HEVC vs h.264

IAM4UK wrote on 10/8/2017, 4:27 PM

VP15 running on PC with these specs:
Intel Core i7-6850K @ stock 3.60GHz (6 cores, 12 threads), 64GB quad-channel RAM
AMD Radeon HD 390 GPU

Rendering a 7.5-minute video with many VideoFX (mostly for color, brightness, contrast, general appearance tweaks)...

Takes about 16 minutes to render h.264, but about 80 minutes to render HEVC (2160p23.976)

Is that typical, for HEVC rendering to take 5 times as long as h.264? I know AMD GPU not yet engaged for GPU rendering as Intel QSV and Nvidia are. Do you expect that to change within the VP15 updates in the next several months?

Comments

Kinvermark wrote on 10/8/2017, 5:54 PM

HEVC encoding & decoding is super compute intensive, so yes it takes a long time. I have tried these renders with different programs and always found them to be very slow. The best solution is hardware encoders/decoders which is why these are starting to appear in cell phones now. I understand that Intel QSV and Nvidia NVENC can help, but I haven't got access to these myself for testing. My solution for now is to go have lunch. :)

 

Musicvid wrote on 10/8/2017, 7:04 PM

Is that typical, for HEVC rendering to take 5 times as long as h.264? 

No, often it takes longer than that. It's come a long ways, though. Just eighteen months ago your render would typically take a couple of weeks.

The release if Vegas updates is irrelevant, except when the ENCODER is also updated.

IAM4UK wrote on 10/8/2017, 7:12 PM

 

The release if Vegas updates is irrelevant, except when the ENCODER is also updated.

I do not understand. Can AMD GPU not encode HEVC? Is that the reason VP15 supports QSV and NVENC only?

Musicvid wrote on 10/8/2017, 9:58 PM

If you are asking if AMD "will" be supported, I don't have that answer for you.

I believe that NVENC and QSV employ their own dedicated encoders. Am I wrong?

fr0sty wrote on 10/9/2017, 1:08 AM

Yeah, they are dedicated encoders. I'm not sure if AMD has such a thing yet.

Systems:

Desktop

AMD Ryzen 7 1800x 8 core 16 thread at stock speed

64GB 3000mhz DDR4

Geforce RTX 3090

Windows 10

Laptop:

ASUS Zenbook Pro Duo 32GB (9980HK CPU, RTX 2060 GPU, dual 4K touch screens, main one OLED HDR)

NickHope wrote on 10/9/2017, 1:52 AM

Yeah, they are dedicated encoders. I'm not sure if AMD has such a thing yet.

HEVC is apparently available from VCE 3.4, which is apparently available in the GCN 4th gen microarchitecture, which apparently applies to the RX460/470/480.

Former user wrote on 10/9/2017, 5:31 AM

Hi IAM4UK, just to give you some idea using a simple NX500 best quality hevc sooc UHD file, no fx added ...

Vegas 15 ...

A 10.3 second NX500 clip ...

Render times ...

With HW acceleration on ...

With Nvenc ... 11 seconds

Without Nvenc ... 32 seconds

 

With HW acceleration off ...

Without Nvenc ... 34 seconds

On a desktop it might well be even higher ratio than 3x. (Just checked, it's 8 seconds.)

Output file was FHD 24/20 mbps