Numerator was being range checked against the
denominator - preventing any frame rate slower
than 1 fps.

I've tested this on a Mac using using ffmpeg and
results are comparable to mp4 and ogg files generated
at the same time.

Not yet tested on Windows.

Johnny Klonaris
google@jawknee.com

Change-Id: Idb358dbc2e7dc000037880ede4a1b0df248a42c8