Speed Ramped Footage Causes Vegas To Render Very Slowly?

JN- wrote on 6/24/2021, 1:10 PM

@LongIslander I’d say it’s probably normal. You can make available a sample speed ramped project in zip to download and other users can give you a comparison render time, just supply the render settings you use also. I can use my i7-6700HQ laptop to compare, although I only have vp16 &17 installed on it.

Alternatively you could look at the benchmarking results, via my signature. Just do a FHD render using the sample project 4k and compare with other similar render times in the screenshots and spreadsheets. No need to submit your results unless you really want to. My laptop with an i7-6700hq , just predates your cpu. Its render times are already there.

Musicvid wrote on 6/24/2021, 6:48 PM

That is because every pixel of every frame gets resampled. That is 24,883,200 calculations for every frame, exactly 1,492,992,000 CPU cycles for every second of video. Slowdown? Yes, I would think so.

LongIslander wrote on 6/25/2021, 7:58 PM

Just did another speed ramp with another project. Same 400% speed envelope; but this time the source file was 4k30 AVC rather than 4k60HEVC. My cpu is being ultized to 100% Something wonky going on. Will upload a source file shortly. When hardware decoding GPU is turned on the render will be fast. But when off software render will only ultilize the CPU by 10% or 20%.

LongIslander wrote on 6/25/2021, 8:12 PM

https://www.dropbox.com/s/bjdxbfqm7qae6me/GX010323.MP4?dl=0

Speed ramp to 400% turn off hardware decoding. You will see the software encoder fails to saturate the CPU.

FernC wrote on 6/25/2021, 10:34 PM

I get the opposite results, did you confuse the 2?

GPU on, GPU decode on, AVC software encode - 7:05

GPU on, GPU decode off, AVC software encode - 3:40

CPU is 100% with both on non speedramped, at speed ramped decode off remains at 100%cpu but decode on is all over the place 35% - 65% cpu

The Vegas GPU decoding is not working well. There's 3 or 4 posts on front page where the answer to their complaints is the same. The hardware decoder does not work well in all situations.

RogerS wrote on 6/25/2021, 11:38 PM

I did a simple project 4K 29.970p, added the video at project frame rate and then ramped up to 800%+.
I made a few renders to ProRes 422. It's using my Intel 630 iGPU to decode.

With hardware decode set to on, legacy HEVC: 1:17

With hardware decode set to off, legacy HEVC:1:17
(CPU/GPU use looks the same so I think it's ignoring the user preference for decoding here)

With hardware decode set to off and legacy HEVC unchecked, 1:29

With hardware decode set to on and legacy HEVC unchecked, 1:28

CPU is around 100% until the speedramp kicks in. Decoding and 3D use goes way up during the speed ramp so it may be GPU limited on this system (i7-7700HQ;i630 GPU)

Edit: hardware decode set to NVIDIA; legacy HEVC unchecked, 1:55

FernC wrote on 6/26/2021, 4:53 AM

I did another test with project set at 4K 29.970p, and conforming file to project properties (50%) speed ramping up to 800% and encoding to 4K422 like RogerS

DECODE ON 2:54
DECODE OFF 1:46

Decode off is 100% cpu throughout the ramp, Decode on starts at 90% cpu by the end it's 35%

@RogerS It doesn't look like it's possible for you to turned off intel hardware decode

RogerS wrote on 6/26/2021, 5:13 AM

I did another test with project set at 4K 29.970p, and conforming file to project properties (50%) speed ramping up to 800% and encoding to 4K422 like RogerS

DECODE ON 2:54
DECODE OFF 1:46

Decode off is 100% cpu throughout the ramp, Decode on starts at 90% cpu by the end it's 35%

@RogerS It doesn't look like it's possible for you to turned off intel hardware decode

@FernC I don't know if I missed it, but what is your CPU & GPU exactly? AMD CPU & ? Based on these tests it appears impossible to disable Intel decoding of HEVC if you have a supported Intel CPU.

JN- wrote on 6/26/2021, 6:12 AM

@LongIslander Can you supply a project file for the GoPro hevc file, that way we are all doing exactly the same type of test? And what render settings to use?

FWIW I rendered out the file to FHD 25 fps, data rate 50/28. In Task Manager, the GPU was ~ 18% varying, and the CPU was ~ 14% varying throughout render. This didn't appear to change at the speed ramped section. I initially selected the mid point in time ~ 34s, velocity at normal to that point. I then raised to 400% and cut away the repeat piece, giving a ~ 42s output.

I did it on a laptop with only Nvidia card, in TM the "Video Encode" graph was very sawtooth encoding, with large empty gaps. This screengrab ...

FernC wrote on 6/26/2021, 9:15 AM

I did another test with project set at 4K 29.970p, and conforming file to project properties (50%) speed ramping up to 800% and encoding to 4K422 like RogerS

DECODE ON 2:54
DECODE OFF 1:46

Decode off is 100% cpu throughout the ramp, Decode on starts at 90% cpu by the end it's 35%

@RogerS It doesn't look like it's possible for you to turned off intel hardware decode

@FernC I don't know if I missed it, but what is your CPU & GPU exactly? AMD CPU & ? Based on these tests it appears impossible to disable Intel decoding of HEVC if you have a supported Intel CPU.

I have Amd 3900 cpu and Nvidia 3600 GPU, the choke point looks like Nvida decoder and you experience the same with intel decoder and speed ramp, reducing processing use of CPU. I have same very high decode, maybe a limitation of GPU decode

LongIslander wrote on 6/26/2021, 7:36 PM

Thanks for all the the help. Turning off hardware decoding is still the best for preserving the best video quality correct?

Musicvid wrote on 6/26/2021, 8:29 PM

No, that really only applies to hardware encoding.

If hardware decoding doesn't cause glitches, I think it's best to leave it on.