Video Drifting In 5.1.1

Having upgraded to 5.1.1 there is a serious issue with drifting video. Both the output from the Declink studio card and the onboard video show a huge drift in sync. Over a period of 2 minutes the picture drifts ahead by at least 6 frames!

When pressing STOP the video resets and plays in sync for about 10 seconds then begins to drift again. This did not happen in 5.1.0 and we are using the same project which has not had any problems until the update to 5.1.1.

Using the latest Decklink Studio card with the latest 7.95 drivers and firmware. Video is AVI file.

What is going on?

Just to eliminate mistakes:

You’re sure the frame rate between project and video hasn’t changed, right?

Yes. All as was and have checked other projects too. Each project has video drift in 5.1.1 but not in 5.1.0.
I have been speaking with Tino about this so I am wondering why no one else has reported a problem!

Very weird - and of course, very concerning. I can not repro here, but that does not mean that there isn’t a problem.

Hm. by your calculations, the drift is 3 frames every 1500 (approx, I used 25fps for the calculation) - which is 1 in 500 - or 0.2%. This is so close to drop frame that I’d say if this is a bug, it has something to do with drop/non drop scenarios. (I realise my maths is in pal, not ntsc, but I only did it to look at the order of magnitude of the problem… and to maybe point folk / SB in the direction of where the problem might reside.)

Cheers, Brendan.

Thanks Brendan,
More worrying is the fact that you don’t have the same problem and neither does anyone else it seems.
We have now reverted back to 5.1.0 and the problem has disappeared.
I am waiting to get more feedback from Steinberg.