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timstephens24 · 2017-05-12, 19:22

I've had that problem the whole time I've had the Shield. It's different colorspaces don't have accurate colors.

wesk05 · 2017-05-12, 19:36

(2017-05-12, 19:22)timstephens24 Wrote: I've had that problem the whole time I've had the Shield. It's different colorspaces don't have accurate colors.

There isn't anything wrong with what the Shield outputs. The output matches exactly to the input in YCbCr mode. In RGB mode there are some rounding errors, but nothing that can be visually perceived (by normal people).

timstephens24 · 2017-05-12, 19:52

RGB is noticeably different than any of the other outputs.

wesk05 · 2017-05-12, 20:30

(2017-05-12, 19:52)timstephens24 Wrote: RGB is noticeably different than any of the other outputs.

RGB Full will look different because 16-235 is scaled and remapped to 0-255. You will also have to manually adjust the black level settings on your TV. Shield doesn't send quantization bits in AVI Infoframe (this is applicable to other Android devices also). If you compare RGB Limited (with your TV set to appropriate black level) to YCbCr, you are unlikely to notice any difference. If you are seeing, then it is unrelated to Shield's output.

timstephens24 · 2017-05-12, 23:23

Ok I just checked. 1080p w/ YCbCr 444 and RGB 8-bit BT.709 look visually the same. 4K w/ YCbCr 420 10-bit BT.2020 looks washed out and the colors are off. Guess the issue is BT.709 and BT.2020 color differences and not specifically the Shield?

cscoppa · 2017-05-12, 23:43

(2017-05-12, 23:23)timstephens24 Wrote: Ok I just checked. 1080p w/ YCbCr 444 and RGB 8-bit BT.709 look visually the same. 4K w/ YCbCr 420 10-bit BT.2020 looks washed out and the colors are off. Guess the issue is BT.709 and BT.2020 color differences and not specifically the Shield?

From my understanding you have to have a properly created 4K (HDR usually) file that was encoded in BT.2020 for it to look correct.

wesk05 · (This post was last modified: 2017-08-05, 20:21 by wesk05.)

(2017-05-12, 23:23)timstephens24 Wrote: 4K w/ YCbCr 420 10-bit BT.2020 looks washed out and the colors are off. Guess the issue is BT.709 and BT.2020 color differences and not specifically the Shield?

If this is based on the home screen or playing BT.709 video, then yes. Shield doesn't really do a BT.709 to BT.2020 color space conversion. It simply sends the 8-bit value as 10-bit. ITU BT.2087-0 is the recommendation for this color space conversion.

**EDIT**
Upon further checking, it looks like Shield does do some sort of BT.709 to BT.2020 conversion. It isn't clear whether the conversion actually follows BT.2087 recommendation.

ggp759 · 2017-05-13, 00:08

(2017-05-12, 19:36)wesk05 Wrote:
(2017-05-12, 19:22)timstephens24 Wrote: I've had that problem the whole time I've had the Shield. It's different colorspaces don't have accurate colors.
There isn't anything wrong with what the Shield outputs. The output matches exactly to the input in YCbCr mode. In RGB mode there are some rounding errors, but nothing that can be visually perceived (by normal people).

(2017-05-12, 23:23)timstephens24 Wrote: Ok I just checked. 1080p w/ YCbCr 444 and RGB 8-bit BT.709 look visually the same. 4K w/ YCbCr 420 10-bit BT.2020 looks washed out and the colors are off. Guess the issue is BT.709 and BT.2020 color differences and not specifically the Shield?

Just played with the color spaces some more. 4K BT 2020 is to be used only for HDR content nothing else. 4K BT 709 and all the combinations of YCbCr gives a weird look in kodi/spmc for 1080p stuff (skin tones especially).The thing is that for 4k netflix or amazon content that are not in HDR (ie Better Call Saul) i have to change the color space yet again to BT 709 and 4k. i guess there is no way for nvidia to make the shield choose the correct color space according to source.

wesk05 · (This post was last modified: 2017-05-13, 00:13 by wesk05.)

(2017-05-13, 00:08)ggp759 Wrote: Just played with the color spaces some more. 4K BT 2020 is to be used only for HDR content nothing else. 4K BT 709 and all the combinations of YCbCr gives a weird look in kodi/spmc for 1080p stuff (skin tones especially).The thing is that for 4k netflix or amazon content that are not in HDR (ie Better Call Saul) i have to change the color space yet again to BT 709 and 4k. i guess there is no way for nvidia to make the shield choose the correct color space according to source.

Hmm... You shouldn't see a difference between 1080p BT.709 and 4K BT.709.

This is what I suggested here: https://forums.geforce.com/default/topic...9/#5145959

ggp759 · (This post was last modified: 2017-05-13, 09:03 by ggp759.)

