Video Offset " drifts " / shifts over time

[Schottlandru]

Hello folks,

weird phenomenon on the new production here and I haven't found a solution yet.
All of a sudden (it seems, or I hope it wasn't like this before) my video offset keeps shifting little by little. And into a negative direction.
(this is NOT THE SLIGHT DELAY DRIFT WITH EVERY PLAY that video hardware etc. have, I rather mean a "growing" video offset over longer time)


I have a syncheck and calibrate / double check for every project. Normally I am on 35ms, but I noticed it shifting over the day and I have been having to go to -180ms on extremes (yes, actually delaying video!)

Updateing from 11.2.1 to 11.3.1 (HD) hasn't solved it.
Plugins should be up to date.
Prefs and DB trashed.

I am on Win7 64x, video is desktop video but I have never had any issues like this before. I hope.

Anybody ever seen this? Searching hasn't found anything other than the usual "video start delay drifts with each playback", which is not the issue here.



Cheers for ANY ideas!
Andrew

[Brandonx1]

Frame Rate mismatch? If the vid in drop and your in non drop or something?

[Schottlandru]

No it's all PAL, 25fps. :-(

[Rich Breen]

So are you saying that if you play a short segment of the program in the afternoon, the video offset consistently has drifted from where it was in the morning on the *same* segment of program starting play from the same location?

If so, does a reboot fix it?

[Schottlandru]

Exactly that, yes. I always jump to the 2pop and verify with syncheck.
About +/- 7ms on fresh load (35 ms offset) over two video being up to 2,5 frames too early. Same 2pop. Nothing changed, no new plugins, routing etc, just standard mixing.

And yes, reloading helps, even changing DISK CACHE to settings seem like they reset things for a while.

[Postman]

What happens if you make a new user account?

Never seen it here on our Win7 machine which is currently running 11.3 (but usually with MojoDX for video output). What you describe seems almost impossible. Are you sure it happens with every session?

[Schottlandru]

Postman, do you mean creating a new Win7 account and installing PT on that?

It is happening with an old session too - I recorded and edited foley in this one, so I would have noticed the 180ms delay. Something must have triggered this.

I will try and see if it only happens with the Fireface 800 or also using onboard sound via Asio4all.

It sure seems unlikely - maybe it is the other way round, like audio buffers hanging and gradually adding up. Though a internally bussed re-record seems fine (a very few ms off, I guess this is either Waves C4 or WLM or Izotope Insight causing this though, have been seeing this for a while.)

[ggegan]

Are you an editor or a mixer? ie., are you working with plugins instantiated on the tracks and with ADC on? I'm wondering whether somehow plugin latency issues might be at work here.

Also, are you importing the correct Synccheck audio and video into the actual session you will be working with and measuring the offset using that exact session, complete with all the tracks and plugins you anticipate using? I would not trust working from a 2 pop, you should use an extended run of matched Synccheck audio and Video for the measurement.

I don't have any answers for you, I'm only trying to suggest ways to eliminate variables that might possibly be affecting the Synccheck measurements.

[Schottlandru]

Gary, thanks for trying to dig deeper!

To answer your questions:
- I am editor and mixer. The foley session I mentioned had no re-record bussing, the current show I am on has.
- ADC is on, Low Latency monitoring off.
- This hasn't been an issue for the last months, as far as I know (after all, I notice the 1-2 frame drift when editing, and it only popped up the other day).
- I usually do a beep on the first bright frame with syncheck in the actual session, through one of my dialogue tracks. So it is beeping through the exact chain I am working with.
- The "sync in the session" usually gives me +/- 10 to 15 ms, so about a quarter frame. The drift goes well over a frame or two, and is consistent once it appears - so not one of your usual desktop video/hdmi-out spans.

What I still want to check:
- I do have new fireface drivers but had an extensive mix session with my system at another studio where I double or rather triple checked sync. Still, a new factor in recent weeks. (but this would mean the asio buffers running out of sync or sth. similar)
- I also have new video drivers that however have been giving me smoother video playback. How these would pull video earlier though I do not know.
- a "new" plugin to these last to sessions has been RComp (Waves). I doubt this might be an issue but who knows, I will check. I do have other waves plugins in my session, but due to working for a fellow mixer I was using his setup and this seems like the only "fresh" ingredient in both sessions.

(as for the Fireface: I just did a playthrough with Asio4all drivers i.e. the onboard sound - and it shifted about 1.4 frames again after a good hour.)

[Schottlandru]

QUICK UPDATE this morning:

so far so good. With R-Comp, same video drivers etc.
What I did:
- uninstalled PT 10 and 11 HD
- reinstalled only PT11.3.1
- disabled core-parking (this is a CPU power saving thing buried into i7 processors)
- no Eucon / Avid Artist+Transport on at the moment
- no SFX library search manager that uses onboard audio to preview

The full reinstall could have helped, seems to have helped with unstable session loading. But this is just a good hour or two into the project...