@c man begin EXAMPLES
@section Video and Audio grabbing
-FFmpeg can use a video4linux compatible video source and any Open Sound
-System audio source:
+FFmpeg can grab video and audio from devices given that you specify the input
+format and device.
@example
-ffmpeg /tmp/out.mpg
+ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
@end example
Note that you must activate the right video source and channel before
FFmpeg can grab the X11 display.
@example
-ffmpeg -f x11grab -vd x11:0.0 /tmp/out.mpg
+ffmpeg -f x11grab -s cif -i :0.0 /tmp/out.mpg
@end example
0.0 is display.screen number of your X11 server, same as
the DISPLAY environment variable.
@example
-ffmpeg -f x11grab -vd x11:0.0+10,20 /tmp/out.mpg
+ffmpeg -f x11grab -s cif -i :0.0+10,20 /tmp/out.mpg
@end example
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
mapping from input stream to output streams:
@example
-ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
+ffmpeg -i /tmp/a.wav -ab 64k /tmp/a.mp2 -ab 128k /tmp/b.mp2 -map 0:0 -map 0:0
@end example
Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. '-map
* You can transcode decrypted VOBs
@example
-ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
+ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800k -g 300 -bf 2 -acodec libmp3lame -ab 128k snatch.avi
@end example
This is a typical DVD ripping example; the input is a VOB file, the
command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
input video. Furthermore, the audio stream is MP3-encoded so you need
-to enable LAME support by passing @code{--enable-mp3lame} to configure.
+to enable LAME support by passing @code{--enable-libmp3lame} to configure.
The mapping is particularly useful for DVD transcoding
to get the desired audio language.
@c man end
@end example
@c man begin DESCRIPTION
-If no input file is given, audio/video grabbing is done.
-
As a general rule, options are applied to the next specified
file. Therefore, order is important, and you can have the same
option on the command line multiple times. Each occurrence is
Overwrite output files.
@item -t duration
-Set the recording time in seconds.
+Restrict the transcoded/captured video sequence
+to the duration specified in seconds.
@code{hh:mm:ss[.xxx]} syntax is also supported.
@item -fs limit_size
@item -r fps
Set frame rate (Hz value, fraction or abbreviation), (default = 25).
@item -s size
-Set frame size. The format is @samp{wxh} (default = 160x128).
+Set frame size. The format is @samp{wxh} (ffserver default = 160x128, ffmpeg default = same as source).
The following abbreviations are recognized:
@table @samp
@item sqcif
352x288
@item 4cif
704x576
+@item qqvga
+160x120
+@item qvga
+320x240
+@item vga
+640x480
+@item svga
+800x600
+@item xga
+1024x768
+@item uxga
+1600x1200
+@item qxga
+2048x1536
+@item sxga
+1280x1024
+@item qsxga
+2560x2048
+@item hsxga
+5120x4096
+@item wvga
+852x480
+@item wxga
+1366x768
+@item wsxga
+1600x1024
+@item wuxga
+1920x1200
+@item woxga
+2560x1600
+@item wqsxga
+3200x2048
+@item wquxga
+3840x2400
+@item whsxga
+6400x4096
+@item whuxga
+7680x4800
+@item cga
+320x200
+@item ega
+640x350
+@item hd480
+852x480
+@item hd720
+1280x720
+@item hd1080
+1920x1080
@end table
@item -aspect aspect
@item -bt tolerance
Set video bitrate tolerance (in bit/s).
@item -maxrate bitrate
-Set max video bitrate tolerance (in bit/s).
+Set max video bitrate (in bit/s).
@item -minrate bitrate
-Set min video bitrate tolerance (in bit/s).
+Set min video bitrate (in bit/s).
@item -bufsize size
-Set rate control buffer size (in bits).
+Set video buffer verifier buffer size (in bits).
@item -vcodec codec
Force video codec to @var{codec}. Use the @code{copy} special value to
tell that the raw codec data must be copied as is.
@table @option
@item -pix_fmt format
-Set pixel format.
+Set pixel format. Use 'list' as parameter to show all the supported
+pixel formats.
+@item -sws_flags flags
+Set SwScaler flags (only available when compiled with SwScaler support).
@item -g gop_size
Set the group of pictures size.
@item -intra
evaluator}) (default = @code{tex^qComp}).
@item -rc_override override
rate control override for specific intervals
-@item -me method
+@item -me_method method
Set motion estimation method to @var{method}.
Available methods are (from lowest to best quality):
@table @samp
@item phods
@item log
@item x1
+@item hex
+@item umh
@item epzs
(default method)
@item full
Calculate PSNR of compressed frames.
@item -vstats
Dump video coding statistics to @file{vstats_HHMMSS.log}.
+@item -vstats_file file
+Dump video coding statistics to @var{file}.
@item -vhook module
Insert video processing @var{module}. @var{module} contains the module
name and its parameters separated by spaces.
@item -ar freq
Set the audio sampling frequency (default = 44100 Hz).
@item -ab bitrate
-Set the audio bitrate in kbit/s (default = 64).
+Set the audio bitrate in bit/s (default = 64k).
@item -ac channels
Set the number of audio channels (default = 1).
