[Stereodude]

Technically is correct but most TV disable processing for RGB signals, leaving with just 300lines motion resolution (from sample-and-hold limitations) and/or judder for 24p movies (no interpolation, pull-down instead frame repetition).

I've never seen a TV that does that exactly. Many TVs will convert RGB input signal back to Y'CbCr 4:2:2 internally in order to use most of the internal processing, but the internal processing is still allowed. If you enable PC mode it will pass RGB video onto the screen without the conversion, but you'll lose most internal processing (which is usually the worse option). In any case, the conversion back to Y'CbCr 4:2:2 isn't really detrimental because the TV works with more than 8-bit per color channel. Some TVs have as much as a 16-bit per color path. Many are 12-bits. The conversion back to Y'CbCr 4:2:2 is really only a problem if you're trying to use the TV as a monitor and are worried about font rendering. Video playback never had 4:4:4 color data to start with. They're all 4:2:0. Sure a TV that allowed all processing when fed a RGB signal without a conversion back to Y'CbCr 4:2:2 would be little bit better, but that's not what's out there.

According to him, whether you run limited-full-limited or full-full-full your device is sending the TV an RGB signal. The conversion from YCbCr to RGB occurs within Kodi regardless. The only difference is how reference black and white are mapped: 16-235 or 0-256.

Kodi, nor any other PC device can output Y'CbCr without having first converted video to RGB. Converting Y'CbCr to RGB and back to Y'CbCr in the PC is bad idea because the last step is done in the video card driver without dithering and are limited to 8 bit per color channel processing.

[VirtualRain]

Kodi, nor any other PC device can output Y'CbCr without having first converted video to RGB. Converting Y'CbCr to RGB and back to Y'CbCr in the PC is bad idea because the last step is done in the video card driver without dithering and are limited to 8 bit per color channel processing.

Do you have any thoughts on why my banding is slightly worse when going full-full-full vs limited-full-limited?

BTW I took my AVR out of the chain briefly and it made no difference to the banding or any other aspect of the video <relief>

[noggin]

Technically is correct but most TV disable processing for RGB signals, leaving with just 300lines motion resolution (from sample-and-hold limitations) and/or judder for 24p movies (no interpolation, pull-down instead frame repetition).

I've never seen a TV that does that exactly. Many TVs will convert RGB input signal back to Y'CbCr 4:2:2 internally in order to use most of the internal processing, but the internal processing is still allowed. If you enable PC mode it will pass RGB video onto the screen without the conversion, but you'll lose most internal processing (which is usually the worse option). In any case, the conversion back to Y'CbCr 4:2:2 isn't really detrimental because the TV works with more than 8-bit per color channel. Some TVs have as much as a 16-bit per color path. Many are 12-bits. The conversion back to Y'CbCr 4:2:2 is really only a problem if you're trying to use the TV as a monitor and are worried about font rendering. Video playback never had 4:4:4 color data to start with. They're all 4:2:0. Sure a TV that allowed all processing when fed a RGB signal without a conversion back to Y'CbCr 4:2:2 would be little bit better, but that's not what's out there.

Oh - that's interesting. I often see a difference between 4:2:2 and 4:4:4 content fed to my TVs (Sony 50Hz, Panasonic 100Hz plasma, Sony UHD 100Hz(+?)) - with the former clearly showing lower chroma resolution. If everything went via 4:2:2 internally, wouldn't I expect to see that chroma resolution reduction on both sources? It's clearly different for saturated fine detailed colour on GUIs (fine text, window edges etc.)

[Stereodude]

Do you have any thoughts on why my banding is slightly worse when going full-full-full vs limited-full-limited?

Your display may not really support full-full-full correctly. It's hard to say exactly. If limited-full-limited looks better, then use that.

[Stereodude]

Oh - that's interesting. I often see a difference between 4:2:2 and 4:4:4 content fed to my TVs (Sony 50Hz, Panasonic 100Hz plasma, Sony UHD 100Hz(+?)) - with the former clearly showing lower chroma resolution. If everything went via 4:2:2 internally, wouldn't I expect to see that chroma resolution reduction on both sources? It's clearly different for saturated fine detailed colour on GUIs (fine text, window edges etc.)

My Samsung F8500 plasma definitely does all processing in 4:2:2 (unless you enable PC mode). You can easy see that font rendering on the Windows desktop doesn't look correct unless you enable PC mode. An older Samsung 120Hz 1080p A630 series LCD does not do its processing in 4:2:2. Fonts are rendered as expected when you feed the TV RGB888. My even older 1080i Hitachi RP-CRT also doesn't work internally in 4:2:2. My understanding from what I've read on AVSforum is that newer TVs, like the F8500 work in 4:2:2 color. UHDTVs may be moving away from that, I'm not sure.

