HDR Discussion Thread

[puddy77]

Originally Posted by Robert Zohn

I'm actually presenting on HLG over the existing FHD OTT and OTA circuits at my NAB session.

I'm still learning about the feasibility of including HLG w/P3 over the existing FHD infrastructure, but from what I know so far HLG w/P3 color can co exist on the 6mHz video bandwidth carrier with the HD SDR rec.709 color signal.

So in that case, the HLG signal isn't meant to be backwards compatible at all? Then the there's no real benefit to HLG? Trying to think of one. I guess lack of metadata could be a plus.

Good luck with your session! Seems to be a real interesting and complicated topic.

[Robert Zohn]

The benefit I'll be speaking about is for consumers with UHD/HLG capable TVs to see HDR and P3 color on live and recorded TV broadcast channels delivered over cable and OTA.

The benefit to the broadcasters will be increased viewership as owners of UHD/HLG TVs will likely switch to channels that deliver HDR/WCG content and therefore increased advertising revenues. I remember very well when NBC began broadcasting color in the late 50's - early 60's loving the Living Color Peacock and lousy rec.601 color.

Hope members will reply with thoughts and opinions as I am now testing my theory here for the first time.

[Penton-Man]

Originally Posted by Richard Paul

It was interesting that the Samsung representative mentioned that it was possible for HDR10 Plus to get added to Ultra HD Blu-ray.

Although not a living document per se like the Ultra HD Forum Guidelines, as I mentioned to DanBa last October,

Originally Posted by Penton-Man

Ultra HD Blu-ray spec is not written in stone.

[Penton-Man]

Originally Posted by Richard Paul

HLG has been added to ATSC and DVB but it was only done in the last few months and it will take a while before it starts really getting used by the broadcast industry.

HLG adoption is beginning to get traction by enabling at the grass roots level….http://www.4kshooters.net/2017/03/27...pdate-in-july/

[Penton-Man]

Originally Posted by Geoff D

I think it's eminently possible, as would be some form of 4K 3D down the road. It's just going to need another long round of discussions and late nights and pressing the flesh and a general consensus before it does.

If this project proceeds beyond the ‘exploration’ phase - http://www.hollywoodreporter.com/beh...llywood-985937 ,
I suspect it won’t help with regards to charming Sony as a robust advocate in expeditiously revising the Ultra HD Blu-ray spec so as to include thee open standard 2094-40.

[puddy77]

Originally Posted by Penton-Man

HLG adoption is beginning to get traction by enabling at the grass roots level….http://www.4kshooters.net/2017/03/27...pdate-in-july/

Nice. After Panasonic announced HLG for their GH5, I expected it would start to get adopted by cameras, especially since YouTube supports HLG. Hoping it becomes more ubiquitous. We'll probably have it on all our phones in a few years.

[Penton-Man]

Originally Posted by puddy77

...Then the there's no real benefit to HLG? Trying to think of one. I guess lack of metadata could be a plus.

Good luck with your session! Seems to be a real interesting and complicated topic.

#16 in the FAQ…. http://www.bbc.co.uk/rd/sites/50335f..._HDRTV_FAQ.pdf

[Penton-Man]

Originally Posted by Robert Zohn

Hope members will reply with thoughts....

HLG in Production and Playout as well as HLG in Receivers (scroll down…. http://www.bbc.co.uk/rd/projects/high-dynamic-range), is in the works, more guides should be forthcoming after the next series of ITU meetings.

[Penton-Man]

Originally Posted by puddy77

Nice. After Panasonic announced HLG for their GH5, I expected it would start to get adopted by cameras, especially since YouTube supports HLG. Hoping it becomes more ubiquitous. We'll probably have it on all our phones in a few years.

I think HLG is mentioned something like 10 times in this recent article from last week… http://www.sony.co.uk/pro/press/pr-s...0317_SPALL__a3

Lunchtime over for me, back to the salt mines.

[Penton-Man]

Originally Posted by Penton-Man

Sony

I get a kick out of the fanboys….https://twitter.com/joblocom/status/846532699300933632
They make the jobs of Tactical Marketing that much easier....and those folks make more money than engineers, even without their(the fans) help.

[Penton-Man]

Dem boys ^ are tweeting machines.