(2017-05-13, 00:11)wesk05 Wrote:
(2017-05-13, 00:08)ggp759 Wrote: Just played with the color spaces some more. 4K BT 2020 is to be used only for HDR content nothing else. 4K BT 709 and all the combinations of YCbCr gives a weird look in kodi/spmc for 1080p stuff (skin tones especially).The thing is that for 4k netflix or amazon content that are not in HDR (ie Better Call Saul) i have to change the color space yet again to BT 709 and 4k. i guess there is no way for nvidia to make the shield choose the correct color space according to source.
Hmm... You shouldn't see a difference between 1080p BT.709 and 4K BT.709.

This is what I suggested here: https://forums.geforce.com/default/topic...9/#5145959

Thanks i know there shouldn't be a difference that's why am puzzled with these settings. I think it has to do with the upsampling being done in spmc and/or the shield. If you select( and now am only talking about SDR 1080p content encoded at 4:2:0) 4:2:0 the shield has to upsample to 4:2:2 because 4:2:0 is not a legal HDMI spec at 23.976p and there is another upsample in the chain to 4:4:4 by the tv in order to finally display it as RGB. If you select 4:4:4 the shield/kodi has to upsample all the way from 4:2:0 to 4:4:4 and then send it to the tv. No more upsampling takes place and the picture is displayed as RGB. Whether its best to let the shield to all the upsampling(send 4:4:4) or the tv (send 4:2:0 or 4:2:2) it depends on the capabilities and the upsampling quality of the tv. All these work for 1080p content. When the resolution changes to 4k though and the colospace remains in BT 709 those anomalies i mentioned earlier take place in spmc/kodi. I dont know and i would like someone from the development team to correct me on this. Isnt primarily spmc/kodi develpoed to work with RGB? Forcing the shield to output in YCbCr introduces unnecessary color errors etc? Thanks alot.

gacama · 2017-05-17, 20:59

I'm trying to set back button in my harmony ir remote, but I can't someone can explain me how to? For dummies please Big Grin

Thanks in advance

Enviado desde mi Z2 Plus mediante Tapatalk

**Tinwarble** · 2017-05-17, 21:28

(2017-05-17, 20:59)gacama Wrote: I'm trying to set back button in my harmony ir remote, but I can't someone can explain me how to? For dummies please

Thanks in advance

Enviado desde mi Z2 Plus mediante Tapatalk

Set it to do what? You need to be more explicit about what you are trying to do.

hoppel118 · (This post was last modified: 2017-05-17, 22:16 by hoppel118.)

How old is your harmony profile? If I remember right Logitech made some changes for the back button one or two months ago. Maybe you can try to delete and setup again the shield device at myharmony.

I am not a harmony user anymore. Since I have the shield, I use the original shield remote only.

Greetings Hoppel

gacama · 2017-05-18, 00:16

(2017-05-17, 21:28)Tinwarble Wrote:
(2017-05-17, 20:59)gacama Wrote: I'm trying to set back button in my harmony ir remote, but I can't someone can explain me how to? For dummies please

Thanks in advance

Enviado desde mi Z2 Plus mediante Tapatalk

Set it to do what? You need to be more explicit about what you are trying to do.

(2017-05-17, 22:14)hoppel118 Wrote: How old is your harmony profile? If I remember right Logitech made some changes for the back button one or two months ago. Maybe you can try to delete and setup again the shield device at myharmony.

I am not a harmony user anymore. Since I have the shield, I use the original shield remote only.

Greetings Hoppel

I have the harmony ultimate one, my profile is one month old, I have all buttons working with this profile, except back, when I press back button, nothing happens...

wesk05 · (This post was last modified: 2017-05-21, 10:45 by wesk05.)

@timstephens24, @ggp759: Looks like I have to eat my words. There is definitely something wrong with the Shield's 12-bit output. There is a difference between the native Photos & Videos app and other video players. 8/10-bit output is OK with Kodi & Photos & Videos, but 12-bit isn't. I have no idea why there is this difference between the native video player and the other video players (Kodi, SPMC, MrMC, Vimu, Archos etc.) All use MediaCodec (Surface) rendering. The tables below only show the values for primary & secondary colors. I have checked 21-point grayscale and classic color checker patterns (8 & 10-bit) and they all show similar errors for 12-bit output.

Values that deviate from reference by more than 10 are in red. Up Sampled is 8-bit pattern to 12-bit YCbCr 4:2:2 (table 2) and 10-bit pattern to 12-bit YCbCr 4:2:2 (table 4).

Edit:
I have updated the table. I had used an incorrect pattern file for 10-bit and that was probably causing the errors for 10-bit YCbCr 4:2:0 output. Now the output is accurate for 8 & 10-bits. There are still some small differences between Kodi and Photos & Videos output.