seems to be related to 49f2056289ab61be8803e86ca4cb0a6fd3116ead (ticket #645), because there is no problem with 8bpp file
C:\>ffmpeg -i 2bpp_gray_odd.png out.bmp
ffmpeg version N-39339-ga0340df Copyright (c) 2000-2012 the FFmpeg developers
built on Mar 28 2012 02:25:58 with gcc 4.5.0 20100414 (Fedora MinGW 4.5.0-1.fc
14)
configuration: --prefix=/var/www/users/research/ffmpeg/snapshots/build --arch=
x86 --target-os=mingw32 --cross-prefix=i686-pc-mingw32- --cc='ccache i686-pc-min
gw32-gcc' --enable-w32threads --enable-memalign-hack --enable-runtime-cpudetect
--enable-cross-compile --enable-static --disable-shared --extra-libs='-lws2_32 -
lwinmm' --extra-cflags='--static -I/var/www/users/research/ffmpeg/snapshots/buil
d/include' --extra-ldflags='-static -L/var/www/users/research/ffmpeg/snapshots/b
uild/lib' --enable-bzlib --enable-zlib --enable-gpl --enable-version3 --enable-n
onfree --enable-libx264 --enable-libspeex --enable-libtheora --enable-libvorbis
--enable-libfaac --enable-libxvid --enable-libopencore-amrnb --enable-libopencor
e-amrwb --enable-libmp3lame --enable-libvpx --disable-decoder=libvpx
libavutil 51. 44.100 / 51. 44.100
libavcodec 54. 12.100 / 54. 12.100
libavformat 54. 3.100 / 54. 3.100
libavdevice 53. 4.100 / 53. 4.100
libavfilter 2. 66.100 / 2. 66.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 10.100 / 0. 10.100
libpostproc 52. 0.100 / 52. 0.100
Input #0, image2, from '2bpp_gray_odd.png':
Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
Stream #0:0: Video: png, gray, 1023x767, 25 tbr, 25 tbn, 25 tbc
[buffer @ 0x1db1ba0] w:1023 h:767 pixfmt:gray tb:1/1000000 sar:0/1 sws_param:
Output #0, image2, to 'out.bmp':
Metadata:
encoder : Lavf54.3.100
Stream #0:0: Video: bmp, gray, 1023x767, q=2-31, 200 kb/s, 90k tbn, 25 tbc
Stream mapping:
Stream #0:0 -> #0:0 (png -> bmp)
Press [q] to stop, [?] for help
frame= 1 fps=0.0 q=0.0 Lsize= 0kB time=00:00:00.04 bitrate= 0.0kbits/
s
video:768kB audio:0kB global headers:0kB muxing overhead -100.000000%
