| 1 | @chapter Muxers |
| 2 | @c man begin MUXERS |
| 3 | |
| 4 | Muxers are configured elements in FFmpeg which allow writing |
| 5 | multimedia streams to a particular type of file. |
| 6 | |
| 7 | When you configure your FFmpeg build, all the supported muxers |
| 8 | are enabled by default. You can list all available muxers using the |
| 9 | configure option @code{--list-muxers}. |
| 10 | |
| 11 | You can disable all the muxers with the configure option |
| 12 | @code{--disable-muxers} and selectively enable / disable single muxers |
| 13 | with the options @code{--enable-muxer=@var{MUXER}} / |
| 14 | @code{--disable-muxer=@var{MUXER}}. |
| 15 | |
| 16 | The option @code{-formats} of the ff* tools will display the list of |
| 17 | enabled muxers. |
| 18 | |
| 19 | A description of some of the currently available muxers follows. |
| 20 | |
| 21 | @anchor{aiff} |
| 22 | @section aiff |
| 23 | |
| 24 | Audio Interchange File Format muxer. |
| 25 | |
| 26 | @subsection Options |
| 27 | |
| 28 | It accepts the following options: |
| 29 | |
| 30 | @table @option |
| 31 | @item write_id3v2 |
| 32 | Enable ID3v2 tags writing when set to 1. Default is 0 (disabled). |
| 33 | |
| 34 | @item id3v2_version |
| 35 | Select ID3v2 version to write. Currently only version 3 and 4 (aka. |
| 36 | ID3v2.3 and ID3v2.4) are supported. The default is version 4. |
| 37 | |
| 38 | @end table |
| 39 | |
| 40 | @anchor{crc} |
| 41 | @section crc |
| 42 | |
| 43 | CRC (Cyclic Redundancy Check) testing format. |
| 44 | |
| 45 | This muxer computes and prints the Adler-32 CRC of all the input audio |
| 46 | and video frames. By default audio frames are converted to signed |
| 47 | 16-bit raw audio and video frames to raw video before computing the |
| 48 | CRC. |
| 49 | |
| 50 | The output of the muxer consists of a single line of the form: |
| 51 | CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to |
| 52 | 8 digits containing the CRC for all the decoded input frames. |
| 53 | |
| 54 | See also the @ref{framecrc} muxer. |
| 55 | |
| 56 | @subsection Examples |
| 57 | |
| 58 | For example to compute the CRC of the input, and store it in the file |
| 59 | @file{out.crc}: |
| 60 | @example |
| 61 | ffmpeg -i INPUT -f crc out.crc |
| 62 | @end example |
| 63 | |
| 64 | You can print the CRC to stdout with the command: |
| 65 | @example |
| 66 | ffmpeg -i INPUT -f crc - |
| 67 | @end example |
| 68 | |
| 69 | You can select the output format of each frame with @command{ffmpeg} by |
| 70 | specifying the audio and video codec and format. For example to |
| 71 | compute the CRC of the input audio converted to PCM unsigned 8-bit |
| 72 | and the input video converted to MPEG-2 video, use the command: |
| 73 | @example |
| 74 | ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc - |
| 75 | @end example |
| 76 | |
| 77 | @anchor{framecrc} |
| 78 | @section framecrc |
| 79 | |
| 80 | Per-packet CRC (Cyclic Redundancy Check) testing format. |
| 81 | |
| 82 | This muxer computes and prints the Adler-32 CRC for each audio |
| 83 | and video packet. By default audio frames are converted to signed |
| 84 | 16-bit raw audio and video frames to raw video before computing the |
| 85 | CRC. |
| 86 | |
| 87 | The output of the muxer consists of a line for each audio and video |
| 88 | packet of the form: |
| 89 | @example |
| 90 | @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, 0x@var{CRC} |
| 91 | @end example |
| 92 | |
| 93 | @var{CRC} is a hexadecimal number 0-padded to 8 digits containing the |
| 94 | CRC of the packet. |
| 95 | |
| 96 | @subsection Examples |
| 97 | |
| 98 | For example to compute the CRC of the audio and video frames in |
| 99 | @file{INPUT}, converted to raw audio and video packets, and store it |
| 100 | in the file @file{out.crc}: |
| 101 | @example |
| 102 | ffmpeg -i INPUT -f framecrc out.crc |
| 103 | @end example |
| 104 | |
| 105 | To print the information to stdout, use the command: |
| 106 | @example |
| 107 | ffmpeg -i INPUT -f framecrc - |
| 108 | @end example |
| 109 | |
| 110 | With @command{ffmpeg}, you can select the output format to which the |
| 111 | audio and video frames are encoded before computing the CRC for each |
| 112 | packet by specifying the audio and video codec. For example, to |
| 113 | compute the CRC of each decoded input audio frame converted to PCM |
| 114 | unsigned 8-bit and of each decoded input video frame converted to |
| 115 | MPEG-2 video, use the command: |
| 116 | @example |
| 117 | ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc - |
| 118 | @end example |
| 119 | |
| 120 | See also the @ref{crc} muxer. |
| 121 | |
| 122 | @anchor{framemd5} |
| 123 | @section framemd5 |
| 124 | |
| 125 | Per-packet MD5 testing format. |
| 126 | |
| 127 | This muxer computes and prints the MD5 hash for each audio |
| 128 | and video packet. By default audio frames are converted to signed |
| 129 | 16-bit raw audio and video frames to raw video before computing the |
| 130 | hash. |
| 131 | |
| 132 | The output of the muxer consists of a line for each audio and video |
| 133 | packet of the form: |
| 134 | @example |
| 135 | @var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{MD5} |
| 136 | @end example |
| 137 | |
| 138 | @var{MD5} is a hexadecimal number representing the computed MD5 hash |
| 139 | for the packet. |
| 140 | |
| 141 | @subsection Examples |
| 142 | |
| 143 | For example to compute the MD5 of the audio and video frames in |
| 144 | @file{INPUT}, converted to raw audio and video packets, and store it |
| 145 | in the file @file{out.md5}: |
| 146 | @example |
| 147 | ffmpeg -i INPUT -f framemd5 out.md5 |
| 148 | @end example |
| 149 | |
| 150 | To print the information to stdout, use the command: |
| 151 | @example |
| 152 | ffmpeg -i INPUT -f framemd5 - |
| 153 | @end example |
| 154 | |
| 155 | See also the @ref{md5} muxer. |
| 156 | |
| 157 | @anchor{gif} |
| 158 | @section gif |
| 159 | |
| 160 | Animated GIF muxer. |
| 161 | |
| 162 | It accepts the following options: |
| 163 | |
| 164 | @table @option |
| 165 | @item loop |
| 166 | Set the number of times to loop the output. Use @code{-1} for no loop, @code{0} |
| 167 | for looping indefinitely (default). |
| 168 | |
| 169 | @item final_delay |
| 170 | Force the delay (expressed in centiseconds) after the last frame. Each frame |
| 171 | ends with a delay until the next frame. The default is @code{-1}, which is a |
| 172 | special value to tell the muxer to re-use the previous delay. In case of a |
| 173 | loop, you might want to customize this value to mark a pause for instance. |
