[Soli]

Sorry, I meant to say "amount of [bits]" are the same. (ie. 24 is still 24bits) To my defense, it was pretty late/early
However it would be correct to say that for 8bit sources, 4:2:0 averages to 12bits pr. pixel in terms of bandwidth, but not in the context of explaining chroma subsampling itself.

[wesk05]

Sorry, I meant to say "amount of [bits]" are the same. (ie. 24 is still 24bits) To my defense, it was pretty late/early

So you admit that you were also sleepy

[Soli]

That is correct

[gwilly7]

Pulled the trigger and got the Ryzen 2400g today. Only installed windows so far, will have to try libreelec later. I am using the Asus B350M-E board and going through a Denon x2300w receiver to a 2016 Vzio P-series.  Below are the displays options I have available. What is the differnce between YCbCr 4:4:4 and RGB 4:4:4

[noggin]

 TL;DR subsampling :

4:4:4 at 8 bit = 32 bits per pixel bandwidth (YCbCr all sent for every pixel) 
4:2:2 at 8 bit = 16 bits per pixel bandwidth (YCb YCr sent for each pair of pixels on every line - full horizontal / vertical luminance res, full vertical chrominance res, half horizontal chrominance res)
4:2:0 at 8 bit = 12 bits per pixel bandwidth (YCb Y sent for each pair of pixels on one line, YCr Y sent for each pair on the next line - full horizonal/vertical luminance res, half vertical and half horizontal chrominance res)

As you can see you need 2.6x the bandwidth for 4:4:4 as you do for 4:2:0... (And you can see why all consumer video - DVD, Blu-ray, SD/HD/UHD TV, Netflix etc. is 4:2:0 as a result...)

Thanx for that, explains why my Apple TV 4K keeps suggesting I use 4:4:4 for better picture quality.
Had to buy a new 18Gbps HDMI cable for that though.  

Someone tell noggin naptime's over.

First, 8 times 3 is 24, not 32.

D'oh! Sorry - very silly mistake... I spent so much time with 4:2:2:4 stuff recently I messed up (embedded alphas will do that to you...)

It's also fundamentally wrong to talk about bits per pixel.

I don't agree that it's fundamentally wrong when discussing HDMI bandwidth issues which was the cause for the original comment about sub-sampling. The whole point of sub-sampling is to get bandwidth down. Using the word average can help - but the word average also can imply that the bits-per-pixel is varying - when it isn't. It would be better to describe the 2x1, 2x2 sampling grids etc. (but then you get into interlace, off-set stuff that takes you out of TL;DR territory - and once you start saying quincuncial people start looking at you strangely... )

Lastly, 4:4:4 is an exact 2 times the bandwidth of 4:2:0, not 2,6.

Yes - of course it is. I was tired when I posted that. Must learn not to post when tired, and thinking about recent work stuff.

Only in rare cases you need to buy a new HDMI cable for UHD resolutions, full chroma subsampling or not. (Exceptions are really sh**y cables, or very long cables) But I'll give you the benefit of the doubt, 

I've had to replace almost all of mine as I went to 18Gb/s as I kept getting intermittent HDMI re-syncs, or 'This resolution is not supported' error messages. I probably started with pretty low cost cables bought 5+ years ago though...

[noggin]

Sorry, I meant to say "amount of [bits]" are the same. (ie. 24 is still 24bits) To my defense, it was pretty late/early
However it would be correct to say that for 8bit sources, 4:2:0 averages to 12bits pr. pixel in terms of bandwidth, but not in the context of explaining chroma subsampling itself.

 The amount of bits per pixel in the source is the same, but not in the subsampled result. 

A 1920x1080 4:4:4 frame is 48Mbits of data uncompressed
A 1920x1080 4:2:0 frame is 24Mbits of data uncompressed (*)

The "bits per pixel" is halved in the 4:2:0 frame compared to the 4:4:4 frame surely?   This is a very good way of illustrating why chroma subsampling is used in the first place - to reduce bandwidth (and thus reduce cable requirements and processing requirements).  Sure I didn't point out that the eye / brain perceives less chrominance detail, hence sub-sampling to 4:2:0, 4:1:1, 4:2:2 etc. is used - but it was a TL;DR to be fair.

