames expr:gte(t,n_forced*5) |
| 702 | @end example |
| 703 | |
| 704 | To force a key frame 5 seconds after the time of the last forced one, |
| 705 | starting from second 13: |
| 706 | @example |
| 707 | -force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5)) |
| 708 | @end example |
| 709 | |
| 710 | Note that forcing too many keyframes is very harmful for the lookahead |
| 711 | algorithms of certain encoders: using fixed-GOP options or similar |
| 712 | would be more efficient. |
| 713 | |
| 714 | @item -copyinkf[:@var{stream_specifier}] (@emph{output,per-stream}) |
| 715 | When doing stream copy, copy also non-key frames found at the |
| 716 | beginning. |
| 717 | |
| 718 | @item -hwaccel[:@var{stream_specifier}] @var{hwaccel} (@emph{input,per-stream}) |
| 719 | Use hardware acceleration to decode the matching stream(s). The allowed values |
| 720 | of @var{hwaccel} are: |
| 721 | @table @option |
| 722 | @item none |
| 723 | Do not use any hardware acceleration (the default). |
| 724 | |
| 725 | @item auto |
| 726 | Automatically select the hardware acceleration method. |
| 727 | |
| 728 | @item vda |
| 729 | Use Apple VDA hardware acceleration. |
| 730 | |
| 731 | @item vdpau |
| 732 | Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration. |
| 733 | |
| 734 | @item dxva2 |
| 735 | Use DXVA2 (DirectX Video Acceleration) hardware acceleration. |
| 736 | |
| 737 | @item qsv |
| 738 | Use the Intel QuickSync Video acceleration for video transcoding. |
| 739 | |
| 740 | Unlike most other values, this option does not enable accelerated decoding (that |
| 741 | is used automatically whenever a qsv decoder is selected), but accelerated |
| 742 | transcoding, without copying the frames into the system memory. |
| 743 | |
| 744 | For it to work, both the decoder and the encoder must support QSV acceleration |
| 745 | and no filters must be used. |
| 746 | @end table |
| 747 | |
| 748 | This option has no effect if the selected hwaccel is not available or not |
| 749 | supported by the chosen decoder. |
| 750 | |
| 751 | Note that most acceleration methods are intended for playback and will not be |
| 752 | faster than software decoding on modern CPUs. Additionally, @command{ffmpeg} |
| 753 | will usually need to copy the decoded frames from the GPU memory into the system |
| 754 | memory, resulting in further performance loss. This option is thus mainly |
| 755 | useful for testing. |
| 756 | |
| 757 | @item -hwaccel_device[:@var{stream_specifier}] @var{hwaccel_device} (@emph{input,per-stream}) |
| 758 | Select a device to use for hardware acceleration. |
| 759 | |
| 760 | This option only makes sense when the @option{-hwaccel} option is also |
| 761 | specified. Its exact meaning depends on the specific hardware acceleration |
| 762 | method chosen. |
| 763 | |
| 764 | @table @option |
| 765 | @item vdpau |
| 766 | For VDPAU, this option specifies the X11 display/screen to use. If this option |
| 767 | is not specified, the value of the @var{DISPLAY} environment variable is used |
| 768 | |
| 769 | @item dxva2 |
| 770 | For DXVA2, this option should contain the number of the display adapter to use. |
| 771 | If this option is not specified, the default adapter is used. |
| 772 | |
| 773 | @item qsv |
| 774 | For QSV, this option corresponds to the values of MFX_IMPL_* . Allowed values |
| 775 | are: |
| 776 | @table @option |
| 777 | @item auto |
| 778 | @item sw |
| 779 | @item hw |
| 780 | @item auto_any |
| 781 | @item hw_any |
| 782 | @item hw2 |
| 783 | @item hw3 |
| 784 | @item hw4 |
| 785 | @end table |
| 786 | @end table |
| 787 | |
| 788 | @item -hwaccels |
| 789 | List all hardware acceleration methods supported in this build of ffmpeg. |
| 790 | |
| 791 | @end table |
| 792 | |
| 793 | @section Audio Options |
| 794 | |
| 795 | @table @option |
| 796 | @item -aframes @var{number} (@emph{output}) |
| 797 | Set the number of audio frames to output. This is an obsolete alias for |
| 798 | @code{-frames:a}, which you should use instead. |
| 799 | @item -ar[:@var{stream_specifier}] @var{freq} (@emph{input/output,per-stream}) |
| 800 | Set the audio sampling frequency. For output streams it is set by |
| 801 | default to the frequency of the corresponding input stream. For input |
| 802 | streams this option only makes sense for audio grabbing devices and raw |
| 803 | demuxers and is mapped to the corresponding demuxer options. |
| 804 | @item -aq @var{q} (@emph{output}) |
| 805 | Set the audio quality (codec-specific, VBR). This is an alias for -q:a. |
| 806 | @item -ac[:@var{stream_specifier}] @var{channels} (@emph{input/output,per-stream}) |
| 807 | Set the number of audio channels. For output streams it is set by |
| 808 | default to the number of input audio channels. For input streams |
| 809 | this option only makes sense for audio grabbing devices and raw demuxers |
| 810 | and is mapped to the corresponding demuxer options. |
| 811 | @item -an (@emph{output}) |
| 812 | Disable audio recording. |
| 813 | @item -acodec @var{codec} (@emph{input/output}) |
| 814 | Set the audio codec. This is an alias for @code{-codec:a}. |
| 815 | @item -sample_fmt[:@var{stream_specifier}] @var{sample_fmt} (@emph{output,per-stream}) |
| 816 | Set the audio sample format. Use @code{-sample_fmts} to get a list |
| 817 | of supported sample formats. |
| 818 | |
| 819 | @item -af @var{filtergraph} (@emph{output}) |
| 820 | Create the filtergraph specified by @var{filtergraph} and use it to |
| 821 | filter the stream. |
| 822 | |
| 823 | This is an alias for @code{-filter:a}, see the @ref{filter_option,,-filter option}. |
| 824 | @end table |
| 825 | |
| 826 | @section Advanced Audio options |
| 827 | |
| 828 | @table @option |
| 829 | @item -atag @var{fourcc/tag} (@emph{output}) |
| 830 | Force audio tag/fourcc. This is an alias for @code{-tag:a}. |
