The ffmpeg console outputs the following (and hangs after the last line):

FFmpeg version git-6a1265c, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --enable-gpl --enable-shared --disable-static --enable-memalign-hack --enable-libmp3lame --extra-cflags=-I/c/msys/local/include --extra-ldflags=-L/c/msys/local/lib --enable-zlib --enable-avfilter --enable-w32threads --extra
-cflags=-fno-common --enable-version3 --enable-avfilter --enable-runtime-cpudetect
  libavutil     50. 3. 0 / 50. 3. 0
  libavcodec    52.30. 2 / 52.30. 2
  libavformat   52.34. 0 / 52.34. 0
  libavdevice   52. 2. 0 / 52. 2. 0
  libavfilter    0. 5. 0 /  0. 5. 0
  libswscale     0. 7. 1 /  0. 7. 1
  built on Jun  9 2009 18:10:24, gcc: 4.2.1-sjlj (mingw32-2)
[avi @ 0xa7af30]non-interleaved AVI
^C

I have to abort using Ctrl+C at this point.

Using libav functions from the DLLs and stepping through the code, I can see that av_find_stream_info() never returns.