I often find that the MP4 hardware encoder HEVC gives very ugly encoding artifacts in darker smooth gradient areas like walls or other background surfaces.
I have noticed with the h264-high these artifacts are not present.

But I decided to test the H264 hardware encoding vs HEVC hardware encoding.
As probably everybody knows HEVC should give around 40% bitrate savings for the same quality or better quality at the same bitrate.
Results I found where incredibly bad.
Not only does the H264 encoding trade blows with the HEVC in quality, the HEVC actually uses more bitrate then the H264 to get that result, its like the world in reverse.
HEVC give a bigger file with the same bitrate specified in Vmix and does not give a better-quality encoded result.

Vmix please fix this hardware encoding or update the ffmpeg so we can make our own profiles.

Give us some parameter control of the hardware encoder instead of only the option to turn it on or off.
Also LLHQ is often not the desired profile.

For all the people who use the MP4 hardware encoder please give this post a like to help this issue get attention because the forum is full of dead topics related to this.

Testing was done on a rtx a6000 and replicated on a 4090. Driver 531.14 W10
Output 1 was set to: HEVC 60 fps 4K 32mbps – Final output size 128mb
Output 2 was set to: H264-high 60fps 4K 32mbps – Final output size 108mb
MSU VQMT was used with the “Netflix” VMAF 0.6.3 4K as video quality measurement
Tested Vmix version 26.0.0.44 & 25.0.0.34

2021 LG OLED l Ink Art 4K HDR 60fps_H264High - 29 05 2023 - 07-05-17 - Output 1_HEVC - 29 05 2023 - 07-05-17_vmaf.png (1,064kb) downloaded 9 time(s).

Hey martin, i have contacted support indeed but let me better show my issue because its not a machine thing.
Just an encoding thing, my guess is turning adaptive quantization on will solve the issue.

Btw thanks for the explanation about the Media Foundation encoder, i will dive some into this but i guess AQ is off and probably also at a sort of quick, fast and dirty profile what was recommended.
Is the encoding of the Stream output also with this media foundation encoder or does that use the FFMPEG?

Below is a picture with reverse colour contrast to make it really clear what I mean with compression encoding artifacting in the banding of gradients.
This was a recording i had at hand but it gets worse with darker gradents.
A picture cannot really explain how annoying this is in video since it's constantly in motion like noise bands of x16 or x8 macroblocks, so I hope you download the video below to see that.
You see the person talking but the background although somewhat blurred because of depth of field its continuously moving in bands and blocks around and it is not a bitrate related issue.
Negative contrast banding in encoding.png (2,068kb) downloaded 3 time(s).
here the link to a small part of the recording, its a part muxed out so to keep file size compact but no transcode so its straight out of the vmix encode.
https://drive.google.com...e5kz/view?usp=share_link (need to download ofcourse for proper play)

And no, its not feasible/practical and unnecessary to do intra frame 4x 4k feeds recordings that last 1 - 3 hours every day should anyone recommend this.

Also to replicate the strange encoding behaviour that i noticed in the encoder here is the short reel that makes the recording size and results very unbalanced.
https://drive.google.com...Mjuk/view?usp=share_link
After this i tested a whole lot of other video's with mixed results, some as you would expect and some more closer in result to encoding this video.
But i welcome everyone to test it out, it's just an short showreel but seems to impact the encoder greatly in h264 vs hevc.
Especially in 4k 60fps recording while you expect at higher resolution hevc would normally get a bigger advantage on h264.

Hi,

Unfortunately I think the expectations are bit too high to expect from live encoding software.
I did run some quick tests on the LG reels at both h264 and hevc @ 25Mbps and could not see anything out of the ordinary, even zooming in 4x.

In fact it goes to show how much optimisation NVIDIA has done to their H264 encoder in recent years!

Not too long ago, semi-professional camcorders recorded HD H264 @ 25Mbps.
Now we have real time encoders like NVENC achieving better quality at 4K60 at almost the same bitrates!

Sure, there are might be some tweaks to be had to deal with edge cases like this, but I think those options are better left to encoding
tools more specialised for ultra high quality encodings.

Regards,

Martin
vMix