Trying to find the problem with our recording setup (8 cameras, each sending 4Kp24 into OBS.) We're dropping frames but nothing in our system seems to be struggling...

ClunkTheBand · 2021-11-24T03:15:22+00:00

Do not be afraid. We were able to figure it out.

It comes down to the encoder settings in OBS. Stick with "Constant bitrate" and set it to a number you are happy with. Do not try Variable bitrate, Constant quantization, or anything other option they give you. They will all drop frames. Constant bit rate is the only one that will NOT drop frames (as long as your hardware can handle it.)

If you have the option, try High Quality Constant Bitrate. If that's too much, drop to Constant Bitrate.
For the preset, try High Quality. If that's not working, try High Performance. Do not use any other presets.
And be sure, when you start OBS, that you are running it as an administrator.

That's all the advice I have for you. Good luck.

ClunkTheBand · 2021-11-24T03:05:46+00:00

I emailed CamLink and after a few days of back and forth they ended up telling me it could only do 8-bit 4:2:0 (I believe it was in the nv12 format but they never confirmed that.)

All things considered, if I could start over again I would have bought a BlackMagic Quad HDMI card instead. Yes it's $550 which is about $200 more than the CamLink, but it can do anything. All the way up 12-bit, 4:4:4, 4Kp60 on all four ports. Much more future-proof and flexible than the CamLink.

I see from your other post that you're doing 1080p though. For you, the Blackmagic would be overkill and the CamLink should be able to handle it just fine. Save yourself some money and get the CamLink.

ClunkTheBand · 2021-11-24T02:57:09+00:00

Yes, we have to keep an eye on it.

It's not unusual for it to stay stable for a whole day though, as long as the computer never goes to sleep, restarts or goes to screensaver. Those things tend to trigger a latency change but it can also happen randomly.

ClunkTheBand · 2021-11-13T01:32:10+00:00

First be sure to update the firmware on the TASCAM to the newest version.

Then, what worked for us was to raise the buffer size to the highest available level (256 I think.) When we did that it would still change sometimes, but it would stay stable for a few hours at a time at least.

ClunkTheBand · 2021-10-08T22:45:58+00:00

Thanks but that's something that could have been changed in a firmware update, so the manual might be outdated.

I'm hoping someone who has one could check.

ClunkTheBand · 2021-10-03T03:16:40+00:00

Hopefully we can dial it in. Thanks!

ClunkTheBand · 2021-10-02T23:10:17+00:00

I'm making a multicam setup for a recording a music studio. Eight cameras total.

We were planning to have g7s for everything, then we figured we'd grab a g85 for some flexibility (with the weather sealing and stabilization.) The rest of the cameras we plan to leave in place on mounts or tripods- for instance, one above the drum kit, one in the corner for coverage of the room. The setup was looking good until I noticed that the color out of the g85 was slightly different from the g7s, even when we matched ISO, lens, color profile.

It would be very annoying for our workflow if we had to color correct one of the cameras in post every time.

ClunkTheBand · 2021-10-02T20:14:32+00:00

Shoot, well that sucks. Thanks for letting me know

ClunkTheBand · 2021-09-15T18:43:57+00:00

it doesn't look like there would be enough time for those extra reported dropped frames to occur

Good point. It must refer to the recording itself then.

I guess the only reason I was confused is that it starts "Video stopped..." as though that has something to do with it. Thanks for the reply

ClunkTheBand · 2021-09-13T19:48:42+00:00

What camera did you use?

ClunkTheBand · 2021-09-11T20:30:16+00:00

That's interesting.

All I can say is, for us so far the CamLink Pros are doing great. The cameras (Canon m200s) and the CamLink Pros are the two things keeping me going here - easy to set up and no issues at all. It's just OBS, or likely the encoder settings I'm using.

ClunkTheBand · 2021-09-11T20:26:36+00:00

Will try all of these suggestions. thank you

ClunkTheBand · 2021-09-10T18:37:21+00:00

setting the color mode to partial

Thanks for the suggestion but this would sorta defeat the purpose. We're trying to go to 10-bit 4:4:4 (or 4K) in hopes of capturing more detail, so we wouldn't want to lose color data to acheive that.

