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Audio Sync Between PAL and NTSC Problems
Hi All,
I think I’ve found quite a major audio sync quirk but not seen mentioned anywhere. It can have serious implications for those working in PAL and NTSC versions of the same project in Final Cut Pro, even if they are in different project files. Especially if you intend to archive back to tape from FCP.
I have worked out a simple and relatively quick proof of the bug that I’ve detailed below and tried it on two machines, and wondered if anyone would want to try out the issue and see if it’s just me!
Details below my sig and FYI I’ve tried going in the other direction and with DV and Blackmagic format clips and it’s always the same result. The only fix I’ve found is to change from PAL to NTSC using the quick setup menu. (Which makes me think maybe it’s linked to Capture Settings maybe?)
I’d be interested to see at what version this bug was introduced (I’m at V5) and some confirmation that I’m not going insane! 🙂
Rgds, Stef Goodchild
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(note: This can be done in the opposite direction ie NTSC -> PAL)
Take a PAL format .mov with a soundtrack. (Can be short maybe two/three mins)
Do software conversion to NTSC using After Effects (or similar) and use the frame blending option so it’s the same speed etc and should be dead on in sync, and output with audio.
So you have moviePAL.mov and MovieNTSC.mov
Open the movieNTSC.mov in Quicktime and export “Sound to AIFF” to a file called audioNTSC.aif (Same Bit depth and Sample Rate) –
(note : The bug also applies with audio that’s lined up and in sync but not exported from the movie, eg. audio back from a mastering house.)
Duplicate audioNTSC.aif and call it audioPAL.aif
Open FCP and drag on movieNTSC.mov and audioNTSC.aif
Drop them into an NTSC timeline.
Plays back fine. The .mov soundtrack is in sync with the exported .aif version as you’d expect.
Close FCP (don’t need to save the project) / Open FCP
change the sequence in the new project to PAL 25fps etc by right clicking on the sequence and using the settings dialogue, you can use the “load sequence preset” button if you like.
drag in the moviePAL.mov and the audioPAL.aif
drop them into the sequence…
You’ll hear very quickly that the .aif audio drifts out of sync with the .mov soundtrack audio, which is very odd seeing as the audioPAL.aif has never been near an NTSC project in FCP, as it was duplicated before the audioNTSC.aif was put on the NTSC timeline and is *a different file altogether*!
Also note that with the waveform drawing on in FCP you can see that the audio waveforms line up correctly and with the video + it’s soundtrack turned off you can see that the audio is playing out of sync with it’s own waveform display.
Quit FCP
To check the sync between the Aiff and the Mov you can open the two PAL files (audio and video) in Quicktime Pro and paste the AIFF into the MOV to check the sync outside of FCP…
All perfect.. Not even out of phase. The sync is only off in FCP.
For those working with multiformats this could cause serious problems with syncing audio to video or for writing out archive tapes in both formats with the same Mastered audio files.
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2 Replies
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OMG!!! Finally, I’ve encountered someone who’s facing the same problem I’ve been having for the past 6 months.
I have a PAL timeline and I imported my audio mix from my sound guy. It’s perfectly synced on his system to a compressed video that I gave him. When I put the audio into my timeline (one hour episode), and I view the audio in my viewer window, my playhead is totally off. E.g.: in the main part of the Viewer window i scrub to the ‘end’ of the audio clip but if I look in the Viewer’s timeline bar (the white strip near the bottom), it’s only about 85% into my audio length).
The best bet to experience this is to grab a one hour AIFF and drag it into a PAL timeline and scrub around. It’ll be ‘on sync’ at the beginning but off sync near the end. The PAL audio was created from a proper Pro Tools session. He also exported the audio to DA-88 tapes with no problems at 25 fps.
I’m from Toronto, Canada (NTSC) incase that’s an issue. I’ve been having lots of troubles with using “PAL” audio files in Final Cut. Have you been able to find any solution? Does the ‘switching’ presets fix the issue? I’ll try when my FCP suite becomes available.
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This thread is sort of old, so probably not alot of replies should be expected. Feel free to e-mail me at phillip.roh@dante-ent.com to discuss this further
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