View Full Version : 25fps video played at 50Hz is a problem?
senzaparole
30th September 2020, 11:13
Hello guys,
I have an LG B9 OLED TV that I also use as a PC monitor. On the desktop I set the fixed frequency to 60Hz.
I use madVR with Mediaportal and MPC-HC. While playing a movie at 50 FPS, in the madVR OSD I display:
https://i.ibb.co/PW24C9D/IMG-20200928-133940.jpg (https://ibb.co/WzrFKPV)
display 50.000 HZ
composition rate 50,000 Hz
movie 25,000 fps
It's correct?
In madVR's "display modes" I set 2160p23, 2160p24, 2160p25 and 2160p50.
I add that if I remove 2160p50 from madVR "display modes" it happens that:
- MPC-HC perfectly reads videos at 25 fps. In madVR OSD you can see: Display 25.000 , composition rate 25,000 Hz, movie 25,000 fps;
- Mediaportal, on the other hand, cannot play videos at 25 fps: The display and composition rate freeze at 60 Hz and the video is not playable (only audio is heard). No problem with standard video playback at 23.976 Hz.
So to sum it all up, if I remove 2160p50 display modes only MPC-HC reads video correctly at 25 fps.
If I add 2160p50 to the "Display modes" both players (MPC-HC and Mediaportal) read the videos at 25 fps but with a frequency of 50 hz. No problem with playing "standard" video at 23.976 Hz.
huhn
30th September 2020, 14:47
playing 25p video at 50hz is totally fine. actually with normal blu rays playing them at 25 hz is wrong because all 1080p25 is not part of the spec only 1080i50 and because no one know if the file is telecine or interlace playing them at 50 hz is correct.
d3d11 can't deint with madVR so you should not use it with pal content.
Ghitulescu
30th September 2020, 20:00
In the past the panels for TV had only one refresh rate, and all rates have been interpolated in the built-in DSP. Most people think that if a TV accepts all kind of formats, it will also display them "natively". Multiple fs makes a TV more expensive, and this is why true multisynch PC monitors are more expensive than a TV.
The only way to know for sure your TV has a native refresh rate, whatever it that (common 60Hz), is to use test BDs and check for artefacts. Or know somebody in the R&D of the manufacturer :).
huhn
30th September 2020, 22:01
he lives in italy we don't have this problem with 50/60 HZ it's super rare a TV can do both in Europe for 20 years as you should know. this happens yes Panasonic plasma are an example.
correct 24p is the "only" refreshrate that is not always working as it should be it even "common" that this doesn't work correctly.
and multi sync PC screens are common too and super cheap you can go and get a freesync screen with native 60, 100, 120 and 144 hz for like 150 euro.
senzaparole
1st October 2020, 14:28
Thanks for your suggestions.
I've included 2160p23, 2160p24, 2160p50, 2160p60 values in madVR's "display modes".
Klaus1189
1st October 2020, 15:23
Please also add "2160p59"
senzaparole
1st October 2020, 18:00
Thank you klaus!
If I had to lower the "rendering" time a little (in some videos, I am at the limit) on which parameter of madVR should I act?
clsid
1st October 2020, 18:49
Lower the Chroma scaling algorithm. That has least impact on quality. Using NGU very high there is totally overkill. Do go beyond NGU medium.
senzaparole
3rd October 2020, 15:16
d3d11 can't deint with madVR so you should not use it with pal content.
Hi Huhn!
I have now noticed your suggestion.
"In Hardware Acceleration - Hardware decoder to use" I have always set D3D11 without noticing any problems. What should I set if D3D11 is not good?
I thought D3D11 was the best setting for me
senzaparole
3rd October 2020, 15:22
Lower the Chroma scaling algorithm. That has least impact on quality. Using NGU very high there is totally overkill. Do go beyond NGU medium.
Hi Clsid,
I found two possibilities to change the chroma. Which of the two possibilities are you refering to?
1. In "Scaling Algorithms" ----> "chroma upscaling" ----> "NGU" -----> from "Sharp high quality" to "Sharp medium quality".
2. In "Scaling Algorithms" ----> "chroma upscaling" ----> "NGU SHARP" -----> "algorithm quality" -----> I have three settings: "luma doubling", "luma quadrupling "," chroma ". Down with this "Chroma"?
Finally, I would like to point out that: "enable smooth motion frame rate conversion" is disabled.
