[SDL] To: sdl at lokigames.com

Sergi Mansilla serman at cetib.ictnet.es
Thu Apr 27 13:01:51 PDT 2000


> Do you want exactly 30fps, or a multiple (or short fraction) of the frame
> rate of your monitor? In the first case you have to resample your movie,
> either by doing very expensive interpolation, or be cheap and just
> duplicate a frame here and there.

Ah, I was ignoring the refresh granularity problem. To get (approx) 30fps
playback on a 100Hz monitor, I guess I'd need to alternate between holding
each video frame for 3 and 4 retraces.

Which makes me even more curious how some Win32 apps seem to be able to do a
good job without any direct control over the hardware. I suppose if the blit
happens fast enough, and the OS has a low latency timer, you could "average"
30fps by sleeping for 33 msec; then the new frame would go out on the next
retrace, whenever that happens to be.

Heh, wish I had a super-high-speed camera to see what really happens =)

Thanks for the insight,
Dan




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