[FFmpeg-trac] #663(undetermined:new): iff ilbm: add ehb color mode

[FFmpeg]

#663: iff ilbm: add ehb color mode
-------------------------------------+-------------------------------------
             Reporter:  ami_stuff    |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 http://en.wikipedia.org/wiki/Amiga_Halfbrite_mode

 SDL_image supports this mode.

 http://www.libsdl.org/projects/SDL_image/

 IMG_lbm.c:
 {{{
                 /* Amiga EHB mode (Extra-Half-Bright) */
                 /* 6 bitplanes mode with a 32 colors palette */
                 /* The 32 last colors are the same but divided by 2 */
                 /* Some Amiga pictures save 64 colors with 32 last wrong
 colors, */
                 /* they shouldn't !, and here we overwrite these 32 bad
 colors. */
                 if ( (nbcolors==32 || flagEHB ) && (1<<bmhd.planes)==64 )
                 {
                         nbcolors = 64;
                         ptr = &colormap[0];
                         for ( i=32; i<64; i++ )
                         {
                                 Image->format->palette->colors[i].r =
 (*ptr++)/2;
                                 Image->format->palette->colors[i].g =
 (*ptr++)/2;
                                 Image->format->palette->colors[i].b =
 (*ptr++)/2;
                         }
                 }
 }}}

 {{{
 C:\>ffmpeg -i KING.IFF
 ffmpeg version N-34704-g985e768, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Nov 11 2011 01:49:15 with gcc 4.6.2
   configuration: --disable-static --enable-shared --enable-gpl --enable-
 version3
  --disable-w32threads --enable-runtime-cpudetect --enable-avisynth
 --enable-bzli
 b --enable-frei0r --enable-libopencore-amrnb --enable-libopencore-amrwb
 --enable
 -libfreetype --enable-libgsm --enable-libmp3lame --enable-libopenjpeg
 --enable-l
 ibrtmp --enable-libschroedinger --enable-libspeex --enable-libtheora
 --enable-li
 bvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx
 --enable-l
 ibx264 --enable-libxavs --enable-libxvid --enable-zlib
   libavutil    51. 24. 1 / 51. 24. 1
   libavcodec   53. 31. 0 / 53. 31. 0
   libavformat  53. 20. 0 / 53. 20. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 47. 2 /  2. 47. 2
   libswscale    2.  1. 0 /  2.  1. 0
   libpostproc  51.  2. 0 / 51.  2. 0
 [iff_byterun1 @ 003EA360] ExtraHalfBrite (EHB) mode not supported
     Last message repeated 1 times
 [IFF @ 003E9B00] Estimating duration from bitrate, this may be inaccurate
 Input #0, IFF, from 'KING.IFF':
   Duration: N/A, bitrate: N/A
     Stream #0:0: Video: iff_byterun1 (ILBM / 0x4D424C49), pal8, 320x256,
 SAR 44:
 44 DAR 5:4, 90k tbr, 90k tbn, 90k tbc
 At least one output file must be specified
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/663>
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