| 831 | @item -absf @var{bitstream_filter} |
| 832 | Deprecated, see -bsf |
| 833 | @item -guess_layout_max @var{channels} (@emph{input,per-stream}) |
| 834 | If some input channel layout is not known, try to guess only if it |
| 835 | corresponds to at most the specified number of channels. For example, 2 |
| 836 | tells to @command{ffmpeg} to recognize 1 channel as mono and 2 channels as |
| 837 | stereo but not 6 channels as 5.1. The default is to always try to guess. Use |
| 838 | 0 to disable all guessing. |
| 839 | @end table |
| 840 | |
| 841 | @section Subtitle options |
| 842 | |
| 843 | @table @option |
| 844 | @item -scodec @var{codec} (@emph{input/output}) |
| 845 | Set the subtitle codec. This is an alias for @code{-codec:s}. |
| 846 | @item -sn (@emph{output}) |
| 847 | Disable subtitle recording. |
| 848 | @item -sbsf @var{bitstream_filter} |
| 849 | Deprecated, see -bsf |
| 850 | @end table |
| 851 | |
| 852 | @section Advanced Subtitle options |
| 853 | |
| 854 | @table @option |
| 855 | |
| 856 | @item -fix_sub_duration |
| 857 | Fix subtitles durations. For each subtitle, wait for the next packet in the |
| 858 | same stream and adjust the duration of the first to avoid overlap. This is |
| 859 | necessary with some subtitles codecs, especially DVB subtitles, because the |
| 860 | duration in the original packet is only a rough estimate and the end is |
| 861 | actually marked by an empty subtitle frame. Failing to use this option when |
| 862 | necessary can result in exaggerated durations or muxing failures due to |
| 863 | non-monotonic timestamps. |
| 864 | |
| 865 | Note that this option will delay the output of all data until the next |
| 866 | subtitle packet is decoded: it may increase memory consumption and latency a |
| 867 | lot. |
| 868 | |
| 869 | @item -canvas_size @var{size} |
| 870 | Set the size of the canvas used to render subtitles. |
| 871 | |
| 872 | @end table |
| 873 | |
| 874 | @section Advanced options |
| 875 | |
| 876 | @table @option |
| 877 | @item -map [-]@var{input_file_id}[:@var{stream_specifier}][?][,@var{sync_file_id}[:@var{stream_specifier}]] | @var{[linklabel]} (@emph{output}) |
| 878 | |
| 879 | Designate one or more input streams as a source for the output file. Each input |
| 880 | stream is identified by the input file index @var{input_file_id} and |
| 881 | the input stream index @var{input_stream_id} within the input |
| 882 | file. Both indices start at 0. If specified, |
| 883 | @var{sync_file_id}:@var{stream_specifier} sets which input stream |
| 884 | is used as a presentation sync reference. |
| 885 | |
| 886 | The first @code{-map} option on the command line specifies the |
| 887 | source for output stream 0, the second @code{-map} option specifies |
| 888 | the source for output stream 1, etc. |
| 889 | |
| 890 | A @code{-} character before the stream identifier creates a "negative" mapping. |
| 891 | It disables matching streams from already created mappings. |
| 892 | |
| 893 | A trailing @code{?} after the stream index will allow the map to be |
| 894 | optional: if the map matches no streams the map will be ignored instead |
| 895 | of failing. Note the map will still fail if an invalid input file index |
| 896 | is used; such as if the map refers to a non-existant input. |
| 897 | |
| 898 | An alternative @var{[linklabel]} form will map outputs from complex filter |
| 899 | graphs (see the @option{-filter_complex} option) to the output file. |
| 900 | @var{linklabel} must correspond to a defined output link label in the graph. |
| 901 | |
| 902 | For example, to map ALL streams from the first input file to output |
| 903 | @example |
| 904 | ffmpeg -i INPUT -map 0 output |
| 905 | @end example |
| 906 | |
| 907 | For example, if you have two audio streams in the first input file, |
| 908 | these streams are identified by "0:0" and "0:1". You can use |
| 909 | @code{-map} to select which streams to place in an output file. For |
| 910 | example: |
| 911 | @example |
| 912 | ffmpeg -i INPUT -map 0:1 out.wav |
| 913 | @end example |
| 914 | will map the input stream in @file{INPUT} identified by "0:1" to |
| 915 | the (single) output stream in @file{out.wav}. |
| 916 | |
| 917 | For example, to select the stream with index 2 from input file |
| 918 | @file{a.mov} (specified by the identifier "0:2"), and stream with |
| 919 | index 6 from input @file{b.mov} (specified by the identifier "1:6"), |
| 920 | and copy them to the output file @file{out.mov}: |
| 921 | @example |
| 922 | ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov |
| 923 | @end example |
| 924 | |
| 925 | To select all video and the third audio stream from an input file: |
| 926 | @example |
| 927 | ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT |
| 928 | @end example |
| 929 | |
| 930 | To map all the streams except the second audio, use negative mappings |
| 931 | @example |
| 932 | ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT |
| 933 | @end example |
| 934 | |
| 935 | To map the video and audio streams from the first input, and using the |
| 936 | trailing @code{?}, ignore the audio mapping if no audio streams exist in |
| 937 | the first input: |
| 938 | @example |
| 939 | ffmpeg -i INPUT -map 0:v -map 0:a? OUTPUT |
| 940 | @end example |
| 941 | |
| 942 | To pick the English audio stream: |
| 943 | @example |
| 944 | ffmpeg -i INPUT -map 0:m:language:eng OUTPUT |
| 945 | @end example |
| 946 | |
| 947 | Note that using this option disables the default mappings for this output file. |
| 948 | |
| 949 | @item -ignore_unknown |
| 950 | Ignore input streams with unknown type instead of failing if copying |
| 951 | such streams is attempted. |
| 952 | |
| 953 | @item -copy_unknown |
| 954 | Allow input streams with unknown type to be copied instead of failing if copying |
| 955 | such streams is attempted. |
| 956 | |