| 174 | @end table |
| 175 | |
| 176 | For example, to encode a gif looping 10 times, with a 5 seconds delay between |
| 177 | the loops: |
| 178 | @example |
| 179 | ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif |
| 180 | @end example |
| 181 | |
| 182 | Note 1: if you wish to extract the frames in separate GIF files, you need to |
| 183 | force the @ref{image2} muxer: |
| 184 | @example |
| 185 | ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif" |
| 186 | @end example |
| 187 | |
| 188 | Note 2: the GIF format has a very small time base: the delay between two frames |
| 189 | can not be smaller than one centi second. |
| 190 | |
| 191 | @anchor{hls} |
| 192 | @section hls |
| 193 | |
| 194 | Apple HTTP Live Streaming muxer that segments MPEG-TS according to |
| 195 | the HTTP Live Streaming (HLS) specification. |
| 196 | |
| 197 | It creates a playlist file, and one or more segment files. The output filename |
| 198 | specifies the playlist filename. |
| 199 | |
| 200 | By default, the muxer creates a file for each segment produced. These files |
| 201 | have the same name as the playlist, followed by a sequential number and a |
| 202 | .ts extension. |
| 203 | |
| 204 | For example, to convert an input file with @command{ffmpeg}: |
| 205 | @example |
| 206 | ffmpeg -i in.nut out.m3u8 |
| 207 | @end example |
| 208 | This example will produce the playlist, @file{out.m3u8}, and segment files: |
| 209 | @file{out0.ts}, @file{out1.ts}, @file{out2.ts}, etc. |
| 210 | |
| 211 | See also the @ref{segment} muxer, which provides a more generic and |
| 212 | flexible implementation of a segmenter, and can be used to perform HLS |
| 213 | segmentation. |
| 214 | |
| 215 | @subsection Options |
| 216 | |
| 217 | This muxer supports the following options: |
| 218 | |
| 219 | @table @option |
| 220 | @item hls_time @var{seconds} |
| 221 | Set the segment length in seconds. Default value is 2. |
| 222 | |
| 223 | @item hls_list_size @var{size} |
| 224 | Set the maximum number of playlist entries. If set to 0 the list file |
| 225 | will contain all the segments. Default value is 5. |
| 226 | |
| 227 | @item hls_ts_options @var{options_list} |
| 228 | Set output format options using a :-separated list of key=value |
| 229 | parameters. Values containing @code{:} special characters must be |
| 230 | escaped. |
| 231 | |
| 232 | @item hls_wrap @var{wrap} |
| 233 | Set the number after which the segment filename number (the number |
| 234 | specified in each segment file) wraps. If set to 0 the number will be |
| 235 | never wrapped. Default value is 0. |
| 236 | |
| 237 | This option is useful to avoid to fill the disk with many segment |
| 238 | files, and limits the maximum number of segment files written to disk |
| 239 | to @var{wrap}. |
| 240 | |
| 241 | @item start_number @var{number} |
| 242 | Start the playlist sequence number from @var{number}. Default value is |
| 243 | 0. |
| 244 | |
| 245 | @item hls_allow_cache @var{allowcache} |
| 246 | Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments. |
| 247 | |
| 248 | @item hls_base_url @var{baseurl} |
| 249 | Append @var{baseurl} to every entry in the playlist. |
| 250 | Useful to generate playlists with absolute paths. |
| 251 | |
| 252 | Note that the playlist sequence number must be unique for each segment |
| 253 | and it is not to be confused with the segment filename sequence number |
| 254 | which can be cyclic, for example if the @option{wrap} option is |
| 255 | specified. |
| 256 | |
| 257 | @item hls_flags single_file |
| 258 | If this flag is set, the muxer will store all segments in a single MPEG-TS |
| 259 | file, and will use byte ranges in the playlist. HLS playlists generated with |
| 260 | this way will have the version number 4. |
| 261 | For example: |
| 262 | @example |
| 263 | ffmpeg -i in.nut -hls_flags single_file out.m3u8 |
| 264 | @end example |
| 265 | Will produce the playlist, @file{out.m3u8}, and a single segment file, |
| 266 | @file{out.ts}. |
| 267 | @end table |
| 268 | |
| 269 | @anchor{ico} |
| 270 | @section ico |
| 271 | |
| 272 | ICO file muxer. |
| 273 | |
| 274 | Microsoft's icon file format (ICO) has some strict limitations that should be noted: |
| 275 | |
| 276 | @itemize |
| 277 | @item |
| 278 | Size cannot exceed 256 pixels in any dimension |
| 279 | |
| 280 | @item |
| 281 | Only BMP and PNG images can be stored |
| 282 | |
| 283 | @item |
| 284 | If a BMP image is used, it must be one of the following pixel formats: |
| 285 | @example |
| 286 | BMP Bit Depth FFmpeg Pixel Format |
| 287 | 1bit pal8 |
| 288 | 4bit pal8 |
| 289 | 8bit pal8 |
| 290 | 16bit rgb555le |
| 291 | 24bit bgr24 |
| 292 | 32bit bgra |
| 293 | @end example |
| 294 | |
| 295 | @item |
| 296 | If a BMP image is used, it must use the BITMAPINFOHEADER DIB header |
| 297 | |
| 298 | @item |
| 299 | If a PNG image is used, it must use the rgba pixel format |
| 300 | @end itemize |
| 301 | |
| 302 | @anchor{image2} |
| 303 | @section image2 |
| 304 | |
| 305 | Image file muxer. |
| 306 | |
| 307 | The image file muxer writes video frames to image files. |
| 308 | |
| 309 | The output filenames are specified by a pattern, which can be used to |
| 310 | produce sequentially numbered series of files. |
| 311 | The pattern may contain the string "%d" or "%0@var{N}d", this string |
| 312 | specifies the position of the characters representing a numbering in |
| 313 | the filenames. If the form "%0@var{N}d" is used, the string |
| 314 | representing the number in each filename is 0-padded to @var{N} |
| 315 | digits. The literal character '%' can be specified in the pattern with |
| 316 | the string "%%". |
| 317 | |
| 318 | If the pattern contains "%d" or "%0@var{N}d", the first filename of |
| 319 | the file list specified will contain the number 1, all the following |
| 320 | numbers will be sequential. |
| 321 | |
| 322 | The pattern may contain a suffix which is used to automatically |
| 323 | determine the format of the image files to write. |
| 324 | |
| 325 | For example the pattern "img-%03d.bmp" will specify a sequence of |
| 326 | filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ..., |
| 327 | @file{img-010.bmp}, etc. |
| 328 | The pattern "img%%-%d.jpg" will specify a sequence of filenames of the |
| 329 | form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg}, |
| 330 | etc. |
| 331 | |
| 332 | @subsection Examples |
| 333 | |
| 334 | The following example shows how to use @command{ffmpeg} for creating a |
| 335 | sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ..., |
