HDR Discussion Thread

[DanBa]

Originally Posted by Stacey Spears

... Player-led is DV low latency mode. ...

What is DV low latency mode? Is it Dolby Vision MEL?

Thanks

[Waboman]

PM, reach into your couch cushions and put bid on this. It will look great next to your 180" 32K prototype wall tv with DVII+

[gkolb]

Originally Posted by Waboman

PM, reach into your couch cushions and put bid on this. It will look great next to your 180" 32K prototype wall tv with DVII+

Wait.

Shipping not included for that price? Gtfo.

[LordoftheRings]

Invisible seal ...

• https://dms.licdn.com/playback/C4E05...p4AhyVr3dtJ2d4

[Stacey Spears]

Originally Posted by DanBa

What is DV low latency mode? Is it Dolby Vision MEL?

Thanks

DV LL is what Xbox One uses to send DV. It is also the only format that Sony TVs support today. It was designed for game consoles so that the display does as little as possible processing wise for the lowest latency. In this case, the source device does the tone mapping by using info in the EDID from the display.

MEL is minimal enhancement layer. Means the video info is only in the base layer (10-bit 4:2:0) and the MEL only has metadata. FEL is full enhancement layer where the FEL layer has the extra picture information bringing the final output to 12-bit. Most DV content today is MEL. There is also the option where the FEL can be 4000 nits while the base layer is only 1000 nits. In our case, the base and FEL are both the max nit value.

[PeterTHX]

Originally Posted by Stacey Spears

Most DV content today is MEL.

Are you sure? Seems the studios that use it most consistently, Lionsgate and Paramount, are FEL. Universal's discs are also FEL. Sony & Warner's are MEL...are you referring to DV content as a whole (including streaming) or just disc?

[avs commenter]

So is MEL and FEL related to the source device or just the content?

[gkolb]

Originally Posted by avs commenter

So is MEL and FEL related to the source device or just the content?

It’s the content. Someone in charge decided whether the content would be 10-bit or 12-bit deep, whether it’s on a disc or a stream.

The device firmware is capable of playing DV metadata regardless of bit depth.

[Geoff D]

Originally Posted by PeterTHX

Are you sure? Seems the studios that use it most consistently, Lionsgate and Paramount, are FEL. Universal's discs are also FEL. Sony & Warner's are MEL...are you referring to DV content as a whole (including streaming) or just disc?

StudioCanal put huge FEL appendages on their DV discs too. Streaming DV is pretty much MEL by default as it all comes packaged within a 10-bit encoded transport stream, but it's in ITP space IIRC so it has its own advantages on that front.

[DanBa]

Originally Posted by Stacey Spears

DV LL is what Xbox One uses to send DV. It is also the only format that Sony TVs support today. It was designed for game consoles so that the display does as little as possible processing wise for the lowest latency. In this case, the source device does the tone mapping by using info in the EDID from the display.

MEL is minimal enhancement layer. Means the video info is only in the base layer (10-bit 4:2:0) and the MEL only has metadata. FEL is full enhancement layer where the FEL layer has the extra picture information bringing the final output to 12-bit. Most DV content today is MEL. There is also the option where the FEL can be 4000 nits while the base layer is only 1000 nits. In our case, the base and FEL are both the max nit value.

Thanks!

I am not quite sure to understand "DV LL is what Xbox One uses to send DV. It is also the only format that Sony TVs support today."

Do you mean "only format" (i.e. Dolby Vision content mapping not performed by Sony TV) for gaming only; because in case of a direct reception of a Dolby Vision file by a Sony TV from a Netflix streaming server, the content mapping has to be carried out by the Sony TV?

[Geoff D]

It would stand to reason that the processing is also done upstream in that case?

[Stacey Spears]

Originally Posted by DanBa

Do you mean "only format" (i.e. Dolby Vision content mapping not performed by Sony TV) for gaming only; because in case of a direct reception of a Dolby Vision file by a Sony TV from a Netflix streaming server, the content mapping has to be carried out by the Sony TV?