| 957 | @item -map_channel [@var{input_file_id}.@var{stream_specifier}.@var{channel_id}|-1][:@var{output_file_id}.@var{stream_specifier}] |
| 958 | Map an audio channel from a given input to an output. If |
| 959 | @var{output_file_id}.@var{stream_specifier} is not set, the audio channel will |
| 960 | be mapped on all the audio streams. |
| 961 | |
| 962 | Using "-1" instead of |
| 963 | @var{input_file_id}.@var{stream_specifier}.@var{channel_id} will map a muted |
| 964 | channel. |
| 965 | |
| 966 | For example, assuming @var{INPUT} is a stereo audio file, you can switch the |
| 967 | two audio channels with the following command: |
| 968 | @example |
| 969 | ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT |
| 970 | @end example |
| 971 | |
| 972 | If you want to mute the first channel and keep the second: |
| 973 | @example |
| 974 | ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT |
| 975 | @end example |
| 976 | |
| 977 | The order of the "-map_channel" option specifies the order of the channels in |
| 978 | the output stream. The output channel layout is guessed from the number of |
| 979 | channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac" |
| 980 | in combination of "-map_channel" makes the channel gain levels to be updated if |
| 981 | input and output channel layouts don't match (for instance two "-map_channel" |
| 982 | options and "-ac 6"). |
| 983 | |
| 984 | You can also extract each channel of an input to specific outputs; the following |
| 985 | command extracts two channels of the @var{INPUT} audio stream (file 0, stream 0) |
| 986 | to the respective @var{OUTPUT_CH0} and @var{OUTPUT_CH1} outputs: |
| 987 | @example |
| 988 | ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1 |
| 989 | @end example |
| 990 | |
| 991 | The following example splits the channels of a stereo input into two separate |
| 992 | streams, which are put into the same output file: |
| 993 | @example |
| 994 | ffmpeg -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 |
| 995 | @end example |
| 996 | |
| 997 | Note that currently each output stream can only contain channels from a single |
| 998 | input stream; you can't for example use "-map_channel" to pick multiple input |
| 999 | audio channels contained in different streams (from the same or different files) |
| 1000 | and merge them into a single output stream. It is therefore not currently |
| 1001 | possible, for example, to turn two separate mono streams into a single stereo |
| 1002 | stream. However splitting a stereo stream into two single channel mono streams |
| 1003 | is possible. |
| 1004 | |
| 1005 | If you need this feature, a possible workaround is to use the @emph{amerge} |
| 1006 | filter. For example, if you need to merge a media (here @file{input.mkv}) with 2 |
| 1007 | mono audio streams into one single stereo channel audio stream (and keep the |
| 1008 | video stream), you can use the following command: |
| 1009 | @example |
| 1010 | ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv |
| 1011 | @end example |
| 1012 | |
| 1013 | @item -map_metadata[:@var{metadata_spec_out}] @var{infile}[:@var{metadata_spec_in}] (@emph{output,per-metadata}) |
| 1014 | Set metadata information of the next output file from @var{infile}. Note that |
| 1015 | those are file indices (zero-based), not filenames. |
| 1016 | Optional @var{metadata_spec_in/out} parameters specify, which metadata to copy. |
| 1017 | A metadata specifier can have the following forms: |
| 1018 | @table @option |
| 1019 | @item @var{g} |
| 1020 | global metadata, i.e. metadata that applies to the whole file |
| 1021 | |
| 1022 | @item @var{s}[:@var{stream_spec}] |
| 1023 | per-stream metadata. @var{stream_spec} is a stream specifier as described |
| 1024 | in the @ref{Stream specifiers} chapter. In an input metadata specifier, the first |
| 1025 | matching stream is copied from. In an output metadata specifier, all matching |
| 1026 | streams are copied to. |
| 1027 | |
| 1028 | @item @var{c}:@var{chapter_index} |
| 1029 | per-chapter metadata. @var{chapter_index} is the zero-based chapter index. |
| 1030 | |
| 1031 | @item @var{p}:@var{program_index} |
| 1032 | per-program metadata. @var{program_index} is the zero-based program index. |
| 1033 | @end table |
| 1034 | If metadata specifier is omitted, it defaults to global. |
| 1035 | |
| 1036 | By default, global metadata is copied from the first input file, |
| 1037 | per-stream and per-chapter metadata is copied along with streams/chapters. These |
| 1038 | default mappings are disabled by creating any mapping of the relevant type. A negative |
| 1039 | file index can be used to create a dummy mapping that just disables automatic copying. |
| 1040 | |
| 1041 | For example to copy metadata from the first stream of the input file to global metadata |
| 1042 | of the output file: |
| 1043 | @example |
| 1044 | ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3 |
| 1045 | @end example |
| 1046 | |
| 1047 | To do the reverse, i.e. copy global metadata to all audio streams: |
| 1048 | @example |
| 1049 | ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv |
| 1050 | @end example |
| 1051 | Note that simple @code{0} would work as well in this example, since global |
| 1052 | metadata is assumed by default. |
| 1053 | |
| 1054 | @item -map_chapters @var{input_file_index} (@emph{output}) |
| 1055 | Copy chapters from input file with index @var{input_file_index} to the next |
| 1056 | output file. If no chapter mapping is specified, then chapters are copied from |
| 1057 | the first input file with at least one chapter. Use a negative file index to |
| 1058 | disable any chapter copying. |
| 1059 | |
| 1060 | @item -benchmark (@emph{global}) |
| 1061 | Show benchmarking information at the end of an encode. |
| 1062 | Shows CPU time used and maximum memory consumption. |
