JamieG Analysis

Recently I have been doing a lot of encoding for Art house digital Cinema presentation. I have been involved in the Cinema industry in Australia for about 10 years.

In many ways I am in a position of relevance as I can see some of the road signs coming up for Digital Cinema and the future of exhibition here and the world over.

I would like to post, what I feel, is an important issue that should be more widely known.

Putting DCI aside, and keeping in mind it is a “recommendation” by a group of incumbent players who have questionable interests..

The current codec technology used by cinemas for digital presentation is largely, MPEG2, and for the luck DCI followers with deep pockets, JPEG2000.

There is nothing wrong with JPEG2000 in terms of quality. It has some technical specs from DCI that makes it , expensive to deal with, but otherwise it does bring a lot of quality to the screen.

MPEG2, has been a work horse of the industry. It has done and will be a main stay for the future. However. Its simply not suited for Digital cinema usage.

MPEG2 and really ALL other available codecs of industrial strength and reliability, are limited in colour depth. And this is the real issue with current open standard digital presentations. It is also the main gripe of the extreme Film fanatic.

Hi quality Digital Cinema projectors have colour depth and contrast ratios that make colour limitations really stand out. For example, you cannot see as much detail on the blacks. Banding in skies or fade in/outs.

There are, however, solutions to this in newer specifications of the more recent codecs.

H.264, for example, is gaining huge popularity for its compression efficiency. I must say, I am impressed. However, like all the rest, current supported specifications of the codec do not go over 4:2:0, 8bit YUV colour space. Ie same as MPEG2 (Apart from MPEG2 can do 4:2:2).

However, if you read the wikipedia page http://en.wikipedia.org/wiki/H.264 you will notice in recent times, the specifications ha sbeen expended to support 4:2:2 with 10bit colour, or even 4:4:4 with 12bit colour.

Personally I think 4:2:2 with 10bit colour should be enough, (But I would like to stay this judgement until I see it) 4:4:4 with 12 bit is equivalent to what they use in Post Production, keeping a few stops (stops as in F stops on a camera, it relates to exposure and amount of colour depth) of information you cannot even see, just so they can push the colour grade around without loosing any visual quality.

H.264 being a temporal compression. (Ie like MPEG 2, uses previous and next frames to help build the current frame more efficiently. Ie archiving better compression and smaller files.) has large advantages over I frame based Jpeg2000. On a ruff guess, films in Jpeg2000 would be about 300gig, and H.264 with similar colour depth and quality, 70gig. This may only be disk space, but it all ads up. And moving 300gig around is not something that happens fast, even on a direct disk to disk copy. What this equates to is HUGE costs to exhibition owners and less functionality in the BIO box.

To me the big advantage of going digital in the cinema is the fact that content creators. Ie, movie makers will be able to bring there feature to the screen far more cheaply. This means, as a consumer, we will have more choose. A person who dreams of making a movie, your reality is far more likely to happen.

DCI has its place, but so does the current technology we are using every day. DCI has a lot of custom, non popular specs that fall out of popular specs we all use today. This makes it expensive and difficult.

I would like to encourage the codec industry to harry up and implement improvements to open codecs that will allow this to happen sooner rather then later.   Its best for all of us.  (Well maybe not the emcumbents.)

Post Note: Other codecs like the new  ApplePro res do also answer this need, however, I would never encourage a proprietary codec.  It is also now suited in other was.