DVDSP changing the length of audio files
by Jane Dow
on
May 6, 2008 at 5:27:27 pm
This is a problem that is driving me crazy. I can't work out what is happening to my audio files when I import them into an NTSC DVDSP project.
I have a PAL and NTSC version of the same project, using two audio tracks, 5.1 and stereo, both AC3 files created by Compressor. When I import them into the PAL project the asset length is correct 01:49:58:02. As soon as I click the NTSC button to change the project settings, the audio asset length is suddenly shorter 01:49:51:15.
When dragged into the timeline, the audio is too short and gets progressively more and more out of sync. The same thing is happening with AIFF files.
The audio was originally edited in Final Cut then exported using Compressor. The only workaround I have discovered is to export the audio out of an NTSC FCP timeline then export to compressor. This worked fine for the stereo track, but it takes quite a bit of time to re-export all the 5.1 tracks then convert to AC3.
I have also tried exporting AIFFs out of FCP then converting to AC3 (using Compressor), but hasn't helped.
Any ideas on what on earth is happening? Shouldn't the audio be exactly the same for PAL and NTSC projects? I have converted projects in the past without this problem.
Thanks in advance for any light you can spread on the subject.
Re: DVDSP changing the length of audio files by Michael Sacci on May 7, 2008 at 2:08:33 am
Well, first off, hitting the NTSC does not make you project change to NTSC, the project needs to be totally re-authored and your assets converted before you bring them into DVDSP.
Re: DVDSP changing the length of audio files by Jane Dow on May 7, 2008 at 2:48:54 am
Yes, I've done all that. Re-encoded all the video material and deleted it from the project etc.
Just as a test I started a brand new project with no assets then imported just the audio track. Then clicking the NTSC/PAL button and seeing the menu window change dimensions between formats, the audio file length also switches. Very frustrating.
I have now re-exported all 6 of the 5.1 tracks out of an NTSC FCP timeline as AIFFs, then used Compressor to create a 5.1 AC3 file. This time when I import it into an NTSC DVDSP project the length is correct.
Why? Shouldn't audio be the same for both formats, as I've read numerous times?