(* - yes it is sub-sampled - which some would argue is crude compression - like interlace)

[noggin]

That is correct

 I think we both were

[gwilly7]

Not sure if others have been using Raven Ridge for Kodi yet or not but everything has been working ok in windows and I was able to install the Ubuntu 18.04 beta this week as well and seems to be working good so far. Just need to tackle getting hdmi audio passthrough working.  4K @60hz is working as well. I prefer using libreelec but have not been able to get libreelec to work yet.

[Dobyken]

I pulled the trigger a few weeks ago on a 2200g but just got it put together yesterday.  The MB wasn't ryzen 2000 ready so I put a request in to AMD for the loaner chip.  The catch is you have to contact the board manufacturer first and wouldn't  you know it...ASRock said to send it back to them for a bios upgrade.  I got 2 4gb sticks of DDR4 ram and one of them turned out to be bad but I was able to play 4K video with no issues even though I only had 512mb of video ram assigned to the board.  The bit rate was peaking at around 50MB/sec and Kodi reported 1 dropped frame right after startup with CPU usage running under 10pct.

[gwilly7]

I pulled the trigger a few weeks ago on a 2200g but just got it put together yesterday.  The MB wasn't ryzen 2000 ready so I put a request in to AMD for the loaner chip.  The catch is you have to contact the board manufacturer first and wouldn't  you know it...ASRock said to send it back to them for a bios upgrade.  I got 2 4gb sticks of DDR4 ram and one of them turned out to be bad but I was able to play 4K video with no issues even though I only had 512mb of video ram assigned to the board.  The bit rate was peaking at around 50MB/sec and Kodi reported 1 dropped frame right after startup with CPU usage running under 10pct.

 Are you using windows or linux.  The one problem I have with windows is the video will randomly freeze while the audio keeps going and I will have to restart the movie or show.  My hdhomerun will randomly freeze as well.

I also have ubuntu 18.04 installed but have not used kodi much yet on it.

[Dobyken]

I'm using Win 10 64bit.    I received my replacement ram from Amazon yesterday so now I'm at 8gb with 1gb assigned to the video card so performance should go up a little bit.  The Windows desktop is set at 3840x2160 as well as the Kodi Gui.  I don't think the board supports 60hz but since most 4k movies are 24 fps I don't think it matters since I don't do any PC gaming.  All my external USB3 drives are connected to the same box so there's no networking involved with 4k playback.  I only played one 4K movie so far but didn't get any lagging or stuttering.

[gwilly7]

I'm using Win 10 64bit.    I received my replacement ram from Amazon yesterday so now I'm at 8gb with 1gb assigned to the video card so performance should go up a little bit.  The Windows desktop is set at 3840x2160 as well as the Kodi Gui.  I don't think the board supports 60hz but since most 4k movies are 24 fps I don't think it matters since I don't do any PC gaming.  All my external USB3 drives are connected to the same box so there's no networking involved with 4k playback.  I only played one 4K movie so far but didn't get any lagging or stuttering.

 So far from reading around even though the board is not rated at hdmi 2.0 it has not been a problem since the processor seams to dictate the speed of the port in this situation. I have an asus b350m-e board and can set both Linix and Windows to 3840X2160 60hz with no issues.

[ars92]

I wonder if this is a better buy than Gemini lake for those looking for a NUC based kodi machine now...

[dwalme]

I wonder if this is a better buy than Gemini lake for those looking for a NUC based kodi machine now...

 Considering Gemini Lake doesn't support HDR I'd say so.

[gwilly7]

Anybody else using Raven Ridge have issues with video freezing while audio keeps playing after about 45 minutes or so. Seems to be worse on Krypton than Leia. Thought it might be a motherboard issue before finding someone on Reddit with same problem. This happens on both windows 10 and ubuntu 18.04 for me.