HDR -> SDR conversion
Re: HDR -> SDR conversion
Guys, I have added a 'HDR' field to the HEVC Info dialog. This will show "PQ" for HDR10, "HLG" for HLG, and is blank for SDR.
I also figured out how to properly detect HDR. There are two ways to signal it: 1) through the transfer_characteristics (16 is PQ, 18 is HLG), and 2) through SEI messages. Previously I was looking only at the presence/absence of SEI messages. Now I look at both. You have to look at both because a HLG stream can signal 709 via transfer_characteristics together with a preferred_transfer_characteristics SEI specifying HLG. This allows for backward compatibility of HLG with 709 displays. Refer to T-REC-H.Sup18-201710-I!!PDF-E.pdf for details:
https://www.itu.int/rec/T-REC-H.Sup18-201710-I
Will slipstream it after some regression testing.
I also figured out how to properly detect HDR. There are two ways to signal it: 1) through the transfer_characteristics (16 is PQ, 18 is HLG), and 2) through SEI messages. Previously I was looking only at the presence/absence of SEI messages. Now I look at both. You have to look at both because a HLG stream can signal 709 via transfer_characteristics together with a preferred_transfer_characteristics SEI specifying HLG. This allows for backward compatibility of HLG with 709 displays. Refer to T-REC-H.Sup18-201710-I!!PDF-E.pdf for details:
https://www.itu.int/rec/T-REC-H.Sup18-201710-I
Will slipstream it after some regression testing.
Re: HDR -> SDR conversion
I found the official HD version here:
https://www.youtube.com/watch?v=ih1l6wb7LhU
for these clips:
trim_187.ts at 35:03
trim_203.ts at 38:02
I can't find trim_162.ts in HD version, I think SDR ver. and HDR ver. are different editions.
https://www.youtube.com/watch?v=ih1l6wb7LhU
for these clips:
trim_187.ts at 35:03
trim_203.ts at 38:02
I can't find trim_162.ts in HD version, I think SDR ver. and HDR ver. are different editions.
Re: HDR -> SDR conversion
Thanks but I don't know how to download youtube videos.
- Bullwinkle
- Posts: 338
- Joined: Thu Sep 05, 2019 6:37 pm
Re: HDR -> SDR conversion
Hello there culture lovers. Today we take a look at the modern day HLG to SDR known as The Good Stuff. Here is one fetching picture. They call me fetching. Fetching all the pixels ain't saving whoa! Ooh. Okay that is all for today next week the meaning of Randomness and Beauty.
Re: HDR -> SDR conversion
Thank you, zys4416.
I have the HLG EOTF coded and apparently working. I want to compare the results to the HD versions you linked, and also to the results of some other conversion filters. If things look good, I'll implement it fully into DGHDRtoSDR (with a mode parameter for PQ or HLG) and add it to DGIndexNV as well.
I have the HLG EOTF coded and apparently working. I want to compare the results to the HD versions you linked, and also to the results of some other conversion filters. If things look good, I'll implement it fully into DGHDRtoSDR (with a mode parameter for PQ or HLG) and add it to DGIndexNV as well.
- Bullwinkle
- Posts: 338
- Joined: Thu Sep 05, 2019 6:37 pm
Re: HDR -> SDR conversion
Sure but watch me pull a rabbit out of a hat... Ooh not what I had in mind randomness is beautiful.
Re: HDR -> SDR conversion
Just discovered there is a BT.2100-2 while I was coding off of BT.2100-1. The HLG EOTF is a bit different in BT.2100-2 so I'll have to revise the implementation accordingly. No big deal.
Re: HDR -> SDR conversion
I tried both of these. Each simply brought up a player and played the stream. I could not see how to download the stream.
Re: HDR -> SDR conversion
Re: HDR -> SDR conversion
Great, thank you. You are so kind.
Re: HDR -> SDR conversion
I've got the HLG EOTF re-coded and working. And I have DGHDRtoSDR() modified to support both PQ and HLG via a mode parameter. I'll add the HLG support to DGIndexNV and then give y'all both of them. Whee!
