Pitch/Tempo Correction Question

[EpheMeroN]

I have a video at 25fps that I am going to do a 25>29.97 pulldown to so I can watch it on my NTSC tv/dvd setup.

But would doing a 25>23.976 pitch/tempo correction using SoundTouch in BeHappy on the AC3 bring the audio back to NTSC rate AND keep it in sync with my new video? Or does that only work when the video is 25>23.976 filtered and not 25>29.97?

[neuron2]

If you do pulldown of 25->29.97 for the video, you don't have to change the audio at all. The playing time of the video remains constant under this transformation.

[EpheMeroN]

If you do pulldown of 25->29.97 for the video, you don't have to change the audio at all. The playing time of the video remains constant under this transformation.
Yes. However this PAL dvd came from NTSC source so I can tell the audio is sped up a little bit from the previous conversion. I'd like to not have to re-encode the video if possible!

[FlimsyFeet]

Assuming it's a film source, I think the easiest way would be to re-encode the video to 23.976fps 720x480, and do a simple slowdown (resample) of the audio by whatever the correct adjustment is, so it no longer has the higher "PAL speedup" pitch.

If you really don't want to re-encode the video, then you could do the 29.97fps pulldown thing, but you'd have to apply a pitch-correction to the audio, so it has the correct lower pitch but remains the same length.

(Out of interest, how does the 25>29.97 pulldown work with PAL resolution of 720x576? Doesn't it need to be 720x480 for NTSC compatibility?)

[EpheMeroN]

(Out of interest, how does the 25>29.97 pulldown work with PAL resolution of 720x576? Doesn't it need to be 720x480 for NTSC compatibility?)
Yes you're exactly right. I completely forgot about the resolution because I was thinking just about the audio.

[EpheMeroN]

If you really don't want to re-encode the video, then you could do the 29.97fps pulldown thing, but you'd have to apply a pitch-correction to the audio, so it has the correct lower pitch but remains the same length.
So would this be how to properly do what you just mentioned using TimeStretch in BeHappy?

http://img183.imageshack.us/img183/5064/25551061nf5.jpg

[tebasuna51]

If duration of video/audio no change and you only want correct a previous 23.976 -> 25 speedup, you need reverse the change with a 25 -> 23.976 'Pitch change preserving tempo'.

With a 25 -> 29.97 your audio is more speedup (acute voices).

[FlimsyFeet]

Yes 25 -> 23.976, but I would think it's the top option "no pitch correction".
Edit - sorry didn't read properly. Yes tebasuna51 is right.

[EpheMeroN]

If duration of video/audio no change and you only want correct a previous 23.976 -> 25 speedup, you need reverse the change with a 25 -> 23.976 'Pitch change preserving tempo'.
Thanks! Worked perfectly.