We talked about this a lot a few years ago over in the Slysoft Reclock forums, which I was very heavily involved in. At the time, and I have not heard anything to say it has changed, there was only ONE, yes one, PAL DVD that anyone knew of that pitch corrected for the 4% speed up (one version of the original Lord of the Rings movie). Not saying there might not be more, but no one had noticed it. They are certainly very rare. The main reason, I believe, again discussed in depth over at Slysoft, is I don't think there is a method of pitch correction for tempo change that doesn't do very nasty things to the sound. The Reclock pitch corrector cuts the sound up into time slices, pitch corrects each slice then stitches them back together. Depending on the track you can sometimes hear the join! Almost worse, the audio is processed in channel pairs, not all 6/8 channels at once, so the phase coherence between fronts and rears and centre/sub is lost. Put more simply, even if the quality of each channel was perfect the surround effect is hopelessly messed up when you put them all together. I don't know what MC uses for pitch correction (it would be interesting to hear), but unless they use a completely different approach it's a bad idea, especially for movies!
So for almost all PAL DVDs when you slow them back to 24p you actually get the right, original, sound. What I believe Matt to be saying is that the pitch doesn't change when the track is slowed down 4%, which would imply that MC is correcting for the pitch shift due to tempo change, which is almost certainly not the right thing to do both because it is unnecessary and because it might well be butchering the sound! On the other hand the audio path does not say that is happening, so either Matt has it wrong or MC, when using Videoclock, pitch corrects silently. I'd find that surprising, but I guess it's possible ?
