James Morrow

There's no reason why not technically - 1080p24 is lower resolution than is captured on well exposed 35mm film with high quality lenses (this was measured in the eighties as around 24MPixels - 6k by 4k), and is based upon the resultant resolution seen in cinemas in the sixties - so direct digitisation of the "old masters" at 1080p should still benefit from the enhanced resolution. Besides, if fed a lower resolution source a good codec will let you choose between a lower bitrate or the normal bitrate and even fewer artifacts.

Digital cinema was launched in 1999 with a resolution of 1280 by 1024 p24, but the revolution is essentially on hold at the moment, as only around 0.1% of all cinemas are capable of displaying it. However, various industry studies suggest that the practical on-screen resolution of celluloid film is between 900 and 2000 lines (the master film negative is used to create an "interpositive" which is in turn used to create a duplicate negative - the "internegative" - which is then used to create the cinema prints - and that's before it's even projected!

If the master film is digitised (using a telecine machine) this is generally carried out at 2k lines - although 4k resolution is used when ultra-fine detail is required. Sony and JVC have produced limited quantities of appropriate modulators for 2k (3840 by 2160) projectors, but not 4k yet. According to Denis Kelly, Kodak's European manager for digital cinema operations, "everybody believes that it will start at 2k, because otherwise you'll wait forever, but that there'll be an upward path for 4k".

2k is probably the highest practical on-screen resolution of 35mm, and is roughly as much above HD as HD is above SD, but 4k is heading towards IMAX territory (although currently at a much lower frame-rate).

It\'s time we Blu-it...

James Morrow

Talking of High Definition, you can download about a dozen short demos of 720p24 and 1080p24 using the WM9 codec from Microsoft at

microsoft.com/windows/windowsmedia/content_provider/film/ContentShowcase.aspx

Note that the 720p24 demos need a 1280 by 1024 display or higher and a 2.4G processor (or AMD equivalent), whilst the 1080p24 demo needs a 1920 by 1440 display and a 3G processor (or AMD equivalent).

...not great if you don't have broadband though, as each clip is around 100MB, which on narrowband will take most of a day (assuming that your supplier doesn't cut you off after two hours or so).

Note that a 50GB Blu-ray disc [BD] can support over four hours of HD video at 24Mbps, so it would be interesting to see modern codecs such as MPeg4 and WM9 optimised for 1080p24 and 24Mbps. Of course, to provide even more headroom and improved transparency, the 72Mbps discs and heads could be used to support over three hours of 32Mbps video coupled to high resolution audio on a single BD.

Ok, so maybe you can't run the 1080p24 demos properly yet, but even the 720p24 demos (which need 1280 by 1024 resolution displays) are far better than 480 line DVD, and will let you see the kind of quality you can expect from the WM9 codec at around 6-8Mbps. You should find the improvement of even 720p24 over a normal DVD pretty significant - but your display must be set to 1280 by 1024 plus lots of colours to get the full effect. Then imagine the same spatial resolution only 50% wider and 50% taller...

Note that the display manufacturers had no particular resolution to aim for until recently, but as high definition sources are starting to become commercially realisable many are now working on and showing their 1920 by 1028 p24 capable large screen displays, and expect to see it soon on the desktop too. The PC demos use the extra lines (over and above 720 or 1080) for the media player controls, and are based on the traditional 4:3 aspect ratio, but the real thing outputs 16:9 720p24 or 1080p24 to an appropriate high definition widescreen display. Current HD displays include a 24”, a 54” and a 57” 1920 by 1080 p60 TFT display from Samsung and 23” TFT displays from Sony and Apple. However, a lot of manufacturers are selling 1280 by 720 pixels displays as high definition capable, so that’s something to watch out for, as well as displays which don’t support 1080p24 resolution or higher

The Blu-ray consortium is now re-examining WM9, due to recent improvements in its performance. These free samples are big enough to let us see the potential and failings of WM9 at around 8Mbps but small enough to download using a reasonable broadband connection. Of course there are loads of HD films available on the internet and to buy, but for me, the chance to see what Microsoft believes shows off WM9's capabilities at 8Mbps in a range of different types of films, packaged into a couple of gigabytes was one I didn't want to miss.

We might end up with 8Mbps high definition if Time-Warner get their way, rather than the 24Mbps or higher that Blu-ray can offer, so the more we understand what 8Mbps quality means, and where it fails to deliver, the more we can push for WM9/MPeg4 etc. optimised for 1080p24 at 24Mbps (or possibly 32Mbps if Sony move to 72Mbps mechanisms).

It\'s time we Blu-it...

John Kotches

James Morrow says:



Typical data rates for HD-DVD (no point in discussing standard DVD) are roughly the same as for Blu-Ray but the use of higher efficiency codecs are approved (MPEG-4/H.264 and VC-9/WM-9). So, Sony can either cave and add a newer generation format, or lose the all important picture quality competition.

For storage, Blu-ray is a better solution. For video, without a newer codec as the answer, IMO, Blu-ray will not win. That's assuming studio support is equal for both formats.

Cheers,

Surround Music Enthusiast / Curmudgeon in Training
Opinions are my own, not representative of the publication I write for.

imported_Brian-W

Remember, it isn't guys like us that decide the winner. Joe six pack will decide who will win (assuming equal studio support).

There are a whole host of other items that will determine the "winner", and video codec to the consumer isn't one of them. Price and availability will determine the winner.

