It’s a well-known fact that Hollywood in general and Disney in particular have been slow to warm to new distribution media for home video, and even to the concept of home media itself. This has been the case with LaserDisc, with VHS, with DVD, with downloads and with streaming. Even though every time it seems a good market in the end where they make healthy margins. And the home video market has long time ago overtaken the box office.
4K Ultra HD Blu-ray has been no exception to Disney’s initial hesitation. Of all the major studios it was the last one to jump on board. And when they finally did, it was somewhat halfheartedly. Their first two releases, Pirates of the Caribbean: Dead Men Tell No Tales and Guardians of the Galaxy vol. 2 lacked Dolby Vision while the releases of these movies on streaming platforms did feature this premium HDR format. That was a temporary issue, Disney indicated.
Early 2018 I wrote a piece about this, expressing my wonderment about this. On the very day the article was ready and went online, Disney announced its first Ultra HD Blu-ray with Dolby Vision: Star Wars: The Last Jedi. This was quite a coincidence. It did at the time undermine the point of my article but I’m still glad I published it, for a number of reasons.
First of all, I learned a lot from the comments posted underneath, in particular those by one Geoff D.Geoff is a professional who authors Blu-ray Discs including Ultra HD ones. He explained some of the intricacies of putting Dolby Vision on disc, and the limited capacity of authoring houses and expert staff who can do this. This may be the reason behind Disney’s restricted use of Dolby Vision.
In case anyone wasn't aware, it's much more technically challenging to implement DV on UHD disc than it is for a streaming version. This isn't FUD, this is FACT: there's a mandatory requirement for all UHD Blu-rays that feature HDR to include an HDR10 version as well as whatever optional version (DV, HDR10+, Philips/Technicolor) is being deployed. Two separate 2160p encodes of reasonable bitrate onto one disc won't go so they devised a dual layer system, the 'base' HDR10 layer 3840x2160 10-bit HEVC stream and an 'enhancement' Dolby Vision layer contained within a 1920x1080 10-bit HEVC stream. The DV stream is not a readable video layer as it's merely a transport which contains the 'difference' data between the 12-bit master and the 10-bit generic layer as well as the payload of dynamic metadata, the Dolby processing then takes these two layers and rebuilds the full 12-bit DV signal at the display end (with more post-processing being pushed back towards the player with Sony's "low latency" DV profile).
"Okay", you might think. "it's a bit more complicated than a single stream OTT delivery, so what?". But DV on disc doesn't just have to contend with this dual-layer authoring, it's also got to contend with the specifics of how this content is physically encoded to disc, namely the dual-zoned High Transfer Rate/Default Transfer Rate portions of the 33GB layers. In order to use the maximum 127.9 Mb/s bitrate for the transport stream the discs need to be spun faster but in doing so the RPM exceeds noise limits in the inner 8% of a disc, so that inner 8% is restricted to a lower default bitrate of 108 Mb/s max while the outer 92% is able to use the highest 127.9 Mb/s max.
For a 66GB disc this isn't so tricky to manage but for a Triple Layer 100GB disc you've got to contend with a possible dip in bitrate at the second layer break where it changes from inner to outer (the pickup having read inner to outer for the first layer, 1st break from outer to inner for the second, 2nd break from inner to outer for the third) and if you're wandering into that inner 8% again then you need to be aware of this bitrate restriction during a key portion of your movie (anywhere between 1hr30 and 2h+ depending on the length of the film) whilst being careful to maintain optimal bitrate for your two HEVC streams (plus audio of course) as mentioned above.
Long story short: DV is much simpler to encode for streaming delivery but a MAJOR pain in the ass to encode onto disc and not all authoring houses have been certified to deal with it, e.g. Deluxe only just got certified late last year whilst Pixelogic (who bought a shitload of disc authoring IP from Sony) have been handling it for most clients from the start. They can only do so much at any one time though, hence the trickle of DV titles on disc rather than a flood. But with Disney announcing that The Last Jedi will be their first title to include Dolby Vision on UHD disc then I'd say that maybe Hollywood doesn't hate us quite so much as you might think...
It's a fact that DV streams do not have to contend with this HDR10 base layer + DV enhancement layer encoding. It's a fact that DV streams do not have to contend with HTR/DTR zones in their encoding (and streams actually use a higher quality method of chroma subsampling too, look up "ICtCp"). It's a fact that streaming presentations themselves don't have to leverage their total available bitrate with, say, 16 extra audio tracks muxed into the transport stream e.g. the worldwide UHD edition of Deathly Hallows Pt 1. (Not a DV disc, just making a point.)