| 1063 | Maximum memory consumption is not supported on all systems, |
| 1064 | it will usually display as 0 if not supported. |
| 1065 | @item -benchmark_all (@emph{global}) |
| 1066 | Show benchmarking information during the encode. |
| 1067 | Shows CPU time used in various steps (audio/video encode/decode). |
| 1068 | @item -timelimit @var{duration} (@emph{global}) |
| 1069 | Exit after ffmpeg has been running for @var{duration} seconds. |
| 1070 | @item -dump (@emph{global}) |
| 1071 | Dump each input packet to stderr. |
| 1072 | @item -hex (@emph{global}) |
| 1073 | When dumping packets, also dump the payload. |
| 1074 | @item -re (@emph{input}) |
| 1075 | Read input at native frame rate. Mainly used to simulate a grab device, |
| 1076 | or live input stream (e.g. when reading from a file). Should not be used |
| 1077 | with actual grab devices or live input streams (where it can cause packet |
| 1078 | loss). |
| 1079 | By default @command{ffmpeg} attempts to read the input(s) as fast as possible. |
| 1080 | This option will slow down the reading of the input(s) to the native frame rate |
| 1081 | of the input(s). It is useful for real-time output (e.g. live streaming). |
| 1082 | @item -loop_input |
| 1083 | Loop over the input stream. Currently it works only for image |
| 1084 | streams. This option is used for automatic FFserver testing. |
| 1085 | This option is deprecated, use -loop 1. |
| 1086 | @item -loop_output @var{number_of_times} |
| 1087 | Repeatedly loop output for formats that support looping such as animated GIF |
| 1088 | (0 will loop the output infinitely). |
| 1089 | This option is deprecated, use -loop. |
| 1090 | @item -vsync @var{parameter} |
| 1091 | Video sync method. |
| 1092 | For compatibility reasons old values can be specified as numbers. |
| 1093 | Newly added values will have to be specified as strings always. |
| 1094 | |
| 1095 | @table @option |
| 1096 | @item 0, passthrough |
| 1097 | Each frame is passed with its timestamp from the demuxer to the muxer. |
| 1098 | @item 1, cfr |
| 1099 | Frames will be duplicated and dropped to achieve exactly the requested |
| 1100 | constant frame rate. |
| 1101 | @item 2, vfr |
| 1102 | Frames are passed through with their timestamp or dropped so as to |
| 1103 | prevent 2 frames from having the same timestamp. |
| 1104 | @item drop |
| 1105 | As passthrough but destroys all timestamps, making the muxer generate |
| 1106 | fresh timestamps based on frame-rate. |
| 1107 | @item -1, auto |
| 1108 | Chooses between 1 and 2 depending on muxer capabilities. This is the |
| 1109 | default method. |
| 1110 | @end table |
| 1111 | |
| 1112 | Note that the timestamps may be further modified by the muxer, after this. |
| 1113 | For example, in the case that the format option @option{avoid_negative_ts} |
| 1114 | is enabled. |
| 1115 | |
| 1116 | With -map you can select from which stream the timestamps should be |
| 1117 | taken. You can leave either video or audio unchanged and sync the |
| 1118 | remaining stream(s) to the unchanged one. |
| 1119 | |
| 1120 | @item -frame_drop_threshold @var{parameter} |
| 1121 | Frame drop threshold, which specifies how much behind video frames can |
| 1122 | be before they are dropped. In frame rate units, so 1.0 is one frame. |
| 1123 | The default is -1.1. One possible usecase is to avoid framedrops in case |
| 1124 | of noisy timestamps or to increase frame drop precision in case of exact |
| 1125 | timestamps. |
| 1126 | |
| 1127 | @item -async @var{samples_per_second} |
| 1128 | Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps, |
| 1129 | the parameter is the maximum samples per second by which the audio is changed. |
| 1130 | -async 1 is a special case where only the start of the audio stream is corrected |
| 1131 | without any later correction. |
| 1132 | |
| 1133 | Note that the timestamps may be further modified by the muxer, after this. |
| 1134 | For example, in the case that the format option @option{avoid_negative_ts} |
| 1135 | is enabled. |
| 1136 | |
| 1137 | This option has been deprecated. Use the @code{aresample} audio filter instead. |
| 1138 | |
| 1139 | @item -copyts |
| 1140 | Do not process input timestamps, but keep their values without trying |
| 1141 | to sanitize them. In particular, do not remove the initial start time |
| 1142 | offset value. |
| 1143 | |
| 1144 | Note that, depending on the @option{vsync} option or on specific muxer |
| 1145 | processing (e.g. in case the format option @option{avoid_negative_ts} |
| 1146 | is enabled) the output timestamps may mismatch with the input |
| 1147 | timestamps even when this option is selected. |
| 1148 | |
| 1149 | @item -start_at_zero |
| 1150 | When used with @option{copyts}, shift input timestamps so they start at zero. |
| 1151 | |
| 1152 | This means that using e.g. @code{-ss 50} will make output timestamps start at |
| 1153 | 50 seconds, regardless of what timestamp the input file started at. |
| 1154 | |
| 1155 | @item -copytb @var{mode} |
| 1156 | Specify how to set the encoder timebase when stream copying. @var{mode} is an |
| 1157 | integer numeric value, and can assume one of the following values: |
| 1158 | |
| 1159 | @table @option |
| 1160 | @item 1 |
| 1161 | Use the demuxer timebase. |
| 1162 | |
| 1163 | The time base is copied to the output encoder from the corresponding input |
| 1164 | demuxer. This is sometimes required to avoid non monotonically increasing |
| 1165 | timestamps when copying video streams with variable frame rate. |
| 1166 | |
| 1167 | @item 0 |
| 1168 | Use the decoder timebase. |
| 1169 | |
| 1170 | The time base is copied to the output encoder from the corresponding input |
| 1171 | decoder. |
| 1172 | |
| 1173 | @item -1 |
| 1174 | Try to make the choice automatically, in order to generate a sane output. |
| 1175 | @end table |
| 1176 | |
