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Strange Choppy Playback

Posted:
Fri Mar 02, 2018 9:28 pm
by MichaelWang
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
Re: Strange Choppy Playback

Posted:
Sat Mar 03, 2018 5:16 am
by Bazzikaster
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?
Re: Strange Choppy Playback

Posted:
Sat Mar 03, 2018 6:43 am
by Piotr Wozniacki
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=69672Piotr
Re: Strange Choppy Playback

Posted:
Sat Mar 03, 2018 1:15 pm
by Bazzikaster
Piotr Wozniacki wrote: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.

Re: Strange Choppy Playback

Posted:
Sat Mar 03, 2018 2:04 pm
by John Paines
MichaelWang wrote: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?
Re: Strange Choppy Playback

Posted:
Sat Mar 03, 2018 9:30 pm
by MichaelWang
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
Re: Strange Choppy Playback

Posted:
Tue May 08, 2018 5:22 pm
by Bazzikaster
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
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 3:27 am
by Uli Plank
Please inform us about your GPU.
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 3:35 am
by Bazzikaster
Uli Plank wrote:Please inform us about your GPU.
it has Nvidia quadro 1000m
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 3:36 am
by Bazzikaster
Performance meter days neither cpu nor hdd or GPU hits their limits...
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 7:29 am
by Uli Plank
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.
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 7:32 am
by Bazzikaster
Uli Plank wrote: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
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 7:38 am
by Uli Plank
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.
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 7:42 am
by Bazzikaster
Uli Plank wrote: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.
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 7:45 am
by Uli Plank
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.
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 6:03 pm
by Bazzikaster
Uli Plank wrote: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...
Re: Strange Choppy Playback

Posted:
Wed May 09, 2018 6:39 pm
by Bazzikaster
Now I see CPU gets overloaded. But why...
Re: Strange Choppy Playback

Posted:
Thu May 10, 2018 1:07 am
by Uli Plank
Could be the smartphone stuff, many of these don't keep the frame rate constant.
Re: Strange Choppy Playback

Posted:
Thu May 10, 2018 4:01 am
by Bazzikaster
The video is from Canon 5d mark 2
Re: Strange Choppy Playback

Posted:
Fri May 11, 2018 7:45 am
by Uli Plank
H.264 or Magic lantern?
Re: Strange Choppy Playback

Posted:
Fri May 11, 2018 7:49 am
by Bazzikaster
Uli Plank wrote: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!
Re: Strange Choppy Playback

Posted:
Fri May 11, 2018 7:49 am
by Bazzikaster
Bazzikaster wrote:Uli Plank wrote: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!
Re: Strange Choppy Playback

Posted:
Fri May 11, 2018 11:37 am
by Charles Bennett
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.
Re: Strange Choppy Playback

Posted:
Fri May 11, 2018 11:40 am
by Bazzikaster
Charles Bennett wrote: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
Re: Strange Choppy Playback

Posted:
Mon May 14, 2018 1:17 am
by Uli Plank
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.