@item -an
Example:
@example
-ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384 test.mpg -acodec mp2 -ab 192 -newaudio
+ffmpeg -i file.mpg -vcodec copy -acodec ac3 -ab 384k test.mpg -acodec mp2 -ab 192k -newaudio
@end example
@item -alang code
Set the ISO 639 language code (3 letters) of the current audio stream.
@section Audio/Video grab options
@table @option
-@item -vd device
-sEt video grab device (e.g. @file{/dev/video0}).
@item -vc channel
Set video grab channel (DV1394 only).
@item -tvstd standard
Set television standard (NTSC, PAL (SECAM)).
-@item -dv1394
-Set DV1394 grab.
-@item -ad device
-Set audio device (e.g. @file{/dev/dsp}).
-@item -grab format
-Request grabbing using.
-@item -gd device
-Set grab device.
+@item -isync
+Synchronize read on input.
@end table
@section Advanced options
the parameter is the maximum samples per second by which the audio is changed.
-async 1 is a special case where only the start of the audio stream is corrected
without any later correction.
+@item -copyts
+Copy timestamps from input to output.
+@item -shortest
+Finish encoding when the shortest input stream ends.
+@item -dts_delta_threshold
+Timestamp discontinuity delta threshold.
+@item -muxdelay seconds
+Set the maximum demux-decode delay.
+@item -muxpreload seconds
+Set the initial demux-decode delay.
@end table
@node FFmpeg formula evaluator
@end itemize
-
-@chapter external libraries
-
-FFmpeg can be hooked up with a number of external libraries to add support
-for more formats.
-
-@section AMR
-
-AMR comes in two different flavors, WB and NB. FFmpeg can make use of the
-AMR WB (floating-point mode) and the AMR NB (both floating-point and
-fixed-point mode) reference decoders and encoders.
-
-@itemize
-
-@item For AMR WB floating-point download TS26.204 V5.1.0 from
-@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.204/26204-510.zip}
-and extract the source to @file{libavcodec/amrwb_float/}.
-
-@item For AMR NB floating-point download TS26.104 REL-5 V5.1.0 from
-@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.104/26104-510.zip}
-and extract the source to @file{libavcodec/amr_float/}.
-If you try this on Alpha, you may need to change @code{Word32} to
-@code{int} in @file{amr/typedef.h}.
-
-@item For AMR NB fixed-point download TS26.073 REL-5 V5.1.0 from
-@url{http://www.3gpp.org/ftp/Specs/archive/26_series/26.073/26073-510.zip}
-and extract the source to @file{libavcodec/amr}.
-You must also add @code{-DMMS_IO} and remove @code{-pedantic-errors}
-to/from @code{CFLAGS} in @file{libavcodec/amr/makefile}, i.e.
-``@code{CFLAGS = -Wall -I. \$(CFLAGS_\$(MODE)) -D\$(VAD) -DMMS_IO}''.
-
-@end itemize
-
-
-@chapter Supported File Formats and Codecs
-
-You can use the @code{-formats} option to have an exhaustive list.
-
-@section File Formats
-
-FFmpeg supports the following file formats through the @code{libavformat}
-library:
-
-@multitable @columnfractions .4 .1 .1 .4
-@item Supported File Format @tab Encoding @tab Decoding @tab Comments
-@item MPEG audio @tab X @tab X
-@item MPEG-1 systems @tab X @tab X
-@tab muxed audio and video
-@item MPEG-2 PS @tab X @tab X
-@tab also known as @code{VOB} file
-@item MPEG-2 TS @tab @tab X
-@tab also known as DVB Transport Stream
-@item ASF@tab X @tab X
-@item AVI@tab X @tab X
-@item WAV@tab X @tab X
-@item Macromedia Flash@tab X @tab X
-@tab Only embedded audio is decoded.
-@item FLV @tab X @tab X
-@tab Macromedia Flash video files
-@item Real Audio and Video @tab X @tab X
-@item Raw AC3 @tab X @tab X
-@item Raw MJPEG @tab X @tab X
-@item Raw MPEG video @tab X @tab X
-@item Raw PCM8/16 bits, mulaw/Alaw@tab X @tab X
-@item Raw CRI ADX audio @tab X @tab X
-@item Raw Shorten audio @tab @tab X
-@item SUN AU format @tab X @tab X
-@item NUT @tab X @tab X @tab NUT Open Container Format
-@item QuickTime @tab X @tab X
-@item MPEG-4 @tab X @tab X
-@tab MPEG-4 is a variant of QuickTime.
-@item Raw MPEG4 video @tab X @tab X
-@item DV @tab X @tab X
-@item 4xm @tab @tab X
-@tab 4X Technologies format, used in some games.
-@item Playstation STR @tab @tab X
-@item Id RoQ @tab @tab X
-@tab Used in Quake III, Jedi Knight 2, other computer games.
-@item Interplay MVE @tab @tab X
-@tab Format used in various Interplay computer games.
-@item WC3 Movie @tab @tab X
-@tab Multimedia format used in Origin's Wing Commander III computer game.
-@item Sega FILM/CPK @tab @tab X
-@tab Used in many Sega Saturn console games.
-@item Westwood Studios VQA/AUD @tab @tab X
-@tab Multimedia formats used in Westwood Studios games.
-@item Id Cinematic (.cin) @tab @tab X
-@tab Used in Quake II.
