Originally posted by: Doctor M
Hmm. First let me nit-pick and say that technically PAL audio isn't time stretched, it is time compressed since the runtime is less than the original. It runs faster, hence the increased frequency. Correcting it requires time expansion. For most PAL material, like it or not, that's really the best alternative out there if you're turning it back to NTSC.
Commenting on the rest (and I could be butt-ass wrong):
As far as pitchshifting. Typically it would not be needed as it only changes the frequency, not the actual speed/length of a clip. In this case (and I thought my ears were playing tricks on me too when I heard the butch C3PO) time expansion is STILL needed. Otherwise when the framerate is slowed to 24fps, the audio will run too short. We are (unfortunately for me) finding that evidentily it will need ADDITIONAL pitchshifting to reverse the whole process they put it through.
From what I gather it's not common practice for films on PAL VHS/DVD/LD to be pitch corrected after/during the 4.096% speedup to 25fps, which is why it surprised me somewhat to find it had been done to the SW VHSs Moth3r used for his DVDs, especially considering how old the recording is.
I was playing with timestreching whilst preserving pitch with CoolEdit earlier, I thought I'd found an optimal setting that didn't destroy the audio till I tried it on a much larger clip... it practically destroyed the intro music completely
I like the idea of resampling first and then adjusting pitch, may have to give that a try, otherwise if I'm not happy with that method I'll just stick to my original plan of resampling and having a 4% higher audio pitch.
So the choices are looking to be: exhaustively edit in an NTSC audio track, give up, or wait for Citizen's release since he will probably not have to add/remove frames to make his audio track match (which will make for an easier match to the DC audio later). Anyone got an external drive they want to send to Citizen for me so I can get the avi files instead
Hmm. First let me nit-pick and say that technically PAL audio isn't time stretched, it is time compressed since the runtime is less than the original. It runs faster, hence the increased frequency. Correcting it requires time expansion. For most PAL material, like it or not, that's really the best alternative out there if you're turning it back to NTSC.
Commenting on the rest (and I could be butt-ass wrong):
As far as pitchshifting. Typically it would not be needed as it only changes the frequency, not the actual speed/length of a clip. In this case (and I thought my ears were playing tricks on me too when I heard the butch C3PO) time expansion is STILL needed. Otherwise when the framerate is slowed to 24fps, the audio will run too short. We are (unfortunately for me) finding that evidentily it will need ADDITIONAL pitchshifting to reverse the whole process they put it through.
From what I gather it's not common practice for films on PAL VHS/DVD/LD to be pitch corrected after/during the 4.096% speedup to 25fps, which is why it surprised me somewhat to find it had been done to the SW VHSs Moth3r used for his DVDs, especially considering how old the recording is.
I was playing with timestreching whilst preserving pitch with CoolEdit earlier, I thought I'd found an optimal setting that didn't destroy the audio till I tried it on a much larger clip... it practically destroyed the intro music completely
I like the idea of resampling first and then adjusting pitch, may have to give that a try, otherwise if I'm not happy with that method I'll just stick to my original plan of resampling and having a 4% higher audio pitch.
So the choices are looking to be: exhaustively edit in an NTSC audio track, give up, or wait for Citizen's release since he will probably not have to add/remove frames to make his audio track match (which will make for an easier match to the DC audio later). Anyone got an external drive they want to send to Citizen for me so I can get the avi files instead
I have on my harddrive a 2.6gb avi of the definitive LD of ANH with no frames lost during the capture, manually removed the 3:2 pulldown then highly compressed it to mjpeg format because each frame is a keyframe, looks terrible but it doesn't matter because I only need it as a guide for syncing up to my PAL capture, the audio was captured & stored in the avi as uncompressed 48khz PCM...