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Old 15th April 2019, 16:15   #61  |  Link
huhn
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Quote:
Originally Posted by chros View Post
So, my question is this: if it can / could be done in the world of SDR (using a PQ curve) then why would you need hardware that will never fullfil the max requirements? Only for sales purposes?
120 nits and 500 nits look very different.
and the problem with tonemapping in general is you are going to miss the creators intend. the problem started with the need of meta data and nit number far from any sanity. even if we could create 10k nit screen putting them into every home is a very very bad idea...
just inform your self what a 1000 watt water cooker can do to the energy grid now add a TV show to that will show an image where the TV needs 1000 watt for about 5-10 sec. taking into account that the dolby vision screen is water cooled i'm very generous here and no there is a limited to power efficiency we are not going to make pure energy like light to use less energy.

i have no problem with PQ and using a bigger colorspace both make sense.

Quote:
LG does support 23p judder free playback in PC mode (meaning chroma 4:4:4)!
you should test for 4:4:4.
http://madshi.net/madVR/ChromaRes.png
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Old 15th April 2019, 21:01   #62  |  Link
Blue_MiSfit
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@huhn - you're absolutely right - Dolby Vision on UHD BluRay is quite different. I only care about Dolby Vision Profile 5 (non backwards compatible) since it's what's being used for VOD streaming these days, so my comments only apply to that flavor
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Old 16th April 2019, 12:20   #63  |  Link
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Quote:
Originally Posted by huhn View Post
you should test for 4:4:4.
http://madshi.net/madVR/ChromaRes.png
Thanks, I did it before, my post is updated.

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Originally Posted by huhn View Post
i have no problem with PQ and using a bigger colorspace both make sense.
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Originally Posted by nevcairiel View Post
HDR content comes with some other improvements bundled up that you didn't get in SDR content, like wider colorspaces
But wider colorspace isn't HDR specific or am I wrong?

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Originally Posted by nevcairiel View Post
The point of HDR screens is offering higher brightness and contrast for highlights.
...
Unfortunately you cannot really enjoy the HDR highlights with current consumer display tech yet
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Originally Posted by huhn View Post
the problem started with the need of meta data and nit number far from any sanity.
Exactly how I feel. What it means that tonemapping is always necessary on existing displays, and later when displays will be evolved the industry can easily master content with higher nits so new displays can be bought

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Originally Posted by huhn View Post
even if we could create 10k nit screen putting them into every home is a very very bad idea...
just inform your self what a 1000 watt water cooker can do to the energy grid now add a TV show to that will show an image where the TV needs 1000 watt for about 5-10 sec.
That's exactly what I meant about hardware limitation.

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Originally Posted by huhn View Post
the problem with tonemapping in general is you are going to miss the creators intend
Personally, I don't like this "excuse" (I already wrote about it a bit on avsforum): looking only at HDR10 (not DV and neither HDR10+), every display manufacturer does whatever they want to do, they even change their own approach in every new series of models, nothing is stone carved, mainly due to the above hardware limitations.
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Old 16th April 2019, 12:27   #64  |  Link
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But wider colorspace isn't HDR specific or am I wrong?
No its not, but for example UHD Blu-rays that use wide color and not HDR are actually relatively rare.
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Old 16th April 2019, 16:29   #65  |  Link
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wait there is a spec for SDR on UBD?
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Old 16th April 2019, 16:52   #66  |  Link
nevcairiel
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wait there is a spec for SDR on UBD?
There really are not many limitations. HDR is fully optional.

From the Blu-ray whitepaper:


The only real limitation is that HEVC has to be 10-bit (8 is not allowed), and that BT.2020 has to use the new chroma sample location, while BT.709 uses the old one.
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Old 16th April 2019, 17:09   #67  |  Link
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thanks the wiki is not well updated: https://en.wikipedia.org/wiki/Blu-ray#Video
and the UBD wiki doesn't have a video part at all.
is there a read about the chroma sub sample position?
that doesn't help me:
Quote:
For ITU-R BT.2020 (colour primaries is set to 9), chroma_loc_info_present_flag shall be set to 1 and
chroma_sample_loc_type_top_field and chroma_sample_loc_type_bottom_field shall be set to 2.
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Old 16th April 2019, 18:39   #68  |  Link
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Conceptually the Chroma stuff is not that complicated.

The image is a bit poor, but it shows it anyhow:


The black dots are Luma, and the Red one is the Chroma sampling location, plus the square to indicate the "area" the subsampled chroma sample covers. Typical 4:2:0 is type 0, "old" mpeg1 is type 1, and UHD now uses Type 2.

I don't know of a good simple article that explains the advantages between them really. Using the TopLeft location may be simpler to interpolate, or something.
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Old 16th April 2019, 19:09   #69  |  Link
huhn
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thanks i know about mpeg1 and mpeg2 chroma subsample position i used this for illustration in the past: http://www.mir.com/DMG/chroma.html
so pretty much the same as SMPTE DV-PAL without interlancing.
only one last thing to ask about this do lav filter and madVR honour this and are able to handle this correctly?
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Old 16th April 2019, 19:13   #70  |  Link
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LAV will send that info to madVR, anything else is at least out of my hands.
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