[theora] DVD NTSC video plays twice as fast when encoded with libtheora

[Jason Self]

https://roundup.ffmpeg.org/roundup/ffmpeg/issue1197

I had originally encountered this problem using ffmpeg2theora. I
switched to ffmpeg proper in an attempt to identify where the problem
was at, and found that the problem persisted. As a result I had
thought this was a problem with ffmpeg, but the ffmpeg folks seem to
indicate that this is specific to Theora (too much finger pointing I
think.) I can confirm that switching codecs does solve the problem,
though. Anyone care to weigh in? A small section (10MB) of the
problematic video can be obtained from
http://shows.bluehome.net/kfp_small.vob.