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   8 <H1>FFmpeg Documentation</H1>
   9 <P>
  10 <P><HR><P>
  11 <H1>Table of Contents</H1>
  12 <UL>
  13 <LI><A NAME="TOC1" HREF="ffmpeg-doc.html#SEC1">1. Introduction</A>
  14 <LI><A NAME="TOC2" HREF="ffmpeg-doc.html#SEC2">2. Quick Start</A>
  15 <UL>
  16 <LI><A NAME="TOC3" HREF="ffmpeg-doc.html#SEC3">2.1 Video and Audio grabbing</A>
  17 <LI><A NAME="TOC4" HREF="ffmpeg-doc.html#SEC4">2.2 Video and Audio file format convertion</A>
  18 </UL>
  19 <LI><A NAME="TOC5" HREF="ffmpeg-doc.html#SEC5">3. Invocation</A>
  20 <UL>
  21 <LI><A NAME="TOC6" HREF="ffmpeg-doc.html#SEC6">3.1 Syntax</A>
  22 <LI><A NAME="TOC7" HREF="ffmpeg-doc.html#SEC7">3.2 Main options</A>
  23 <LI><A NAME="TOC8" HREF="ffmpeg-doc.html#SEC8">3.3 Video Options</A>
  24 <LI><A NAME="TOC9" HREF="ffmpeg-doc.html#SEC9">3.4 Audio Options</A>
  25 <LI><A NAME="TOC10" HREF="ffmpeg-doc.html#SEC10">3.5 Advanced options</A>
  26 <LI><A NAME="TOC11" HREF="ffmpeg-doc.html#SEC11">3.6 Protocols</A>
  27 </UL>
  28 <LI><A NAME="TOC12" HREF="ffmpeg-doc.html#SEC12">4. Tips</A>
  29 <LI><A NAME="TOC13" HREF="ffmpeg-doc.html#SEC13">5. Supported File Formats and Codecs</A>
  30 <UL>
  31 <LI><A NAME="TOC14" HREF="ffmpeg-doc.html#SEC14">5.1 File Formats</A>
  32 <LI><A NAME="TOC15" HREF="ffmpeg-doc.html#SEC15">5.2 Video Codecs</A>
  33 <LI><A NAME="TOC16" HREF="ffmpeg-doc.html#SEC16">5.3 Audio Codecs</A>
  34 </UL>
  35 <LI><A NAME="TOC17" HREF="ffmpeg-doc.html#SEC17">6. Platform Specific information</A>
  36 <UL>
  37 <LI><A NAME="TOC18" HREF="ffmpeg-doc.html#SEC18">6.1 Linux</A>
  38 <LI><A NAME="TOC19" HREF="ffmpeg-doc.html#SEC19">6.2 BSD</A>
  39 <LI><A NAME="TOC20" HREF="ffmpeg-doc.html#SEC20">6.3 Windows</A>
  40 <LI><A NAME="TOC21" HREF="ffmpeg-doc.html#SEC21">6.4 MacOS X</A>
  41 <LI><A NAME="TOC22" HREF="ffmpeg-doc.html#SEC22">6.5 BeOS</A>
  42 </UL>
  43 <LI><A NAME="TOC23" HREF="ffmpeg-doc.html#SEC23">7. Developpers Guide</A>
  44 <UL>
  45 <LI><A NAME="TOC24" HREF="ffmpeg-doc.html#SEC24">7.1 API</A>
  46 <LI><A NAME="TOC25" HREF="ffmpeg-doc.html#SEC25">7.2 Integrating libavcodec or libavformat in your program</A>
  47 <LI><A NAME="TOC26" HREF="ffmpeg-doc.html#SEC26">7.3 Coding Rules</A>
  48 <LI><A NAME="TOC27" HREF="ffmpeg-doc.html#SEC27">7.4 Submitting patches</A>
  49 <LI><A NAME="TOC28" HREF="ffmpeg-doc.html#SEC28">7.5 Regression tests</A>
  50 </UL>
  51 </UL>
  52 <P><HR><P>
  53
  54 <P>
  55 FFmpeg Documentation
  56
  57
  58
  59
  60 <H1><A NAME="SEC1" HREF="ffmpeg-doc.html#TOC1">1. Introduction</A></H1>
  61
  62 <P>
  63 FFmpeg is a very fast video and audio converter. It can also grab from
  64 a live audio/video source.