| 336 | taking one image every second from the input video: |
| 337 | @example |
| 338 | ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg' |
| 339 | @end example |
| 340 | |
| 341 | Note that with @command{ffmpeg}, if the format is not specified with the |
| 342 | @code{-f} option and the output filename specifies an image file |
| 343 | format, the image2 muxer is automatically selected, so the previous |
| 344 | command can be written as: |
| 345 | @example |
| 346 | ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg' |
| 347 | @end example |
| 348 | |
| 349 | Note also that the pattern must not necessarily contain "%d" or |
| 350 | "%0@var{N}d", for example to create a single image file |
| 351 | @file{img.jpeg} from the input video you can employ the command: |
| 352 | @example |
| 353 | ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg |
| 354 | @end example |
| 355 | |
| 356 | The @option{strftime} option allows you to expand the filename with |
| 357 | date and time information. Check the documentation of |
| 358 | the @code{strftime()} function for the syntax. |
| 359 | |
| 360 | For example to generate image files from the @code{strftime()} |
| 361 | "%Y-%m-%d_%H-%M-%S" pattern, the following @command{ffmpeg} command |
| 362 | can be used: |
| 363 | @example |
| 364 | ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg" |
| 365 | @end example |
| 366 | |
| 367 | @subsection Options |
| 368 | |
| 369 | @table @option |
| 370 | @item start_number |
| 371 | Start the sequence from the specified number. Default value is 1. Must |
| 372 | be a non-negative number. |
| 373 | |
| 374 | @item update |
| 375 | If set to 1, the filename will always be interpreted as just a |
| 376 | filename, not a pattern, and the corresponding file will be continuously |
| 377 | overwritten with new images. Default value is 0. |
| 378 | |
| 379 | @item strftime |
| 380 | If set to 1, expand the filename with date and time information from |
| 381 | @code{strftime()}. Default value is 0. |
| 382 | @end table |
| 383 | |
| 384 | The image muxer supports the .Y.U.V image file format. This format is |
| 385 | special in that that each image frame consists of three files, for |
| 386 | each of the YUV420P components. To read or write this image file format, |
| 387 | specify the name of the '.Y' file. The muxer will automatically open the |
| 388 | '.U' and '.V' files as required. |
| 389 | |
| 390 | @section matroska |
| 391 | |
| 392 | Matroska container muxer. |
| 393 | |
| 394 | This muxer implements the matroska and webm container specs. |
| 395 | |
| 396 | @subsection Metadata |
| 397 | |
| 398 | The recognized metadata settings in this muxer are: |
| 399 | |
| 400 | @table @option |
| 401 | @item title |
| 402 | Set title name provided to a single track. |
| 403 | |
| 404 | @item language |
| 405 | Specify the language of the track in the Matroska languages form. |
| 406 | |
| 407 | The language can be either the 3 letters bibliographic ISO-639-2 (ISO |
| 408 | 639-2/B) form (like "fre" for French), or a language code mixed with a |
| 409 | country code for specialities in languages (like "fre-ca" for Canadian |
| 410 | French). |
| 411 | |
| 412 | @item stereo_mode |
| 413 | Set stereo 3D video layout of two views in a single video track. |
| 414 | |
| 415 | The following values are recognized: |
| 416 | @table @samp |
| 417 | @item mono |
| 418 | video is not stereo |
| 419 | @item left_right |
| 420 | Both views are arranged side by side, Left-eye view is on the left |
| 421 | @item bottom_top |
| 422 | Both views are arranged in top-bottom orientation, Left-eye view is at bottom |
| 423 | @item top_bottom |
| 424 | Both views are arranged in top-bottom orientation, Left-eye view is on top |
| 425 | @item checkerboard_rl |
| 426 | Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first |
| 427 | @item checkerboard_lr |
| 428 | Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first |
| 429 | @item row_interleaved_rl |
| 430 | Each view is constituted by a row based interleaving, Right-eye view is first row |
| 431 | @item row_interleaved_lr |
| 432 | Each view is constituted by a row based interleaving, Left-eye view is first row |
| 433 | @item col_interleaved_rl |
| 434 | Both views are arranged in a column based interleaving manner, Right-eye view is first column |
| 435 | @item col_interleaved_lr |
| 436 | Both views are arranged in a column based interleaving manner, Left-eye view is first column |
| 437 | @item anaglyph_cyan_red |
| 438 | All frames are in anaglyph format viewable through red-cyan filters |
| 439 | @item right_left |
| 440 | Both views are arranged side by side, Right-eye view is on the left |
| 441 | @item anaglyph_green_magenta |
| 442 | All frames are in anaglyph format viewable through green-magenta filters |
| 443 | @item block_lr |
| 444 | Both eyes laced in one Block, Left-eye view is first |
| 445 | @item block_rl |
| 446 | Both eyes laced in one Block, Right-eye view is first |
| 447 | @end table |
| 448 | @end table |
| 449 | |
| 450 | For example a 3D WebM clip can be created using the following command line: |
| 451 | @example |
| 452 | ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm |
| 453 | @end example |
| 454 | |
| 455 | @subsection Options |
| 456 | |
| 457 | This muxer supports the following options: |
| 458 | |
| 459 | @table @option |
| 460 | @item reserve_index_space |
| 461 | By default, this muxer writes the index for seeking (called cues in Matroska |
| 462 | terms) at the end of the file, because it cannot know in advance how much space |
| 463 | to leave for the index at the beginning of the file. However for some use cases |
| 464 | -- e.g. streaming where seeking is possible but slow -- it is useful to put the |
| 465 | index at the beginning of the file. |
| 466 | |
| 467 | If this option is set to a non-zero value, the muxer will reserve a given amount |
| 468 | of space in the file header and then try to write the cues there when the muxing |
| 469 | finishes. If the available space does not suffice, muxing will fail. A safe size |
| 470 | for most use cases should be about 50kB per hour of video. |
| 471 | |
| 472 | Note that cues are only written if the output is seekable and this option will |
| 473 | have no effect if it is not. |
| 474 | @end table |
| 475 | |
| 476 | @anchor{md5} |
| 477 | @section md5 |
| 478 | |
| 479 | MD5 testing format. |
| 480 | |
| 481 | This muxer computes and prints the MD5 hash of all the input audio |
| 482 | and video frames. By default audio frames are converted to signed |
