Help... Been attacking an audio drift problem for 25 hours straight, no sleep. FCP

[Austen Collins]

I am exhausted. I don't know what else to try. Everything looks fuzzy now.

I have been trying to burn a dvd of an hour long project - cut in FCP, compressed in Compressor, and authored in Encore.

The problem is drifting audio. It starts off fine, then drifts 12 and a half frames out of sync. When I lay down the encoded assets in a timeline in Encore, the tracks are uneven at the end. The audio runs 12.5 frames longer than the video. I suspect this is the problem. But I have exhausted all possible solutions. This is just how it is, straight from compressor.

First I exported a self-contained quicktime from my 23.98 1080 ProRes HQ sequence in FCP. The only audio in the sequence comes from a final mix exported from STP, it is all 48 KHz, matching my sequence settings. Then I ran the quicktime file through compressor, using it's high quality DVD settings. And the result is a file that does not sync up. The problem appears to be a compressor problem.

This is a common issue. I have absorbed at least 200-300 message board postings regarding this issue in the last 15 hours, each thread ending in tragic failure.

Now, I'm wondering, is there any special person out there, who has a REAL fix for this issue...

[Vito DeFilippo]

You're using Encore?

Try this. Export a wave file (or aiff on Mac) from your timeline. In Encore, right click on the audio track (that came from compressor) on the DVD timeline and choose "replace asset". Choose the new audio file you exported from your timeline.

If they match up, you're home free. If not, I'll let someone else chime in....

[Austen Collins]

Thanks for giving it a shot Vito, but it's a no go. After replacing the asset, the audio track is still twelve frames ahead of the video. I tried burning a DVD anyway, but it is still out of sync.

The saga continues...

[Vito DeFilippo]

Okay, the next thing I would try is importing your self-contained quicktime into Encore, and letting Encore's internal compressor make the mpeg2 file for you. Perhaps there was a glitch in the Compressor encode.

You could also try re-encoding the file in Compressor and see if it works.

[Austen Collins]

I've re-encoded in Compressor 6 times now. I will try compressing via Encore's transcoder.

I've been reading lately, that the issue arises when using Qmaster with Compressor to encode a piece of content with an editing time-base of 23.98. So right now I'm doing an excruciating 4 hour compression without Qmaster to see how it turns out.

Will keep the thread updated with results.

[Noah Kadner]

How do you know the Soundtrack Pro audio matches the 23.98 video?

Noah

[Austen Collins]

"How do you know the Soundtrack Pro audio matches the 23.98 video?"

Well I'm assuming it does because the exported self contained file from FCP plays fine, with no audio problems at all.

UPDATE: After compressing again via compressor WITHOUT using Qmaster virtual cluster, the audio now only appears to be half a frame longer than the video file, when I lay it down in an Encore timeline. Unfortunately the sound drifting is now exacerbated, and starts off in sync for the first few minutes, then by the end it drifts 8 seconds behind.

Trying to solve this for 17 hours and still counting...

[Austen Collins]

Alright, I've solved it, many many hours later. I'll post my findings in here for others to reference.

The problem is using compressor with Qmaster. Yes, it encodes real fast and that's very exciting, but for some reason it is screws up the file. Don't do it. Especially if you have a 23.98 frame rate. It will result in audio drift.

Instead, I compressed the self-contained file without Qmaster. This resulted in a significantly worse audio drift problem, but I ditched the audio track, and exported an .aiff from my FCP timeline. I brought this is to Adobe Encore and it worked! It was still 1/4 of a frame longer than the video track, but everything was in sync.

Good luck out there. Time to sleep.

[Vito DeFilippo]

Glad you worked it out!