James Morrow

Hi John, Brian,

Absolutely, if Sony et al don't support and use modern codecs they're throwing away any advantage Blu-ray has. Yes, support MPeg2 for legacy material if they can't easily convert to MPeg4/WM9 without introducing more artifacts, but focus on modern technology as the primary codec of choice. As far as the typical consumer is concerned, if MPeg4/WM9 can produce similar or better quality video to MPeg2 at half the data-rate, why go for dual-layer 50GB Blu-ray using MPeg2 over dual-layer 30GB HD-DVD using MPeg4/WM9? They're hardly going to say "well, I'll go for lower video quality because I want to support Blu-ray to use in my PC, and because it has the potential to be better than HD-DVD in the future."

So, assuming that Blu-ray employs modern codecs, both it and HD-DVD are designed to support 24Mbps high definition encoding - Blu-ray around four hours or so and HD-DVD around two (both assuming dual-layer discs), leaving some space for DD/DTS. Given the improved performance of MPeg4/WM9 over MPeg2, HD-DVD might even drop this to 16Mbps in order to achieve a capacity of approaching four hours (including DD/DTS). However, for a typical film, 50GB Blu-ray has more capacity than is required. Although the current maximum data-rate of Blu-ray and HD-DVD is 36Mbps, Sony's professional disc for data [PDD] has a data-rate of twice this - 72Mbps, and some of its current video recorders (in the XD-CAM range) go up to 144Mbps. With a 50GB disc, increased headroom would allow either high resolution multi-channel audio - for live music videos, for example - or higher quality video - over three hours at 32Mbps, for example.

If the Blu-ray crowd produced 720p24 and 12080p24 demos on the internet (much as Microsoft has for WM9), as DVD-Roms on magazine covers, etc., at 24Mbps (and even 32Mbps), they should be able to run off the hard drive on a modern PC using software decoding. Even if real time was not possible, half-speed (say) would allow potential consumers to see the benefits of Mpeg4 at 24Mbps over WM9 at 8Mbps – and as Blu-ray can easily support 24Mbps, and its capacity is needed for next generation PC data backup and storage anyway, they could then show people what they would be missing if the go with Microsoft’s (unnecessary) lowest possible bandwidth approach. As quad-layer 100GB 144Mbps Blu-ray discs are due in a couple of years (TDK have already demonstrated them), they might also want to put some high-end demonstrations on the internet too – such as 1080p24 at 48Mbps or higher.

I believe the best way to beat the push towards unnecessarily low bitrate encoding (such as Microsoft's WM9 demonstrating 1080p24 at 8Mbps) is to demonstrate the superiority of modern codecs at 24Mbps or higher - rates applicable to next generation discs. If 1080p24 at 8Mbps WM9 was transparent, there would be no reason for going for higher bitrates, but it isn't anywhere near transparency - in my opinion, it looks brilliant compared to typical DVDs but dreadful compared to film.

But Mr Public is going to compare HD on 8M WM9 to DVD of course, and if there are no other better examples to compare it against he will fall for it. At 8Mbps, WM9 appears to work very well with man-made objects, but natural objects such as trees look artificial, colour gradients are obviously stepped, there’s a “cogging” effect on trees and similar as the camera moves through the scene – a bit like insufficiently accurate sub-pixel processing, etc..

It\'s time we Blu-it...

James Morrow

... note that following recent improvements in the performance of WM9 with high definition 1080p24 at low bitrates (below 10Mbps) Microsoft (you may have heard of them) are now pushing to have HD content agreed as a DVD standard, and for it to be released on a large scale at 8Mbps on standard DVDs within months, using DVD9/DVD18. Now would be a good time to produce demonstrations of the advantages of 24Mbps etc. using modern codecs ...

It\'s time we Blu-it...

Lee Scoggins

There is a story on HFR about the DVD Forum approving the Dual Disc format. It will be interesting to see where this goes. I don't think the tests in Boston or Seattle were very successful but perhaps Warners or others will do a bigger marketing push soon. This creates, however, yet a third format to further confuse the market.

Seems to me that the big labels should just try to unify behind one hidef video and music format when that is ready...

no fears alone at night she's sailing through the crowd
in her ears the phones are tight and the music's playing loud
~skateaway

Lee Scoggins

Details:

http://www.highfidelityreview.com/ne...umber=12004614

no fears alone at night she's sailing through the crowd
in her ears the phones are tight and the music's playing loud
~skateaway

James Morrow

Interesting Lee. I knew that they'd got it down from 1.8mm to 1.5mm - maybe it'll be a selling point, like 180gram LPs? Seriously it sounds like the shot in the arm that DVDA needed - and the shock in the arm SACD needed too.

Moving on to next generation discs, as long as they at least settle on 24Mbps or better for high definition I'll be relieved. Ideally some agreement centred around blu-ray technology. The worst case scenario would be the mass-market take-up of high definition at 8Mbps on DVD9, DVD14 or DVD18 (i.e. 2, 3 or 4 hours with compressed DD/DTS audio).

It\'s time we Blu-it...

John Kotches

James,

Your obsession with 24Mb/second is unwarranted if talking about MPEG-4/H.264 or VC-9/WM-9

They will do quite well at 16-20Mbits/second, arguably better than MPEG-2 @ 24Mbits/second or higher.

Cheers,

Surround Music Enthusiast / Curmudgeon in Training
Opinions are my own, not representative of the publication I write for.