add suppoer for iff anim

[ami_stuff]

IFF ANIM file format info:

 http://amigan.1emu.net/reg/iff.html

IFF ANIM player with source code:

 http://aminet.net/package/gfx/show/iffanimplay_68k

Sample IFF ANIM files:

 http://aminet.net/pix/anim

C:\>ffmpeg -i 040.anim
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
040.anim: Invalid data found when processing input

[ami_stuff]

I forgot about XAnim.

 http://xanim.polter.net/

IFF Animations and Images

    * Color cycling with single images and animations.
    * Supported IFF Compressions:
          o Anim3
          o Anim5
          o Anim7
          o AnimJ
          o Animl
    * Supported Amiga Display modes:
          o normal(BitPlanes) depths 1 - 8.
          o Extra Half-Brite(EHB) depth 6
          o HAM(Hold And Modify) depth 6 and 8

[ami_stuff]

I have created some samples:

 http://www.datafilehost.com/download-0ecca2be.html

I will attache win32 player since the author's site seems to be down for good.