GTX 970, HDR and HEVC - Does this effect my image quality?

shasoosh · 5th January 2018, 15:03

I have a problem that some HDR samples are stuttering and unplayable.

For example: http://4kmedia.org/lg-chess-hdr-demo/

I've read around and found that my GTX 970 decodes HEVC in an hybrid mode and that's the cause of the problem.
My CPU is i7-4770. When I play a laggy video, my CPU is on 60% and my GPU is on 30% so I'm not sure why this is happening.

Most movies I tried to play using MPC-BE & madVR are playing fine except those HDR samples. (I'm guessing I'll find more problematic movies in the future)

If I understood correct, according to this bit of info:

Quote:

Feature Set E
Similar to feature set D but added support for decoding H.264 with a resolution of up to 4096 × 4096 and MPEG-1/MPEG-2 with a resolution of up to 4080 × 4080 pixels. GPUs with VDPAU feature set E support an enhanced error concealment mode which provides more robust error handling when decoding corrupted video streams. Cards with this feature set use a combination of the PureVideo hardware and software running on the shader array to decode HEVC (H.265) as partial/hybrid hardware video decoding.
GeForce GTX 745, GTX 750, GTX 750 Ti, GTX 850M, GTX 860M,GeForce 830M, 840M,GeForce GTX 970, GTX 980, GTX 970M, GTX 980M,GeForce GTX TITAN X, GeForce GTX 980 Ti

Feature Set F
Introduced dedicated HEVC Main (8-bit) & Main 10 (10-bit) and VP9 hardware decoding video decoding up to 4096 × 2304 pixels resolution.
GeForce GTX 750 SE, GTX 950, GTX 960

My 970 doesn't decode 10 bit ?

My questions are:

1. In the current state with my current card, stuttering aside, am I'm loosing image quality watching HDR due to the 8 bit 10 bit stuff?
2. Is there a player that I'm not aware of that can handle HEVC better?

sneaker_ger · 5th January 2018, 15:13

1. You are not losing quality because of the lack of 10 bit hardware decoding. (If you have a HDR display you might miss out on HDR pass-through you could have with newer card & OS. Though I'm not really sure how quality compares to the other madvr output modes.)

2. What video filter are you using for the decoding? Try LAV Video 64 bit in software mode. (We have a whole thread dedicated to HEVC decoding performance.)

shasoosh · 5th January 2018, 15:48

I've just installed LAV filters (knowing nothing about it) while following a guide on "How to play Youtube HDR on PC".

I'll start digging the HEVC decoding performance thread.

Thanks

huhn · 5th January 2018, 16:02

while youtube HDR is barely possible with that system high bit rate HEVC should be impossible no matter what.

the topic is pretty simple the hybrid decoder from nvidia are pretty bad and doesn't have to be faster than software decoder is used with an modern i7.
so it all comes down to your CPU and i doubt it can decode 100 mbit HEVC.

i can't test it but i don'T see a reason why HDR output should not work with a 970 it has HDMI 2.0 and nvidia is mostly interested in HDR gaming and this card should be good enough for that.

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5th January 2018, 15:13	#2 \| Link
sneaker_ger Registered User Join Date: Dec 2002 Posts: 5,565	1. You are not losing quality because of the lack of 10 bit hardware decoding. (If you have a HDR display you might miss out on HDR pass-through you could have with newer card & OS. Though I'm not really sure how quality compares to the other madvr output modes.) 2. What video filter are you using for the decoding? Try LAV Video 64 bit in software mode. (We have a whole thread dedicated to HEVC decoding performance.)

5th January 2018, 15:48	#3 \| Link
shasoosh Registered User Join Date: Aug 2012 Posts: 5	I've just installed LAV filters (knowing nothing about it) while following a guide on "How to play Youtube HDR on PC". I'll start digging the HEVC decoding performance thread. Thanks

5th January 2018, 16:02	#4 \| Link
huhn Registered User Join Date: Oct 2012 Posts: 7,922	while youtube HDR is barely possible with that system high bit rate HEVC should be impossible no matter what. the topic is pretty simple the hybrid decoder from nvidia are pretty bad and doesn't have to be faster than software decoder is used with an modern i7. so it all comes down to your CPU and i doubt it can decode 100 mbit HEVC. i can't test it but i don'T see a reason why HDR output should not work with a 970 it has HDMI 2.0 and nvidia is mostly interested in HDR gaming and this card should be good enough for that.