[VirtualRain]

Do you have any thoughts on why my banding is slightly worse when going full-full-full vs limited-full-limited?

Your display may not really support full-full-full correctly. It's hard to say exactly. If limited-full-limited looks better, then use that.

Yeah, so your post above questioning the OPs advice really should be qualified.

Bottom line... Whether limited-full-limited vs full-full-full is better appears to depend on your equipment.

BTW, I'm not even convinced people around here know with certainty what's going on inside the Kodi playback stack never mind what's happening in the TV.

[fritsch]

BTW, I'm not even convinced people around here know with certainty what's going on inside the Kodi playback stack never mind what's happening in the TV.

^^ this is fully true. As it is quite different highly depending on hardware / acceleration and so on.

[noggin]

BTW, I'm not even convinced people around here know with certainty what's going on inside the Kodi playback stack never mind what's happening in the TV.

^^ this is fully true. As it is quite different highly depending on hardware / acceleration and so on.

^^^ THIS!

[Ned Scott]

I was in a wiki-fying mood: Video levels and color space (wiki)

Feel free to modify as you see fit :)

[mwake]

Thank you for this post glad I found it, however, I'm total noob but I'd still like the best picture quality. I have Intel nuc celeron braswell running latest official openelec build. From my limited understanding at the moment I have to disable one of the hardware drivers and put Kodi on limited and my Samsung TV to low mode to get best picture mode? Or would it be easier to wait for Jarvis official and then I didn't have to do any Kodi tweaks? Sorry if I'm not coming across clearly, appreciate any help.

[Jagsta]

A big thank you for this post, it's helped me experiment with options on my kodi installations, however i'm still slightly confused, would appreciate some feedback on my setups and understanding.

First setup is pretty straightforward, I think:

1. Intel NUC (Celeron 847), Ubuntu 14.04, Kodi 16 -> Panasonic VT50 Plasma
Kodi is set to limited, prefer VAAPI disabled
GPU Is set to Full
TV doesn't have a setting for colour space (that i'm aware of)

AVS809 black and white clipping show BTB and WTW, no banding on greyscale ramp.

So as I understand it this is Limited -> Full -> Limited, no conversion, no crushing, no clipping, and i'm happy with the calibrated picture, it looks great!

The second setup is the one that's confusing me:

2. Raspberry Pi 3, LibreElec test build with Kodi 17 (28th April) -> Sony DN1040 AVR -> Optoma HD33 Projector

Kodi has no setting for limited or full that I can locate
Pi is set to limited
AVR has no setting for color space
Optoma is set to full

With this setup, WTW and BTB is clipped, but no black or white crush, there is no banding on the greyscale ramp, and i'm happy with the calibrated picture. BUT I don't see how that fits with the possible configurations in this thread?

Surely this is either Limited -> Limited -> Full, or Full -> Limited -> Full? Both of these are listed as WRONG, with washed out colours, but that's not what i'm seeing in practice.

Also, if I set the Projector to limited, with the Pi set either to limited or full, I get crushed blacks, no BTB and no WTW, and noticeable banding on the greyscale ramp. I don't understand how this relates to the configurations listed, it's surely either:

Limited -> Limited -> Limited (no black crush?, WTW, BTB clipped)
Full -> Limited -> Limited (no black crush?)
Limited -> Full -> Limited (no black crush?)
Full -> Full -> Limited (Black Crush)

Confused :/ Maybe I should just forget about it as i'm happy with the picture on the projector, i'd like to understand what's actually going on though.

I can't easily remove the AVR from the HDMI path, but I can swap out the pi 3 for the NUC, which would at least let me confirm I can get WTW and BTB at the projector.

[john.cord]

pi to limited and projector to full is not a good idea...

[Jagsta]

pi to limited and projector to full is not a good idea...

Thanks for replying, given the projector supports either full or limited range RGB, what would the recommended configuration be? Assumedly limited on both the Pi and projector?

The reality observed from testing in my case is that if I set the projector to limited colour space, regardless of whether I set the pi to limited or full, I get crushed blacks (17-25), whereas if I set the projector to full I don't get crushed blacks.

Also if I set the pi GPU to full and the projector to full there is visible banding on the greyscale ramp, whereas with the Pi GPU set to limited there is no banding on the greyscale ramp so I don't see what choice I have?

There are 3 parts of the chain in the examples here, the player, GPU and display, I still don't understand what the player is outputting in the case of Kodi on a raspberry Pi.

[john.cord]

Avshd709 greyscale MP4?

[Jagsta]

Avshd709 greyscale MP4?

Yes, I see the banding on the Misc Patterns/A - Additional/1-Greyscale Ramp.mp4 and the crush of 17-25 and clipping of 0-16 on Basic Settings/1-Black Clipping.mp4.

I'm going to retest all 4 permutations of Pi/Projector again this evening to sanity check my findings.