  65
  66 The command line interface is designed to be intuitive, in the sense
  67 that ffmpeg tries to figure out all the parameters, when
  68 possible. You have usually to give only the target bitrate you want.
  69
  70
  71 <P>
  72 FFmpeg can also convert from any sample rate to any other, and resize
  73 video on the fly with a high quality polyphase filter.
  74
  75
  76
  77
  78 <H1><A NAME="SEC2" HREF="ffmpeg-doc.html#TOC2">2. Quick Start</A></H1>
  79
  80
  81
  82 <H2><A NAME="SEC3" HREF="ffmpeg-doc.html#TOC3">2.1 Video and Audio grabbing</A></H2>
  83
  84 <P>
  85  FFmpeg can use a video4linux compatible video source and any Open Sound
  86   System audio source:
  87
  88 <PRE>
  89   ffmpeg /tmp/out.mpg
  90 </PRE>
  91
  92 <P>
  93   Note that you must activate the right video source and channel
  94   before launching ffmpeg. You can use any TV viewer such as xawtv by
  95   Gerd Knorr which I find very good. You must also set correctly the
  96   audio recording levels with a standard mixer.
  97
  98
  99
 100
 101 <H2><A NAME="SEC4" HREF="ffmpeg-doc.html#TOC4">2.2 Video and Audio file format convertion</A></H2>
 102
 103 <P>
 104 * ffmpeg can use any supported file format and protocol as input:
 105
 106
 107 <P>
 108 Examples:
 109
 110
 111 <P>
 112 * You can input from YUV files:
 113
 114
 115
 116 <PRE>
 117   ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
 118 </PRE>
 119
 120 <P>
 121   It will use the files:
 122
 123 <PRE>
 124        /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
 125        /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
 126 </PRE>
 127
 128 <P>
 129   The Y files use twice the resolution of the U and V files. They are
 130   raw files, without header. They can be generated by all decent video
 131   decoders. You must specify the size of the image with the '-s' option
 132   if ffmpeg cannot guess it.
 133
 134
 135 <P>
 136 * You can input from a RAW YUV420P file:
 137
 138
 139
 140 <PRE>
 141   ffmpeg -i /tmp/test.yuv /tmp/out.avi
 142 </PRE>
 143
 144 <P>
 145   The RAW YUV420P is a file containing RAW YUV planar, for each frame first
 146   come the Y plane followed by U and V planes, which are half vertical and
 147   horizontal resolution.
 148
 149
 150 <P>
 151 * You can output to a RAW YUV420P file:
 152
 153
 154
 155 <PRE>
 156   ffmpeg -i mydivx.avi -o hugefile.yuv
 157 </PRE>
 158
 159 <P>
 160 * You can set several input files and output files:
 161
 162
 163
 164 <PRE>
 165   ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
 166 </PRE>
 167
 168 <P>
 169   Convert the audio file a.wav and the raw yuv video file a.yuv
 170   to mpeg file a.mpg
 171
 172
 173 <P>
 174 * You can also do audio and video convertions at the same time:
 175
 176
 177
 178 <PRE>
 179   ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
 180 </PRE>
 181
 182 <P>
 183   Convert the sample rate of a.wav to 22050 Hz and encode it to MPEG audio.
 184
 185
 186 <P>
 187 * You can encode to several formats at the same time and define a
 188   mapping from input stream to output streams:
 189
 190
 191
 192 <PRE>
 193   ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
 194 </PRE>
 195
 196 <P>
 197   Convert a.wav to a.mp2 at 64 kbits and b.mp2 at 128 kbits. '-map
 198   file:index' specify which input stream is used for each output
 199   stream, in the order of the definition of output streams.