| 483 | 16-bit raw audio and video frames to raw video before computing the |
| 484 | hash. |
| 485 | |
| 486 | The output of the muxer consists of a single line of the form: |
| 487 | MD5=@var{MD5}, where @var{MD5} is a hexadecimal number representing |
| 488 | the computed MD5 hash. |
| 489 | |
| 490 | For example to compute the MD5 hash of the input converted to raw |
| 491 | audio and video, and store it in the file @file{out.md5}: |
| 492 | @example |
| 493 | ffmpeg -i INPUT -f md5 out.md5 |
| 494 | @end example |
| 495 | |
| 496 | You can print the MD5 to stdout with the command: |
| 497 | @example |
| 498 | ffmpeg -i INPUT -f md5 - |
| 499 | @end example |
| 500 | |
| 501 | See also the @ref{framemd5} muxer. |
| 502 | |
| 503 | @section mov, mp4, ismv |
| 504 | |
| 505 | MOV/MP4/ISMV (Smooth Streaming) muxer. |
| 506 | |
| 507 | The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4 |
| 508 | file has all the metadata about all packets stored in one location |
| 509 | (written at the end of the file, it can be moved to the start for |
| 510 | better playback by adding @var{faststart} to the @var{movflags}, or |
| 511 | using the @command{qt-faststart} tool). A fragmented |
| 512 | file consists of a number of fragments, where packets and metadata |
| 513 | about these packets are stored together. Writing a fragmented |
| 514 | file has the advantage that the file is decodable even if the |
| 515 | writing is interrupted (while a normal MOV/MP4 is undecodable if |
| 516 | it is not properly finished), and it requires less memory when writing |
| 517 | very long files (since writing normal MOV/MP4 files stores info about |
| 518 | every single packet in memory until the file is closed). The downside |
| 519 | is that it is less compatible with other applications. |
| 520 | |
| 521 | @subsection Options |
| 522 | |
| 523 | Fragmentation is enabled by setting one of the AVOptions that define |
| 524 | how to cut the file into fragments: |
| 525 | |
| 526 | @table @option |
| 527 | @item -moov_size @var{bytes} |
| 528 | Reserves space for the moov atom at the beginning of the file instead of placing the |
| 529 | moov atom at the end. If the space reserved is insufficient, muxing will fail. |
| 530 | @item -movflags frag_keyframe |
| 531 | Start a new fragment at each video keyframe. |
| 532 | @item -frag_duration @var{duration} |
| 533 | Create fragments that are @var{duration} microseconds long. |
| 534 | @item -frag_size @var{size} |
| 535 | Create fragments that contain up to @var{size} bytes of payload data. |
| 536 | @item -movflags frag_custom |
| 537 | Allow the caller to manually choose when to cut fragments, by |
| 538 | calling @code{av_write_frame(ctx, NULL)} to write a fragment with |
| 539 | the packets written so far. (This is only useful with other |
| 540 | applications integrating libavformat, not from @command{ffmpeg}.) |
| 541 | @item -min_frag_duration @var{duration} |
| 542 | Don't create fragments that are shorter than @var{duration} microseconds long. |
| 543 | @end table |
| 544 | |
| 545 | If more than one condition is specified, fragments are cut when |
| 546 | one of the specified conditions is fulfilled. The exception to this is |
| 547 | @code{-min_frag_duration}, which has to be fulfilled for any of the other |
| 548 | conditions to apply. |
| 549 | |
| 550 | Additionally, the way the output file is written can be adjusted |
| 551 | through a few other options: |
| 552 | |
| 553 | @table @option |
| 554 | @item -movflags empty_moov |
| 555 | Write an initial moov atom directly at the start of the file, without |
| 556 | describing any samples in it. Generally, an mdat/moov pair is written |
| 557 | at the start of the file, as a normal MOV/MP4 file, containing only |
| 558 | a short portion of the file. With this option set, there is no initial |
| 559 | mdat atom, and the moov atom only describes the tracks but has |
| 560 | a zero duration. |
| 561 | |
| 562 | This option is implicitly set when writing ismv (Smooth Streaming) files. |
| 563 | @item -movflags separate_moof |
| 564 | Write a separate moof (movie fragment) atom for each track. Normally, |
| 565 | packets for all tracks are written in a moof atom (which is slightly |
| 566 | more efficient), but with this option set, the muxer writes one moof/mdat |
| 567 | pair for each track, making it easier to separate tracks. |
| 568 | |
| 569 | This option is implicitly set when writing ismv (Smooth Streaming) files. |
| 570 | @item -movflags faststart |
| 571 | Run a second pass moving the index (moov atom) to the beginning of the file. |
| 572 | This operation can take a while, and will not work in various situations such |
| 573 | as fragmented output, thus it is not enabled by default. |
| 574 | @item -movflags rtphint |
| 575 | Add RTP hinting tracks to the output file. |
| 576 | @item -movflags disable_chpl |
| 577 | Disable Nero chapter markers (chpl atom). Normally, both Nero chapters |
| 578 | and a QuickTime chapter track are written to the file. With this option |
| 579 | set, only the QuickTime chapter track will be written. Nero chapters can |
| 580 | cause failures when the file is reprocessed with certain tagging programs, like |
| 581 | mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well. |
| 582 | @item -movflags omit_tfhd_offset |
| 583 | Do not write any absolute base_data_offset in tfhd atoms. This avoids |
| 584 | tying fragments to absolute byte positions in the file/streams. |
| 585 | @item -movflags default_base_moof |
| 586 | Similarly to the omit_tfhd_offset, this flag avoids writing the |
| 587 | absolute base_data_offset field in tfhd atoms, but does so by using |
| 588 | the new default-base-is-moof flag instead. This flag is new from |
| 589 | 14496-12:2012. This may make the fragments easier to parse in certain |
| 590 | circumstances (avoiding basing track fragment location calculations |
| 591 | on the implicit end of the previous track fragment). |
| 592 | @end table |
| 593 | |
| 594 | @subsection Example |
| 595 | |
| 596 | Smooth Streaming content can be pushed in real time to a publishing |
| 597 | point on IIS with this muxer. Example: |
| 598 | @example |
| 599 | ffmpeg -re @var{<normal input/transcoding options>} -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1) |
| 600 | @end example |
| 601 | |
| 602 | @section mp3 |
| 603 | |
| 604 | The MP3 muxer writes a raw MP3 stream with the following optional features: |
| 605 | @itemize @bullet |
| 606 | @item |
| 607 | An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and |
