Easy way to see RGB values sent to each LED?

[chcore]

Pretty much what the title says. I'd like to see the RGB values being sent to the LEDs in real time. Is that possible? Maybe it could be a nice addition to the live preview window?

[awawa-dev]

LED Hardware -> File and then use some text editor to view the output file. I use Far Manager to view it in the real time.

[awawa-dev]

Yes, it's the same frame as it's processed in HyperHDR. So if the tone mapping is enabled it affects both LEDs and live preview.

[chcore]

OK so I decided to test using a color that already exists in the SDR test video. The LUT translates this color (and everything else!) correctly, according to the log:

[144 80 224] => [144 80 225]

When I fill the entire screen with rgb(144,80,225) I can see the LEDs are actually receiving rgb(143,56,232) with my gamma values set to 1.0, or rgb(107,26,221) when set to 1.5.

Is this normal behavior? Shouldn't the LEDs be receiving rgb(144,80,225) instead?

[awawa-dev]

The calibration process targeting MP4 files&player&TV, that color is present in the MP4 test files because it's divided by 16 so can have a approximation in the result. If you inject the color in any other way or mixing calibration 420 limited MP4 with color injected in 420 full range MP4 then there is no guarantee how webOS or any grabber will process that color later: must be tested to confirm it.

[chcore]

The calibration process targeting MP4 files&player&TV, that color is present in the MP4 test files because it's divided by 16 so can have a approximation in the result. If you inject the color in any other way or mixing calibration 420 limited MP4 with color injected in 420 full range MP4 then there is no guarantee how webOS or any grabber will process that color later.

Interesting. My method of filling the screen with rgb(144,80,225) is generating a 4k solid PNG image using ImageMagick, and viewing that image in Kodi. Does that still apply?

[awawa-dev]

use ffmpeg and create test file with solids boards just like in the latest source directory

[chcore]

I used the following command and the attached rgb(144,80,224) image to create the attached test video. For me, the color is off in the test video, no matter where I play it (kodi, mpv, chrome, etc). Is that expected?

ffmpeg -loop 1 -t 30 -framerate 1/3 -i rgb-144-80-224.png -shortest -map 0:v:0 -vf fps=25,colorspace=space=bt709:primaries=bt709:range=pc:trc=iec61966-2-1:ispace=bt709:iprimaries=bt709:irange=pc:itrc=iec61966-2-1:format=yuv444p12:fast=0:dither=none -c:v libx265 -pix_fmt yuv420p10le -profile:v main10 -preset veryslow -x265-params keyint=75:min-keyint=75:bframes=0:scenecut=0:psy-rd=0:psy-rdoq=0:rdoq=0:sao=false:cutree=false:deblock=false:strong-intra-smoothing=0:lossless=1:colorprim=bt709:transfer=iec61966-2-1:colormatrix=bt709:range=full -f mp4 rgb-144-80-224.mp4

rgb-144-80-224.mp4

[awawa-dev]

You can always use 2 full range test files for SDR.

Two?

https://github.com/awawa-dev/awawa-dev.github.io/tree/master/calibration/misc_test_files

test_SDR_yuv420_low_quality.mp4
test_SDR_yuv444_high_quality.mp4

[chcore]

You can always use 2 full range test files for SDR.

Two?

https://github.com/awawa-dev/awawa-dev.github.io/tree/master/calibration/misc_test_files

test_SDR_yuv420_low_quality.mp4 test_SDR_yuv444_high_quality.mp4

Are the black parts of these test videos supposed to be pure black when played? They don't look pure black when played in Kodi.

[chcore]

test_SDR_yuv420_low_quality.mp4
test_SDR_yuv444_high_quality.mp4

I was already using these (rather, the yuv420 one) until you updated the repo and moved them into the misc folder.

[chcore]

test_SDR_yuv420_low_quality.mp4
test_SDR_yuv444_high_quality.mp4

Calibrated using both of these, neither correctly sent 144,80,224 to the LEDs. The yuv444 LUT sent 142,36,243 while yuv420 sent 143,56,232.

[awawa-dev]

OK, give me more time. I will investigate the SDR issue. Probably colorspace plugin cannot perform color range conversion or the container is missing the tag. HDR processing is using different plugin.

[awawa-dev]

Hi @chcore
I managed to fixed the SDR files by using limited/full range tag for colorspace. For zscale it is unnecessary.
Your color is of course present in the test files from 0:12 to 0:15, first top row as on the snapshot.
I used VLC and took the screenshot (Video->Take Snapshot)

So the (144,80,224) is (144,79,224) in the calibration file. Thats also explains why we never will achieve 0 score in the calibration process ;-) but I think we are OK with that. There is a small noise inside this rectangle both for YUV420 limited and full range, YUV444 has almost no noise.

