Intel Quick Sync quality dependency

[JustEncode]

Description of problem or question:

Hello support team,

I have a general question, maybe someone can help me. Can someone tell me what is the most important factor for quality when converting with Quicksync? This means whether it depends on the intel driver or, for example, the libraries that are used or even which iGPU technology is used?

My question is whether the quality will be better in the future with an update from Handbrake, or whether the limit has been set by using a intel i9 9900k with iGPU UHD 630, for example.

Is the quality better with an intel CPU with Gen 11 iGPU UHD 750 or is the encode just faster?

Source: https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video

Version 7 (Ice Lake)
The Ice Lake (microprocessor) adds VP9 4:4:4 decoding, VP9 encoding (up to 10-bit and 4:4:4), HEVC 4:2:2 and 4:4:4 decoding and encoding,[14] HDR10 Tone Mapping[15] and Open Source Media Shaders.[16] HEVC hardware encoding quality has also been improved.[17]

What is the reason for improving the quality with Ice Lake HEVC hardware encoding? Is it because of the technology used or the software such as Handbrake, which gets better and better over the years?

Have any of you already converted with a UHD 630 and a UHD 750 and could, for example, determine a better quality with the same encode settings?

I am asking because I would like to continue using Quicksync because the performance is good, but I would also like to improve the quality in the future. The latest Gen12 Xe CPUs will soon come onto the market and the performance of the iGPU is up to 50% faster than Gen 11. My question is whether maybe the quality of the videos can get better as well.

I hope someone has already had experience and can share the results with us.

Best Regards

[s55]

The Hardware is the driving factor since the encoder is in hardware.

I'd wager at this point, we won't see much improvement in H264/H265 side of things past 11th gen.
I'd expect they'll have moved onto adding AV1 encoding support for future generations of hardware now.
That said, we don't have inside information.

We are at the point now where quicksync is good enough for performance and quality. The latter may require a little bit more bitrate than say x264/5 but at the end of the day, users are not going to notice much of a quality difference unless it's mis configured or they pixel peep.

Speed, Quality, Filesize. You can only have 2. That's never really changed with any encoder.


For performance, the speed of the GPU is largely irrelevant since encoding is handled by discrete hardware. Thus, doubling of GPU performance does not mean you'll get double the encode performance. If Intel improve the media engine hardware, it could get faster.

[mduell]

Can someone tell me what is the most important factor for quality when converting with Quicksync?

Bitrate.

[JustEncode]

@s55
Thanks for the information.

I am currently converting with a gen9 i9 9900k UHD 630. My question is whether the quality is better with the same settings with an i9 11990k with a UHD 750? H265 10bit is used. The settings are chosen as they are set up in Handbrake for h.265 QSV 1080p.

I've tried many tests with different settings such as b-pyramid, gop-ref-dist, gop-pic-size etc. but in the end the default values ​​were the best. I can hardly see any difference between speed, balanced and quality. When comparing the images directly, the difference was so small that it is absolutely not worth doing without the fps. With speed approx. 210fps, with balanced approx. 80-90fps and quality with approx. 50-60fps. The problem is the missing parameters to really change the quality, as is possible with CPU-Encode.

But if the basis for quality is the hardware, would a change to a newer CPU or iGUP bring better quality in principle?

@mduell

Yes and no in my experience. At least with the UHD 630, Quicksync is not able to retain the details and fine structures of the source. Even if the bitrate is higher than the source bitrate, there will be a noticeable deterioration in the result. In comparison with CPU encode, it is even possible to improve the quality compared to Source. Things like deblock, sao, strong-intra-smoothing, b-adapt or ctu can have a strong influence on the image quality at a comparably low bitrate. So for me, Bitrate is not the same as quality. What is missing in Quicksync is a preset such as Fast, Medium, Slow, Very Slow etc. The default settings Speed, Balanced and Quality have a very strong influence on the FPS / performance in a comparably very poor ratio to the visible quality.

But since the performance is very decisive, the question is in which direction the development is going and whether Quicksync will be better in the future with newer hardware.

[mduell]

Reference to the source bitrate depends a lot on the encoder and settings for the source! The hardware encoders are all about speed (and uniformly do very well here!), and may need an order of magnitude higher bitrates to match the software encoders.

The quality of the hardware encoders depends primarily on bitrate of the output.

[JustEncode]

ok I understand. I still have a question. Since the encode is hardware-based, I still wanted to ask if someone can say whether there is a difference in quality between the individual generations of intel.

I read in a little further and what I found out is that, for example, from generation 10 onwards, other techniques are used. My question is whether the quality automatically improves with the same settings in Handbrake or does Handbrake define the quality through the settings.

As a specific example. I convert with 5000 kbits once with 9900k iGPU UHD 630 and once with 11900k with iGPU UHD 750. Is the quality better with UHD 750 with the same settings or is the encode only faster?

[Scs66]

Better late...
I think your question was not understood.

You read over all kinds of updates of the iGPU on the new gen cpus, and want to know if HandBrake can use that.

I think the mentioned improvements are PURE for the playback of a video.

I am pretty sure HandBrake can't use that. I think HandBrake runs its own code on the GPU-hardware in the core.
If the advances are due to new hardware in the core, so some HandBrake programmer has to adept the code to used that.
(While still be able to be compatible with old iGpu, and I don't know if Intel shares much data on how to use it??)

[s55]

I still have a question. Since the encode is hardware-based, I still wanted to ask if someone can say whether there is a difference in quality between the individual generations of intel.

Yes there is differences between generations of the quick sync hardware. Typically though, if your on 6th gen Intel CPUs or newer, it's not going to matter for most people.

I think HandBrake runs its own code on the GPU-hardware in the core.

It does not. Quicksync is discrete hardware. The basic version is, all we do is pass uncompressed video to it to encode.

If the advances are due to new hardware in the core, so some HandBrake programmer has to adept the code to used that.

Only to a limited degree. The vast majority of work is handled by the Intel Driver and hardware itself, so changes to support new features are often no-code or minimal code.

(While still be able to be compatible with old iGpu, and I don't know if Intel shares much data on how to use it??)

Compatibility is handled by the Intel Frameworks we use so is a non-issue