| 1177 | Default value is -1. |
| 1178 | |
| 1179 | @item -shortest (@emph{output}) |
| 1180 | Finish encoding when the shortest input stream ends. |
| 1181 | @item -dts_delta_threshold |
| 1182 | Timestamp discontinuity delta threshold. |
| 1183 | @item -muxdelay @var{seconds} (@emph{input}) |
| 1184 | Set the maximum demux-decode delay. |
| 1185 | @item -muxpreload @var{seconds} (@emph{input}) |
| 1186 | Set the initial demux-decode delay. |
| 1187 | @item -streamid @var{output-stream-index}:@var{new-value} (@emph{output}) |
| 1188 | Assign a new stream-id value to an output stream. This option should be |
| 1189 | specified prior to the output filename to which it applies. |
| 1190 | For the situation where multiple output files exist, a streamid |
| 1191 | may be reassigned to a different value. |
| 1192 | |
| 1193 | For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for |
| 1194 | an output mpegts file: |
| 1195 | @example |
| 1196 | ffmpeg -i inurl -streamid 0:33 -streamid 1:36 out.ts |
| 1197 | @end example |
| 1198 | |
| 1199 | @item -bsf[:@var{stream_specifier}] @var{bitstream_filters} (@emph{output,per-stream}) |
| 1200 | Set bitstream filters for matching streams. @var{bitstream_filters} is |
| 1201 | a comma-separated list of bitstream filters. Use the @code{-bsfs} option |
| 1202 | to get the list of bitstream filters. |
| 1203 | @example |
| 1204 | ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264 |
| 1205 | @end example |
| 1206 | @example |
| 1207 | ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt |
| 1208 | @end example |
| 1209 | |
| 1210 | @item -tag[:@var{stream_specifier}] @var{codec_tag} (@emph{input/output,per-stream}) |
| 1211 | Force a tag/fourcc for matching streams. |
| 1212 | |
| 1213 | @item -timecode @var{hh}:@var{mm}:@var{ss}SEP@var{ff} |
| 1214 | Specify Timecode for writing. @var{SEP} is ':' for non drop timecode and ';' |
| 1215 | (or '.') for drop. |
| 1216 | @example |
| 1217 | ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg |
| 1218 | @end example |
| 1219 | |
| 1220 | @anchor{filter_complex_option} |
| 1221 | @item -filter_complex @var{filtergraph} (@emph{global}) |
| 1222 | Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or |
| 1223 | outputs. For simple graphs -- those with one input and one output of the same |
| 1224 | type -- see the @option{-filter} options. @var{filtergraph} is a description of |
| 1225 | the filtergraph, as described in the ``Filtergraph syntax'' section of the |
| 1226 | ffmpeg-filters manual. |
| 1227 | |
| 1228 | Input link labels must refer to input streams using the |
| 1229 | @code{[file_index:stream_specifier]} syntax (i.e. the same as @option{-map} |
| 1230 | uses). If @var{stream_specifier} matches multiple streams, the first one will be |
| 1231 | used. An unlabeled input will be connected to the first unused input stream of |
| 1232 | the matching type. |
| 1233 | |
| 1234 | Output link labels are referred to with @option{-map}. Unlabeled outputs are |
| 1235 | added to the first output file. |
| 1236 | |
| 1237 | Note that with this option it is possible to use only lavfi sources without |
| 1238 | normal input files. |
| 1239 | |
| 1240 | For example, to overlay an image over video |
| 1241 | @example |
| 1242 | ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map |
| 1243 | '[out]' out.mkv |
| 1244 | @end example |
| 1245 | Here @code{[0:v]} refers to the first video stream in the first input file, |
| 1246 | which is linked to the first (main) input of the overlay filter. Similarly the |
| 1247 | first video stream in the second input is linked to the second (overlay) input |
| 1248 | of overlay. |
| 1249 | |
| 1250 | Assuming there is only one video stream in each input file, we can omit input |
| 1251 | labels, so the above is equivalent to |
| 1252 | @example |
| 1253 | ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map |
| 1254 | '[out]' out.mkv |
| 1255 | @end example |
| 1256 | |
| 1257 | Furthermore we can omit the output label and the single output from the filter |
| 1258 | graph will be added to the output file automatically, so we can simply write |
| 1259 | @example |
| 1260 | ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv |
| 1261 | @end example |
| 1262 | |
| 1263 | To generate 5 seconds of pure red video using lavfi @code{color} source: |
| 1264 | @example |
| 1265 | ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv |
| 1266 | @end example |
| 1267 | |
| 1268 | @item -filter_complex_threads @var{nb_threads} (@emph{global}) |
| 1269 | Defines how many threads are used to process a filter_complex graph. |
| 1270 | Similar to filter_threads but used for @code{-filter_complex} graphs only. |
| 1271 | The default is the number of available CPUs. |
| 1272 | |
| 1273 | @item -lavfi @var{filtergraph} (@emph{global}) |
| 1274 | Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or |
| 1275 | outputs. Equivalent to @option{-filter_complex}. |
| 1276 | |
| 1277 | @item -filter_complex_script @var{filename} (@emph{global}) |
| 1278 | This option is similar to @option{-filter_complex}, the only difference is that |
| 1279 | its argument is the name of the file from which a complex filtergraph |
| 1280 | description is to be read. |
| 1281 | |
| 1282 | @item -accurate_seek (@emph{input}) |
| 1283 | This option enables or disables accurate seeking in input files with the |
| 1284 | @option{-ss} option. It is enabled by default, so seeking is accurate when |
| 1285 | transcoding. Use @option{-noaccurate_seek} to disable it, which may be useful |
| 1286 | e.g. when copying some streams and transcoding the others. |
| 1287 | |
| 1288 | @item -seek_timestamp (@emph{input}) |
| 1289 | This option enables or disables seeking by timestamp in input files with the |
| 1290 | @option{-ss} option. It is disabled by default. If enabled, the argument |
