tiff: support "old style LZW"

[ami_stuff]

quad-lzw.tif 512x384 8-bit RGB (lzw) "quadric surfaces"

C:\>ffmpeg -i quad-lzw.tif out.bmp
ffmpeg version N-36635-gceb0dd9 Copyright (c) 2000-2012 the FFmpeg developers
  built on Jan  9 2012 17:39:58 with gcc 4.6.2
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-ru
ntime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libope
ncore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-libgsm --en
able-libmp3lame --enable-libopenjpeg --enable-librtmp --enable-libschroedinger -
-enable-libspeex --enable-libtheora --enable-libvo-aacenc --enable-libvo-amrwben
c --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-
libxvid --enable-zlib
  libavutil      51. 34.100 / 51. 34.100
  libavcodec     53. 54.100 / 53. 54.100
  libavformat    53. 29.100 / 53. 29.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 58.100 /  2. 58.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    51.  2.100 / 51.  2.100
[tiff @ 02645B60] Decoded only 3 bytes of 1536
Input #0, image2, from 'quad-lzw.tif':
  Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: tiff, rgb24, 512x384, 25 tbr, 25 tbn, 25 tbc
Incompatible pixel format 'rgb24' for codec 'bmp', auto-selecting format 'bgr24'

[buffer @ 020F1760] w:512 h:384 pixfmt:rgb24 tb:1/1000000 sar:0/1 sws_param:
[buffersink @ 020F19E0] auto-inserting filter 'auto-inserted scale 0' between th
e filter 'src' and the filter 'out'
[scale @ 020F1E60] w:512 h:384 fmt:rgb24 -> w:512 h:384 fmt:bgr24 flags:0x4
Output #0, image2, to 'out.bmp':
  Metadata:
    encoder         : Lavf53.29.100
    Stream #0:0: Video: bmp, bgr24, 512x384, q=2-31, 200 kb/s, 90k tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (tiff -> bmp)
Press [q] to stop, [?] for help
[tiff @ 02645B60] Decoded only 3 bytes of 1536
frame=    1 fps=  0 q=0.0 Lsize=       0kB time=00:00:00.04 bitrate=   0.0kbits/
s
video:576kB audio:0kB global headers:0kB muxing overhead -100.000000%

[Elon Musk]

Do we really need to support old style LZW codes?

[ami_stuff]

We need at least reject files like this, though support would be nice.

[compn]

i'm curious why we support any of these old weird image formats. are we going to overtake imagemagick? :)

[ami_stuff]

Well, I like bug free/full feaured software. Since FFmpeg already supports weird image formats I see no reason why it shouldn't decode them correctly (or at leaast not try to incorrectly decode files with features which are not supported).

[Michael Niedermayer]

added a error message