Post by Paul S PersonOn Sun, 3 Oct 2021 19:53:28 -0000 (UTC), Torbjorn Lindgren
This presupposes that we are using "blanks" the same way. I am using
it to mean the discs purchased from the manufacturer with no program
on them which the publisher then puts the program on, presumably by
pressing as opposed to recording.
I doubt that this exists for pressed Blu-ray or DVD media, it's how
writable media is done but that's a VERY different kettle of fish.
Even the simplest single-layer DVD has the data layer deep inside the
media for protection so it can't just be "pressed" with groves/pits
like it was a vinyl.
Post by Paul S PersonBut perhaps you were using "blanks" to refer to something the
manufacturer first produces, which the manufacturer then presses into
one or two /blank/ layers.
Ah, found a picture of how a dual-layer Blu-ray is layers (there's no
better word).
https://azuradisc.com/about-discs/how-a-cd-is-made-2-2/
What I called blank earlier is the second layer in that picture, the
"base" which combined with the very thin "dampproof layer" makes up
the top 1.1mm of the finished disk, I expect the front picture is on
or part of the dampproof layer.
Under the base (towards the laser) is the (pressed) L0 layer, an
intermediate layer, the (pressed) L1 layer, the transparent cover
layer and the hard coat, all this combined takes up 0.1mm. Together
with the top and base layers (above) this give the finished disk the
same thickness as an DVD, IE 1.2mm.
For say a 4 layer disk add 4 more layers (I/L2/I/L3) between the L1
and the cover layer, all the layers needs to be thinner since it's now
9 layers in 0.1mm (7 for 3 layer disk) instead of "only" 5/3
(dual/single-layer Blu-ray).
Obviously that kind of disk can't be made as a full blank, there's no way
to create the pits once all the layers on top are on it. Laser could
in theory make the pits IF it's just one layer but would cause enough
damage that the disk wouldn't be readable.
My GUESS would be that the L0/L1(/L2/L3) layers are made separately
and then all the layers are stacked and then it's.. pressed together
which fuses everything together, it needs to be sealed because if any
water gets to the inner layers the disk will go bad very quickly (this
did happen on some early DVDs).
All this stuff could be delivered as bulk material or in a partially
finished state, my bet would be that in most cases it would arrive as
"bulk" because that gives them much more control over the thin layers
necessary and they use a LOT.
AFAIK most/all? Vinyl pressing starts with bulk material too
(granulate, no disks), so it seems likely even the "base" likely comes
to the factory as bulk material.
Post by Paul S PersonPost by Torbjorn LindgrenGoogling on "Ben-Hur UHD" I don't see a UHD edition of it in the
normal places, but specialist places say it's available for pre-order.
The specification say it comes with two disks, one UHD and one HD (for
those that don't have UHD player yet).
So I assume they either already had an updated single disks Ben-Hur HD
Blu-ray that or that they created it when they were re-mastering for
UHD, it would have been trivial to do so (and likely significantly
improve the quality of the HD Blu-ray).
https://www.blu-ray.com/
The latest /Ben-Hur/ appears to be
https://www.blu-ray.com/movies/Ben-Hur-Blu-ray/106655/
but whether the BD-50 has the film on it is unknown -- unless, when I
checked with the Forum some years back, it was out and so included in
the clear statement that no film-on-one-disk version existed.
No, as I said I was discussing an no yet relased UHD variant that some
sites are offering pre-orders on, not the old HD variant you are
referring to.
https://www.blu-ray.com/movies/Ben-Hur-4K-Blu-ray/251140/
https://www.hdmoviesource.com/Ben-Hur-1959-4K-Ultra-HD-Blu-ray-p/13589.htm
Without a release date it's possible it won't see the light of day
though hdmoviesource seems fairly confident. I'm confident a
BD-50+BD-100 set definitely could have both a number of extras and
very high quality these days.
