by Qyot27 » Mon May 04, 2009 12:04 pm
You'd want to use 30000,1001 if you want 29.97, not 29.97,1001 (but really, that's only if you're wanting to be anal about NTSC standard - 29.97,sync_audio=true works fine for most purposes). Even at that, though, you have a couple other options:
A) DirectShowSource's fps=29.97,convertfps=true parameters, which will keep the audio sync. Or if you'd prefer, fps=59.94,convertfps=true and then Decimate(2). Likewise, FFmpegSource's (2.00 only) fpsnum and fpsden parameters are meant to deal with VFR conversion. And you'd want to use fpsnum=30000,fpsden=1001 if you want 29.97.
B) If you sync_audio=true with AssumeFPS, follow that up with SSRC to fix the sample rate back to 44100 or 48000. The change from 31.25 may or may not result in a noticeable pitch change - 24->23.976 and 30->29.97 don't (at least to my ears), but those values are still very close, rather than more than a whole frame off.