[Dudeman]

I've been using KODI on an original Fire Cube for about a couple of years and never had any issues other than the poor GUI performance.  So when Amazon released the new Hexa-Core models and made them available for only $75 during Christmas I got one.

The performance of the new model is so much better, the GUI is pretty smooth and even with 2200 movies and some 270 TV shows scraped, it handles its own.

Now to the problem.  Some shows that play just fine on the older Firecube and on other machines, are having playback quality problems.  Most 2160p and 1080p content seems to be fine, but lower resolution (SD or 720p) content suffers from "over-processing"?  It's hard to explain, but it look as if this content is over processed during up scaling (it think).  Images become flat and devoid of detail, and subtle shading becomes posterized.  Below are links to a few photos I took off the screen.

https://www.dropbox.com/s/ct6ajul653je3bp/trek-001.jpg
https://www.dropbox.com/s/7gn9wz1cwtwgg2w/trek-002.jpg
https://www.dropbox.com/s/pmprw855y272q8q/trek-003.jpg

The original Trek episode (Season 1 Episode 18 - Arena) is a 720p rip from the BluRay, and it plays just fine in the old FireCube.  It also plays fine on my other (PC based) KODI setups. 

Basic information on the file:

Container:  MKV Matroska v2
Format:  AVC
File Size:  698MB
Resolution:  960 x 720
Frame Rate 23.976 fps
Bitrate: 1930 Kbps
CODEC ID:  V_MPEG4/ISO/AVC
Audio: AAC 6 channel

One other bit of information.  During basic troubleshooting I disabled the hardware acceleration (both normal and surface), and it plays much better. 

So I'm wondering if this is an issue with GPU drivers, differences between the original Fire Cube GPU and the new one?

RESOLVED:
See post #7 for the solution

[Hitcher]

That looks awful. Have you tried whitelisting those resolutions so your TV does the upscaling instead of the Cube?

Also make sure 'Always HDR' is off.

[Dudeman]

How do you do this whitelisting? 

I thought that Kodi always scales everything up.  How do you prevent Kodi from up-scaling?

And yes, I had already disabled "Always HDR" because

1. I don't like the "warm" look,
and
2. it disables my TV's 3D functionality.  If Dolby Vision is on, 3D is not available

[Hitcher]

https://kodi.wiki/view/Settings/System/D...#Whitelist

[Dudeman]

Yes, I found the Settings/Whitelist, and tried quite a few permutations last night.

When I look there it shows the resolutions the TV is capable of, 2160p, 1080p and 720p in a variety of refresh rates.  By default none of these resolutions are selected, but if I select just one of them, like for example 720p @ 60Hz, then it looks like all videos will play at that resolutions.

Best I can figure it out is If I select all of the resolutions, then they are all available in the OSD menu to select from during playback.  If no resolutions are selected, then there is no option In the OSD.  So I assume that the argument here would be that having all these resolutions available in the OSD, would allow me to force the video to be played at a specific resolution (other than the original one?).

Anyway I tried a variety of permutations, and was able to get the video quality to improve, but now I'm running into stuttering issues, video and audio out of sync, especially if bouncing around in the video.  One of the most common issues is when pausing, the video stops, but the audio continues for a 3-4 seconds, and when you resume, there is no audio for about the same length.

Anyway, all this stuff is really weird, and it's only on the new Fire Cube.  I have both cubes loaded with the same configuration, as the DATA resides on a an external USB, which I move from one unit to the other.  So with the same configuration th eold quad core Cube works fine, but the new hexa-core doesn't.

[Hitcher]

That doesn't right at all. The whole point of the whitelist is to enable all the resolutions your TV supports so when a video is played that has one of these matching resolutions that what is output by the device so the TV can do all the scaling.

[Dudeman]

So I think I found the solution to this problem.

First let me say that this it has nothing to do with Kodi itself.  I was able to replicate the problem using VLC and MX Player as well. 

Secondly, the problem seems to be isolated, at least in my case, to my 4K TV, which may explain why some folks don't see the problem.  I put the FireCube on my Vizio TV which is and older only 1080p that doesn't support HDR, and playback was flawless.  When I moved it back to my LG 4K OLED, the problem came back.  I also tested the same files with VLC, as well as MX Player, and they all had the same problem.  I then put the files on a thumb drive, plugged it into the TV directly, and they played perfectly.  So the issue is with the FireCube.

I then tried disabling HDR Always on, no luck, forced playback to only 1080p, no luck.  I also tried 8bit, 10bit and 12bit, no help.  Then, as a last ditch effort, I selected the Color Mode from Auto to RGB, and "miracle of miracles", it played perfectly.  I then selected YCbCr, and that plays fine too.  So I really don't know what Auto does, but obviously it's not either of these 2, it's something else.

So, as it stands, now have everything running correctly, with YCbCr as my color space, and no more playback quality issues.  I hope this helps other folks in the same boat as I was.