tiff: support G3FAX1D

[ami_stuff]

attached "hack" allows decoding files from issue 1432

​http://www.voy.com/5188/466.html

C:\>ffmpeg -i Test_G3FAX1D.tif
ffmpeg version N-36088-gdd1fb65, Copyright (c) 2000-2011 the FFmpeg developers
  built on Dec 22 2011 12:39:23 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. 32.100 / 51. 32.100
  libavcodec     53. 47.100 / 53. 47.100
  libavformat    53. 28.100 / 53. 28.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 53.  0 /  2. 53.  0
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  5.100 /  0.  0.100
  libpostproc    51.  2.100 / 51.  2.100
Input #0, image2, from 'Test_G3FAX1D.tif':
  Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: tiff, monob, 1024x768, 25 tbr, 25 tbn, 25 tbc
At least one output file must be specified

[reimar]

If instead of commenting out, you change the condition to:
if(compr!=TIFF_CCITT_RLE && !g3d1 && find_group3_syncmarker(&gb, srcsize*8) < 0)
Does this then fix the issue without breaking any other of you fax samples?

[ami_stuff]

It breaks "CCITT Fax3" saved with IrfanView, sample attached.