| 1291 | to the @option{-ss} option is considered an actual timestamp, and is not |
| 1292 | offset by the start time of the file. This matters only for files which do |
| 1293 | not start from timestamp 0, such as transport streams. |
| 1294 | |
| 1295 | @item -thread_queue_size @var{size} (@emph{input}) |
| 1296 | This option sets the maximum number of queued packets when reading from the |
| 1297 | file or device. With low latency / high rate live streams, packets may be |
| 1298 | discarded if they are not read in a timely manner; raising this value can |
| 1299 | avoid it. |
| 1300 | |
| 1301 | @item -override_ffserver (@emph{global}) |
| 1302 | Overrides the input specifications from @command{ffserver}. Using this |
| 1303 | option you can map any input stream to @command{ffserver} and control |
| 1304 | many aspects of the encoding from @command{ffmpeg}. Without this |
| 1305 | option @command{ffmpeg} will transmit to @command{ffserver} what is |
| 1306 | requested by @command{ffserver}. |
| 1307 | |
| 1308 | The option is intended for cases where features are needed that cannot be |
| 1309 | specified to @command{ffserver} but can be to @command{ffmpeg}. |
| 1310 | |
| 1311 | @item -sdp_file @var{file} (@emph{global}) |
| 1312 | Print sdp information for an output stream to @var{file}. |
| 1313 | This allows dumping sdp information when at least one output isn't an |
| 1314 | rtp stream. (Requires at least one of the output formats to be rtp). |
| 1315 | |
| 1316 | @item -discard (@emph{input}) |
| 1317 | Allows discarding specific streams or frames of streams at the demuxer. |
| 1318 | Not all demuxers support this. |
| 1319 | |
| 1320 | @table @option |
| 1321 | @item none |
| 1322 | Discard no frame. |
| 1323 | |
| 1324 | @item default |
| 1325 | Default, which discards no frames. |
| 1326 | |
| 1327 | @item noref |
| 1328 | Discard all non-reference frames. |
| 1329 | |
| 1330 | @item bidir |
| 1331 | Discard all bidirectional frames. |
| 1332 | |
| 1333 | @item nokey |
| 1334 | Discard all frames excepts keyframes. |
| 1335 | |
| 1336 | @item all |
| 1337 | Discard all frames. |
| 1338 | @end table |
| 1339 | |
| 1340 | @item -abort_on @var{flags} (@emph{global}) |
| 1341 | Stop and abort on various conditions. The following flags are available: |
| 1342 | |
| 1343 | @table @option |
| 1344 | @item empty_output |
| 1345 | No packets were passed to the muxer, the output is empty. |
| 1346 | @end table |
| 1347 | |
| 1348 | @item -xerror (@emph{global}) |
| 1349 | Stop and exit on error |
| 1350 | |
| 1351 | @item -max_muxing_queue_size @var{packets} (@emph{output,per-stream}) |
| 1352 | When transcoding audio and/or video streams, ffmpeg will not begin writing into |
| 1353 | the output until it has one packet for each such stream. While waiting for that |
| 1354 | to happen, packets for other streams are buffered. This option sets the size of |
| 1355 | this buffer, in packets, for the matching output stream. |
| 1356 | |
| 1357 | The default value of this option should be high enough for most uses, so only |
| 1358 | touch this option if you are sure that you need it. |
| 1359 | |
| 1360 | @end table |
| 1361 | |
| 1362 | As a special exception, you can use a bitmap subtitle stream as input: it |
| 1363 | will be converted into a video with the same size as the largest video in |
| 1364 | the file, or 720x576 if no video is present. Note that this is an |
| 1365 | experimental and temporary solution. It will be removed once libavfilter has |
| 1366 | proper support for subtitles. |
| 1367 | |
| 1368 | For example, to hardcode subtitles on top of a DVB-T recording stored in |
| 1369 | MPEG-TS format, delaying the subtitles by 1 second: |
| 1370 | @example |
| 1371 | ffmpeg -i input.ts -filter_complex \ |
| 1372 | '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \ |
| 1373 | -sn -map '#0x2dc' output.mkv |
| 1374 | @end example |
| 1375 | (0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video, |
| 1376 | audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too) |
| 1377 | |
| 1378 | @section Preset files |
| 1379 | A preset file contains a sequence of @var{option}=@var{value} pairs, |
| 1380 | one for each line, specifying a sequence of options which would be |
| 1381 | awkward to specify on the command line. Lines starting with the hash |
| 1382 | ('#') character are ignored and are used to provide comments. Check |
| 1383 | the @file{presets} directory in the FFmpeg source tree for examples. |
| 1384 | |
| 1385 | There are two types of preset files: ffpreset and avpreset files. |
| 1386 | |
| 1387 | @subsection ffpreset files |
| 1388 | ffpreset files are specified with the @code{vpre}, @code{apre}, |
| 1389 | @code{spre}, and @code{fpre} options. The @code{fpre} option takes the |
| 1390 | filename of the preset instead of a preset name as input and can be |
| 1391 | used for any kind of codec. For the @code{vpre}, @code{apre}, and |
| 1392 | @code{spre} options, the options specified in a preset file are |
| 1393 | applied to the currently selected codec of the same type as the preset |
| 1394 | option. |
| 1395 | |
| 1396 | The argument passed to the @code{vpre}, @code{apre}, and @code{spre} |
| 1397 | preset options identifies the preset file to use according to the |
| 1398 | following rules: |
| 1399 | |
| 1400 | First ffmpeg searches for a file named @var{arg}.ffpreset in the |
| 1401 | directories @file{$FFMPEG_DATADIR} (if set), and @file{$HOME/.ffmpeg}, and in |
| 1402 | the datadir defined at configuration time (usually @file{PREFIX/share/ffmpeg}) |
| 1403 | or in a @file{ffpresets} folder along the executable on win32, |
| 1404 | in that order. For example, if the argument is @code{libvpx-1080p}, it will |
| 1405 | search for the file @file{libvpx-1080p.ffpreset}. |
| 1406 | |
| 1407 | If no such file is found, then ffmpeg will search for a file named |
