-
Why my audio be wacky and out of sync?
Hello all.
I’ll start by saying I very much do not understand the underlying principals of DVD authoring, I just hit the buttons and it makes the pretty pictures, so please be gentle.
Situation- 95 DV minute feature, export it from FCP 4.5 with Compressor using the “120 minute High Quality Encode” preset, burn it in DVD Studio Pro 3 with no menu, just one track and a few chapter markers.
Why is my audio out of sync on ONLY some shots when I play the DVD? And the sync is not drifting, it just suddenly jumps out and then back in for different shots. Different DVD players = different shots out of sync. I have never noticed this issue when I used the “Fast Encode” preset in Compressor in the past.
What am I doing wrong?
thanks muchly
rita -
6 Replies
-
Forgive me for asking, but you have checked to make sure that the audio is in sync for those shots on your tape, right?
Arnie
https://www.arniepix.com -
Yes I have,and it’s very good of you to ask. This is footage that has been used for months, and it has never been out of sync on the tape or in the captured file or in the FCP timeline. And the shots that are out of sync CHANGE when the SAME dvd is played in different dvd players. And the same footage has been made into dvds in DSP 3 many times before without any sync issues. So, it’s gremlins right? I’ve got a gremlin problem in my G5?
thanks!
-
[RitaKSanders] ” And the shots that are out of sync CHANGE when the SAME dvd is played in different dvd players. And the same footage has been made into dvds in DSP 3 many times before without any sync issues. “
Which leads to the next obvious question: did you use uncompressed audio, or did you encode the audio to AC3? If you’re using uncompressed audio, that’s the most likely culprit. You should use aPack to encode it to AC3.
Arnie
https://www.arniepix.com -
Yes, the audio is uncompressed. In the past I have had audio sync drift issues (drifitng in and out over ten minutes or so) when using AC3 audio. And I’ve never had a sync problem with uncompressed audio. Why is it that my uncompressd audio is suddenly jumping out of sync? And if AC3 is the only solution, how can I avoid sync drift in the future?
thanks kindly
-
Rita,
If you’re exporting to Compressor directly from FCP, that method is generally considered to be the most unreliable way of encoding prior to creating your DVD. The fact that you’ve always done it this way in the past doesn’t mean that you’ll continue to have good luck with this particular workflow.
May I recommend a more reliable way: export your QT movie from FCP as self-contained, video only. Export your audio separately using the ‘export audio to .aif’ command. Open the Compressor app. and use any of the presets available, just like you did when exporting from within FCP. Convert your .aif audio to AC3 audio using A.Pack and then you can bring all of these elements into DVDSP. I’m assuming you have the first version of Compressor. If you use Compressor 2 then you can convert your .aif audio from within the new version.
The above method has worked for me for quite some time now with not one audio sync issue. Another advantage of this method is that you can still use FCP while Compressor works in the background. Using AC3 file format audio will also prove to be more DVD player ‘friendly’, as the high bit rates of .aif audio tend to make some players choke.
As always, it’s up to you whether or not you choose to export your QT movie as self-contained or as a reference movie. Hard drive space limitations will be your guide in that respect.
Hope this helps.
– Don
-
Wow, thanks so much, that was very helpful. I’ll use this workflow in the future!
rita
Reply to this Discussion! Login or Sign Up