Re: HDR -> SDR conversion
I've got HLG to SDR working in DGIndexNV. It's kinda nice. You can set up the HLG conversion and then just click and unclick 'Enable HDR to SDR' to see the difference between real HLG conversion and backwards compatible display. The color shifts from backwards compatible handling become very obvious.
Now I have to do code reviews, regression testing, and documentation.
Now I have to do code reviews, regression testing, and documentation.
Re: HDR -> SDR conversion
Thanks. Gonna be a few days as I have to complete some coaching certification renewal training first.
Re: HDR -> SDR conversion
Finished all my certs, concussion protocol and doping stuff was new this year. Good to go until end of 2020.
Back to work...
Back to work...
Re: HDR -> SDR conversion
OK, girls and boys, I have stuff ready for your testing. I want to wait for your feedback before releasing formally. The package is here:
http://rationalqm.us/misc/hlg_test.rar
Please read the docs carefully as the parameters have changed. This was quite a non-trivial revision so your careful testing under Avisynth+ and Vapoursynth (native), as well as checking the docs, would be very helpful. Thank you and have fun.
Delete your INI file first and then open and close DGIndexNV! Then begin testing.
http://rationalqm.us/misc/hlg_test.rar
Please read the docs carefully as the parameters have changed. This was quite a non-trivial revision so your careful testing under Avisynth+ and Vapoursynth (native), as well as checking the docs, would be very helpful. Thank you and have fun.
Delete your INI file first and then open and close DGIndexNV! Then begin testing.
- Bullwinkle
- Posts: 338
- Joined: Thu Sep 05, 2019 6:37 pm
Re: HDR -> SDR conversion
Sure, sure, thanks Rocky, but why bother when UHD is useless? People call me useful. Whoo. Look at the last figure on this page and tell me I am a foolish Moose.
https://www.lightillusion.com/uhdtv.html
Also, while we're pointing out the insanity remember that HDR10 PQ (absolute brightness) requires a very controlled viewing environment, and horrors metadata. But HLG is relative and a simple control can scale things very well for different environmental brightness. Just google up some PQ versus HLG action. PQ should be sent to Siberia!
https://www.smpte.org/sites/default/fil ... andout.pdf
Finally, this may enlighten you:
https://www.youtube.com/watch?v=--PyKhohVcY
https://www.lightillusion.com/uhdtv.html
Also, while we're pointing out the insanity remember that HDR10 PQ (absolute brightness) requires a very controlled viewing environment, and horrors metadata. But HLG is relative and a simple control can scale things very well for different environmental brightness. Just google up some PQ versus HLG action. PQ should be sent to Siberia!
https://www.smpte.org/sites/default/fil ... andout.pdf
Finally, this may enlighten you:
https://www.youtube.com/watch?v=--PyKhohVcY
Re: HDR -> SDR conversion
Umm, OK.
I fixed a small bug in DGIndexNV in the test package, so please re-download and update for testing.
I fixed a small bug in DGIndexNV in the test package, so please re-download and update for testing.
Re: HDR -> SDR conversion
Found some more bugs. Temporarily withdrawing. Standby...
Re: HDR -> SDR conversion
OK, hlg_test.rar is back online so re-download and update DGIndexNV. Have at it!
Re: HDR -> SDR conversion
I've tuned Meari sample to match mpv's output (slightly brighter, but looks better for me)
PC: RTX 2070 | Ryzen R9 5950X (no OC) | 64 GB RAM
Notebook: RTX 4060 | Ryzen R9 7945HX | 32 GB RAM
Notebook: RTX 4060 | Ryzen R9 7945HX | 32 GB RAM
Re: HDR -> SDR conversion
Ah, good to hear. Thank you.
You probably noticed most of the goodness for PQ is at the top end of the range for white and it is nonlinear. HLG in contrast works much better and feels linear. I'm going to try linearizing the PQ parameter range, it's a GUI issue and a functional one, because we are lacking granularity at the top end.
You probably noticed most of the goodness for PQ is at the top end of the range for white and it is nonlinear. HLG in contrast works much better and feels linear. I'm going to try linearizing the PQ parameter range, it's a GUI issue and a functional one, because we are lacking granularity at the top end.