 200
 201
 202 <P>
 203 * You can transcode decrypted VOBs
 204
 205
 206
 207 <PRE>
 208   ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
 209 </PRE>
 210
 211 <P>
 212   This is a typicall DVD ripper example, input from a VOB file, output
 213   to an AVI file with MPEG-4 video and MP3 audio, note that in this
 214   command we use B frames so the MPEG-4 stream is DivX5 compatible, GOP
 215   size is 300 that means an INTRA frame every 10 seconds for 29.97 fps
 216   input video.  Also the audio stream is MP3 encoded so you need LAME
 217   support which is enabled using <CODE>--enable-mp3lame</CODE> when
 218   configuring.  The mapping is particullary usefull for DVD transcoding
 219   to get the desired audio language.
 220
 221
 222 <P>
 223   NOTE: to see the supported input formats, use <CODE>ffmpeg -formats</CODE>.
 224
 225
 226
 227
 228 <H1><A NAME="SEC5" HREF="ffmpeg-doc.html#TOC5">3. Invocation</A></H1>
 229
 230
 231
 232 <H2><A NAME="SEC6" HREF="ffmpeg-doc.html#TOC6">3.1 Syntax</A></H2>
 233
 234 <P>
 235  The generic syntax is:
 236
 237
 238
 239 <PRE>
 240   ffmpeg [[options][-i input_file]]... {[options] output_file}...
 241 </PRE>
 242
 243 <P>
 244   If no input file is given, audio/video grabbing is done.
 245
 246
 247 <P>
 248   As a general rule, options are applied to the next specified
 249   file. For example, if you give the '-b 64' option, it sets the video
 250   bitrate of the next file. Format option may be needed for raw input
 251   files.
 252
 253
 254 <P>
 255   By default, ffmpeg tries to convert as losslessly as possible: it
 256   uses the same audio and video parameter fors the outputs as the one
 257   specified for the inputs.
 258
 259
 260
 261
 262 <H2><A NAME="SEC7" HREF="ffmpeg-doc.html#TOC7">3.2 Main options</A></H2>
 263
 264 <DL COMPACT>
 265
 266 <DT><SAMP>`-L'</SAMP>
 267 <DD>
 268 show license
 269 <DT><SAMP>`-h'</SAMP>
 270 <DD>
 271                   show help
 272 <DT><SAMP>`-formats'</SAMP>
 273 <DD>
 274 show available formats, codecs, protocols, ...
 275 <DT><SAMP>`-f fmt'</SAMP>
 276 <DD>
 277 force format
 278 <DT><SAMP>`-i filename'</SAMP>
 279 <DD>
 280 input file name
 281
 282 <DT><SAMP>`-y'</SAMP>
 283 <DD>
 284 overwrite output files
 285
 286 <DT><SAMP>`-t duration'</SAMP>
 287 <DD>
 288 set the recording time in seconds. <CODE>hh:mm:ss[.xxx]</CODE> syntax is also
 289 supported.
 290
 291 <DT><SAMP>`-title string'</SAMP>
 292 <DD>
 293 set the title
 294
 295 <DT><SAMP>`-author string'</SAMP>
 296 <DD>
 297 set the author
 298
 299 <DT><SAMP>`-copyright string'</SAMP>
 300 <DD>
 301 set the copyright
 302
 303 <DT><SAMP>`-comment string'</SAMP>
 304 <DD>
 305 set the comment
 306
 307 <DT><SAMP>`-b bitrate'</SAMP>
 308 <DD>
 309 set video bitrate (in kbit/s)
 310 </DL>
 311
 312
 313
 314 <H2><A NAME="SEC8" HREF="ffmpeg-doc.html#TOC8">3.3 Video Options</A></H2>
 315
 316 <DL COMPACT>
 317
 318 <DT><SAMP>`-s size'</SAMP>
 319 <DD>
 320 set frame size                       [160x128]
 321 <DT><SAMP>`-r fps'</SAMP>
 322 <DD>
 323 set frame rate                       [25]
 324 <DT><SAMP>`-b bitrate'</SAMP>
 325 <DD>
 326 set the video bitrate in kbit/s      [200]
 327 <DT><SAMP>`-vn'</SAMP>
 328 <DD>
 329 disable video recording              [no]
 330 <DT><SAMP>`-bt tolerance'</SAMP>
 331 <DD>
 332 set video bitrate tolerance (in kbit/s)
 333 <DT><SAMP>`-sameq'</SAMP>
 334 <DD>
 335 use same video quality as source (implies VBR)
 336
 337 <DT><SAMP>`-pass n'</SAMP>
 338 <DD>
 339 select the pass number (1 or 2). It is useful to do two pass encoding. The statistics of the video are recorded in the first pass and the video at the exact requested bit rate is generated in the second pass.
