Video Sync Offset in PT11 not that useful
 

In the reference manual it says:

"When using a video peripheral which is locked to video reference, offsets will be rounded to the nearest full frame."

The Syncheck reveals this to be true, but with an AJA T-Tap (not a genlockable device) it is also true. In my project studio, settings of zero get me under 0.1 frames discrepancy (pretty good). But in our main studio, Syncheck reports a consistent 0.4 frame, or about 20ms discrepancy. You can't correct for this using the video sync offset window! So I resorted to using a Time Adjuster plug-in on the 5.1 monitoring bus. A little weird.

That's the bad news. The good news is that PT11 without genlock is much, much tighter than PT10 without genlock. The Syncheck results suggest that you don't need to genlock if all you're doing is playback.

Using a Mac Pro 6,1, PTHD 11.3.1, and an AJA T-Tap.

Re: Video Sync Offset in PT11 not that useful
 

hasn't that always been the case? Good that PT11 without genlock is good enough for playback.

Re: Video Sync Offset in PT11 not that useful
 

Yes, I think that always has been the case, but my discovery was that even the cheapo AJA T-Tap without genlock is rounding to the nearest frame. If you have a subframe discrepancy, you must use Time Adjuster, you can't use the Video Sync Offset window.

Re: Video Sync Offset in PT11 not that useful
 

Ah that is odd. I wonder if it's getting some sort of clock from the T-Tap. be interesting to see if the same happens with Blackmagic Intensity range which also have no ref.

Re: Video Sync Offset in PT11 not that useful
 

We consider to transfer one of out room to MP 6.1 too. So it might be more general rather specific your system question.
Have you contacted Aja about this issue? Their support is pretty good.

Re: Video Sync Offset in PT11 not that useful
 

When playing back via a video peripheral, yes. Whether it is PT 10 with the QuickTime video engine or PT 11 with the Avid Video Engine, the offset is always rounded to the nearest whole frame. This means that there is +/- 0.5 frames of error. Research has shown that erring on the side of having video lead audio is less distracting than having audio lead video.

Just remember to not use that TimeAdjuster when bouncing to QuickTime or laying back to tape. Otherwise, your deliverable could be out of sync.

Re: Video Sync Offset in PT11 not that useful
 

Silly to offer quarter frame adjustment if it's just going to round it to a full frame.

That being said I've found the quicktime sync via a BM card so consistent when properly offset I feel no need for genlock, especially if while genlocked it's still going to round off. I can get it within a 16th of a frame consistently without it.

Re: Video Sync Offset in PT11 not that useful
 

You get quarter frame accuracy with Pro Tools v10 if you playback in the QuickTime video window on a computer display. Otherwise, the offset is rounded to the nearest whole frame.

Re: Video Sync Offset in PT11 not that useful
 

I finally got around to checking our PT 12 systems with the Syncheck II. We use the Blackmagic Intensity Pro cards, and the result is very stable. With our previous setup, the Canopus with PT 9, it was all over the place, sometimes locking almost a frame out, and constantly drifting. Now it is stable within a ms or 2 with no genlock. Adjusting milliseconds, it doesn't change until you go above or below 20 ms. Anything between -20 and +20 keeps it at zero. At a setting of +21 ms, Syncheck reads +32 ms (about 1 video frame). At a setting of -21 ms, Syncheck reads -49 ms (a little over 1 film frame). We have delay for our projector built into our B-chain (crossovers), so the 1 frame resolution isn't a problem for us. When I first saw the ms setting, I thought "This is awesome!" Too bad it doesn't work.

Re: Video Sync Offset in PT11 not that useful
 

I thought I read somewhere that slaving both the Sync HD and a video card to a reference signal in PT11 and 12 locks the audio and video to the frame edge. If that is true, there would be no need for quarter frame adjustments.