| 608 | 2.4 are supported, the @code{id3v2_version} private option controls which one is |
| 609 | used (3 or 4). Setting @code{id3v2_version} to 0 disables the ID3v2 header |
| 610 | completely. |
| 611 | |
| 612 | The muxer supports writing attached pictures (APIC frames) to the ID3v2 header. |
| 613 | The pictures are supplied to the muxer in form of a video stream with a single |
| 614 | packet. There can be any number of those streams, each will correspond to a |
| 615 | single APIC frame. The stream metadata tags @var{title} and @var{comment} map |
| 616 | to APIC @var{description} and @var{picture type} respectively. See |
| 617 | @url{http://id3.org/id3v2.4.0-frames} for allowed picture types. |
| 618 | |
| 619 | Note that the APIC frames must be written at the beginning, so the muxer will |
| 620 | buffer the audio frames until it gets all the pictures. It is therefore advised |
| 621 | to provide the pictures as soon as possible to avoid excessive buffering. |
| 622 | |
| 623 | @item |
| 624 | A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by |
| 625 | default, but will be written only if the output is seekable. The |
| 626 | @code{write_xing} private option can be used to disable it. The frame contains |
| 627 | various information that may be useful to the decoder, like the audio duration |
| 628 | or encoder delay. |
| 629 | |
| 630 | @item |
| 631 | A legacy ID3v1 tag at the end of the file (disabled by default). It may be |
| 632 | enabled with the @code{write_id3v1} private option, but as its capabilities are |
| 633 | very limited, its usage is not recommended. |
| 634 | @end itemize |
| 635 | |
| 636 | Examples: |
| 637 | |
| 638 | Write an mp3 with an ID3v2.3 header and an ID3v1 footer: |
| 639 | @example |
| 640 | ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3 |
| 641 | @end example |
| 642 | |
| 643 | To attach a picture to an mp3 file select both the audio and the picture stream |
| 644 | with @code{map}: |
| 645 | @example |
| 646 | ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1 |
| 647 | -metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3 |
| 648 | @end example |
| 649 | |
| 650 | Write a "clean" MP3 without any extra features: |
| 651 | @example |
| 652 | ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3 |
| 653 | @end example |
| 654 | |
| 655 | @section mpegts |
| 656 | |
| 657 | MPEG transport stream muxer. |
| 658 | |
| 659 | This muxer implements ISO 13818-1 and part of ETSI EN 300 468. |
| 660 | |
| 661 | The recognized metadata settings in mpegts muxer are @code{service_provider} |
| 662 | and @code{service_name}. If they are not set the default for |
| 663 | @code{service_provider} is "FFmpeg" and the default for |
| 664 | @code{service_name} is "Service01". |
| 665 | |
| 666 | @subsection Options |
| 667 | |
| 668 | The muxer options are: |
| 669 | |
| 670 | @table @option |
| 671 | @item -mpegts_original_network_id @var{number} |
| 672 | Set the original_network_id (default 0x0001). This is unique identifier |
| 673 | of a network in DVB. Its main use is in the unique identification of a |
| 674 | service through the path Original_Network_ID, Transport_Stream_ID. |
| 675 | @item -mpegts_transport_stream_id @var{number} |
| 676 | Set the transport_stream_id (default 0x0001). This identifies a |
| 677 | transponder in DVB. |
| 678 | @item -mpegts_service_id @var{number} |
| 679 | Set the service_id (default 0x0001) also known as program in DVB. |
| 680 | @item -mpegts_pmt_start_pid @var{number} |
| 681 | Set the first PID for PMT (default 0x1000, max 0x1f00). |
| 682 | @item -mpegts_start_pid @var{number} |
| 683 | Set the first PID for data packets (default 0x0100, max 0x0f00). |
| 684 | @item -mpegts_m2ts_mode @var{number} |
| 685 | Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode. |
| 686 | @item -muxrate @var{number} |
| 687 | Set a constant muxrate (default VBR). |
| 688 | @item -pcr_period @var{numer} |
| 689 | Override the default PCR retransmission time (default 20ms), ignored |
| 690 | if variable muxrate is selected. |
| 691 | @item -pes_payload_size @var{number} |
| 692 | Set minimum PES packet payload in bytes. |
| 693 | @item -mpegts_flags @var{flags} |
| 694 | Set flags (see below). |
| 695 | @item -mpegts_copyts @var{number} |
| 696 | Preserve original timestamps, if value is set to 1. Default value is -1, which |
| 697 | results in shifting timestamps so that they start from 0. |
| 698 | @item -tables_version @var{number} |
| 699 | Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively). |
| 700 | This option allows updating stream structure so that standard consumer may |
| 701 | detect the change. To do so, reopen output AVFormatContext (in case of API |
| 702 | usage) or restart ffmpeg instance, cyclically changing tables_version value: |
| 703 | @example |
| 704 | ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111 |
| 705 | ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111 |
| 706 | ... |
| 707 | ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111 |
| 708 | ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111 |
| 709 | ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111 |
| 710 | ... |
| 711 | @end example |
| 712 | @end table |
| 713 | |
| 714 | Option mpegts_flags may take a set of such flags: |
| 715 | |
| 716 | @table @option |
| 717 | @item resend_headers |
| 718 | Reemit PAT/PMT before writing the next packet. |
| 719 | @item latm |
| 720 | Use LATM packetization for AAC. |
| 721 | @end table |
| 722 | |
| 723 | @subsection Example |
| 724 | |
| 725 | @example |
| 726 | ffmpeg -i file.mpg -c copy \ |
| 727 | -mpegts_original_network_id 0x1122 \ |
| 728 | -mpegts_transport_stream_id 0x3344 \ |
| 729 | -mpegts_service_id 0x5566 \ |
| 730 | -mpegts_pmt_start_pid 0x1500 \ |
| 731 | -mpegts_start_pid 0x150 \ |
| 732 | -metadata service_provider="Some provider" \ |
| 733 | -metadata service_name="Some Channel" \ |
| 734 | -y out.ts |
| 735 | @end example |
| 736 | |
| 737 | @section null |
| 738 | |
| 739 | Null muxer. |
| 740 | |
| 741 | This muxer does not generate any output file, it is mainly useful for |
| 742 | testing or benchmarking purposes. |
| 743 | |
| 744 | For example to benchmark decoding with @command{ffmpeg} you can use the |
| 745 | command: |
| 746 | @example |
| 747 | ffmpeg -benchmark -i INPUT -f null out.null |
| 748 | @end example |
| 749 | |
| 750 | Note that the above command does not read or write the @file{out.null} |
| 751 | file, but specifying the output file is required by the @command{ffmpeg} |
| 752 | syntax. |
| 753 | |
| 754 | Alternatively you can write the command as: |
