Video Sync problem

[VRS]

I have a very strange video problem.

In the past few weeks I've had a problem where after 8 to 10 minutes of playing the video will start losing frames. Then it will slow down and I look up and it's a couple seconds behind the audio.

Always running either DNX36 or ProRes picture. Never H.264. I've been working with ProTools with video for over 20 years.

I did a 90 minute project that I finished in April where everything was fine. I updated to 2024.3 since then. The problem started surfacing a month or so ago (well, that's when I noticed it - I was working on a bunch of non-video music for a couple months). I was working on a short film and noticed that when I'd play then entire video, it started going out of sync. Stop and start and everything is back in. I thought it was an error in the video that was sent to me.

I started working on another short and I have the same thing. On this video it always seems to be at the same point. It's like some buffer gets filled and starts slowing the video down.
I loaded the project from April and now it's doing the same thing. It played for 90 minutes without an issue back in April.

I have never had this with ProTools before. I've had lots of other video engine problems but not this.

When it happens, the red dot starts appearing in the video track in the edit window. Like it's getting errors. I loaded just the video and guide track into a separate session and played over and over again without a problem. So maybe a plug in? I tried disabling the plug ins that have been updated in the past few months but nothing changes.

I tried going back to 2023.12. Same issue. This morning I ran the ProTools uninstaller and the HD Driver uninstaller. Then manually deleted any file that was remotely associated with ProTools. (Except the plug-ins). Reloaded the 2023.3 HD driver and PT 2023.12.1. Same problem.

This has been weeks of trying to find out what's changed. It's very time consuming because the error takes so long to surface. I've run out of ideas.

I'm looking very seriously at "Video Sync Pro 6". Which seems so stupid that I have to buy this expensive program because PT won't play video properly (But I know many who have done just that!). With the industry slow down I don't really want to spend almost 500 euros right now.

Anyone?

Thanks, Vince

ProToosl HDX2, Sync HD, 2012 Mac Pro, Mac OS 12.7 (Ventura), 128G RAM, All SSDs, separate video SSD, ProTools 2023.12.1, BM SDI 4K, House sync,

[BScout]

Check this:
BM SDI 4K

Remove it from your system and and see if just playing a video straight out is fine

[VRS]

Originally Posted by BScout

Check this:
BM SDI 4K

Remove it from your system and and see if just playing a video straight out is fine

Well, it's definitely a BlackMagic issue.

If I un-install the BM software and try ProTools it will play fine. The video looks terrible, and the sync is not steady (which is why I got the SDI card a dozen years ago) but I don't get the video slow down errors.

I went down the rabbit hole of BM drivers and the only driver that works with Monterey is 12.1. There are others that are supposed to work but don't as many on the forum can attest.

I don't know what has changed from April to now. I tried just playing the video and mix track (disabling all source tracks) and it plays fine. Tried just SFX (there isn't much in this little walk and talk) and it started dropping frames right at the end. The processor is at 20% - with all the tracks it's at 50%.
Tried just Dx and just Mx and it seemed to work fine. Could be just when I played it. Sometimes it doesn't do it.
I tried disabling automation. Thought that was it. 30 seconds to the end of the piece, the video starts to lag. Grrrr

Going to get a demo of Video Sync Pro 6 and see what happens. What a giant waste of time.

[BScout]

You should be running 12.8.1
https://avidtech.my.salesforce-sites...eo-Peripherals

(Avid ones are just Blackmagic rebranded.)

However, running Monterey is its own problem. You should move up to Ventura.
If you plan on using Video Sync with the BM SDI, most likely you'll have the same issues.

[VRS]

Yes, I was wondering about moving to Ventura.

I just don't understand why it worked so well until just a couple months ago. That's what really baffles me.

[BScout]

Just curious, have you cold booted your system at any point in your testing?
i remember a BM problem once where that was the fix. Turned out I was changing PT sessions with different picture (DNxHD and Apple ProRes.) Somehow the frame buffer on the card (at this point, it was a PCIe card) was not clearing its memory. Had to stop a whole playback for about 30 mins trying to get it solved why picture was drifting. Amazingly embarrassing -- and the fix ended up being just as embarrassing (restart the system) but a reboot was doing it. It had to be a cold reboot. (which I hadn't done because the system was in a far away Central Machine Room.)

So wondering if at some point you opened a different picture session, went back to your normal sessions, and it's never cleared the problematic stuff.
(BTW, that day became where I swore off BM. We ended up flipping to an AJA card and those have worked flawlessly. Ever since, I have run into BM problems in many post studios. It's always a bit of voodoo getting the right PT version, right macOS version, and right BM driver version. And, sometimes, that still doesn't work)

[VRS]

Yes I have cold booted. Many times. Good suggestion though.
I also rebooted the SDI to HDMI box just in case.

I know about the BM problems. I wished I'd bought a AJA card years ago. I was seriously looking at replacing the BM card a few times - then I fix the problem, and it just works for a few years until the next problem.

It's also weird that it works in ProTools with just the picture and guide audio - nothing else in the session. So is it a PT thing or a BM thing? This session is very light though. It was messing up with just the SFX tracks on which was just 50 voices and barely any plugins.

I've mixed scores that are at the limit of both voices and CPU and never have had this video error. In fact, this error is very new - never experienced it before. If I have a problem with the BM card it just stops working for some reason (usually a driver update that it doesn't like). When it works, PT never has a problem playing back the video through it no matter how big the session is.

[Frank Kruse]

For what it's worth, I ran an AJA Lhi (only because I came from a BM SDI non-4k which doesn't work on M-Macs and I had an ancient LHi lying around) for a while but purchased the BM SDI card as I had problems. The BM card has been running great with the below setup just like before on my old 5,1 Mac with the non-4k card. I have not seen those issues you describe so far and the rig is fully genlocked as yours too but I do not have HDX2 in my machine.

There's one thing I found about the BM cards having recently worked on a 60fps project. The BM cards are unable to genlock to 1080 60fps trilevel sync (they just won't recognise it). You can work around it by feeding it 720p 60fps sync signal. It's nowhere mentioned in their documentation and I had to ask BM support about it. Other than that it's been fine.

I have seen picture stutter and other oddities on mixing stages that ran AJA and HDX cards in the same machine which were usually resolved by restarting the rig.

Since you're on a 5,1 Mac. Maybe it's because of OpenLegacy patcher? Have you tried a new post install update with a recent OLP? Or one of your SSDs is acting up? Have your tried running the video off a different SSD?

[VRS]

Thanks for your input Frank,

Yes I've tried different SSDs. Haven't tried updating the Open Core stuff.

I just ran 110 minutes of just picture and guide audio without a problem - imported the tracks from the April session into a new ProTools session. I then ran the same original session and within 10 minutes the picture starts dropping frames and stuttering.
This is the session that ran fine in April. 225 voices, CPU is at about 50% (no spikes, no errors), Disk activity is at 1%, Disk Cache 32%, Memory 16%. So all the audio is cached in RAM and the only disk activity is the picture.

If it's a BM problem, or a Mac problem, why does it play fine with just picture and 1 audio track? If it won't play back the video properly because of something other than ProTools then it should happen with just the video in a session.

[Frank Kruse]

This could be session specific. I had an odd thing a couple of months ago where the picture would always show a black frame when starting and stopping. Only in one of my sessions. Even importing the tracks into a new one didn't help.

The only way to fix it was to only import all audio tracks into a new empty session and manually spot the QT to a brand new video track. (do NOT import the video tracks from the offending session)

After that the issue went away. Maybe try that?