 340
 341 <DT><SAMP>`-passlogfile file'</SAMP>
 342 <DD>
 343 select two pass log file name
 344
 345 </DL>
 346
 347
 348
 349 <H2><A NAME="SEC9" HREF="ffmpeg-doc.html#TOC9">3.4 Audio Options</A></H2>
 350
 351 <DL COMPACT>
 352
 353 <DT><SAMP>`-ab bitrate'</SAMP>
 354 <DD>
 355 set audio bitrate (in kbit/s)
 356 <DT><SAMP>`-ar freq'</SAMP>
 357 <DD>
 358  set the audio sampling freq          [44100]
 359 <DT><SAMP>`-ab bitrate'</SAMP>
 360 <DD>
 361  set the audio bitrate in kbit/s      [64]
 362 <DT><SAMP>`-ac channels'</SAMP>
 363 <DD>
 364  set the number of audio channels     [1]
 365 <DT><SAMP>`-an'</SAMP>
 366 <DD>
 367  disable audio recording              [no]
 368 </DL>
 369
 370
 371
 372 <H2><A NAME="SEC10" HREF="ffmpeg-doc.html#TOC10">3.5 Advanced options</A></H2>
 373
 374 <DL COMPACT>
 375
 376 <DT><SAMP>`-map file:stream'</SAMP>
 377 <DD>
 378 set input stream mapping
 379 <DT><SAMP>`-g gop_size'</SAMP>
 380 <DD>
 381 set the group of picture size
 382 <DT><SAMP>`-intra'</SAMP>
 383 <DD>
 384 use only intra frames
 385 <DT><SAMP>`-qscale q'</SAMP>
 386 <DD>
 387 use fixed video quantiser scale (VBR)
 388 <DT><SAMP>`-qmin q'</SAMP>
 389 <DD>
 390 min video quantiser scale (VBR)
 391 <DT><SAMP>`-qmax q'</SAMP>
 392 <DD>
 393 max video quantiser scale (VBR)
 394 <DT><SAMP>`-qdiff q'</SAMP>
 395 <DD>
 396 max difference between the quantiser scale (VBR)
 397 <DT><SAMP>`-qblur blur'</SAMP>
 398 <DD>
 399 video quantiser scale blur (VBR)
 400 <DT><SAMP>`-qcomp compression'</SAMP>
 401 <DD>
 402 video quantiser scale compression (VBR)
 403 <DT><SAMP>`-vd device'</SAMP>
 404 <DD>
 405 set video device
 406 <DT><SAMP>`-vcodec codec'</SAMP>
 407 <DD>
 408 force video codec
 409 <DT><SAMP>`-me method'</SAMP>
 410 <DD>
 411 set motion estimation method
 412 <DT><SAMP>`-bf frames'</SAMP>
 413 <DD>
 414 use 'frames' B frames (only MPEG-4)
 415 <DT><SAMP>`-hq'</SAMP>
 416 <DD>
 417 activate high quality settings
 418 <DT><SAMP>`-4mv'</SAMP>
 419 <DD>
 420 use four motion vector by macroblock (only MPEG-4)
 421 <DT><SAMP>`-ad device'</SAMP>
 422 <DD>
 423 set audio device
 424 <DT><SAMP>`-acodec codec'</SAMP>
 425 <DD>
 426 force audio codec
 427 <DT><SAMP>`-deinterlace'</SAMP>
 428 <DD>
 429 deinterlace pictures
 430 <DT><SAMP>`-benchmark'</SAMP>
 431 <DD>
 432 add timings for benchmarking
 433 <DT><SAMP>`-hex'</SAMP>
 434 <DD>
 435 dump each input packet
 436 <DT><SAMP>`-psnr'</SAMP>
 437 <DD>
 438 calculate PSNR of compressed frames
 439 <DT><SAMP>`-vstats'</SAMP>
 440 <DD>
 441 dump video coding statistics to file
 442 </DL>
 443
 444
 445
 446 <H2><A NAME="SEC11" HREF="ffmpeg-doc.html#TOC11">3.6 Protocols</A></H2>
 447
 448 <P>
 449 The filename can be <TT>`-'</TT> to read from the standard input or to write
 450 to the standard output.
