Film-Tech Forum ARCHIVE: "Ben Hur" -- DCP Sound Sync Issues

This is topic "Ben Hur" -- DCP Sound Sync Issues in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Manny Knowles (Member # 1171) on 03-26-2013, 07:17 PM:

"Ben Hur" 4K DCP is out of sync here -- is anyone else running this? Are you having sound behind picture?

We've been running DCP's with 100ms delay for over 2 years. I'm running this with no delay, and sound still seems to lag behind picture by about a frame.

Actually, the lip sync is "rubbery" -- meaning the discrepancy seems inconsistent -- sometimes bad, sometimes worse.

Update -- It's definitely gotten worse -- we're about a full second out of sync now.

Here's the link to the "Ben Hur" thread in the Feature Info Forum.

Posted by Manny Knowles (Member # 1171) on 03-26-2013, 10:21 PM:

Update:

Rebooted both DSS200 and CP650 during intermission. Part Two played fine.

I am testing Part One and, so far, the problem seems to have cleared.

In other words, the DCP seems fine now.

CP650 is running version 2.3.6.6
DSS200 is running version 4.3.5.13

Posted by Sam King (Member # 4029) on 03-26-2013, 11:17 PM:

The Dolby show players have a nasty little habit of randomly going out of sync slightly. Hit pause, pause the movie for a second, then hit play. That always worked for us when we had Dolby.

Posted by Manny Knowles (Member # 1171) on 03-27-2013, 12:07 AM:

Thanks -- I'm documenting this now for the other operators -- I'll add that as the first line of defense -- then a full stop/restart (that's how we used to get our subtitles back sometimes) -- then, if those don't work, a full reboot.

To err is human, but to really f*ck it up, you need computers! [Big Grin]

Posted by Richard Fowler (Member # 893) on 03-27-2013, 12:31 AM:

Had that happen on a 30 second clip prior to a feature start for a premiere.....pausing during the QC check worked and at show time no problem.

Posted by Manny Knowles (Member # 1171) on 03-27-2013, 01:00 AM:

I'm curious if anyone reported this to Dolby when it happened..?

Posted by Steve Guttag (Member # 268) on 03-27-2013, 06:51 AM:

I have seen this too and have reported to Dolby. However the sync is was on the order of seconds off...not just a little! Pause/start seemed to get it resynced. Dolby did see the issue in the logs too. The 4.5.4 (2) can also exhibit the problem and that is the one that I reported the problem to Dolby.

I don't know if I've ever heard of this problem with 4.5.3 (9)...which I maintain is the most stable non-DCI version of the software.

Note, I've had other oddities with other brands too...like odd channel remapping...in that case, only rebooting solved it.

Posted by Manny Knowles (Member # 1171) on 03-27-2013, 06:14 PM:

The word from Dolby is that the black frames during the Overture are the culprit.

I was informed that the black frames were heavily compressed, possibly to save disk space.

This problem came up a year ago with "Ben Hur" and this was their finding.