2010/6/23 Doug Semler <dougsemler@gmail.com>
Without looking at the code, I wouldn't be surprised if this is inline
assembly code that was written for 32 bit assembler.

You should ask/report this on the ffmpeg mailing list. I was planning on doing that myself, but  I've tried to subscribe to both ffmpeg-users and ffmpeg-dev and haven't heard back yet.

You could try configure --disable-asm, but as far as I remember it didn't help much in my case.