As far as I know, Sony TVs only support DV in low latency mode, which means the source does the primary tone mapping.

I thought that Robin Hood was MEL as well. Have not confirmed myself.

[DisplayCalNoob]

Going back to the new trim pass features, this discussion on DVLL, is it possible, a LL display can process the additional trim features. Say the output source doesn't have the horsepower, but is LL enabled. Can the display then pick up the slack to handle all 21 trim passes, assuming the display needs all 21?

[Stacey Spears]

Originally Posted by DisplayCalNoob

Going back to the new trim pass features, this discussion on DVLL, is it possible, a LL display can process the additional trim features. Say the output source doesn't have the horsepower, but is LL enabled. Can the display then pick up the slack to handle all 21 trim passes, assuming the display needs all 21?

It should. The new trim pass controls (L8) are in DM4 (Dolby Vision 4.0). Only the 2019 LGs support it today. We would have used it, but the profile 7 encoding tools for Blu-ray don't support it yet. SDR should be greatly improved with 4.0.

[Geoff D]

^ And yet how many people here watch Dolby Vision in SDR? How many people even have a TV that is Dolby Vision compatible yet is only SDR? Those are rhetorical questions BTW, as it mainly applies for broadcast/streaming applications for DV where a single mezzanine file set is provided and all other versions are trimmed from that, including SDR.

This is why I find DCN's ongoing fascination with the updated trim tools to be somewhat misplaced: DV metadata is primarily about controlling the downconversion, NOT about creatively guiding the underlying HDR content itself at the source mastering level. They can certainly creatively guide the downconversion - the effect of things like grey bar syndrome and Sony too-dim and Panasonic too-bright aside - but the better the HDR TV you have the less onus is placed on this downconversion process in the first place.

[Penton-Man]

Originally Posted by Waboman

PM, reach into your couch cushions and put bid on this.....

now what the hell am I ever going to do with dinosaur bones?

[Penton-Man]

Originally Posted by Geoff D

....This is why I find DCN's ongoing fascination with the updated trim tools to be somewhat misplaced: DV metadata is primarily about controlling the downconversion, NOT about creatively guiding the underlying HDR content itself at the source mastering level.....

True, but the Dolby Vision Version 4.0 could also potentially be helpful with (optional) intermediate HDR grades (especially useful for when the consumer owner has a not so great HDR tv) and as indicated here from last year - https://forum.blu-ray.com/showthread...s#post14755601

After producing the HDR master and the required SDR version, an optional HDR intermediate grade (ex. at 1000 nits) takes at the most, 2 hrs. of trim time, often less.

[Stacey Spears]

Originally Posted by Penton-Man

True, but the Dolby Vision Version 4.0 could also potentially be helpful with (optional) intermediate HDR grades (especially useful for when the consumer owner has a not so great HDR tv) and as indicated here from last year - https://forum.blu-ray.com/showthread...s#post14755601

After producing the HDR master and the required SDR version, an optional HDR intermediate grade (ex. at 1000 nits) takes at the most, 2 hrs. of trim time, often less.

Exactly!

At a bare minimum, you must do a the primary HDR grade and the SDR trim pass. Then, by default, everything is interpolated between the two. Then you can do more intermediate trim passes at 600, 1000 and 2000. And then the interpolation is done between those points.

I am told at least one studio uses the SDR trim pass for their SD releases. Those will be better once 4.0 is in full swing. There are other improvements too, such as much better tone mapping in general.

All of this is only as good as the effort put into adjusting the trim pass controls. I know some have done less than others. It all comes down to time / money.

[Wendell R. Breland]

The April/May issue of Sound & Vision magazine has an HDR article by Kris Deering. IMHO, if you do not sub to S&V then I would purchase a copy just for this article.

[Penton-Man]

For those do-it-yourselfers, especially more into streaming who don’t have access to Dolby’s DV software encoder, a possible alternative, albeit with limited support - http://x265.org/x265-delivers-dolby-vision-streams/