st/va encode handle ntsc framerate rate control

Tested with ffmpeg and gst-vaapi. Without this bits per
frame is set way too low for fractional framerates.

v2: Mark Thompson: simplify calculation.
    Use float.

Signed-off-by: Andy Furniss <adf.lists@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
1 file changed