Roger, see two up. How does his video test on your system?

Not so well. The screenshot in the middle of my post was of Vegas + Task manager/performance.

And once you gain some experience with x264, you will find that GOP lengths of <= 450 are "normal and expected." See you then.

I'll take your word for it, I'm sure you are right as I see various software producing such files.
I'm mainly interested in its playback performance in Vegas. Constant framerate AVC 4K at keyint=480 triggers the inefficient media warning. Just tested an x264 file at 450 and it does as well:

Tested at 350 which does not trigger it. Even without the warning, Vegas seems to have decoding issues with larger GOP files.

@RogerS I'm working a lot with Artlist stock videos, can't re-encode every single video I download from there since hat would definitely take up all my time.

 

I see the problem, I show it here with a 9frame disolve transition, and show how it doesn't have the problem when gpu decoding is turned off. without GPU decoding you will use more cpu, for my 12 core CPU useage increased to 40%, so maybe on your 8core that may be 60% ? If that's acceptable maybe that is a solution for this frame rate. At higher frame rate 4K you will run out of CPU

It is a software fault to do with GPU decoding, you can see decoding go nu-naturally high which prevents reading of further frames, but with GPU decoding turned off, no problems

 

 

 

Same thing for me... I try to turn the GPU decoding off but since my CPU is running pretty high then and the 12900K is well known for his higher temperatures, it can peek at 90 degrees. Not the perfect solution in my opinion...

The best easy solution I see is creating proxy files and editing in preview quality vs best.

 Here is an example
https://www52.zippyshare.com/v/btcQxHd8/file.html

Thanks

@Kayu can't download?

Can you put it on Google Drive in a zipped folder, change the share option to Anyone with this link, ?

@Former user You can download it here https://www.amazon.com/photos/shared/VGib0DJjSV6IAhniQtEVqw.WO8TeKs-PXaJjvyAQeTU-W (click the 3 dots, right hand corner)

Thanks @Former user 👍

Hi, I'm fully aware that my PC is no comparison to the average PC but if there is a prob with a file or as in this case a poss clash with an RTX3000 series + this file, it will show no matter what my PC specs are.

This file plays as smoothly as it gets, poss even better than most,

I screen capture video'd it. & messed around a little,

Vegas always has a slight stutter when starting play but this file jumped to 25fps very quickly,

as i've wrote in previous comments crossfades often need to play through once or twice to play smoothly, this file did & played those as expected with no prob,

In the video below the Taskmanager is showing the Geforce screen capture so isn't showing a true CPU/GPU playback of this file, this pic is playback with no video screen capture

@Kayu Sorry, for me this is a good file. 😕🤷‍♂️👍

As i say i know my PC is no normal PC so all i can do is share my results.

Keyframe interval is normal and just fine...

GOPs of 250-400 have previewed just fine in Vegas for as long as I can remember, Roger.

@Musicvid Is this something you might be interested in looking into?

At edit points this file plays back poorly causing the GPU decoder overload problem, but plenty of other 4K25 AVC video files don't have this problem. If it isn't to do with keyframe interval finding the problem would be very useful. Although this file is perfectly normal as you say, what Vegas prefers to play smoothly over edit points and scrubs smoothly is a much smaller subset of normal, but what are the characteristics of these files?

This file as example doesn't have the GPU decoder overload bug, so what's the difference between the 2?

Camera file is 24fps, so I conformed this test file to 24fps so should be apples to apples.

This is the camera file if you were interested https://www.amazon.com/photos/shared/B1WI20HIQM29RMY7DNBt0g.F619V9_y5sR_-StOJibKkJ

@Former user you had GPU decoding off, the problem is with GPU decoding turned on

@Former user Ah i had Legacy AVC ticked 🤦‍♂️😂 guess that over rides things, 🤔

so like this ?

I've just read all this thread again & it seems that turning GPU increases the CPU &

In the OP's first comment - Tried to enable "legacy AVC decoding" but that spiked up my processor to 80-100% when I playback the video and the computer is getting really loud because of my fan config.

I had Legacy AVC turned on in the video above but my CPU was very low, AMD - Intel?

@Former user Legacy AVC unticked, Vegas restarted, it faltered at the end of the second event but 3rd time around it completed at full 25fps,

In the video, Video Encode is the screen capture so this is a screenshot of playing on it's 4th go around after i'd stopped recording.

Have i done it wrong again?

@Former user That looks good, the more edit points and dissolves more likely to see problem. The GPU decode at 100% problem did not happen at every edit point for me either, maybe it only happens only at specific frames for various technical reasons relating to file structure, or something else

I think what the Vegas engineer said about long GOPs hitting decode plugin cache limits is the most likely explanation.

If multiple runs improve things that could be because it's caching with dynamic ram preview?