-@item FLIC format @tab @tab X
-@tab .fli/.flc files
-@item Sierra VMD @tab @tab X
-@tab Used in Sierra CD-ROM games.
-@item Sierra Online @tab @tab X
-@tab .sol files used in Sierra Online games.
-@item Matroska @tab @tab X
-@item Electronic Arts Multimedia @tab @tab X
-@tab Used in various EA games; files have extensions like WVE and UV2.
-@item Nullsoft Video (NSV) format @tab @tab X
-@item ADTS AAC audio @tab X @tab X
-@item Creative VOC @tab X @tab X @tab Created for the Sound Blaster Pro.
-@item American Laser Games MM @tab @tab X
-@tab Multimedia format used in games like Mad Dog McCree
-@item AVS @tab @tab X
-@tab Multimedia format used by the Creature Shock game.
-@item Smacker @tab @tab X
-@tab Multimedia format used by many games.
-@item GXF @tab X @tab X
-@tab General eXchange Format SMPTE 360M, used by Thomson Grass Valley playout servers.
-@item CIN @tab @tab X
-@tab Multimedia format used by Delphine Software games.
-@item MXF @tab @tab X
-@tab Material eXchange Format SMPTE 377M, used by D-Cinema, broadcast industry.
-@item SEQ @tab @tab X
-@tab Tiertex .seq files used in the DOS CDROM version of the game Flashback.
-@end multitable
-
-@code{X} means that encoding (resp. decoding) is supported.
-
-@section Image Formats
-
-FFmpeg can read and write images for each frame of a video sequence. The
-following image formats are supported:
-
-@multitable @columnfractions .4 .1 .1 .4
-@item Supported Image Format @tab Encoding @tab Decoding @tab Comments
-@item PGM, PPM @tab X @tab X
-@item PAM @tab X @tab X @tab PAM is a PNM extension with alpha support.
-@item PGMYUV @tab X @tab X @tab PGM with U and V components in YUV 4:2:0
-@item JPEG @tab X @tab X @tab Progressive JPEG is not supported.
-@item .Y.U.V @tab X @tab X @tab one raw file per component
-@item animated GIF @tab X @tab X @tab Only uncompressed GIFs are generated.
-@item PNG @tab X @tab X @tab 2 bit and 4 bit/pixel not supported yet.
-@item Targa @tab @tab X @tab Targa (.TGA) image format.
-@item TIFF @tab @tab X @tab Only 24 bit/pixel images are supported.
-@item SGI @tab X @tab X @tab SGI RGB image format
-@end multitable
-
-@code{X} means that encoding (resp. decoding) is supported.
-
-@section Video Codecs
-
-@multitable @columnfractions .4 .1 .1 .4
-@item Supported Codec @tab Encoding @tab Decoding @tab Comments
-@item MPEG-1 video @tab X @tab X
-@item MPEG-2 video @tab X @tab X
-@item MPEG-4 @tab X @tab X
-@item MSMPEG4 V1 @tab X @tab X
-@item MSMPEG4 V2 @tab X @tab X
-@item MSMPEG4 V3 @tab X @tab X
-@item WMV7 @tab X @tab X
-@item WMV8 @tab X @tab X @tab not completely working
-@item WMV9 @tab @tab X @tab not completely working
-@item VC1 @tab @tab X
-@item H.261 @tab X @tab X
-@item H.263(+) @tab X @tab X @tab also known as RealVideo 1.0
-@item H.264 @tab @tab X
-@item RealVideo 1.0 @tab X @tab X
-@item RealVideo 2.0 @tab X @tab X
-@item MJPEG @tab X @tab X
-@item lossless MJPEG @tab X @tab X
-@item JPEG-LS @tab X @tab X @tab fourcc: MJLS, lossless and near-lossless is supported
-@item Apple MJPEG-B @tab @tab X
-@item Sunplus MJPEG @tab @tab X @tab fourcc: SP5X
-@item DV @tab X @tab X
-@item HuffYUV @tab X @tab X
-@item FFmpeg Video 1 @tab X @tab X @tab experimental lossless codec (fourcc: FFV1)
-@item FFmpeg Snow @tab X @tab X @tab experimental wavelet codec (fourcc: SNOW)
-@item Asus v1 @tab X @tab X @tab fourcc: ASV1
-@item Asus v2 @tab X @tab X @tab fourcc: ASV2
-@item Creative YUV @tab @tab X @tab fourcc: CYUV
-@item Sorenson Video 1 @tab X @tab X @tab fourcc: SVQ1
-@item Sorenson Video 3 @tab @tab X @tab fourcc: SVQ3
-@item On2 VP3 @tab @tab X @tab still experimental
-@item On2 VP5 @tab @tab X @tab fourcc: VP50
-@item On2 VP6 @tab @tab X @tab fourcc: VP60,VP61,VP62
-@item Theora @tab X @tab X @tab still experimental
-@item Intel Indeo 3 @tab @tab X
-@item FLV @tab X @tab X @tab Sorenson H.263 used in Flash
-@item Flash Screen Video @tab X @tab X @tab fourcc: FSV1
-@item ATI VCR1 @tab @tab X @tab fourcc: VCR1
-@item ATI VCR2 @tab @tab X @tab fourcc: VCR2
-@item Cirrus Logic AccuPak @tab @tab X @tab fourcc: CLJR
-@item 4X Video @tab @tab X @tab Used in certain computer games.
