-
Strange sound/sync problem in CS4
Hi guys and gals, wonder if anyone can help me out on this one?
I’m running PPro CS4 on a purpose-built matrox rtx2 system, working mostly from DVCAM.
I’ve done a complete edit, cutting various interview soundbites over music to make a testimonial montage. After doing the complete audio mix, everything sounds fine and dandy when I preview it after rendering. The problem occurs when I output the film using AME to a variety of different formats. Where previously I had precise edits on the timeline, the audio cuts sound to be a couple of frames out. For example, one cut occurs just after the line ‘ideal product for our needs’ and sounds exactly as it should on the timeline, but on the outputted file it sounds like he says ‘ideal product for our nee…’.
Same thing occasionally happens on music mixes, when I cut to the beat to use different sections of the backing track and crossfade through, it sounds fine on the timeline but then after I output the file then cuts the sound off the beat and the music sounds like it goes slightly out of time on the transition.
I’ve even tried rendering it out as a wav file, but that doesn’t work either.
Is it something I’m doing wrong? I’ve checked and it’s all 48k sound (and if it was a sample rate issue I assume it would appear on the timeline as well). Or is it another to add to the long list of problems we’ve had with the matrox setup?
Any help will be greatly appreciated!
-
5 Replies
-
What player are you previewing your video with? I know for instance, Quicktime (Mac and Win) has a bug that causes sync issues for MP4 wrapped videos.
Can you bring your rendered file back into premiere, put it on a dummy timeline and check the sync?
-
I’ve tried with Quicktime and VLC. I’ve also tried outputting to a wav file and then replacing the audio tracks with it, but it still happens. Strangley it seems to only be the sync on the out points of certain audio clips, rather than the whole film.
-
Are these audio clips from a sync or from camera? Are you conforming either in any exotic fashion? I’m a little stumped as Premiere usually conforms and retimes automatically and you don’t usually get sync issues.
Did you start on a 30fps timeline and go “damn” and paste your cut into a 29.97fps timeline? I’ve don’t similar and it’ll cause gaps and throw things out of whack.
Just throwing out random stuff.
-
Thanks Angelo, I’m pretty sure it’s not the frame rate, as we work exclusively with PAL DV at the moment, so every sequence we create is 25fps. All of the material comes from dvcam tape.
I’ve tried rendering everything, including the audio. The workaround I found through a lot of trial and error was to leave a few extra frames on the end of the voice, so that it now includes the first sound of the interviewee’s next line, so ‘ideal product for our needs an….’ so although now it sounds completely wrong on the timeline, it sounds fine on the outputted file.
I’m not even sure if out of sync is the correct way to describe this problem, as lip sync etc is all seemingly ok, and the cuts that were on the beat on the timeline come out so in the final output, but it’s the out points of certain audio clips that seem to be coming out incorrectly.
Another side effect of this is when you cut the music track to change the volume level of a section and cross fade between the two, even though it’s the EXACT same piece of music with no edits made to it apart from the volume, it still sounds like it skips half a beat when it hits the cut. Again this only happens on the outputted file, whether it is wav, avi, flv, whatever, and the timeline in Premiere always sounds as it should, before and after rendering.
Thanks,
Kev
-
In the upper right of the timeline window, use the menu icon to switch timecode to audio units and then zoom in to look for fine sized gaps and overlaps.
As another possible issue, just make sure Premiere is up to date too.
Reply to this Discussion! Login or Sign Up