[awawa-dev]

I think it's a Kodi range configuration problem, not only for the calibration file but for all yuv420 limited files

WHITE_0: [ 0 0 0] => [ 29 29 29] (YUV: [ 41 128 128]), [ 28 28 28] (YUV: [ 40 128 128]) [source noise detected]
it should be YUV [16 128 128]

One of user currently testing this case on webOS for me, will let you know about the result.

[chcore]

One of user currently testing this case on webOS for me, will let you know about the result.

Thank you. In case it is relevant, I have the TV, GPU and Kodi all set to full range.

[awawa-dev]

So according to Kodi documentation it's wrong. I'm not sure, I dont use it. Content (test file) is limited so it should be rather limited => full => limited

[chcore]

I also noticed that, but it says Full,Full,Full will have desktop (i.e. video games) and video both looking correct, which is what I'm after.

I might give limited,full,limited a go but it seems like that's the best option for a device that will only ever be playing video.

[chcore]

I played around with limited-full-limited and various test videos but couldn't get anything that ends up sending the right color to the LEDs for the purple PNG image (i.e. non-video content).

[awawa-dev]

@chcore
1 After testing we decided to revert changes introduced in #1000 (comment) . Colorspace worked just fine for webOS.
2 For testing RGB444 12bit mode was used (SDR) windows and VLC in fullscreen mode.
3 Calibration shows correct WHITE_0 range: 16 no 29 or higher.

2024-12-04T23:46:30.459Z [CALIBRATOR] (LutCalibrator.cpp:381) Using flatbuffers/protobuffers as a sourceWaiting for first captured test board..
2024-12-04T23:46:30.479Z [CALIBRATOR] The YUV range is LIMITED
Captured colors:

     WHITE_0: [  0   0   0] => [  0   0   0] (YUV: [ 16 128 128]) 
     WHITE_1: [ 16  16  16] => [ 14  14  14] (YUV: [ 28 128 128]) 
     WHITE_2: [ 32  32  32] => [ 28  28  28] (YUV: [ 40 128 128]) 
     WHITE_3: [ 48  48  48] => [ 43  43  43] (YUV: [ 53 128 128]) 
     WHITE_4: [ 64  64  64] => [ 57  57  57] (YUV: [ 65 128 128]) 
     WHITE_5: [ 80  80  80] => [ 72  72  72] (YUV: [ 78 128 128]) 
     WHITE_6: [ 96  96  96] => [ 86  86  86] (YUV: [ 90 128 128]) 
     WHITE_7: [112 112 112] => [101 101 101] (YUV: [103 128 128]) 
     WHITE_8: [128 128 128] => [116 116 116] (YUV: [116 128 128]) 
     WHITE_9: [144 144 144] => [132 132 132] (YUV: [129 128 128]) 
    WHITE_10: [160 160 160] => [146 146 146] (YUV: [141 128 128]) 
    WHITE_11: [176 176 176] => [161 161 161] (YUV: [154 128 128]) 
    WHITE_12: [192 192 192] => [176 176 176] (YUV: [167 128 128]) 
    WHITE_13: [208 208 208] => [191 191 191] (YUV: [180 128 128]) 
    WHITE_14: [224 224 224] => [205 205 205] (YUV: [192 128 128]) 
    WHITE_15: [240 240 240] => [220 220 220] (YUV: [205 128 128]) 
    WHITE_16: [255 255 255] => [234 234 234] (YUV: [217 128 128]) 

and purple is calibrated as below:
[144 80 224] => [144 82 227]

4 After calibration and forwarded LEDs output to the file that purple test file was played:
purple_limited_range_SDR_yuv420.zip

5 The purple result in the output file:

6 From my point of view it closes the subject, but I'm open for further ffmpeg command improvements.
Probably it's mismatch range configuration in Kodi but I dont use it so cant support it.
BTW make sure you have tone mapping enabled for SDR content on webOS when testing: after calibration it can be turned off for flatbuffers when USB grabber was not excluded from build (PC/Rpi versions).

[chcore]

@awawa-dev thank you so much for looking into it. I will review kodi/driver/OS configurations and see if I can produce the right results.

[chcore]

I thought I would try running the calibration just by opening the PNG images (the ones used to make the HyperHDR test videos) in Kodi and manually skipping through them so that HyperHDR can collect the data. To my surprise, it all worked. The colors for SDR are now very accurate.

I'll see if I can produce similar results for HDR.

[awawa-dev]

You would achieve a similar effect much more easily by selecting the second calibration mode via the browser in SDR mode. You are still missing one important thing in your Kodi setup: by displaying RGB images you are completely ignoring what happens with YUV material described here: https://kodi.wiki/view/Video_levels_and_color_space#Limited_vs_Full_Video_Levels.

[chcore]

You would achieve a similar effect much more easily by selecting the second calibration mode via the browser in SDR mode. You are still missing one important thing in your Kodi setup: by displaying RGB images you are completely ignoring what happens with YUV material described here: https://kodi.wiki/view/Video_levels_and_color_space#Limited_vs_Full_Video_Levels.

Agreed, will play with it.