-@item Sony Playstation MDEC @tab @tab X
-@item Id RoQ @tab @tab X @tab Used in Quake III, Jedi Knight 2, other computer games.
-@item Xan/WC3 @tab @tab X @tab Used in Wing Commander III .MVE files.
-@item Interplay Video @tab @tab X @tab Used in Interplay .MVE files.
-@item Apple Animation @tab @tab X @tab fourcc: 'rle '
-@item Apple Graphics @tab @tab X @tab fourcc: 'smc '
-@item Apple Video @tab @tab X @tab fourcc: rpza
-@item Apple QuickDraw @tab @tab X @tab fourcc: qdrw
-@item Cinepak @tab @tab X
-@item Microsoft RLE @tab @tab X
-@item Microsoft Video-1 @tab @tab X
-@item Westwood VQA @tab @tab X
-@item Id Cinematic Video @tab @tab X @tab Used in Quake II.
-@item Planar RGB @tab @tab X @tab fourcc: 8BPS
-@item FLIC video @tab @tab X
-@item Duck TrueMotion v1 @tab @tab X @tab fourcc: DUCK
-@item Duck TrueMotion v2 @tab @tab X @tab fourcc: TM20
-@item VMD Video @tab @tab X @tab Used in Sierra VMD files.
-@item MSZH @tab @tab X @tab Part of LCL
-@item ZLIB @tab X @tab X @tab Part of LCL, encoder experimental
-@item TechSmith Camtasia @tab @tab X @tab fourcc: TSCC
-@item IBM Ultimotion @tab @tab X @tab fourcc: ULTI
-@item Miro VideoXL @tab @tab X @tab fourcc: VIXL
-@item QPEG @tab @tab X @tab fourccs: QPEG, Q1.0, Q1.1
-@item LOCO @tab @tab X @tab
-@item Winnov WNV1 @tab @tab X @tab
-@item Autodesk Animator Studio Codec @tab @tab X @tab fourcc: AASC
-@item Fraps FPS1 @tab @tab X @tab
-@item CamStudio @tab @tab X @tab fourcc: CSCD
-@item American Laser Games Video @tab @tab X @tab Used in games like Mad Dog McCree
-@item ZMBV @tab X @tab X @tab Encoder works only on PAL8
-@item AVS Video @tab @tab X @tab Video encoding used by the Creature Shock game.
-@item Smacker Video @tab @tab X @tab Video encoding used in Smacker.
-@item RTjpeg @tab @tab X @tab Video encoding used in NuppelVideo files.
-@item KMVC @tab @tab X @tab Codec used in Worms games.
-@item VMware Video @tab @tab X @tab Codec used in videos captured by VMware.
-@item Cin Video @tab @tab X @tab Codec used in Delphine Software games.
-@item Tiertex Seq Video @tab @tab X @tab Codec used in DOS CDROM FlashBack game.
-@end multitable
-
-@code{X} means that encoding (resp. decoding) is supported.
-
-@section Audio Codecs
-
-@multitable @columnfractions .4 .1 .1 .1 .7
-@item Supported Codec @tab Encoding @tab Decoding @tab Comments
-@item MPEG audio layer 2 @tab IX @tab IX
-@item MPEG audio layer 1/3 @tab IX @tab IX
-@tab MP3 encoding is supported through the external library LAME.
-@item AC3 @tab IX @tab IX
-@tab liba52 is used internally for decoding.
-@item Vorbis @tab X @tab X
-@item WMA V1/V2 @tab @tab X
-@item AAC @tab X @tab X
-@tab Supported through the external library libfaac/libfaad.
-@item Microsoft ADPCM @tab X @tab X
-@item MS IMA ADPCM @tab X @tab X
-@item QT IMA ADPCM @tab @tab X
-@item 4X IMA ADPCM @tab @tab X
-@item G.726 ADPCM @tab X @tab X
-@item Duck DK3 IMA ADPCM @tab @tab X
-@tab Used in some Sega Saturn console games.
-@item Duck DK4 IMA ADPCM @tab @tab X
-@tab Used in some Sega Saturn console games.
-@item Westwood Studios IMA ADPCM @tab @tab X
-@tab Used in Westwood Studios games like Command and Conquer.
-@item SMJPEG IMA ADPCM @tab @tab X
-@tab Used in certain Loki game ports.
-@item CD-ROM XA ADPCM @tab @tab X
-@item CRI ADX ADPCM @tab X @tab X
-@tab Used in Sega Dreamcast games.
-@item Electronic Arts ADPCM @tab @tab X
-@tab Used in various EA titles.
-@item Creative ADPCM @tab @tab X
-@tab 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2
-@item RA144 @tab @tab X
-@tab Real 14400 bit/s codec
-@item RA288 @tab @tab X
-@tab Real 28800 bit/s codec
-@item RADnet @tab X @tab IX
-@tab Real low bitrate AC3 codec, liba52 is used for decoding.
-@item AMR-NB @tab X @tab X
-@tab Supported through an external library.
-@item AMR-WB @tab X @tab X
-@tab Supported through an external library.
