add support for "Brooktree YUV 411 Raw (Y41P)" codec

[ami_stuff]

issue 1123

​http://roundup.libav.org/file329/AVI-Y41P_MP3.avi

seems to be supported by old xanim

​http://xanim.polter.net/files/xanim2801.tar.gz

----------------------------------------------------------------
2.80.0
----------------------------------------------------------------
  + Added support for the following AVI codecs:
    DMB1,BW10,Y41P,I420,VYUY,V422,YV12,Y41P,YUY2,IV41,IV50,H261,M263
  + Added support for the following QT codecs:
    MJPA, 8BPS, IV41, IV50
  + Added support for QT3.0 compressed headers.
  + Added support for video decompression dlls.
  + Fixed problems with X11 remote displays of different endianness.
  + Minor bugs fixes.

C:\>ffmpeg -i AVI-Y41P_MP3.avi
FFmpeg version SVN-r18938, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --enable-memalign-hack --prefix=/mingw --cross-prefix=i686-ming
w32- --cc=ccache-i686-mingw32-gcc --target-os=mingw32 --arch=i686 --cpu=i686 --e
nable-avisynth --enable-gpl --enable-zlib --enable-bzlib --enable-libgsm --enabl
e-libfaad --enable-pthreads --enable-libvorbis --enable-libtheora --enable-libsp
eex --enable-libmp3lame --enable-libopenjpeg --enable-libxvid --enable-libschroe
dinger --enable-libx264
  libavutil     50. 3. 0 / 50. 3. 0
  libavcodec    52.29. 0 / 52.29. 0
  libavformat   52.33. 0 / 52.33. 0
  libavdevice   52. 2. 0 / 52. 2. 0
  libswscale     0. 7. 1 /  0. 7. 1
  built on May 25 2009 04:04:51, gcc: 4.2.4
Input #0, avi, from 'AVI-Y41P_MP3.avi':
  Duration: 00:00:06.00, start: 0.000000, bitrate: 7368 kb/s
    Stream #0.0: Video: Y41P / 0x50313459, 192x128, 23.81 tbr, 23.81 tbn, 23.81
tbc
    Stream #0.1: Audio: mp3, 11025 Hz, mono, s16, 24 kb/s
At least one output file must be specified

[Carl Eugen Hoyos]

Implemented by Paul B Mahol.
(Do samples exist where width % 8 != 0?)

[ami_stuff]

FOURCC code: 'y41p'
Driver name: btvvc32.drv

Format restrictions:
Didth must be multiple of 8
Valid depths: 16, 24

FOURCC code: 'bt20'
Driver name: btvvc32.drv

Format restrictions:
Didth must be multiple of 8
Valid depths: 16, 24

[Elon Musk]

bt20 is compressed codec, so if first need some RE.

Is Didth typo?

Valid depths is just flag set in avi?

[ami_stuff]

Is Didth typo?

Yes.

Valid depths is just flag set in avi?

This is what VirtualDub display as an info for compressor, but whatever I select 16bit or 24bit as an "output format for compressor" I get files with the same size and the files plays ok with FFplay.

[Elon Musk]

OT, about encoding y41p with ffmpeg:

btvvc32.drv expect the "Depth" byte in avi to be 0x0c (12) but ffmpeg avi muxer sets this byte to 0x18 (24) so y41p muxed in avi with ffmpeg are causing mplayer to crash when using bt411 codec (btvvc32.drv).

Once you change that byte to 0x0c in hex editor files plays fine with mplayer -vfc bt411

[Carl Eugen Hoyos]

Thank you for the hint, I applied a patch that sets the relevant value when encoding (it is still set incorrectly in case of stream-copy).