I don't know if enabling this setting can lower the render value and thus avoid losing frames ..
clsid
3rd October 2020, 17:04
Use "let madvr decide" for the second option.
Smooth motion is only used if framerate and refreshrate do not match.
VBB
3rd October 2020, 19:13
@senza - D3D11 is the best setting, unless you need de-interlacing and a few other things that are not normally needed. The first chroma upscaling option is the important one. You want to lower that, if you're dropping frames. If you leave the second option at "let madvr decide", it will scale along with the first option.
senzaparole
3rd October 2020, 20:08
My doubt is whether D3D11 is still the best setting for me living in Italy.
Maybe Huhn lives in Germany and is informed because he is very close to my country
@Huhn what do you say?
VBB
3rd October 2020, 20:19
Like huhn said, it isn't the best if you watch a lot of interlaced content, i.e. 25fps, 30fps. I'm also from Germany originally ;)
senzaparole
3rd October 2020, 20:32
Ahhh Long Beach made me wrong :-) : I thought you were a citizen of the United States.
Very well then. The 25fps and 30fps content is truly residual in my library. So the best setting is D3D11! ;););)
senzaparole
3rd October 2020, 20:39
Use "let madvr decide" for the second option.
The first chroma upscaling option is the important one. You want to lower that, if you're dropping frames. If you leave the second option at "let madvr decide", it will scale along with the first option.
I ask for a little clarification here.
So if I have to lower the madVR settings because the high rendering causes me to lose frames, I must, first of all:
In "Scaling Algorithms" ----> "chroma upscaling" ----> "NGU" -----> from "Sharp high quality" I switch to "Sharp medium quality".
I did not understand what I have to do in the second option. I understand that:
In "Scaling Algorithms" ----> "chroma upscaling" ----> "NGU SHARP" -----> "algorithm quality" -----> I have three settings: "luma doubling", " luma quadrupling "," chroma ".
I don't have to change this Chroma (it is currently set to very high) because I already changed the first option.
I have to change "luma doubling" and "luma quadrupling" to "let madvr decide" or do I leave the current settings: "very high" and "double again -> very high" ?
VBB
3rd October 2020, 20:54
In "Scaling Algorithms" ----> "chroma upscaling" ----> "NGU SHARP" -----> "algorithm quality" -----> set to "let madvr decide".
This setting is for when chroma gets upscaled a second time, after it got upscaled the first time from 4:2:0 to 4:4:4. Unless you use your B9 in PC mode, chroma is not really all that important anyway, because outside of PC mode the TV subsamples to 4:2:2 anyway. So, don't waste your resources on chroma. Luma should always take priority.
senzaparole
3rd October 2020, 22:13
In "Scaling Algorithms" ----> "chroma upscaling" ----> "NGU SHARP" -----> "algorithm quality" -----> set to "let madvr decide".
For all three of these fields ("luma doubling", " luma quadrupling "," chroma ) I select:
"let madvr decide"?
https://i.ibb.co/hcjXJzS/madvr.png (https://ibb.co/r3SbRrV)
I use my LG B9 in Pc Mode. I have never encountered any problems between using the TV in Pc Mode or using it in another mode. So I use PC mode and I have 4: 4: 4
VBB
3rd October 2020, 22:33
As you can see, the first two settings are for luma. Of those two, I change only the first one and leave the second one at "let madVR decide". The third setting is for chroma, and that is also best left at "let madVR decide", unless you have plenty of headroom to mess with chroma settings. In the madVR OSD you can find that chroma setting in the third upscaling line, underneath luma. Looking at your screenshot, I would also leave the rest of the settings at "let madVR decide", unless you feel the need to tweak something in particular.
senzaparole
4th October 2020, 16:45
Hi Henry,
so you advise me to set everything as in this photo ( in the 720p60 profile, except "luma doubling" I have set in "image upscaling" all fields in "let madVR decide"):
https://i.ibb.co/7XsGm4m/Immagine-mod.jpg (https://ibb.co/g3kDKVK)
Do I do the same thing for all the other profiles (2160p30, 1080p30 etc ..)?
VBB
4th October 2020, 18:34
Yes, I would start with setting everything like in your screenshot and then tweak from there. Of course you'll also have to adjust the luma doubling option for the different combos.
senzaparole
5th October 2020, 17:34
"luma doubling" in the different combos is set to maximum: "very high".
Only in the "720p60" profile was I forced to go down to "high"
vBulletin® v3.8.11, Copyright ©2000-2026, vBulletin Solutions Inc.