[Penton-Man]

At NAB 2017, along with demo of HLG on HDR TV, the Ultra HD Forum is planning on showing HLG content on SDR TVs (which support BT.2020).

[puddy77]

Originally Posted by Penton-Man

At NAB 2017, along with demo of HLG on HDR TV, the Ultra HD Forum is planning on showing HLG content on SDR TVs (which support BT.2020).

Could you shed a little more light on the bolded? Which TVs?

[Geoff D]

Originally Posted by puddy77

Could you shed a little more light on the bolded? Which TVs?

I can tell you one which can: my own Sony KD55X9005B

[Geoff D]

And given that the current Panny players will apparently be upgraded with HLG (even having an HLG to PQ transcoding feature) it makes me wonder if I'll also be able to get SDR 2020 when playing HLG back through the Panny, given all the noise made about its wonderful backwards compatible nature. I downloaded an HLG clip a few weeks ago, I hope to be able to put it to good use soon!

[batman2000]

which one is the better one dolby vision or technicolor.

[Richard Paul]

Originally Posted by Penton-Man

#16 in the FAQ…. http://www.bbc.co.uk/rd/sites/50335f..._HDRTV_FAQ.pdf

And in terms of complexity the conversion from wide color gamut to standard color gamut is fairly simple with a 2 to 1 compression ratio while converting from PQ to standard dynamic range can have a 100 to 1 compression ratio or more.

Originally Posted by puddy77

Could you shed a little more light on the bolded? Which TVs?

The DVB MPEG specification (which is used for broadcasting) requires that UHDTVs support the BT.2020 color space. I don't know how many UHDTVs that would include but the ones in Europe are supposed to support it.

Originally Posted by batman2000

which one is the better one dolby vision or technicolor.

I think Dolby Vision is better since it can encode a HDR video stream. Technicolor HDR encodes a SDR video stream and than uses metadata to change it into HDR.

[HeatEquation]

Perhaps someone more knowledgeable on the subject can shed some light on this.

I downloaded an HLG version of the LG Cymatic Jazz demo (http://demo-uhd3d.com/fiche.php?cat=uhd&id=158) and was actually able to play it on my Samsung KS8000. The TV recognized it as an HDR video and went into the HDR mode. Then I downloaded TravelXP 4K (http://demo-uhd3d.com/fiche.php?cat=uhd&id=154) which is another HLG video, but the TV could not play it.

My question is - what exactly is going on? As far as I'm aware, my TV hasn't been firmware updated to support HLG, but it can play the LG Cymatic Jazz HLG video, while it refuses to play the TravelXP 4K HLG one.

[DanBa]

Apparently, "there are two methods of signaling the HLG transfer function, as as shown in the table below.

In one method, the SDR transfer function indicator is signaled in the VUI and the HLG transfer function indicator is transmitted using an alternative transfer characteristics SEI message embedded in the bitstream. In this way, an "HLG aware” STB or decoder/display would recognize that the bitstream refers to content coded with HLG (since it is indicated by the preferred_transfer_characteristics syntax element of the SEI). If an “HLG aware” STB is connected to a TV that does not support HLG, the STB would transmit the SDR indicator over HDMI to the TV. If it is connected to a TV that supports HLG, the STB would copy over the transfer function value in the SEI (to indicate HLG) and transmit this over HDMI to the TV.

In the other method, the HLG transfer function indicator is directly signaled in the VUI in the same way PQ or SDR would be signaled.

In theory it is possible to losslessly convert between the two methods of signaling HLG by flipping the VUI transfer function characteristics indicator value and inserting or removing the alternative transfer characteristic SEI.
Using the first method (i.e., including the SDR transfer function indicator in the VUI and the HLG transfer function indicator in the SEI) enables backward compatibility with SDR displays.
Using the second method (i.e., including the HLG transfer function indicator in the VUI) may also produce acceptable results on SDR displays. Service providers may wish to test both methods.

The table below summarizes HEVC Main10 Profile bitstream PQ and HLG indicators. (In HEVC and AVC specifications, the bitstream elements are bolded to distinguish them from temporary variables and labels.)"
http://ultrahdforum.org/wp-content/u...ummer-2016.pdf

[batman2000]

out of all versions of hdr is dolby vision still the best?