| 1408 | @var{codec_name}-@var{arg}.ffpreset in the above-mentioned |
| 1409 | directories, where @var{codec_name} is the name of the codec to which |
| 1410 | the preset file options will be applied. For example, if you select |
| 1411 | the video codec with @code{-vcodec libvpx} and use @code{-vpre 1080p}, |
| 1412 | then it will search for the file @file{libvpx-1080p.ffpreset}. |
| 1413 | |
| 1414 | @subsection avpreset files |
| 1415 | avpreset files are specified with the @code{pre} option. They work similar to |
| 1416 | ffpreset files, but they only allow encoder- specific options. Therefore, an |
| 1417 | @var{option}=@var{value} pair specifying an encoder cannot be used. |
| 1418 | |
| 1419 | When the @code{pre} option is specified, ffmpeg will look for files with the |
| 1420 | suffix .avpreset in the directories @file{$AVCONV_DATADIR} (if set), and |
| 1421 | @file{$HOME/.avconv}, and in the datadir defined at configuration time (usually |
| 1422 | @file{PREFIX/share/ffmpeg}), in that order. |
| 1423 | |
| 1424 | First ffmpeg searches for a file named @var{codec_name}-@var{arg}.avpreset in |
| 1425 | the above-mentioned directories, where @var{codec_name} is the name of the codec |
| 1426 | to which the preset file options will be applied. For example, if you select the |
| 1427 | video codec with @code{-vcodec libvpx} and use @code{-pre 1080p}, then it will |
| 1428 | search for the file @file{libvpx-1080p.avpreset}. |
| 1429 | |
| 1430 | If no such file is found, then ffmpeg will search for a file named |
| 1431 | @var{arg}.avpreset in the same directories. |
| 1432 | |
| 1433 | @c man end OPTIONS |
| 1434 | |
| 1435 | @chapter Examples |
| 1436 | @c man begin EXAMPLES |
| 1437 | |
| 1438 | @section Video and Audio grabbing |
| 1439 | |
| 1440 | If you specify the input format and device then ffmpeg can grab video |
| 1441 | and audio directly. |
| 1442 | |
| 1443 | @example |
| 1444 | ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg |
| 1445 | @end example |
| 1446 | |
| 1447 | Or with an ALSA audio source (mono input, card id 1) instead of OSS: |
| 1448 | @example |
| 1449 | ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg |
| 1450 | @end example |
| 1451 | |
| 1452 | Note that you must activate the right video source and channel before |
| 1453 | launching ffmpeg with any TV viewer such as |
| 1454 | @uref{http://linux.bytesex.org/xawtv/, xawtv} by Gerd Knorr. You also |
| 1455 | have to set the audio recording levels correctly with a |
| 1456 | standard mixer. |
| 1457 | |
| 1458 | @section X11 grabbing |
| 1459 | |
| 1460 | Grab the X11 display with ffmpeg via |
| 1461 | |
| 1462 | @example |
| 1463 | ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg |
| 1464 | @end example |
| 1465 | |
| 1466 | 0.0 is display.screen number of your X11 server, same as |
| 1467 | the DISPLAY environment variable. |
| 1468 | |
| 1469 | @example |
| 1470 | ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg |
| 1471 | @end example |
| 1472 | |
| 1473 | 0.0 is display.screen number of your X11 server, same as the DISPLAY environment |
| 1474 | variable. 10 is the x-offset and 20 the y-offset for the grabbing. |
| 1475 | |
| 1476 | @section Video and Audio file format conversion |
| 1477 | |
| 1478 | Any supported file format and protocol can serve as input to ffmpeg: |
| 1479 | |
| 1480 | Examples: |
| 1481 | @itemize |
| 1482 | @item |
| 1483 | You can use YUV files as input: |
| 1484 | |
| 1485 | @example |
| 1486 | ffmpeg -i /tmp/test%d.Y /tmp/out.mpg |
| 1487 | @end example |
| 1488 | |
| 1489 | It will use the files: |
| 1490 | @example |
| 1491 | /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V, |
| 1492 | /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc... |
| 1493 | @end example |
| 1494 | |
| 1495 | The Y files use twice the resolution of the U and V files. They are |
| 1496 | raw files, without header. They can be generated by all decent video |
| 1497 | decoders. You must specify the size of the image with the @option{-s} option |
| 1498 | if ffmpeg cannot guess it. |
| 1499 | |
| 1500 | @item |
| 1501 | You can input from a raw YUV420P file: |
| 1502 | |
| 1503 | @example |
| 1504 | ffmpeg -i /tmp/test.yuv /tmp/out.avi |
| 1505 | @end example |
| 1506 | |
| 1507 | test.yuv is a file containing raw YUV planar data. Each frame is composed |
| 1508 | of the Y plane followed by the U and V planes at half vertical and |
| 1509 | horizontal resolution. |
| 1510 | |
| 1511 | @item |
| 1512 | You can output to a raw YUV420P file: |
| 1513 | |
| 1514 | @example |
| 1515 | ffmpeg -i mydivx.avi hugefile.yuv |
| 1516 | @end example |
| 1517 | |
| 1518 | @item |
| 1519 | You can set several input files and output files: |
| 1520 | |
| 1521 | @example |
| 1522 | ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg |
| 1523 | @end example |
| 1524 | |
| 1525 | Converts the audio file a.wav and the raw YUV video file a.yuv |
| 1526 | to MPEG file a.mpg. |
| 1527 | |
| 1528 | @item |
| 1529 | You can also do audio and video conversions at the same time: |
| 1530 | |
| 1531 | @example |
| 1532 | ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2 |
| 1533 | @end example |
| 1534 | |
| 1535 | Converts a.wav to MPEG audio at 22050 Hz sample rate. |
| 1536 | |
| 1537 | @item |
| 1538 | You can encode to several formats at the same time and define a |
| 1539 | mapping from input stream to output streams: |
| 1540 | |
| 1541 | @example |
| 1542 | ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2 |
| 1543 | @end example |
| 1544 | |
| 1545 | Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map |
| 1546 | file:index' specifies which input stream is used for each output |
| 1547 | stream, in the order of the definition of output streams. |
| 1548 | |
| 1549 | @item |
| 1550 | You can transcode decrypted VOBs: |