To address the 3-disk HD Blu-ray set, it says 2xBD-25+1xBD-50. If we
add up the listed audio and video bitrates we end up a bit above 50GB
for the main feature of 222 minutes.
It's a bit weird since the bitrates is definitely too high for a 222
minute BD-50 and unnecessarily low for a BD-50+BD25 for the movie...
But the DTS-HD MA stream could be really huge I guess or the way they
sliced into two parts resulted in lot of wasted space (IE say perhaps
40+20 GB)
The other option is that the listed bitrates are a bit too high and
the two BD-25 are both for "extras" but then why not just use a single
cheaper BD-50, this makes even less sense.
Post by Paul S PersonThe Amazon version
<https://www.amazon.com/Ben-Hur-Blu-ray/dp/B00LB3O9OI?tag=bluray-027-20&linkCode=ogi&th=1&psc=1&m=>
appears to be missing one of the 3 discs. The description can
certainly be interpreted as "one film spread over two discs".
I get the WD Diamond Deluxe 3 disk edition via that link, the one you
referenced above. But I see other HD Blu-ray editions as options, all
those seems to have 2 disks but it's unclear if that's one disk for
movie and one for extras or if the movie spans both disks.
The ones I checked didn't have average video bitrates listed so I
couldn't rule out either option without access to the disks.
[... The Ten Commandments ...]
Post by Paul S Personhttps://www.blu-ray.com/movies/The-Ten-Commandments-4K-Blu-ray/282780/
1 BD-100
2 BD-50
which illustrates something I've seen with other films: originally,
the two discs/two sides originally were single-layer, but, at some
point, they became dual-layer /with no indication of a new transfer/.
IOW, the single-layer files were simply used on a dual-layer disc.
This is one reason I suspected that single-layer had become disfavored
even for programs that would fit on it: dual-layer appears to have
been used when there is clearly no need for the extra space.
Except the database you says that's NOT the case here, IE even the
earliest 2011 Blu-rayÂŽ+DVD releases was already 2xBD-50 so they
started with dual-layer, not single-layer.
And... it also lists the average video bitrate for some of the 2011
releases which means we can see that for those 2xBD-50 sets just the
video data for the movie (231 minutes) would need at least 59GB.
So that transfer/encoding can't possibly ever have fit on 2xBD-25...
With audio the main movie I'm guessing the is probably in the 63-66GB
range but could be larger, up to ~84GB in theory! if they went
absolute bonkers on the audio streams which I really doubt.
Even at reasonable audio bitrates it wouldn't take that much extras
for it to no longer fit on say BD-50+BD-25 and that ignores the fact
that they likely split the movie in a much better place than "oops, we
just ran out disk space" so the first disk likely have quite a bit of
free space.
So basically 2xBD-50 was the obvious option with an 34.59 Mbps average
video bitrate and some extras. BD-50+2xBD-25 with extras on the second
BD-25 might also have worked but depends on where they cut the movie.
Post by Paul S PersonI don't know that I am interested in buying a UHD player just to get
these on one side of one disk. For one thing, I use a convertor chain
to convert HDMI 1080p to SVGA for input to my NTSC TV set, and I'm not
sure that would work with whatever a UHD player produces.
UHD players generally produce HDMI 2.0, but (post 2014) Blu-ray and
(all) UHD players "should" output a 480p signal or nothing rather than
1080p/2160p if they can't get end-to-end HDCP encryption. And your
chain most definitely shouldn't qualify for that.
I assume you have a workaround for whatever player you currently have
or that it's pre-2014, it wasn't enforced at all on the first wave of
players and the first few implementations now have easy ways to get
around it..
But all these UHD players are, well, newer, and the rules are enforced
much harder now. There ARE still ways around it but I'm fairly
confident your existing Heath Robinson inspired chain won't work well.
And given the description of the chain I'm also confident that the
chain (and likely the display) can't use the extra resolution anyway.
And if you get a 4K capable device it'll have the appropriate ports
and you just connect it via a simple HDMI cable, there's generally no
need to faff around.