 451
 452
 453 <P>
 454 ffmpeg handles also many protocols specified with the URL syntax.
 455
 456
 457 <P>
 458  Use 'ffmpeg -formats' to have a list of the supported protocols.
 459
 460
 461 <P>
 462  The protocol <CODE>http:</CODE> is currently used only to communicate with
 463  ffserver (see the ffserver documentation). When ffmpeg will be a
 464  video player it will also be used for streaming :-)
 465
 466
 467
 468
 469 <H1><A NAME="SEC12" HREF="ffmpeg-doc.html#TOC12">4. Tips</A></H1>
 470
 471
 472 <UL>
 473 <LI>For streaming at very low bit rate application, use a low frame rate
 474
 475   and a small gop size. This is especially true for real video where
 476   the Linux player does not seem to be very fast, so it can miss
 477   frames. An example is:
 478
 479
 480 <PRE>
 481   ffmpeg -g 3 -r 3 -t 10 -b 50 -s qcif -f rv10 /tmp/b.rm
 482 </PRE>
 483
 484 <LI>The parameter 'q' which is displayed while encoding is the current
 485
 486   quantizer. The value of 1 indicates that a very good quality could
 487   be achieved. The value of 31 indicates the worst quality. If q=31
 488   too often, it means that the encoder cannot compress enough to meet
 489   your bit rate. You must either increase the bit rate, decrease the
 490   frame rate or decrease the frame size.
 491
 492 <LI>If your computer is not fast enough, you can speed up the
 493
 494   compression at the expense of the compression ratio. You can use
 495   '-me zero' to speed up motion estimation, and '-intra' to disable
 496   completly motion estimation (you have only I frames, which means it
 497   is about as good as JPEG compression).
 498
 499 <LI>To have very low bitrates in audio, reduce the sampling frequency
 500
 501   (down to 22050 kHz for mpeg audio, 22050 or 11025 for ac3).
 502
 503 <LI>To have a constant quality (but a variable bitrate), use the option
 504
 505   '-qscale n' when 'n' is between 1 (excellent quality) and 31 (worst
 506   quality).
 507
 508 <LI>When converting video files, you can use the '-sameq' option which
 509
 510   uses in the encoder the same quality factor than in the decoder. It
 511   allows to be almost lossless in encoding.
 512
 513 </UL>
 514
 515
 516
 517 <H1><A NAME="SEC13" HREF="ffmpeg-doc.html#TOC13">5. Supported File Formats and Codecs</A></H1>
 518
 519 <P>
 520 You can use the <CODE>-formats</CODE> option to have an exhaustive list.
 521
 522
 523
 524
 525 <H2><A NAME="SEC14" HREF="ffmpeg-doc.html#TOC14">5.1 File Formats</A></H2>
 526
 527 <P>
 528 FFmpeg supports the following file formats thru the <CODE>libavformat</CODE>
 529 library.
