Originally Posted by Brian Hampton
Would the Chromecast as a TPG work with HCFR to calibrate HDR?..
I have no problems using HCFR to calibrate SDR on my Projector. (The default settings of my projector all are under 5 Delta E from the start also) but I haven't really done anything about HDR. I know my projector only does HDR10 and most likely at a low NIT level. Reading some of Zoyd's posts suggests that I can at least adjust the gamut of HDR using HCFR but I don't know if the Chromecast can be used for this ? ... My laptop has a second HDMI output and I suppose I could figure out it's levels and save a little money I would spend on a TPG
Chromecast is generally not recommended for any patch generation, especially for HDR10 where a small error like 1-2 digital codes can provide 35-70 nits difference between the reading the software expect from your to display from the one the inaccurate generator has display.
You need a bit-perfect RGB output to perform HDR10 patch generation.
About SDR patch generation, Dominic Chan has posted comparison between Ted's disc (Samsung M8500), GDI (Internal), and Chromecast from HCFR here: https://www.avsforum.com/forum/139-d...l#post57249506
Based to Dominic's data, I have created these 3 animated PNG files, which will change per 1 sec. between Ted's Disk - ChromeCast as generator results:
But you can test your Video Card to see if it can be used for patch generation, if you configure the VideoCard it to output Full range (and disable any enhancement, VCGT, ICC), set HCFR to 16-235 and the display to expect to receive video levels.
Doing that you will be able to output 16-255 patterns from your PC/Notebook.
The next test is to test who is that output has agreement with some patterns which are accurate for HCFR (as my calibration disk for example), to compare for example Grayscale and ColorChecker/Saturation Sweep generated from a standalone player, the player you watch your movies (with YCbCr output), and then take the same measurements with your video card (as Dominic did basically but you need more colors to measure to be sure), compare also what black/white levels you have.
If your VideoCard can match closely the results from your player, this can confirm that you can use it for patch generation.
For HDR you can't use ChromaCast is it can output REC709 YCbCr and REC.2020 YCbCr has differenent code values after conversion from RGB.
Google devices take 0-255 digital codes at input and then compress to Video Levels, then they perform a colorspace conversion from RGB to REC.709 YCbCr; to provide REC.709 YCbCr 4:4:4 colorspace video output.