Vegas Pro 18 Preview Stutter on Windows 10

James-Clow wrote on 6/3/2021, 7:59 PM

Hi, I'm new to Vegas Pro 18, and I've run into an issue straight away with performance. I have a 2080Ti and a 12 Core threadripper, and a 970 NVME and I've got stutter playback in the preview window for 20 second long 4k 60fps footage.

Whether I choose the lowest draft quality or best for preview playback it still stutters. The hardware decoder is set to use NVIDIA NVDEC in File I/O. Also in the video tab I've set dynamic RAM to 0 and the NVidia option is selected.

What I've noticed looking at task manager is that in the task manager in the GPU engine column the GPU engine alternates between GPU 0 - Copy at about 30% utilization and GPU 0 Video Decode at about 40% GPU utilization. When is shows "GPU 0 Video Decode" it stutters. It's as if there is some kind of constant buffering going on. I realize I'm probably doing something really daft, so if anyone could advise me I'd be very grateful. Thanks.

Comments

RogerS wrote on 6/3/2021, 8:19 PM

What exactly is the media? Bit depth, color depth, container, codec?

James-Clow wrote on 6/3/2021, 8:28 PM

mp4
Type: AVC
Size: 197.13 MB

Streams
Video: 00:00:22.456, 59.711 (VFR) fps progressive, 3840x2160x32, AVC
Audio: 00:00:22.399, 48,000 Hz, Stereo, AAC

Data rate 73135kbps

Bit rate 261kbps

I'm not sure what the colour depth is, it's just h.264 4k 60fps footage from my phone, non-HDR

RogerS wrote on 6/3/2021, 8:48 PM

Okay, phone is a clue, and the first line says variable frame rate which doesn't always work so well in Vegas. 4K60 is also challenging. Do you plan to deliver at 60fps or is it for slow motion (if so, go with an easier to play back 30p timeline)?

Is it 10-bit footage? 10-bit, 4:2:2, etc. challenge the hardware and software more.

If you search the forum there are threads on converting variable frame rate to constant frame rate. You could try it on a file or two and see if it helps.

Other general advice is to use the NVIDIA Studio Driver (not gaming one).

Dr Zen wrote on 6/3/2021, 9:18 PM

As RogerS has already pointed out, Variable Frame Rate video does not work well in Vegas.
I recommend all VFR video is converted into Constant Frame Rate, before you import into Vegas.
If you still get bad lagging after doing this, I would also use the Create Video Proxies function in Vegas, which will render easier to play versions of your videos while editing.

Use Handbrake to convert your videos.
Handbrake has a really good preset for converting video that you plan to edit with.
It is called Production Preset

Select Production Preset, then go to Video tab.
The slider controls the quality & size of your video.
10 will produce quite a large file size, so if that is too big, you can drag it to about 18 or slightly higher.

If you would like to learn more about how to use Handbrake, I have an in-depth tutorial on my website:
https://www.moviestudiozen.com/free-tutorials/miscellaneous-help-tutorials/595-handbrake-v1-1-1-beginners-guide-for-best-video-export-settings

To create Video Proxies in Vegas, follow these instructions:

Step 1 - Import all your video clips

Step 2 - Open the Project Media tab and then select/highlight all your video clips as a group.

Step 3 - Now right-click highlighted group and select Create Video Proxy. Movie Studio/Vegas Pro will now render video proxy versions for all your video clips. The proxy versions will be easier to play and work with. The will be saved into the same folder location as your original videos. Please note that it may take quite some time for your video proxies to be rendered, especially if they are large in file size.

Step 4 - Drag your videos onto the timeline as you normally would. The program will automatically play back the new proxy versions for you. However you must set the Preview Window to Draft or Preview quality for the proxy video versions to playback while you edit.

If you set the Preview Window to Good or Best, your original HD or 4K video versions will play instead.

Step 5 - When it is time to render/export your project, you don't have to do anything different or swap any files out. The program will automatically render your project using the original video files.

paul-marshall wrote on 6/4/2021, 6:56 AM

DONT set dynamic RAM preview to 0 - set it to 200MB as recommended when editing/previewing.

However you will most likely need to set it back to 0 to render with NVEC successfully. You need to close and restart Vegas for any change to take effect.

Sounds daft but true for me at least. It seems like this buffer has some effect when NVidia hardware is in use beyond building a RAM preview.

James-Clow wrote on 6/4/2021, 9:54 AM

Thanks everyone, I've tried all of the suggestions with minimal difference in preview playback performance. I'm going to have a look at my system to see if there is any software that might be interfering and causing the issue etc.

JN- wrote on 6/4/2021, 7:39 PM

@James-Clow If possible can you make available a sample clip for other users to check out for playback. As DR. Zen says, convert first, but you’ve already done that.

James-Clow wrote on 6/4/2021, 9:03 PM

@James-Clow If possible can you make available a sample clip for other users to check out for playback. As DR. Zen says, convert first, but you’ve already done that.

Hi JN, thanks, I think I've fixed my issue. I saw some YouTube videos suggesting people having preview lag turn off OpenCL within preferences and internal settings. I didn't see that option within VP18 but I did find an option for OpenCL for intel CPU. I unchecked this and noticed a dramatic reduction in preview lag, even in footage that had vbr and no proxy. I tried to prove that this was the cause by checking it again and restarting VP18 but it still played ok. Perhaps just a coincidence, I don't know. There is still a bit of minor stutter every not and then, but I'm sure converting to FBR, using proxies would sort that out. Maybe one of the settings values was corrupted somewhere and checking/unchecking sorted it out. Whatever the cause, I'm now very relieved as I was starting to wonder if my 2080TI wasn't up to the job. The issue was originally present even on 30fps 1080p video and lower resolutions.