-@item DV audio @tab @tab X
-@item Id RoQ DPCM @tab @tab X
-@tab Used in Quake III, Jedi Knight 2, other computer games.
-@item Interplay MVE DPCM @tab @tab X
-@tab Used in various Interplay computer games.
-@item Xan DPCM @tab @tab X
-@tab Used in Origin's Wing Commander IV AVI files.
-@item Sierra Online DPCM @tab @tab X
-@tab Used in Sierra Online game audio files.
-@item Apple MACE 3 @tab @tab X
-@item Apple MACE 6 @tab @tab X
-@item FLAC lossless audio @tab @tab X
-@item Shorten lossless audio @tab @tab X
-@item Apple lossless audio @tab @tab X
-@tab QuickTime fourcc 'alac'
-@item FFmpeg Sonic @tab X @tab X
-@tab experimental lossy/lossless codec
-@item Qdesign QDM2 @tab @tab X
-@tab there are still some distortions
-@item Real COOK @tab @tab X
-@tab All versions except 5.1 are supported
-@item DSP Group TrueSpeech @tab @tab X
-@item True Audio (TTA) @tab @tab X
-@item Smacker Audio @tab @tab X
-@item WavPack Audio @tab @tab X
-@item Cin Audio @tab @tab X
-@tab Codec used in Delphine Software games.
-@item Intel Music Coder @tab @tab X
-@item Musepack @tab @tab X
-@tab Only SV7 is supported
-@end multitable
-
-@code{X} means that encoding (resp. decoding) is supported.
-
-@code{I} means that an integer-only version is available, too (ensures high
-performance on systems without hardware floating point support).
-
-@chapter Platform Specific information
-
-@section BSD
-
-BSD make will not build FFmpeg, you need to install and use GNU Make
-(@file{gmake}).
-
-@section Windows
-
-@subsection Native Windows compilation
-
-@itemize
-@item Install the current versions of MSYS and MinGW from
-@url{http://www.mingw.org/}. You can find detailed installation
-instructions in the download section and the FAQ.
-
-@item If you want to test the FFplay, also download
-the MinGW development library of SDL 1.2.x
-(@file{SDL-devel-1.2.x-mingw32.tar.gz}) from
-@url{http://www.libsdl.org}. Unpack it in a temporary directory, and
-unpack the archive @file{i386-mingw32msvc.tar.gz} in the MinGW tool
-directory. Edit the @file{sdl-config} script so that it gives the
-correct SDL directory when invoked.
-
-@item Extract the current version of FFmpeg.
-
-@item Start the MSYS shell (file @file{msys.bat}).
-
-@item Change to the FFmpeg directory and follow
- the instructions of how to compile FFmpeg (file
-@file{INSTALL}). Usually, launching @file{./configure} and @file{make}
-suffices. If you have problems using SDL, verify that
-@file{sdl-config} can be launched from the MSYS command line.
-
-@item You can install FFmpeg in @file{Program Files/FFmpeg} by typing
-@file{make install}. Don't forget to copy @file{SDL.dll} to the place
-you launch @file{ffplay} from.
-
-@end itemize
-
-Notes:
-@itemize
-
-@item The target @file{make wininstaller} can be used to create a
-Nullsoft based Windows installer for FFmpeg and FFplay. @file{SDL.dll}
-must be copied to the FFmpeg directory in order to build the
-installer.
-
-@item By using @code{./configure --enable-shared} when configuring FFmpeg,
-you can build @file{avcodec.dll} and @file{avformat.dll}. With
-@code{make install} you install the FFmpeg DLLs and the associated
-headers in @file{Program Files/FFmpeg}.
-
-@item Visual C++ compatibility: If you used @code{./configure --enable-shared}
-when configuring FFmpeg, FFmpeg tries to use the Microsoft Visual
-C++ @code{lib} tool to build @code{avcodec.lib} and
-@code{avformat.lib}. With these libraries you can link your Visual C++
-code directly with the FFmpeg DLLs (see below).
-
-@end itemize
-
-@subsection Visual C++ compatibility
-
-FFmpeg will not compile under Visual C++ -- and it has too many
-dependencies on the GCC compiler to make a port viable. However,
-if you want to use the FFmpeg libraries in your own applications,
-you can still compile those applications using Visual C++. An
-important restriction to this is that you have to use the
-dynamically linked versions of the FFmpeg libraries (i.e. the
-DLLs), and you have to make sure that Visual-C++-compatible
-import libraries are created during the FFmpeg build process.
-
-This description of how to use the FFmpeg libraries with Visual C++ is
-based on Visual C++ 2005 Express Edition Beta 2. If you have a different
-version, you might have to modify the procedures slightly.
-
-Here are the step-by-step instructions for building the FFmpeg libraries
-so they can be used with Visual C++:
-
-@enumerate
-
-@item Install Visual C++ (if you haven't done so already).
-
-@item Install MinGW and MSYS as described above.
-
-@item Add a call to @file{vcvars32.bat} (which sets up the environment
-variables for the Visual C++ tools) as the first line of
-@file{msys.bat}. The standard location for @file{vcvars32.bat} is
-@file{C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat},
-and the standard location for @file{msys.bat} is
-@file{C:\msys\1.0\msys.bat}. If this corresponds to your setup, add the
-following line as the first line of @file{msys.bat}:
-
-@code{call "C:\Program Files\Microsoft Visual Studio 8\VC\bin\vcvars32.bat"}
-
-@item Start the MSYS shell (file @file{msys.bat}) and type @code{link.exe}.
