Strange Choppy Playback

Hello,

We experienced a strange choppy playback issue. The playback starts in realtime for 2 seconds (23.976), then got stuck and skips a few frames. Then it would resume in realtime, then get stuck and skip a few frames.

All clips are configured as "render cache clip source on" and "render cache clip output". Render cache is USER mode. Codec is DNxHR HQ. Cache location I/O bandwidth is abundant.

Resolve version: 14.2.0.012 Studio

What's been tried:
1. Delete render cache and re-cache
2. Switch to lower quality codec
3. Toggle "Show all video frames"

Any help is appreciated!

Michael

More System Information:
OS Name Microsoft Windows 10 Pro
Version 10.0.16299 Build 16299
Processor Intel(R) Xeon(R) CPU E5-2697 v3 @ 2.60GHz, 2601 Mhz, 14 Core(s), 28 Logical Processor(s)
Processor Intel(R) Xeon(R) CPU E5-2697 v3 @ 2.60GHz, 2600 Mhz, 14 Core(s), 28 Logical Processor(s)
Total Physical Memory 256 GB
GPU NVIDIA GeForce GTX TITAN X
GPU NVIDIA GeForce GTX TITAN X
GPU NVIDIA GeForce GTX TITAN X

I have the same issue and tried the same thing. The question is does Resolve apply some FX in real-time even after rendering all caches and optimizing media?

Are you guys using Decklink or other video I//O device? If so, try to tick the option Use 444 SDI in the monitoring section.

This is what helps here; I also cannot get full speed playing from the DNxHR HDR cache without this option on. All interesting and unexplained details here:

viewtopic.php?f=21&t=69672

Piotr

Are you guys using Decklink or other video I//O device? If so, try to tick the option Use 444 DI in the monitoring section.

This is what helps here; I also cannot get full speed playing from the cache without this option on.

Piotr

No, I'm on free version. An old HP Elitebook with i7 and 16 GB of a RAM. That's my first try on color grading just for some low-budget video. But I optimized media using dnxhr SQ and quarter resolution, so I assumed it should play it back with no problem after cashing, but it's not.

All clips are configured as "render cache clip source on" and "render cache clip output". Render cache is USER mode. Codec is DNxHR HQ. Cache location I/O bandwidth is abundant.

There have been reports of poor performance with cache enabled, but why are you caching both source and output?

And what's the type and resolution of the source footage? What happens when you play without caching?

I have to say turning both render source cache clip and render cache clip output on is a no brainer. We don't have much grade going on so perhaps I should have just left render source cache clip on. Though that didn't solve the problem.

We are using different formats of src footage. Red, canon 5DSR CR2 sequences, etc. All drawn from RAW format. The timeline is UHD@23.976.

What caught my attention though, was that if I zoom in on the timeline to a finer level, the stutter playback would go away. While if I zoom out to coarser detail, the stutter will reappear.

My suspect is that perhaps the UI thread performing update to the current time marker and the playback viewer at the same time. When zoomed out, the algorithm behind poses heavier computation burden to the marker update and thus blocking the update of the playback viewer.

My timeline is around 2 hours long. And by saying "coarser detail", it means the entire timeline would take up just about the whole timeline window, like this.

[img][https://preview.ibb.co/fp4Knn/timeline.png/img]

Can anyone reproduce the problem on their machine?


Thanks.

Michael

I have really poor playback performance even with media optimized to DNx LB. Beta 15 claimed to be better with H264, but it's not better here at all. Granted, my hp 8570w isn't hi end laptop, but it's i7 and has 16 gB of RAM. And it's getting very-very slow when I resize and zoom in inspector, for example. Is it OK? I work with Full HD video, not 2k, 4 k

Please inform us about your GPU.

Please inform us about your GPU.

it has Nvidia quadro 1000m

Performance meter days neither cpu nor hdd or GPU hits their limits...

That's an mid-level laptop GPU with a maximum of 2 GB VRAM. If you are working with 4K, it will not be up to it.
You machine doesn't compare at all to the one of the thread opener.

That's an older laptop GPU with a maximum of 2 GB VRAM. If you are working with 4K, it will not be up to it.
You machine doesn't compare at all to the one of the thread opener.

I am not working with 4k. I am working with full hd and asked why it's so slow with full hd and DNx LB. Sure it doesn't compare. Just symptoms the same

Where does the footage reside? With such light codec and only HD, it should play smoothly. Could only be a problem of data throughput, then.

Where does the footage reside? With such light codec and only HD, it should play smoothly. Could only be a problem of data throughput, then.

That's why I asked... It must play smoothly. The footage is on the toshiba 1 tb HDD I placed instead of dvd drive.

I had to correct myself regarding the GPU – not so old, but mid-range mobile.

Well, if it's an internal HDD, I'm stumped. Maybe you should try to re-install Resolve.

But first please double-check if you have really set the source footage (under Clip Attributes) to the exakt same frame rate your timeline has and there is no speed change activated on that clip. And switch off all overlays in the viewer.

I had to correct myself regarding the GPU – not so old, but mid-range mobile.

Well, if it's an internal HDD, I'm stumped. Maybe you should try to re-install Resolve.

But first please double-check if you have really set the source footage (under Clip Attributes) to the exakt same frame rate your timeline has and there is no speed change activated on that clip. And switch off all overlays in the viewer.

Thanks! Just reinstalled and double-checked. I've captured small video on mobile phone to show the problem...

Now I see CPU gets overloaded. But why...

Could be the smartphone stuff, many of these don't keep the frame rate constant.

The video is from Canon 5d mark 2

H.264 or Magic lantern?

H.264 or Magic lantern?

H264, but let me check laptop hardware first. Its CPU throttling. Could be just overheating. Not sure though. Also I've get new PC with i7 4770, 16 gb of a RAM and GTX 1060 so I can really see what is going on here.. Thanks for helping! Much appreciated!

H.264 or Magic lantern?

H264, but let me check laptop hardware first. Its CPU throttling. Could be just overheating. Not sure though. Also I've got new PC with i7 4770, 16 gb of a RAM and GTX 1060 so I can really see what is going on here.. Thanks for helping! Much appreciated!

What speed is your Toshiba HDD? If it's 5400rpm it is not fast enough to output the data. You need at least a 7200rpm drive.

What speed is your Toshiba HDD? If it's 5400rpm it is not fast enough to output the data. You need at least a 7200rpm drive.

It's 7200

I'm not familiar with newer 5D cameras. Do they still record H.264 I 8 bit 402 or better than that?
H.264 at 10 bit or 422 is not decoded by hardware, even under DR Studio.