| 755 | @example |
| 756 | ffmpeg -benchmark -i INPUT -f null - |
| 757 | @end example |
| 758 | |
| 759 | @section nut |
| 760 | |
| 761 | @table @option |
| 762 | @item -syncpoints @var{flags} |
| 763 | Change the syncpoint usage in nut: |
| 764 | @table @option |
| 765 | @item @var{default} use the normal low-overhead seeking aids. |
| 766 | @item @var{none} do not use the syncpoints at all, reducing the overhead but making the stream non-seekable; |
| 767 | Use of this option is not recommended, as the resulting files are very damage |
| 768 | sensitive and seeking is not possible. Also in general the overhead from |
| 769 | syncpoints is negligible. Note, -@code{write_index} 0 can be used to disable |
| 770 | all growing data tables, allowing to mux endless streams with limited memory |
| 771 | and wihout these disadvantages. |
| 772 | @item @var{timestamped} extend the syncpoint with a wallclock field. |
| 773 | @end table |
| 774 | The @var{none} and @var{timestamped} flags are experimental. |
| 775 | @item -write_index @var{bool} |
| 776 | Write index at the end, the default is to write an index. |
| 777 | @end table |
| 778 | |
| 779 | @example |
| 780 | ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor |
| 781 | @end example |
| 782 | |
| 783 | @section ogg |
| 784 | |
| 785 | Ogg container muxer. |
| 786 | |
| 787 | @table @option |
| 788 | @item -page_duration @var{duration} |
| 789 | Preferred page duration, in microseconds. The muxer will attempt to create |
| 790 | pages that are approximately @var{duration} microseconds long. This allows the |
| 791 | user to compromise between seek granularity and container overhead. The default |
| 792 | is 1 second. A value of 0 will fill all segments, making pages as large as |
| 793 | possible. A value of 1 will effectively use 1 packet-per-page in most |
| 794 | situations, giving a small seek granularity at the cost of additional container |
| 795 | overhead. |
| 796 | @end table |
| 797 | |
| 798 | @anchor{segment} |
| 799 | @section segment, stream_segment, ssegment |
| 800 | |
| 801 | Basic stream segmenter. |
| 802 | |
| 803 | This muxer outputs streams to a number of separate files of nearly |
| 804 | fixed duration. Output filename pattern can be set in a fashion similar to |
| 805 | @ref{image2}. |
| 806 | |
| 807 | @code{stream_segment} is a variant of the muxer used to write to |
| 808 | streaming output formats, i.e. which do not require global headers, |
| 809 | and is recommended for outputting e.g. to MPEG transport stream segments. |
| 810 | @code{ssegment} is a shorter alias for @code{stream_segment}. |
| 811 | |
| 812 | Every segment starts with a keyframe of the selected reference stream, |
| 813 | which is set through the @option{reference_stream} option. |
| 814 | |
| 815 | Note that if you want accurate splitting for a video file, you need to |
| 816 | make the input key frames correspond to the exact splitting times |
| 817 | expected by the segmenter, or the segment muxer will start the new |
| 818 | segment with the key frame found next after the specified start |
| 819 | time. |
| 820 | |
| 821 | The segment muxer works best with a single constant frame rate video. |
| 822 | |
| 823 | Optionally it can generate a list of the created segments, by setting |
| 824 | the option @var{segment_list}. The list type is specified by the |
| 825 | @var{segment_list_type} option. The entry filenames in the segment |
| 826 | list are set by default to the basename of the corresponding segment |
| 827 | files. |
| 828 | |
| 829 | See also the @ref{hls} muxer, which provides a more specific |
| 830 | implementation for HLS segmentation. |
| 831 | |
| 832 | @subsection Options |
| 833 | |
| 834 | The segment muxer supports the following options: |
| 835 | |
| 836 | @table @option |
| 837 | @item reference_stream @var{specifier} |
| 838 | Set the reference stream, as specified by the string @var{specifier}. |
| 839 | If @var{specifier} is set to @code{auto}, the reference is chosen |
| 840 | automatically. Otherwise it must be a stream specifier (see the ``Stream |
| 841 | specifiers'' chapter in the ffmpeg manual) which specifies the |
| 842 | reference stream. The default value is @code{auto}. |
| 843 | |
| 844 | @item segment_format @var{format} |
| 845 | Override the inner container format, by default it is guessed by the filename |
| 846 | extension. |
| 847 | |
| 848 | @item segment_format_options @var{options_list} |
| 849 | Set output format options using a :-separated list of key=value |
| 850 | parameters. Values containing the @code{:} special character must be |
| 851 | escaped. |
| 852 | |
| 853 | @item segment_list @var{name} |
| 854 | Generate also a listfile named @var{name}. If not specified no |
| 855 | listfile is generated. |
| 856 | |
| 857 | @item segment_list_flags @var{flags} |
| 858 | Set flags affecting the segment list generation. |
| 859 | |
| 860 | It currently supports the following flags: |
| 861 | @table @samp |
| 862 | @item cache |
| 863 | Allow caching (only affects M3U8 list files). |
| 864 | |
| 865 | @item live |
| 866 | Allow live-friendly file generation. |
| 867 | @end table |
| 868 | |
| 869 | @item segment_list_type @var{type} |
| 870 | Select the listing format. |
| 871 | @table @option |
| 872 | @item @var{flat} use a simple flat list of entries. |
| 873 | @item @var{hls} use a m3u8-like structure. |
| 874 | @end table |
| 875 | |
| 876 | @item segment_list_size @var{size} |
| 877 | Update the list file so that it contains at most @var{size} |
| 878 | segments. If 0 the list file will contain all the segments. Default |
| 879 | value is 0. |
| 880 | |
| 881 | @item segment_list_entry_prefix @var{prefix} |
| 882 | Prepend @var{prefix} to each entry. Useful to generate absolute paths. |
| 883 | By default no prefix is applied. |
| 884 | |
| 885 | The following values are recognized: |
| 886 | @table @samp |
| 887 | @item flat |
| 888 | Generate a flat list for the created segments, one segment per line. |
| 889 | |
| 890 | @item csv, ext |
| 891 | Generate a list for the created segments, one segment per line, |
| 892 | each line matching the format (comma-separated values): |
| 893 | @example |
| 894 | @var{segment_filename},@var{segment_start_time},@var{segment_end_time} |
| 895 | @end example |
| 896 | |
| 897 | @var{segment_filename} is the name of the output file generated by the |
| 898 | muxer according to the provided pattern. CSV escaping (according to |
| 899 | RFC4180) is applied if required. |
| 900 | |
| 901 | @var{segment_start_time} and @var{segment_end_time} specify |