-If you get a help message with the command line options of @code{link.exe},
-this means your environment variables are set up correctly, the
-Microsoft linker is on the path and will be used by FFmpeg to
-create Visual-C++-compatible import libraries.
-
-@item Extract the current version of FFmpeg and change to the FFmpeg directory.
-
-@item Type the command
-@code{./configure --enable-shared --disable-static --enable-memalign-hack}
-to configure and, if that didn't produce any errors,
-type @code{make} to build FFmpeg.
-
-@item The subdirectories @file{libavformat}, @file{libavcodec}, and
-@file{libavutil} should now contain the files @file{avformat.dll},
-@file{avformat.lib}, @file{avcodec.dll}, @file{avcodec.lib},
-@file{avutil.dll}, and @file{avutil.lib}, respectively. Copy the three
-DLLs to your System32 directory (typically @file{C:\Windows\System32}).
-
-@end enumerate
-
-And here is how to use these libraries with Visual C++:
-
-@enumerate
-
-@item Create a new console application ("File / New / Project") and then
-select "Win32 Console Application". On the appropriate page of the
-Application Wizard, uncheck the "Precompiled headers" option.
-
-@item Write the source code for your application, or, for testing, just
-copy the code from an existing sample application into the source file
-that Visual C++ has already created for you. (Note that your source
-filehas to have a @code{.cpp} extension; otherwise, Visual C++ won't
-compile the FFmpeg headers correctly because in C mode, it doesn't
-recognize the @code{inline} keyword.) For example, you can copy
-@file{output_example.c} from the FFmpeg distribution (but you will
-have to make minor modifications so the code will compile under
-C++, see below).
-
-@item Open the "Project / Properties" dialog box. In the "Configuration"
-combo box, select "All Configurations" so that the changes you make will
-affect both debug and release builds. In the tree view on the left hand
-side, select "C/C++ / General", then edit the "Additional Include
-Directories" setting to contain the complete paths to the
-@file{libavformat}, @file{libavcodec}, and @file{libavutil}
-subdirectories of your FFmpeg directory. Note that the directories have
-to be separated using semicolons. Now select "Linker / General" from the
-tree view and edit the "Additional Library Directories" setting to
-contain the same three directories.
-
-@item Still in the "Project / Properties" dialog box, select "Linker / Input"
-from the tree view, then add the files @file{avformat.lib},
-@file{avcodec.lib}, and @file{avutil.lib} to the end of the "Additional
-Dependencies". Note that the names of the libraries have to be separated
-using spaces.
-
-@item Now, select "C/C++ / Code Generation" from the tree view. Select
-"Debug" in the "Configuration" combo box. Make sure that "Runtime
-Library" is set to "Multi-threaded Debug DLL". Then, select "Release" in
-the "Configuration" combo box and make sure that "Runtime Library" is
-set to "Multi-threaded DLL".
-
-@item Click "OK" to close the "Project / Properties" dialog box and build
-the application. Hopefully, it should compile and run cleanly. If you
-used @file{output_example.c} as your sample application, you will get a
-few compiler errors, but they are easy to fix. The first type of error
-occurs because Visual C++ doesn't allow an @code{int} to be converted to
-an @code{enum} without a cast. To solve the problem, insert the required
-casts (this error occurs once for a @code{CodecID} and once for a
-@code{CodecType}). The second type of error occurs because C++ requires
-the return value of @code{malloc} to be cast to the exact type of the
-pointer it is being assigned to. Visual C++ will complain that, for
-example, @code{(void *)} is being assigned to @code{(uint8_t *)} without
-an explicit cast. So insert an explicit cast in these places to silence
-the compiler. The third type of error occurs because the @code{snprintf}
-library function is called @code{_snprintf} under Visual C++. So just
-add an underscore to fix the problem. With these changes,
-@file{output_example.c} should compile under Visual C++, and the
-resulting executable should produce valid video files.
-
-@end enumerate
-
-@subsection Cross compilation for Windows with Linux
-
-You must use the MinGW cross compilation tools available at
-@url{http://www.mingw.org/}.
-
-Then configure FFmpeg with the following options:
-@example
-./configure --enable-mingw32 --cross-prefix=i386-mingw32msvc-
-@end example
-(you can change the cross-prefix according to the prefix chosen for the
-MinGW tools).
-
-Then you can easily test FFmpeg with Wine
-(@url{http://www.winehq.com/}).
-
-@subsection Compilation under Cygwin
-
-Cygwin works very much like Unix.
-
-Just install your Cygwin with all the "Base" packages, plus the
-following "Devel" ones:
-@example
-binutils, gcc-core, make, subversion
-@end example
-
-Do not install binutils-20060709-1 (they are buggy on shared builds);
-use binutils-20050610-1 instead.
-
-Then run
-
-@example
-./configure --enable-static --disable-shared
-@end example
-
-to make a static build or
-
-@example
-./configure --enable-shared --disable-static
-@end example
-
-to build shared libraries.
