HDR -> SDR conversion

[gonca]

I'll be setting up my new 4K system this weekend.
If it is of any help I can run test scripts right afterward and report back
Or if I can of some help beforehand please let me know

[admin]

All help will be welcome. Thanks!

What do you mean by a "4K system"?

[gonca]

GTX 1080Ti hooked up to a receiver which goes to a 65" 4K TV
All HDR10 and Dolby Vision capable

[admin]

[gonca]

Hopefully I'll be able to do a comparison of HDR to HDR>SDR to a native SDR clip
P.S.
Santa was good to me... until he stuck me with the bill for this stuff

[hydra3333]

my goodness gonca, envious of the equipment if not the bill.

A query ...

I have (a) an old PC with a 750Ti nvidia card and another with a low-cost 1050Ti (b) a low cost samsung telly which claims to do 4k and hdr ... but no media player which does 4k or hdr.
I do have a chromecast ultra attached to that telly though.
In your view, would this be reasonable to test and compare with ?
1. for HDR
save native HDR file -> on a chromecast server filesystem (on a raspberry pi3) -> use a tablet to cast the HDR file from the Pi3 to the chromecast ultra
2. for SDR:
convert HDR file -> h.264.avc.SDR.mp4 using NVENC to a chromecast server filesystem (on a raspberry pi3) -> use a tablet to cast the SDR file from the Pi3 to the chromecast ultra

PS IIRC the 750Ti won't encode h.265 nor HDR using NVENC in ffmpeg, but does a 1050Ti do either/both ?

[gonca]

You need to make all your devices are HDMI 2.0 capable.
Make your HDMI cables are rated, Amazon basics cables are good enough (18Gbps)
The 1050Ti can decode and encode HEVC, don't think the 750 can do hardware decoding of HEVC
CPU decoding of 4K HEVC would be a massive load
If everything is decrypted HDCP is not an issue

1050Ti > TV (4K+HDR) with proper cables sounds good enough
NVEnc does not retain the HDR metadata, (it does use the parameters) meaning you have to turn on HDR manually on the TV
or
Use nvhsp to apply the metadata back into the HEVC stream
Its quite easy to use

[admin]

Link for nvhsp?

[gonca]

https://github.com/SK-Hardwired/nv_hevc ... /nvhsp.zip

my template command line

"C:\Program Files (Portable)\HDRpatcher\nvhsp.exe" -full_range tv -colorprim bt2020 -colormatrix bt2020nc -transfer smpte-st-2084 -chromaloc 2 -maxcll 1000,300 -masterdisplay "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,0)" "T:\IMPORTS\.hevc" "I:\.hevc"

This is good for P65? I believe, change maxcll and L values as required
MediaInfo 17.10 still gives the actual numbers
G, B, R, and WP are the numbers reported by MediaInfo x 50000

Edit
P65 should actually read DCI-P3 D65

[admin]

Thanks!