Add it all up and it means that DV on disc is potentially a much more involved process with regards to both mastering and encoding. Not impossible, not improbable, not insurmountable, because we wouldn't have any DV content on disc at all if that were the case. But it absolutely requires a higher degree of complexity in the encoding vs a stream and even though a respected post house like Deluxe has been grading in Dolby Vision for several years already, they were only certified to handle the specific process of encoding DV for UHD Blu-ray late last year. I'm not making this up: Deluxe Helps Answer Growing Demand for 4K Ultra HD Blu-ray™ Content with Dolby Vision Approved Authoring Services
Note the mention of Paramount in that article, for now that Deluxe's DV-on-disc authoring facilities are up and running Parmount are putting out DV like there's no tomorrow, e.g. Transformers 1-5, mother!, Cloverfield & 10 CL, Daddy's Home 1 & 2, Tomb Raider 1 & 2. This is not a coincidence.
And yet, all of these complexities are not holding back Sony Pictures, Warner Bros, Paramount or Universal Pictures from routinely releasing Ultra HD Blu-ray Discs with Dolby Vision.
An entirely different explanation for Disney’s initial hesitation with Dolby Vision was offered at a 2018 NAB Panel ‘The Future of HDR in Cinema’ by Eric Pearson of Disney Pixar, who formulated the HDR policy for home video releases as follows:
HDR10 to disc for now, Dolby Vision (DV) for digital distribution where possible. We love DV but it’s too risky right now to send out on disc; on digital distro we can always re-tweak; so on disc it’s HDR10 for now. DV for the next disc release
Too risky? It’s not clear what risks he referred to, but whatever they are, they have not stopped the other studios from using DV on UHD BD.
For Disney that next release with Dolby Vision became The Last Jedi, for Pixar none ever came so far. The Disney-owned animation company has released a string of titles on Ultra HD Blu-ray but all of them with HDR10 only.
How insignificant Disney seems to find Dolby Vision is illustrated also by fact that while the US packaging of The Last Jedi includes the logo among the many elements on the always overly cluttered back cover, Disney UK chose to drop the logo even though the disc actually carries Dolby Vision (see).
The Last Jedi
They did the same with Black Panther, released a few months later that same year, 2018. The US packaging includes the logo, the UK one does not.
And that’s where Disney’s use of Dolby Vision on Ultra HD Blu-ray ended, if we ignore Fox’s releases for the moment. The score: one Star Wars movie, one Marvel movie, zero Pixar movies, zero Disney Animation movies and zero live action movies from the Walt Disney Pictures label.
And yet all of the above 80 movies are available on iTunes and Disney+ in 4K HDR with Dolby Vision (and most of them with Dolby Atmos as well). There are two additional titles here that Disney has not yet released on Ultra HD Blu-ray: Tucker: The Man and his Dream and The Santa Clause.
Should you decide to buy The Last Jedi on UHD BD, be warned that there are two versions: the original 2018 release and the 2020 reissue as part of The Skywalker Saga, and latter version – like all nine movies in the series – lacks Dolby Vision. The same holds true for Rogue One and Solo.
As pretty much the only studio, Fox briefly flirted with HDR10+ but that affair ended when Disney bought the studio. One title featured both of the dynamic metadata HDR formats, Dolby Vision and HDR10+, namely Alita: Battle Angel. The experiment with HDR10+ was cut short when Disney took the reins, and not long after the use of Dolby Vision on disc was also over. X-Men: Dark Phoenix, The New Mutants and Home Alone are all with HDR10 only.
Worse still, Disney has decided to stop altogether reissuing on Ultra HD Blu-ray back catalog titles from Fox’s vast library of movies, as well as from Disney’s vaults. As Bill Hunt of The Digital Bits reported, the only exceptions are going to be new movies and back catalog titles from Disney Animation, Pixar, MCU and perhaps James Cameron’s work. Everything else we may expect to see on Disney+ at some point but not on the ultimate disc format.
That’s sad news if you were hoping to collect Tron: Legacy, Speed or Kingdom of Heaven in 4K HDR, to name just a few examples. The move is even more surprising considering that in the Covid19-stricken world we live in in 2020, new movie production has more or less ground to a halt, leading to a dearth of home entertainment releases a few months down the line, prompting most studios to step up their efforts to remaster classic movies for reissuing on Ultra HD Blu-ray – but not Disney.
Of course there are going to be plenty of reissues from Warner, Sony, Paramount, Universal and other studios for cinephile collectors to spend their money on. In very encouraging news several boutique labels like Arrow and Kino Lorber have joined Shout Factory and begun to embrace the collectors’ favorite format.
Still, it’s a shame Disney’s love for Ultra HD Blu-ray has proven so lukewarm, and their commitment to Dolby Vision so selective.
Yoeri Geutskens works as a consultant in media technology with years of experience in consumer electronics and telecommunications. He writes about high-resolution audio and video. You can find his blogs about Ultra HD at @UHD4k and @UltraHDBluray.
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