| 902 | the segment start and end time expressed in seconds. |
| 903 | |
| 904 | A list file with the suffix @code{".csv"} or @code{".ext"} will |
| 905 | auto-select this format. |
| 906 | |
| 907 | @samp{ext} is deprecated in favor or @samp{csv}. |
| 908 | |
| 909 | @item ffconcat |
| 910 | Generate an ffconcat file for the created segments. The resulting file |
| 911 | can be read using the FFmpeg @ref{concat} demuxer. |
| 912 | |
| 913 | A list file with the suffix @code{".ffcat"} or @code{".ffconcat"} will |
| 914 | auto-select this format. |
| 915 | |
| 916 | @item m3u8 |
| 917 | Generate an extended M3U8 file, version 3, compliant with |
| 918 | @url{http://tools.ietf.org/id/draft-pantos-http-live-streaming}. |
| 919 | |
| 920 | A list file with the suffix @code{".m3u8"} will auto-select this format. |
| 921 | @end table |
| 922 | |
| 923 | If not specified the type is guessed from the list file name suffix. |
| 924 | |
| 925 | @item segment_time @var{time} |
| 926 | Set segment duration to @var{time}, the value must be a duration |
| 927 | specification. Default value is "2". See also the |
| 928 | @option{segment_times} option. |
| 929 | |
| 930 | Note that splitting may not be accurate, unless you force the |
| 931 | reference stream key-frames at the given time. See the introductory |
| 932 | notice and the examples below. |
| 933 | |
| 934 | @item segment_atclocktime @var{1|0} |
| 935 | If set to "1" split at regular clock time intervals starting from 00:00 |
| 936 | o'clock. The @var{time} value specified in @option{segment_time} is |
| 937 | used for setting the length of the splitting interval. |
| 938 | |
| 939 | For example with @option{segment_time} set to "900" this makes it possible |
| 940 | to create files at 12:00 o'clock, 12:15, 12:30, etc. |
| 941 | |
| 942 | Default value is "0". |
| 943 | |
| 944 | @item segment_time_delta @var{delta} |
| 945 | Specify the accuracy time when selecting the start time for a |
| 946 | segment, expressed as a duration specification. Default value is "0". |
| 947 | |
| 948 | When delta is specified a key-frame will start a new segment if its |
| 949 | PTS satisfies the relation: |
| 950 | @example |
| 951 | PTS >= start_time - time_delta |
| 952 | @end example |
| 953 | |
| 954 | This option is useful when splitting video content, which is always |
| 955 | split at GOP boundaries, in case a key frame is found just before the |
| 956 | specified split time. |
| 957 | |
| 958 | In particular may be used in combination with the @file{ffmpeg} option |
| 959 | @var{force_key_frames}. The key frame times specified by |
| 960 | @var{force_key_frames} may not be set accurately because of rounding |
| 961 | issues, with the consequence that a key frame time may result set just |
| 962 | before the specified time. For constant frame rate videos a value of |
| 963 | 1/(2*@var{frame_rate}) should address the worst case mismatch between |
| 964 | the specified time and the time set by @var{force_key_frames}. |
| 965 | |
| 966 | @item segment_times @var{times} |
| 967 | Specify a list of split points. @var{times} contains a list of comma |
| 968 | separated duration specifications, in increasing order. See also |
| 969 | the @option{segment_time} option. |
| 970 | |
| 971 | @item segment_frames @var{frames} |
| 972 | Specify a list of split video frame numbers. @var{frames} contains a |
| 973 | list of comma separated integer numbers, in increasing order. |
| 974 | |
| 975 | This option specifies to start a new segment whenever a reference |
| 976 | stream key frame is found and the sequential number (starting from 0) |
| 977 | of the frame is greater or equal to the next value in the list. |
| 978 | |
| 979 | @item segment_wrap @var{limit} |
| 980 | Wrap around segment index once it reaches @var{limit}. |
| 981 | |
| 982 | @item segment_start_number @var{number} |
| 983 | Set the sequence number of the first segment. Defaults to @code{0}. |
| 984 | |
| 985 | @item reset_timestamps @var{1|0} |
| 986 | Reset timestamps at the begin of each segment, so that each segment |
| 987 | will start with near-zero timestamps. It is meant to ease the playback |
| 988 | of the generated segments. May not work with some combinations of |
| 989 | muxers/codecs. It is set to @code{0} by default. |
| 990 | |
| 991 | @item initial_offset @var{offset} |
| 992 | Specify timestamp offset to apply to the output packet timestamps. The |
| 993 | argument must be a time duration specification, and defaults to 0. |
| 994 | @end table |
| 995 | |
| 996 | @subsection Examples |
| 997 | |
| 998 | @itemize |
| 999 | @item |
| 1000 | Remux the content of file @file{in.mkv} to a list of segments |
| 1001 | @file{out-000.nut}, @file{out-001.nut}, etc., and write the list of |
| 1002 | generated segments to @file{out.list}: |
| 1003 | @example |
| 1004 | ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.list out%03d.nut |
| 1005 | @end example |
| 1006 | |
| 1007 | @item |
| 1008 | Segment input and set output format options for the output segments: |
| 1009 | @example |
| 1010 | ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4 |
| 1011 | @end example |
| 1012 | |
| 1013 | @item |
| 1014 | Segment the input file according to the split points specified by the |
| 1015 | @var{segment_times} option: |
| 1016 | @example |
| 1017 | ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 out%03d.nut |
| 1018 | @end example |
| 1019 | |
| 1020 | @item |
| 1021 | Use the @command{ffmpeg} @option{force_key_frames} |
| 1022 | option to force key frames in the input at the specified location, together |
| 1023 | with the segment option @option{segment_time_delta} to account for |
| 1024 | possible roundings operated when setting key frame times. |
| 1025 | @example |
| 1026 | ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \ |
| 1027 | -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut |
| 1028 | @end example |
| 1029 | In order to force key frames on the input file, transcoding is |
| 1030 | required. |
| 1031 | |
| 1032 | @item |
| 1033 | Segment the input file by splitting the input file according to the |
| 1034 | frame numbers sequence specified with the @option{segment_frames} option: |
| 1035 | @example |
| 1036 | ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut |
| 1037 | @end example |
| 1038 | |
| 1039 | @item |
| 1040 | Convert the @file{in.mkv} to TS segments using the @code{libx264} |
| 1041 | and @code{libfaac} encoders: |
| 1042 | @example |
| 1043 | ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a libfaac -f ssegment -segment_list out.list out%03d.ts |
