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Topic: Blu-Ray vs DCI

Peter Castle
Expert Film Handler

Posts: 220
From: Wollongong University, NSW ,Australia
Registered: Oct 2003

posted 04-14-2007 08:49 AM

Now that there is a supply of Blu-Ray (and HD-DVD) discs available, has anyone done a comparison of DCI-compliant print and high-definition disc. Resolution should be comparable. But what about colour palette and compression artifacts?

I've compared film to Blu-Ray on a full-HD projector and the comparison is good (but colours are not as "deep").

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Patrick de Groot
Expert Film Handler

Posts: 161
From: Sprang-Capelle, Netherlands
Registered: Apr 2001

posted 04-14-2007 09:24 AM

I attended a meeting about the implementation of Digital Cinema. They showed a screening of the Fantastic Four. There was some notable lack of detail and some strange colours. After a while they said it was a Blu-Ray screening. We agreed that this format is usable for some special purpose presentations like showing classics. The distributors agreed it is a possibility for some situations.

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 04-14-2007 10:33 AM

And how did they get around the HDCP? DCinema projectors are DCI compliant, not HDCP (which sucks).

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Alan Gouger
Jedi Master Film Handler

Posts: 501
From: Bradenton, FL, USA
Registered: Jul 2000

posted 04-14-2007 12:43 PM

HDCP has been nothing but a nightmare for both manufacture and end user. Nothing hand shakes properly between any two components. The confused consumer ends up the beta tester. Who ever came up with this one should be forced to live the rest of his life in a home with all appliance and media interfaced with his HDMI. Id give him a month before he has a nervous breakdown.

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Fabrice Dubourg
Film Handler

Posts: 43
From: Granville, France
Registered: Feb 2003

posted 04-14-2007 12:53 PM

is HD format dci compliant ?

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Tristan Lane
Master Film Handler

Posts: 444
From: Nampa, Idaho
Registered: Feb 2002

posted 04-14-2007 01:22 PM

According to this: Video

The new Christie projector will be HDCP compliant.

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Kyle Anderson
Film Handler

Posts: 86
From: Tyler, TX, USA
Registered: Dec 2005

posted 04-14-2007 03:59 PM

seems dumb to ask why they didn't just use an encrypted form of dual link DVI ( which supports monitors right now with resolution > 2k x 1k )

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Bobby Henderson
"Ask me about Trajan."

Posts: 10973
From: Lawton, OK, USA
Registered: Apr 2001

posted 04-14-2007 06:20 PM

quote: Peter Castle
Resolution should be comparable. But what about colour palette and compression artifacts?

Differences in resolution between 1080p video on HD-DVD or Blu-Ray and the 2K imagery in DCI digital cinema are slight. For a long time I have thought this will be a big potential marketing problem for commercial movie theaters as either of those disc-based HD formats gain more popularity.

Bit rate is quite a bit different. The best disc-based movies run at maximum bit rates of around 30 million bits per second. A JPEG2000 server can play 2K movies at rates up to 250 million bits per second.

I've seen some Blu-Ray movies played on HDTV monitors with native 1920 X 1080 resolution and they usually look pretty impressive -and a lot better than standard 480p DVD. Still, I think 2K digital cinema in a commercial movie theater looks better. But the quality differences are fairly subtle.

Perhaps on more challenging material, like footage with lots of motion and lots of image details, then the heavier compression in HD-DVD and Blu-Ray footage may reveal more flaws.

DCI digital cinema is supposed to have a minimal amount of "tiles" that are encoded into the video stream -like only 2 or 3 tiles at most. When you watch certain video footage with high levels of compression you'll see that it is divided up into a lot more tiles. That leads to visible blocking artifacts along with other issues in compression.

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Patrick de Groot
Expert Film Handler

Posts: 161
From: Sprang-Capelle, Netherlands
Registered: Apr 2001

posted 04-15-2007 02:57 PM

I've read some interesting information at Film-Tech.nl, a Dutch website that's just running for a couple of weeks now [Smile]

They used a Leeza Scaler that accepts all kind of input. Because of time constraints for preparing the demo it was connected through 720P component. You would get better results ofcourse by using the HDMI connection (1080P).

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Bastiaan Fleerkate
Film Handler

Posts: 85
From: Linschoten, Utrecht, The Netherlands
Registered: Jun 2006

posted 04-15-2007 04:59 PM

quote: Patrick de Groot
I've read some interesting information at Film-Tech.nl, a Dutch website that's just running for a couple of weeks now
They used a Leeza Scaler that accepts all kind of input. Because of time constraints for preparing the demo it was connected through 720P component. You would get better results ofcourse by using the HDMI connection (1080P).

The presentation of the Quicktime trailers at 720p were with digital dust particles (artifacts), stereo sound, and pixilation was everywhere. The highest Quicktime files you can get are 720p and not 1080p. That's why you can't show quicktime trailers on a big screen.
Most projector manufacturers have made boxes which you can attach to the projector and make it do everything, VGA, S-Video to HDMI, DVI, whatever... This is how you can connect the video. Connecting the sound sources is a second...

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Patrick de Groot
Expert Film Handler

Posts: 161
From: Sprang-Capelle, Netherlands
Registered: Apr 2001

posted 04-16-2007 02:22 AM

I totally agree that the quicktime videos were clearly of too low quality.

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Carl Martin
Phenomenal Film Handler

Posts: 1424
From: Oakland, CA, USA
Registered: Feb 2002

posted 04-16-2007 01:54 PM

quote: Patrick de Groot
There was some notable lack of detail and some strange colours. After a while they said it was a Blu-Ray screening. We agreed that this format is usable for some special purpose presentations like showing classics.

you're kidding, right?

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Patrick de Groot
Expert Film Handler

Posts: 161
From: Sprang-Capelle, Netherlands
Registered: Apr 2001

posted 04-16-2007 02:04 PM

No, I'm not kidding. When you want to show some rare classic or you want to show a 80's movie and all you can get are some beaten-up prints you're better of with showing HDTV.

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Bastiaan Fleerkate
Film Handler

Posts: 85
From: Linschoten, Utrecht, The Netherlands
Registered: Jun 2006

posted 04-16-2007 06:48 PM

I agree with Patrick... Blu-Ray is ok to show. It's better than a beaten up print. They said that the HD-DVD picture quality wasn't good enough, so they showed Blu-ray instead...

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Bobby Henderson
"Ask me about Trajan."

Posts: 10973
From: Lawton, OK, USA
Registered: Apr 2001

posted 04-16-2007 07:29 PM

quote: Bastiaan Fleerkate
The highest Quicktime files you can get are 720p and not 1080p.

That's not true. Most of the HD trailers at Apple's Quicktime trailer park have real 1080p versions. I've even grabbed frames out of those 1920 pixel wide trailers and found they have a lot more image detail in them than the 720p versions.

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