 530
 531
 532 <TABLE BORDER>
 533
 534 <TR><TD>Supported File Format </TD><TD> Encoding </TD><TD> Decoding </TD><TD> Comments</TD>
 535
 536 </TR>
 537 <TR><TD>MPEG audio </TD><TD> X </TD><TD> X</TD>
 538
 539 </TR>
 540 <TR><TD>MPEG1 systems </TD><TD> X  </TD><TD>  X</TD>
 541
 542 </TD><TD> muxed audio and video
 543 </TR>
 544 <TR><TD>MPEG2 PS </TD><TD> X  </TD><TD>  X</TD>
 545
 546 </TD><TD> also known as <CODE>VOB</CODE> file
 547 </TR>
 548 <TR><TD>MPEG2 TS </TD><TD>    </TD><TD>  X</TD>
 549
 550 </TD><TD> also known as DVB Transport Stream
 551 </TR>
 552 <TR><TD>ASF</TD><TD> X </TD><TD> X</TD>
 553
 554 </TR>
 555 <TR><TD>AVI</TD><TD> X </TD><TD> X</TD>
 556
 557 </TR>
 558 <TR><TD>WAV</TD><TD> X </TD><TD> X</TD>
 559
 560 </TR>
 561 <TR><TD>Macromedia Flash</TD><TD> X </TD><TD> X</TD>
 562
 563 </TD><TD> Only embedded audio is decoded
 564 </TR>
 565 <TR><TD>Real Audio and Video </TD><TD> X </TD><TD> X</TD>
 566
 567 </TR>
 568 <TR><TD>PGM, YUV, PPM, JPEG images </TD><TD> X </TD><TD> X</TD>
 569
 570 </TR>
 571 <TR><TD>Animated GIF </TD><TD> X </TD><TD></TD>
 572
 573 </TD><TD> Only uncompressed GIFs are generated
 574 </TR>
 575 <TR><TD>Raw AC3 </TD><TD> X  </TD><TD>  X</TD>
 576
 577 </TR>
 578 <TR><TD>Raw MJPEG </TD><TD> X  </TD><TD>  X</TD>
 579
 580 </TR>
 581 <TR><TD>Raw MPEG video </TD><TD> X  </TD><TD>  X</TD>
 582
 583 </TR>
 584 <TR><TD>Raw PCM8/16 bits, mulaw/Alaw</TD><TD> X  </TD><TD>  X</TD>
 585
 586 </TR>
 587 <TR><TD>SUN AU format </TD><TD> X  </TD><TD>  X</TD>
 588
 589 </TR>
 590 <TR><TD>Quicktime        </TD><TD>   </TD><TD>  X</TD>
 591
 592 </TR>
 593 <TR><TD>MPEG4            </TD><TD>  </TD><TD>  X</TD>
 594
 595 </TD><TD> MPEG4 is a variant of Quicktime
 596 </TR>
 597 <TR><TD>Raw MPEG4 video  </TD><TD>  </TD><TD>  X</TD>
 598
 599 </TD><TD> Only small files are supported.
 600 </TR>
 601 <TR><TD>DV               </TD><TD>  </TD><TD> X</TD>
 602
 603 </TD><TD> Only the video track is decoded.
 604 </TR></TABLE>
 605
 606 <P>
 607 <CODE>X</CODE> means that the encoding (resp. decoding) is supported.
 608
 609
 610
 611
 612 <H2><A NAME="SEC15" HREF="ffmpeg-doc.html#TOC15">5.2 Video Codecs</A></H2>
 613
 614 <TABLE BORDER>
 615
 616 <TR><TD>Supported Codec </TD><TD> Encoding </TD><TD> Decoding </TD><TD> Comments</TD>
 617
 618 </TR>
 619 <TR><TD>MPEG1 video            </TD><TD>  X  </TD><TD>  X</TD>
 620
 621 </TR>
 622 <TR><TD>MPEG2 video            </TD><TD>     </TD><TD>  X</TD>
 623
 624 </TR>
 625 <TR><TD>MPEG4                  </TD><TD>  X  </TD><TD>  X </TD><TD> Also known as DIVX4/5</TD>
 626
 627 </TR>
 628 <TR><TD>MSMPEG4 V1             </TD><TD>  X  </TD><TD>  X</TD>
 629
 630 </TR>
 631 <TR><TD>MSMPEG4 V2             </TD><TD>  X  </TD><TD>  X</TD>
 632
 633 </TR>
 634 <TR><TD>MSMPEG4 V3             </TD><TD>  X  </TD><TD>  X </TD><TD> Also known as DIVX3</TD>
 635
 636 </TR>
 637 <TR><TD>WMV7                   </TD><TD>  X  </TD><TD>  X</TD>
 638
 639 </TR>
 640 <TR><TD>H263(+)                </TD><TD>  X  </TD><TD>  X </TD><TD> Also known as Real Video 1.0</TD>
 641
 642 </TR>
 643 <TR><TD>MJPEG                  </TD><TD>  X  </TD><TD>  X</TD>
 644
 645 </TR>
 646 <TR><TD>DV                     </TD><TD>     </TD><TD>  X</TD>
 647
 648 </TR>
 649 <TR><TD>Huff YUV               </TD><TD>  X  </TD><TD>  X</TD>
 650
 651 </TR></TABLE>
 652
 653 <P>
 654 <CODE>X</CODE> means that the encoding (resp. decoding) is supported.