| 1551 | |
| 1552 | @example |
| 1553 | ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi |
| 1554 | @end example |
| 1555 | |
| 1556 | This is a typical DVD ripping example; the input is a VOB file, the |
| 1557 | output an AVI file with MPEG-4 video and MP3 audio. Note that in this |
| 1558 | command we use B-frames so the MPEG-4 stream is DivX5 compatible, and |
| 1559 | GOP size is 300 which means one intra frame every 10 seconds for 29.97fps |
| 1560 | input video. Furthermore, the audio stream is MP3-encoded so you need |
| 1561 | to enable LAME support by passing @code{--enable-libmp3lame} to configure. |
| 1562 | The mapping is particularly useful for DVD transcoding |
| 1563 | to get the desired audio language. |
| 1564 | |
| 1565 | NOTE: To see the supported input formats, use @code{ffmpeg -demuxers}. |
| 1566 | |
| 1567 | @item |
| 1568 | You can extract images from a video, or create a video from many images: |
| 1569 | |
| 1570 | For extracting images from a video: |
| 1571 | @example |
| 1572 | ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg |
| 1573 | @end example |
| 1574 | |
| 1575 | This will extract one video frame per second from the video and will |
| 1576 | output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg}, |
| 1577 | etc. Images will be rescaled to fit the new WxH values. |
| 1578 | |
| 1579 | If you want to extract just a limited number of frames, you can use the |
| 1580 | above command in combination with the @code{-frames:v} or @code{-t} option, |
| 1581 | or in combination with -ss to start extracting from a certain point in time. |
| 1582 | |
| 1583 | For creating a video from many images: |
| 1584 | @example |
| 1585 | ffmpeg -f image2 -framerate 12 -i foo-%03d.jpeg -s WxH foo.avi |
| 1586 | @end example |
| 1587 | |
| 1588 | The syntax @code{foo-%03d.jpeg} specifies to use a decimal number |
| 1589 | composed of three digits padded with zeroes to express the sequence |
| 1590 | number. It is the same syntax supported by the C printf function, but |
| 1591 | only formats accepting a normal integer are suitable. |
| 1592 | |
| 1593 | When importing an image sequence, -i also supports expanding |
| 1594 | shell-like wildcard patterns (globbing) internally, by selecting the |
| 1595 | image2-specific @code{-pattern_type glob} option. |
| 1596 | |
| 1597 | For example, for creating a video from filenames matching the glob pattern |
| 1598 | @code{foo-*.jpeg}: |
| 1599 | @example |
| 1600 | ffmpeg -f image2 -pattern_type glob -framerate 12 -i 'foo-*.jpeg' -s WxH foo.avi |
| 1601 | @end example |
| 1602 | |
| 1603 | @item |
| 1604 | You can put many streams of the same type in the output: |
| 1605 | |
| 1606 | @example |
| 1607 | ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut |
| 1608 | @end example |
| 1609 | |
| 1610 | The resulting output file @file{test12.nut} will contain the first four streams |
| 1611 | from the input files in reverse order. |
| 1612 | |
| 1613 | @item |
| 1614 | To force CBR video output: |
| 1615 | @example |
| 1616 | ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v |
| 1617 | @end example |
| 1618 | |
| 1619 | @item |
| 1620 | The four options lmin, lmax, mblmin and mblmax use 'lambda' units, |
| 1621 | but you may use the QP2LAMBDA constant to easily convert from 'q' units: |
| 1622 | @example |
| 1623 | ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext |
| 1624 | @end example |
| 1625 | |
| 1626 | @end itemize |
| 1627 | @c man end EXAMPLES |
| 1628 | |
| 1629 | @include config.texi |
| 1630 | @ifset config-all |
| 1631 | @ifset config-avutil |
| 1632 | @include utils.texi |
| 1633 | @end ifset |
| 1634 | @ifset config-avcodec |
| 1635 | @include codecs.texi |
| 1636 | @include bitstream_filters.texi |
| 1637 | @end ifset |
| 1638 | @ifset config-avformat |
| 1639 | @include formats.texi |
| 1640 | @include protocols.texi |
| 1641 | @end ifset |
| 1642 | @ifset config-avdevice |
| 1643 | @include devices.texi |
| 1644 | @end ifset |
| 1645 | @ifset config-swresample |
| 1646 | @include resampler.texi |
| 1647 | @end ifset |
| 1648 | @ifset config-swscale |
| 1649 | @include scaler.texi |
| 1650 | @end ifset |
| 1651 | @ifset config-avfilter |
| 1652 | @include filters.texi |
| 1653 | @end ifset |
| 1654 | @end ifset |
| 1655 | |
| 1656 | @chapter See Also |
| 1657 | |
| 1658 | @ifhtml |
| 1659 | @ifset config-all |
| 1660 | @url{ffmpeg.html,ffmpeg} |
| 1661 | @end ifset |
| 1662 | @ifset config-not-all |
| 1663 | @url{ffmpeg-all.html,ffmpeg-all}, |
| 1664 | @end ifset |
| 1665 | @url{ffplay.html,ffplay}, @url{ffprobe.html,ffprobe}, @url{ffserver.html,ffserver}, |
| 1666 | @url{ffmpeg-utils.html,ffmpeg-utils}, |
| 1667 | @url{ffmpeg-scaler.html,ffmpeg-scaler}, |
| 1668 | @url{ffmpeg-resampler.html,ffmpeg-resampler}, |
| 1669 | @url{ffmpeg-codecs.html,ffmpeg-codecs}, |
| 1670 | @url{ffmpeg-bitstream-filters.html,ffmpeg-bitstream-filters}, |
| 1671 | @url{ffmpeg-formats.html,ffmpeg-formats}, |
| 1672 | @url{ffmpeg-devices.html,ffmpeg-devices}, |
| 1673 | @url{ffmpeg-protocols.html,ffmpeg-protocols}, |
| 1674 | @url{ffmpeg-filters.html,ffmpeg-filters} |
| 1675 | @end ifhtml |
| 1676 | |
| 1677 | @ifnothtml |
| 1678 | @ifset config-all |
| 1679 | ffmpeg(1), |
| 1680 | @end ifset |
| 1681 | @ifset config-not-all |
| 1682 | ffmpeg-all(1), |
| 1683 | @end ifset |
| 1684 | ffplay(1), ffprobe(1), ffserver(1), |
| 1685 | ffmpeg-utils(1), ffmpeg-scaler(1), ffmpeg-resampler(1), |
| 1686 | ffmpeg-codecs(1), ffmpeg-bitstream-filters(1), ffmpeg-formats(1), |
| 1687 | ffmpeg-devices(1), ffmpeg-protocols(1), ffmpeg-filters(1) |
| 1688 | @end ifnothtml |
| 1689 | |
| 1690 | @include authors.texi |
| 1691 | |
| 1692 | @ignore |
| 1693 | |
| 1694 | @setfilename ffmpeg |
| 1695 | @settitle ffmpeg video converter |
| 1696 | |
| 1697 | @end ignore |
| 1698 | |
| 1699 | @bye |
| 1700 |