(2017-04-16, 15:24)dumpling Wrote: (2017-04-16, 15:06)noggin Wrote: (2017-04-16, 14:44)dumpling Wrote: which are 4k, 60Hz, H265/HEVC, 10bit, HDR, BT2020(not sure latter two are base on encode only or both)
AIUI you can have SDR BT.2020 video as well as HDR. There are multiple variations for HDR - some (Dolby Vision and HDR10) are Perceptual Quantiser based - using SMPTE ST2084 EOTF (which is separate to BT 2020), others are using Hybrid Log Gamma which uses a different standard. Both standards are ratified in BT.2100.
I'd look for BT 2020 and BT 2100 support to be future proof - though I have no idea if that's how support is reported.
After some online research, If I'm not mistaken, HDR comes in two major formats on blu ray release. HDR10 and Dolby Vision.
HDR10 is software base decode while Dobly Vision is hardware base decode.
Both can be implemented in software I believe - though Dolby licence their tech.
HLG isn't used for UHD Blu-ray, but is likely to be a leading contender for broadcast (the signal remains SDR compatible avoiding the need for separate SDR and HDR broadcasts), and also potentially for live streaming (there are fewer licensing issues AIUI)
Quote:So J3455 can do HDR10 as many members including me already tested, I mean even though I don't have a HDR TV but as long as the file can playback normally without flicker or black screen I'm assuming it's HDR10 proof? Not sure about Dolby Vision.
What puzzles me is 10bit and BT2020. 10bit is color depth, BT2020 is color space? I never truly understand the difference.
10 bit is the bit-depth of the luminance and colour difference signals (not quite the same as colour depth - but good enough for conceptualising). 10 bit has been pretty standard for SDR broadcast video even back to the SD days (though 8 bit processes also exist in some areas) - long before HDR was around.
BT 2020 is the colour-space typically used for UHD. HD typically uses BT.709 (though some UHD stuff is 709 not 2020), SD typically uses BT.601. These standards define things like the colours of the RGB primaries used, how the RGB signals are converted to YCbCr luminance and colour-difference signals etc., as well as gamma (I think)
BT 2100 defines Electro Optical Transfer Functions for HDR - i.e. the way the light output from the screen is mapped to the incoming video signal (it's not linear)
This is all broad brush stuff - but should help a bit?
HDR requires 10 or 12 bit video, but not all 10 or 12 bit video is HDR.
UHD can use BT2020 colour space, but not all UHD does. BT2020 can be used for both SDR and HDR video.