 655
 656
 657 <P>
 658 Check at <A HREF="http://www.mplayerhq.hu/~michael/codec-features.html">http://www.mplayerhq.hu/~michael/codec-features.html</A> to
 659 get a precise comparison of FFmpeg MPEG4 codec compared to the other
 660 solutions.
 661
 662
 663
 664
 665 <H2><A NAME="SEC16" HREF="ffmpeg-doc.html#TOC16">5.3 Audio Codecs</A></H2>
 666
 667 <TABLE BORDER>
 668
 669 <TR><TD>Supported Codec </TD><TD> Encoding </TD><TD> Decoding </TD><TD> Comments</TD>
 670
 671 </TR>
 672 <TR><TD>MPEG audio layer 2     </TD><TD>  IX  </TD><TD>  IX</TD>
 673
 674 </TR>
 675 <TR><TD>MPEG audio layer 1/3   </TD><TD> IX   </TD><TD>  IX</TD>
 676
 677 </TD><TD> MP3 encoding is supported thru the external library LAME
 678 </TR>
 679 <TR><TD>AC3                    </TD><TD>  IX  </TD><TD>  X</TD>
 680
 681 </TD><TD> liba52 is used internally for decoding.
 682 </TR>
 683 <TR><TD>Vorbis                 </TD><TD>  X   </TD><TD></TD>
 684
 685 </TD><TD> encoding is supported thru the external library libvorbis.
 686 </TR>
 687 <TR><TD>WMA V1/V2              </TD><TD>      </TD><TD> X</TD>
 688
 689 </TR></TABLE>
 690
 691 <P>
 692 <CODE>X</CODE> means that the encoding (resp. decoding) is supported.
 693
 694
 695 <P>
 696 <CODE>I</CODE> means that an integer only version is available too (ensures highest
 697 performances on systems without hardware floating point support).
 698
 699
 700
 701
 702 <H1><A NAME="SEC17" HREF="ffmpeg-doc.html#TOC17">6. Platform Specific information</A></H1>
 703
 704
 705
 706 <H2><A NAME="SEC18" HREF="ffmpeg-doc.html#TOC18">6.1 Linux</A></H2>
 707
 708 <P>
 709 ffmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the
 710 prefered compiler now for ffmpeg. All futur optimizations will depend on
 711 features only found in GCC 3.2.
 712
 713
 714
 715
 716 <H2><A NAME="SEC19" HREF="ffmpeg-doc.html#TOC19">6.2 BSD</A></H2>
 717
 718
 719
 720 <H2><A NAME="SEC20" HREF="ffmpeg-doc.html#TOC20">6.3 Windows</A></H2>
 721
 722
 723
 724 <H2><A NAME="SEC21" HREF="ffmpeg-doc.html#TOC21">6.4 MacOS X</A></H2>
 725
 726
 727
 728 <H2><A NAME="SEC22" HREF="ffmpeg-doc.html#TOC22">6.5 BeOS</A></H2>
 729
 730 <P>
 731 The configure script should guess the configuration itself.
 732 Networking support is currently not finished.
 733 errno issues fixed by Andrew Bachmann.
 734
 735
 736 <P>
 737 Old stuff:
 738
 739
 740 <P>
 741 François Revol - revol at free dot fr - April 2002
 742
 743
 744 <P>
 745 The configure script should guess the configuration itself,
 746 however I still didn't tested building on net_server version of BeOS.
 747
 748
 749 <P>
 750 ffserver is broken (needs poll() implementation).
 751
 752
 753 <P>
 754 There is still issues with errno codes, which are negative in BeOs, and
 755 that ffmpeg negates when returning. This ends up turning errors into
 756 valid results, then crashes.