-
-If you want to build FFmpeg with additional libraries, download Cygwin
-"Devel" packages for Ogg and Vorbis from any Cygwin packages repository
-and/or SDL, xvid, faac, faad2 packages from Cygwin Ports,
-(@url{http://cygwinports.dotsrc.org/}).
-
-@subsection Crosscompilation for Windows under Cygwin
-
-With Cygwin you can create Windows binaries that don't need the cygwin1.dll.
-
-Just install your Cygwin as explained before, plus these additional
-"Devel" packages:
-@example
-gcc-mingw-core, mingw-runtime, mingw-zlib
-@end example
-
-and add some special flags to your configure invocation.
-
-For a static build run
-@example
-./configure --enable-mingw32 --enable-memalign-hack --enable-static --disable-shared --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
-@end example
-
-and for a build with shared libraries
-@example
-./configure --enable-mingw32 --enable-memalign-hack --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
-@end example
-
-@section BeOS
-
-The configure script should guess the configuration itself.
-Networking support is currently not finished.
-errno issues fixed by Andrew Bachmann.
-
-Old stuff:
-
-François Revol - revol at free dot fr - April 2002
-
-The configure script should guess the configuration itself,
-however I still didn't test building on the net_server version of BeOS.
-
-FFserver is broken (needs poll() implementation).
-
-There are still issues with errno codes, which are negative in BeOS, and
-that FFmpeg negates when returning. This ends up turning errors into
-valid results, then crashes.
-(To be fixed)
-
-@chapter Developers Guide
-
-@section API
-@itemize @bullet
-@item libavcodec is the library containing the codecs (both encoding and
-decoding). Look at @file{libavcodec/apiexample.c} to see how to use it.
-
-@item libavformat is the library containing the file format handling (mux and
-demux code for several formats). Look at @file{ffplay.c} to use it in a
-player. See @file{output_example.c} to use it to generate audio or video
-streams.
-
-@end itemize
-
-@section Integrating libavcodec or libavformat in your program
-
-You can integrate all the source code of the libraries to link them
-statically to avoid any version problem. All you need is to provide a
-'config.mak' and a 'config.h' in the parent directory. See the defines
-generated by ./configure to understand what is needed.
-
-You can use libavcodec or libavformat in your commercial program, but
-@emph{any patch you make must be published}. The best way to proceed is
-to send your patches to the FFmpeg mailing list.
-
-@node Coding Rules
-@section Coding Rules
-
-FFmpeg is programmed in the ISO C90 language with a few additional
-features from ISO C99, namely:
-@itemize @bullet
-@item
-the @samp{inline} keyword;
-@item
-@samp{//} comments;
-@item
-designated struct initializers (@samp{struct s x = @{ .i = 17 @};})
-@item
-compound literals (@samp{x = (struct s) @{ 17, 23 @};})
-@end itemize
-
-These features are supported by all compilers we care about, so we won't
-accept patches to remove their use unless they absolutely don't impair
-clarity and performance.
-
-All code must compile with GCC 2.95 and GCC 3.3. Currently, FFmpeg also
-compiles with several other compilers, such as the Compaq ccc compiler
-or Sun Studio 9, and we would like to keep it that way unless it would
-be exceedingly involved. To ensure compatibility, please don't use any
-additional C99 features or GCC extensions. Especially watch out for:
-@itemize @bullet
-@item
-mixing statements and declarations;
-@item
-@samp{long long} (use @samp{int64_t} instead);
-@item
-@samp{__attribute__} not protected by @samp{#ifdef __GNUC__} or similar;
-@item
-GCC statement expressions (@samp{(x = (@{ int y = 4; y; @})}).
-@end itemize
-
-Indent size is 4.
-The presentation is the one specified by 'indent -i4 -kr -nut'.
-The TAB character is forbidden outside of Makefiles as is any
-form of trailing whitespace. Commits containing either will be
-rejected by the Subversion repository.
-
-Main priority in FFmpeg is simplicity and small code size (=less
-bugs).
-
-Comments: Use the JavaDoc/Doxygen
-format (see examples below) so that code documentation
-can be generated automatically. All nontrivial functions should have a comment
-above them explaining what the function does, even if it's just one sentence.
-All structures and their member variables should be documented, too.
-@example
-/**
- * @@file mpeg.c
- * MPEG codec.
- * @@author ...
- */
-
-/**
- * Summary sentence.
- * more text ...
- * ...
- */
-typedef struct Foobar@{
- int var1; /**< var1 description */
- int var2; ///< var2 description
- /** var3 description */
- int var3;
-@} Foobar;
-
-/**
- * Summary sentence.
- * more text ...
- * ...
- * @@param my_parameter description of my_parameter
- * @@return return value description
- */
-int myfunc(int my_parameter)
-...
-@end example
-
-fprintf and printf are forbidden in libavformat and libavcodec,
-please use av_log() instead.
-
-@section Development Policy
-
-@enumerate
-@item
- You must not commit code which breaks FFmpeg! (Meaning unfinished but
- enabled code which breaks compilation or compiles but does not work or
- breaks the regression tests)
- You can commit unfinished stuff (for testing etc), but it must be disabled
- (#ifdef etc) by default so it does not interfere with other developers'
- work.
-@item
- You don't have to over-test things. If it works for you, and you think it
- should work for others, then commit. If your code has problems
- (portability, triggers compiler bugs, unusual environment etc) they will be
- reported and eventually fixed.
