@Former user

This article explains key concepts related to video compression in a simple way.

https://aws.amazon.com/blogs/media/part-1-back-to-basics-gops-explained/

Jøran Toresen

... In the first video I posted I show Vegas doing a proficient job at seeking with GPU decoder OFF. With GPU decoder on Vegas stutters and lags. I then go on to show with the same GPU decoder it works fine on another NLE, so how on earth have you not deduced there's a problem with the Vegas GPU decoder (the software plugin, not the hardware that's works just fine)

@Former user I think you proved that your gpu isn't a very good decoder when it's trying to do everything else. Before the dirt-cheap Arc a380 became available I used Nvidia 1660's as decoders and they were fine as long as another gpu, like an amd 5700xt, was doing the timeline, fx processing, and encoding. For that reason, your system probably benefits from letting the cpu do a little more.

Auto GOP 250 is a default for X264

Long gop seems to be the favorite of camera makers who want to write the smallest clips to the lowest performance media. But the options are there in ffmpeg as well as Zoom for those inclined to be more sensible. I don't agree with most Apple thinking, but I gotta go with them on this one.

@Former user I think you proved that your gpu isn't a very good decoder when it's trying to do everything else. Before the dirt-cheap Arc a380 became available I used Nvidia 1660's as decoders and they were fine as long as another gpu, like an amd 5700xt, was doing the timeline, fx processing, and encoding. For that reason, your system probably benefits from letting the cpu do a little more.

@Howard-Vigorita Let's test this idea that it's my hardware that's the problem. I do think it's possible those with the latest Intel and AMD CPU's may do better with Vegas GPU decoding. Keep in mind though this same problem has been brought up hundreds of times since VP15, it's not a new thing, the fact that it's new to Wolfgang a beta tester is disturbing.

This is the file I was testing press play and skip to various parts while play remains active. If it works great on Best/Auto try Best/Full and report back. Currently until I see otherwise I believe this is a bug and if affects everyone. Please fact check me Vegas Community

https://www.dropbox.com/s/yk3xmebt5lls6ix/Meridian_UHD4k5994_P3PQ_Cut.mp4?dl=0

@Former user Just tried it on my laptop. Thought the behavior was curious testing as you described even though play would start smoothly at 59.94 fps, which was surprising because Vegas in the past has had trouble with double rates. Anyway, the curious part was that if I clicked on some spots, play continued instantaneously at 59.94 fps. But in other spots there would be a short period of jumpiness starting up at like .5 fps before it jumped back to 59.94.

Then I looked at the gop structure histogram. Apparently I was blindly clicking into a box of chocolates:

 --- GOP histogram : 1 @ 0 : 1 @ 60 : 1 @ 250 : 1 @ 174 : 1 @ 68 : 1 @ 234 : 1 @ 152 : 1 @ 115 : 1 @ 154 : 1 @ 177 : 1 @ 220 : 5 @ 249 : 1 @ 66 : 1 @ 249 : 1 @ 131 : 3 @ 249 : 1 @ 54 : 4 @ 249 : 1 @ 68 : 8 @ 249 : 1 @ 31 : 1 @ 249 : 1 @ 48 : 2 @ 56 : 3 @ 249 : 1 @ 125 : 3 @ 249 : 1 @ 88 : 2 @ 249 : 1 @ 93 : 1 @ 39 : 2 @ 249 : 1 @ 99 : 1 @ 128 : 3 @ 249 : 1 @ 54 : 1 @ 249 : 1 @ 168 : 1 @ 249 : 1 @ 143 : 6 @ 249 : 1 @ 55 : 2 @ 249 : 1 @ 44 : 1 @ 28 [ maxGOPlen=250 ]

Only way I see around that kind of encoding mess is to decode it all before trying to edit it. Maybe that's what Resolve is doing while I wait for clips to load and their database is busy filling up my hard drive.

Btw, I did this at Good-Auto. Could not get smooth play at 59.94, even without clicking around. My laptop just isn't fast enough. When I edit my double-rate 4k material on the laptop, I generally knock the project rate in half or a quarter for smooth editing. Be nice if Vegas had that as an automatic preview option so I wouldn't have to remember to restore it before rendering.

@Howard-Vigorita That's AUTO GOP 250, it's really common, and Vegas's GPU decoder should be compatible even if as an example it would not pass QC for broadcast applications. It will use a maximum GOP of 250, but will insert a new I-frame at a scene change, thus reducing the GOP where necessary. I assume this gives maximum quality at lowest bitrate, highly efficient, without any corruption at scene changes(which is another Vegas Problem) where it requires the highest bandwidth.

I had no problems with captcut or Resolve. With Premiere Pro I did see minor stutter at a couple of places, but not to the extent that's seen when I used Vegas

this same problem has been brought up hundreds of times since VP15, it's not a new thing, the fact that it's new to Wolfgang a beta tester is disturbing.

If something disturbes you, well then this is your point of view.

And I never said, that the playback behaviour cannot be improved. But that is not in my hand.

But I will test your download file when I am able to access it (dropbox is not possible here as download, but I can download it in the evening). Even if I still do not see much sense to edit files, that have been the outcome of an render process.

Meridian G.O.P.