| 1044 | @end example |
| 1045 | |
| 1046 | @item |
| 1047 | Segment the input file, and create an M3U8 live playlist (can be used |
| 1048 | as live HLS source): |
| 1049 | @example |
| 1050 | ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \ |
| 1051 | -segment_list_flags +live -segment_time 10 out%03d.mkv |
| 1052 | @end example |
| 1053 | @end itemize |
| 1054 | |
| 1055 | @section smoothstreaming |
| 1056 | |
| 1057 | Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server. |
| 1058 | |
| 1059 | @table @option |
| 1060 | @item window_size |
| 1061 | Specify the number of fragments kept in the manifest. Default 0 (keep all). |
| 1062 | |
| 1063 | @item extra_window_size |
| 1064 | Specify the number of fragments kept outside of the manifest before removing from disk. Default 5. |
| 1065 | |
| 1066 | @item lookahead_count |
| 1067 | Specify the number of lookahead fragments. Default 2. |
| 1068 | |
| 1069 | @item min_frag_duration |
| 1070 | Specify the minimum fragment duration (in microseconds). Default 5000000. |
| 1071 | |
| 1072 | @item remove_at_exit |
| 1073 | Specify whether to remove all fragments when finished. Default 0 (do not remove). |
| 1074 | |
| 1075 | @end table |
| 1076 | |
| 1077 | @section tee |
| 1078 | |
| 1079 | The tee muxer can be used to write the same data to several files or any |
| 1080 | other kind of muxer. It can be used, for example, to both stream a video to |
| 1081 | the network and save it to disk at the same time. |
| 1082 | |
| 1083 | It is different from specifying several outputs to the @command{ffmpeg} |
| 1084 | command-line tool because the audio and video data will be encoded only once |
| 1085 | with the tee muxer; encoding can be a very expensive process. It is not |
| 1086 | useful when using the libavformat API directly because it is then possible |
| 1087 | to feed the same packets to several muxers directly. |
| 1088 | |
| 1089 | The slave outputs are specified in the file name given to the muxer, |
| 1090 | separated by '|'. If any of the slave name contains the '|' separator, |
| 1091 | leading or trailing spaces or any special character, it must be |
| 1092 | escaped (see @ref{quoting_and_escaping,,the "Quoting and escaping" |
| 1093 | section in the ffmpeg-utils(1) manual,ffmpeg-utils}). |
| 1094 | |
| 1095 | Muxer options can be specified for each slave by prepending them as a list of |
| 1096 | @var{key}=@var{value} pairs separated by ':', between square brackets. If |
| 1097 | the options values contain a special character or the ':' separator, they |
| 1098 | must be escaped; note that this is a second level escaping. |
| 1099 | |
| 1100 | The following special options are also recognized: |
| 1101 | @table @option |
| 1102 | @item f |
| 1103 | Specify the format name. Useful if it cannot be guessed from the |
| 1104 | output name suffix. |
| 1105 | |
| 1106 | @item bsfs[/@var{spec}] |
| 1107 | Specify a list of bitstream filters to apply to the specified |
| 1108 | output. |
| 1109 | |
| 1110 | It is possible to specify to which streams a given bitstream filter |
| 1111 | applies, by appending a stream specifier to the option separated by |
| 1112 | @code{/}. @var{spec} must be a stream specifier (see @ref{Format |
| 1113 | stream specifiers}). If the stream specifier is not specified, the |
| 1114 | bitstream filters will be applied to all streams in the output. |
| 1115 | |
| 1116 | Several bitstream filters can be specified, separated by ",". |
| 1117 | |
| 1118 | @item select |
| 1119 | Select the streams that should be mapped to the slave output, |
| 1120 | specified by a stream specifier. If not specified, this defaults to |
| 1121 | all the input streams. |
| 1122 | @end table |
| 1123 | |
| 1124 | @subsection Examples |
| 1125 | |
| 1126 | @itemize |
| 1127 | @item |
| 1128 | Encode something and both archive it in a WebM file and stream it |
| 1129 | as MPEG-TS over UDP (the streams need to be explicitly mapped): |
| 1130 | @example |
| 1131 | ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a |
| 1132 | "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/" |
| 1133 | @end example |
| 1134 | |
| 1135 | @item |
| 1136 | Use @command{ffmpeg} to encode the input, and send the output |
| 1137 | to three different destinations. The @code{dump_extra} bitstream |
| 1138 | filter is used to add extradata information to all the output video |
| 1139 | keyframes packets, as requested by the MPEG-TS format. The select |
| 1140 | option is applied to @file{out.aac} in order to make it contain only |
| 1141 | audio packets. |
| 1142 | @example |
| 1143 | ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental |
| 1144 | -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac" |
| 1145 | @end example |
| 1146 | |
| 1147 | @item |
| 1148 | As below, but select only stream @code{a:1} for the audio output. Note |
| 1149 | that a second level escaping must be performed, as ":" is a special |
| 1150 | character used to separate options. |
| 1151 | @example |
| 1152 | ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental |
| 1153 | -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac" |
| 1154 | @end example |
| 1155 | @end itemize |
| 1156 | |
| 1157 | Note: some codecs may need different options depending on the output format; |
| 1158 | the auto-detection of this can not work with the tee muxer. The main example |
| 1159 | is the @option{global_header} flag. |
| 1160 | |
| 1161 | @section webm_dash_manifest |
| 1162 | |
| 1163 | WebM DASH Manifest muxer. |
| 1164 | |
| 1165 | This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML. |
| 1166 | |
| 1167 | @subsection Options |
| 1168 | |
| 1169 | This muxer supports the following options: |
| 1170 | |
| 1171 | @table @option |
| 1172 | @item adaptation_sets |
| 1173 | This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the |
| 1174 | unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding |
| 1175 | audio and video streams. Any number of adaptation sets can be added using this option. |
| 1176 | @end table |
| 1177 | |
| 1178 | @subsection Example |
| 1179 | @example |
| 1180 | ffmpeg -f webm_dash_manifest -i video1.webm \ |
| 1181 | -f webm_dash_manifest -i video2.webm \ |
| 1182 | -f webm_dash_manifest -i audio1.webm \ |
| 1183 | -f webm_dash_manifest -i audio2.webm \ |
| 1184 | -map 0 -map 1 -map 2 -map 3 \ |
| 1185 | -c copy \ |
| 1186 | -f webm_dash_manifest \ |
| 1187 | -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \ |
| 1188 | manifest.xml |
| 1189 | @end example |
| 1190 | |
| 1191 | @c man end MUXERS |