[root@S80145-web video]# ffmpeg -i 90.mov -r 12 -b 10 90.flv                                                     ffmpeg version CVS, build 3277056, Copyright (c) 2000-2004 Fabrice Bellard
  configuration:  --prefix=/usr --libdir=/usr/lib --mandir=/usr/share/man --enable-mp3lame --enable-libogg --enable-vorbis --enable-theora --enable-faad --enable-faac --enable-libgsm --enable-xvid --enable-x264 --enable-a52 --enable-a52bin --enable-dts --enable-pp --enable-shared-pp --enable-shared --enable-pthreads --enable-gpl --disable-opts --disable-strip
  built on Jan  6 2006 21:05:55, gcc: 3.4.4 20050721 (Red Hat 3.4.4-2)

Seems that stream 1 comes from film source: 2997.00 (2997/1) -> 12.00 (12/1)
Input #0, mov,mp4,m4a,3gp,3g2, from '90.mov':
  Duration: 00:01:55.1, start: 0.000000, bitrate: 182 kb/s
  Stream #0.0: Audio: aac, 96000 Hz, 0 channels
  Stream #0.1, 12.00 fps: Video: h264, yuv420p, 320x240
File '90.flv' already exists. Overwrite ? [y/N] y
Output #0, flv, to '90.flv':
  Stream #0.0,   nan fps: Video: flv, yuv420p, 320x240, q=2-31, 10 kb/s
  Stream #0.1: Audio: mp3, 96000 Hz, 0 channels, 64 kb/s
Stream mapping:
  Stream #0.1 -> #0.0
  Stream #0.0 -> #0.1
[flv @ 0x3b35c8]removing common factors from framerate
Error while opening codec for output stream #0.1 - maybe incorrect parameters such as bit_rate, rate, width or height