-@item
- Do not commit unrelated changes together, split them into self-contained
- pieces.
-@item
- Do not change behavior of the program (renaming options etc) without
- first discussing it on the ffmpeg-devel mailing list. Do not remove
- functionality from the code. Just improve!
-
- Note: Redundant code can be removed.
-@item
- Do not commit changes to the build system (Makefiles, configure script)
- which change behavior, defaults etc, without asking first. The same
- applies to compiler warning fixes, trivial looking fixes and to code
- maintained by other developers. We usually have a reason for doing things
- the way we do. Send your changes as patches to the ffmpeg-devel mailing
- list, and if the code maintainers say OK, you may commit. This does not
- apply to files you wrote and/or maintain.
-@item
- We refuse source indentation and other cosmetic changes if they are mixed
- with functional changes, such commits will be rejected and removed. Every
- developer has his own indentation style, you should not change it. Of course
- if you (re)write something, you can use your own style, even though we would
- prefer if the indentation throughout FFmpeg was consistent (Many projects
- force a given indentation style - we don't.). If you really need to make
- indentation changes (try to avoid this), separate them strictly from real
- changes.
-
- NOTE: If you had to put if()@{ .. @} over a large (> 5 lines) chunk of code,
- then either do NOT change the indentation of the inner part within (don't
- move it to the right)! or do so in a separate commit
-@item
- Always fill out the commit log message. Describe in a few lines what you
- changed and why. You can refer to mailing list postings if you fix a
- particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
-@item
- If you apply a patch by someone else, include the name and email address in
- the log message. Since the ffmpeg-cvslog mailing list is publicly
- archived you should add some SPAM protection to the email address. Send an
- answer to ffmpeg-devel (or wherever you got the patch from) saying that
- you applied the patch.
-@item
- Do NOT commit to code actively maintained by others without permission.
- Send a patch to ffmpeg-devel instead. If noone answers within a reasonable
- timeframe (12h for build failures and security fixes, 3 days small changes,
- 1 week for big patches) then commit your patch if you think it's OK.
- Also note, the maintainer can simply ask for more time to review!
-@item
- Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
- are sent there and reviewed by all the other developers. Bugs and possible
- improvements or general questions regarding commits are discussed there. We
- expect you to react if problems with your code are uncovered.
-@item
- Update the documentation if you change behavior or add features. If you are
- unsure how best to do this, send a patch to ffmpeg-devel, the documentation
- maintainer(s) will review and commit your stuff.
-@item
- Never write to unallocated memory, never write over the end of arrays,
- always check values read from some untrusted source before using them
- as array index or other risky things.
-@item
- Remember to check if you need to bump versions for the specific libav
- parts (libavutil, libavcodec, libavformat) you are changing. You need
- to change the version integer and the version string.
- Incrementing the first component means no backward compatibility to
- previous versions (e.g. removal of a function from the public API).
- Incrementing the second component means backward compatible change
- (e.g. addition of a function to the public API).
- Incrementing the third component means a noteworthy binary compatible
- change (e.g. encoder bug fix that matters for the decoder).
-@item
- If you add a new codec, remember to update the changelog, add it to
- the supported codecs table in the documentation and bump the second
- component of the @file{libavcodec} version number appropriately. If
- it has a fourcc, add it to @file{libavformat/avienc.c}, even if it
- is only a decoder.
-@end enumerate
-
-We think our rules are not too hard. If you have comments, contact us.
-
-Note, these rules are mostly borrowed from the MPlayer project.
-
-@section Submitting patches
-
-First, (@pxref{Coding Rules}) above if you didn't yet.
-
-When you submit your patch, try to send a unified diff (diff '-up'
-option). I cannot read other diffs :-)
-
-Also please do not submit patches which contain several unrelated changes.
-Split them into individual self-contained patches; this makes reviewing
-them much easier.
-
-Run the regression tests before submitting a patch so that you can
-verify that there are no big problems.
-
-Patches should be posted as base64 encoded attachments (or any other
-encoding which ensures that the patch won't be trashed during
-transmission) to the ffmpeg-devel mailing list, see
-@url{http://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel}
-
-It also helps quite a bit if you tell us what the patch does (for example
-'replaces lrint by lrintf'), and why (for example '*BSD isn't C99 compliant
-and has no lrint()')
-
-We reply to all submitted patches and either apply or reject with some
-explanation why, but sometimes we are quite busy so it can take a week or two.
-
-@section Regression tests
-
-Before submitting a patch (or committing to the repository), you should at least
-test that you did not break anything.
-
-The regression tests build a synthetic video stream and a synthetic
-audio stream. These are then encoded and decoded with all codecs or
-formats. The CRC (or MD5) of each generated file is recorded in a
-result file. A 'diff' is launched to compare the reference results and
-the result file.
-
-The regression tests then go on to test the FFserver code with a
-limited set of streams. It is important that this step runs correctly
-as well.
-
-Run 'make test' to test all the codecs and formats.
-
-Run 'make fulltest' to test all the codecs, formats and FFserver.
-
-[Of course, some patches may change the results of the regression tests. In
-this case, the reference results of the regression tests shall be modified
-accordingly].
-
@bye