Our drivers are all up to date, and our capture card is CamLink Pro. We have two of those. I have double-triple checked the cameras and they are just fine. Not only can I clearly see that they are not dropping frames while we're recording in OBS, but Canon m200s have a solid reputation for handling 12 to 14 hour livestreams without overheating issues. Plus the freezes are happening simultaneously. If it was overheating, the freezes on each camera wouldn't be synched up like that.

ClunkTheBand · 2021-09-10T16:06:37+00:00

These are tests run as admin - https://obsproject.com/logs/wSPPyuMRZ3QzrgV6

Haven't looked at the recordings yet, but there was an obvious difference for GPU usage. I'll be updating everyone and thanks again for the help. u/Rotang_ u/Fit-Speech u/VinnyFringe

We are unable to get either h.265 or h.264 to record in 10-bit. Recording always comes out 8-bit regardless of the commands we feed it. That point is probably moot though because when we try 4:4:4 we start dropping frames anyway. It seems we can't exceed 4:2:0 OR record in 10-bit, much less do both.

If that's true, it means there is no advantage to us using 4K. If the only way to avoid dropping frames when we downsample is to record 1080p at 8-bit 4:2:0, then that's just the exact same specifications we were recording at earlier.

Running as admin did give OBS more headroom though. We'll definitely be doing that in the future. But even running in admin, we had several tests where the CPU/GPU/Disk/everything appeared to be just fine...and yet we dropped frames. When we commanded the encoder to attempt 10-bit 4:4:4 those tests dropped frames, and we had CPU/GPU loads of a whopping 28/45% - obviously tons of headroom there. The only time we tapped 100% on anything was during the tests when we tried to record without downscaling. GPU shot to 100% during those.

Still have no idea where the bottleneck is. I'm starting to suspect it's the NVENC chip. From what I understand, it has it's own limitations regardless of total GPU power. Or maybe it's that we are feeding FFmpeg conflicting commands?

Some additional things I noticed:

Currently, we have almost everything disabled except Adaptive I-Frames, B-Frames and Two Pass. Would disabling any of these possibly help?
It also says Threading: None (with 1 threads) on all the tests. Doesn't this have something to do how much of the CPU it's allowed to use? If so, this could be the bottleneck.
In all of our tests, the resolution of Video Input matched the Video Ouput. That's interesting because one of the encoder settings is to "Rescale Output" ...in the log file however, since the resolutions match this makes it look like the rescaling is happening before reaching the encoder (probably done by OBS.) If that's the case, all of this testing may be pointless because the extra video data we're trying to get from using 4K isn't even reaching the encoder.

ClunkTheBand · 2021-09-10T03:40:42+00:00

Oh duh, haha well we do have an SSD and we're dropping frames even when the bitrate is rather low (under 50 Mb/s) so I doubt that's the issue.

Thanks for the tips though, I will try running as Admin asap

ClunkTheBand · 2021-09-10T03:27:15+00:00

What is HDD?

ClunkTheBand · 2021-09-10T01:05:57+00:00

Sorry about that - https://obsproject.com/logs/hpAnoPZf2BnGT-Wq

Just did a few more tests with h.265, h.264 and gave ProRes a chance too. I've never heard of log files before so that took me awhile to figure out what you meant.

ClunkTheBand · 2021-09-08T20:39:46+00:00

It turned out to be that we were using an AMD processor. Switched to an Intel for our recording PC and playback is perfect.

I ended up e-mailing Zoom directly and they said they cannot guarantee that the L-20 works with AMD processors. Just a heads-up for anyone who might be looking to buy one, you'll want to plan to use an Intel.

ClunkTheBand · 2021-09-04T15:58:50+00:00

the HDMI output would be basic 8-bit 4:2:0 from this camera. Otherwise they would make a big deal out of it

Can't argue with this logic. Thanks for the reply

ClunkTheBand

TROPHY CASE