 757 (To be fixed)
 758
 759
 760
 761
 762 <H1><A NAME="SEC23" HREF="ffmpeg-doc.html#TOC23">7. Developpers Guide</A></H1>
 763
 764
 765
 766 <H2><A NAME="SEC24" HREF="ffmpeg-doc.html#TOC24">7.1 API</A></H2>
 767
 768 <UL>
 769 <LI>libavcodec is the library containing the codecs (both encoding and
 770
 771   decoding). See <TT>`libavcodec/apiexample.c'</TT> to see how to use it.
 772
 773 <LI>libavformat is the library containing the file formats handling (mux and
 774
 775   demux code for several formats). (no example yet, the API is likely to
 776   evolve).
 777 </UL>
 778
 779
 780
 781 <H2><A NAME="SEC25" HREF="ffmpeg-doc.html#TOC25">7.2 Integrating libavcodec or libavformat in your program</A></H2>
 782
 783 <P>
 784 You can integrate all the source code of the libraries to link them
 785 statically to avoid any version problem. All you need is to provide a
 786 'config.mak' and a 'config.h' in the parent directory. See the defines
 787 generated by ./configure to understand what is needed.
 788
 789
 790 <P>
 791 You can use libavcodec or libavformat in your commercial program, but
 792 <EM>any patch you make must be published</EM>. The best way to proceed is
 793 to send your patches to the ffmpeg mailing list.
 794
 795
 796
 797
 798 <H2><A NAME="SEC26" HREF="ffmpeg-doc.html#TOC26">7.3 Coding Rules</A></H2>
 799
 800 <P>
 801 ffmpeg is programmed in ANSI C language. GCC extensions are
 802 tolerated. Indent size is 4. The TAB character should not be used.
 803
 804
 805 <P>
 806 The presentation is the one specified by 'indent -i4 -kr'.
 807
 808
 809 <P>
 810 Main priority in ffmpeg is simplicity and small code size (=less
 811 bugs).
 812
 813
 814 <P>
 815 Comments: for functions visible from other modules, use the JavaDoc
 816 format (see examples in <TT>`libav/utils.c'</TT>) so that a documentation
 817 can be generated automatically.
 818
 819
 820
 821
 822 <H2><A NAME="SEC27" HREF="ffmpeg-doc.html#TOC27">7.4 Submitting patches</A></H2>
 823
 824 <P>
 825 When you submit your patch, try to send a unified diff (diff '-u'
 826 option). I cannot read other diffs :-)
 827
 828
 829 <P>
 830 Run the regression tests before submitting a patch so that you can
 831 verify that there is no big problems.
 832
 833
 834 <P>
 835 Except if your patch is really big and adds an important feature, by
 836 submitting it to me, you accept implicitely to put it under my
 837 copyright. I prefer to do this to avoid potential problems if
 838 licensing of ffmpeg changes.
 839
 840
 841 <P>
 842 Patches should be posted as base64 encoded attachments (or any other
 843 encoding which ensures that the patch wont be trashed during
 844 transmission) to the ffmpeg-devel mailinglist, see
 845 <A HREF="http://lists.sourceforge.net/lists/listinfo/ffmpeg-devel">http://lists.sourceforge.net/lists/listinfo/ffmpeg-devel</A>
 846
 847
 848
 849
 850 <H2><A NAME="SEC28" HREF="ffmpeg-doc.html#TOC28">7.5 Regression tests</A></H2>
 851
 852 <P>
 853 Before submitting a patch (or commiting with CVS), you should at least
 854 test that you did not break anything.
 855
 856
 857 <P>
 858 The regression test build a synthetic video stream and a synthetic
 859 audio stream. Then there are encoded then decoded with all codecs or
 860 formats. The CRC (or MD5) of each generated file is recorded in a
 861 result file. Then a 'diff' is launched with the reference results and
 862 the result file.
 863
 864
 865 <P>
 866 Run 'make test' to test all the codecs.
 867
 868
 869 <P>
 870 Run 'make libavtest' to test all the codecs.
 871
 872
 873 <P>
 874 [Of course, some patches may change the regression tests results. In
 875 this case, the regression tests reference results shall be modified
 876 accordingly].
 877
 878
 879 <P><HR><P>
 880 This document was generated on 19 November 2002 using
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