The theater in my smallish home town has recently upgraded their projector systems to DLP Cinema...does anyone here know what kind of physical media the DLP format movies reside on when they are sent to the theater from the film distributors? Is it hard disk format or some optical format similar to BD/HD DVD?

On a related note I am wondering why theaters find it necessary to use audio compression like Dolby or DTS when they show movies...is there some technical reason that either 35mm film or DLP films can't offer uncompressed PCM tracks like we find on many current BD disks?

I believe they are distributed on external hard drives with USB interfaces...I just read about it at a local cinema here: http://www.elivermore.com/photos/lvr_cinema03.htm

Scroll down and there's a photo of a movie being uploaded to the server.

I believe they are distributed on external hard drives with USB interfaces...I just read about it at a local cinema here: http://www.elivermore.com/photos/lvr_cinema03.htm

Scroll down and there's a photo of a movie being uploaded to the server.

Wow, what great and interesting information!! Thanks! :cool:

On a related note I am wondering why theaters find it necessary to use audio compression like Dolby or DTS when they show movies...is there some technical reason that either 35mm film or DLP films can't offer uncompressed PCM tracks like we find on many current BD disks?

I'm not sure about DLP theaters, but in traditional theaters Dolby Digital & SDDS are literally incorporated onto the film stock. DTS has time codes incorporated onto the film stock. The time codes synchronize playback of the audio which are stored externally on CD-ROM disc.

I'm *guessing* that lossy compression is (was) required (at the time) simply because there isn't enough area on the film stock to store all the data required for uncompressed audio. DTS again is probably just practical considerations of wanting to limit the amount of data distributed via CD-ROM to convenient / reasonable levels.

The use PCM for audio and JPEG2000 for video compression.

The use PCM for audio and JPEG2000 for video compression.

Wow! - JPEG2000 :eek:

Does anyone know the details on JPEG 2000... if it uses some amount of temporal compression when used with motion video? If it doesn't... holy smokes the amout of data must be huge.

Wow! - JPEG2000 :eek:

Does anyone know the details on JPEG 2000... if it uses some amount of temporal compression when used with motion video? If it doesn't... holy smokes the amout of data must be huge.

According to that link.

The movie in this case is 1 hour, 49 minutes, 16 seconds long, and takes 193Gbytes of disk space.

This comes out to about 29Mbytes per second, which is about 50 times the data rate of the average movie on DVD. Why so large? The movies are in High Definition, and use much less compression to provide the highest quality picture. There is still compression required. Totally uncompressed at 45 bits per pixel would be 2Terabytes for this length of movie.

Note : 29MBytes = 232 Mbits

JPEG 2000 uses wavelet transform instead of DCT.

http://en.wikipedia.org/wiki/JPEG_2000

According to that link.

Note : 29MBytes = 232 Mbits

JPEG 2000 uses wavelet transform instead of DCT.

http://en.wikipedia.org/wiki/JPEG_2000

Yeah - I got that part, and I know that JPEG 2K is wavelet based, but what I didn't know (still don't) if JPEG 2K uses any interframe temporal compression like MPEG. JPEG 92 had "Motion JPEG" encoding, but I think it was just encoding a bunch of individual still frames. If JPEG 2K is doing the same thing, it seems like a terribly wasteful choice for digital cinema.

Also, that article says it's 45 bits per pixel!? Wow, what's up with that?

Some digital cinemas also use satellite download to hard drives.

If HDDVD and BluRAy are as good as they purport to be, then digital cinemas should be using them ;)

I recognize that the commercial digital cinema movie format uses less compression and more color resolution (and possibly higher spatial resolution in the media file, at least), but most digital cinema projectors are 1280x1024 or 1920x1080 or so.

Yeah - I got that part, and I know that JPEG 2K is wavelet based, but what I didn't know (still don't) if JPEG 2K uses any interframe temporal compression like MPEG. JPEG 92 had "Motion JPEG" encoding, but I think it was just encoding a bunch of individual still frames. If JPEG 2K is doing the same thing, it seems like a terribly wasteful choice for digital cinema.

The only diff is the actual compression algo. Both are intraframe only.

If HDDVD and BluRAy are as good as they purport to be, then digital cinemas should be using them ;)

I recognize that the commercial digital cinema movie format uses less compression and more color resolution (and possibly higher spatial resolution in the media file, at least), but most digital cinema projectors are 1280x1024 or 1920x1080 or so.
The majority of theaters are getting either Barco or Christie 2K projectors. A 2K image with a 2.39:1 ("scope") aspect ratio could be supplied having 2048 x 858 pixels. A 2K image with a 1.85:1 ("flat") aspect ratio could be supplied having 1998 x 1080 pixels.
Sony, Christie, and some other manufacturers are also developing 4K projectors. A 4K image with a 2.39:1 ("scope") aspect ratio could be supplied having 4096 x 1714 pixels. A 4K image with a 1.85:1 ("flat") aspect ratio could be supplied having 3996 x 2160 pixels.

In terms of delivery and storage of content, the company I work for is installing 1.8 meter VSAT dishes on a bunch of major theater chains so that the movies can be downloaded over a satellite network and stored on Dell rack servers. At the theaters that dont have the dishes installed, but the digital projection systems are installed, they are using SCSI swappable HDD.

I saw a Sony 4K projector in action at ILM as part of AES 2006. It looked better than the best film projection I've ever seen. It was unbelievably detailed with no film grain, no jitter from frame to frame, and the pixels were completely invisible. They also used a 2k projector on the same screen for part of the demo; it looked fantastic, but the 4k was noticeably better.

The majority of theaters are getting either Barco or Christie 2K projectors. A 2K image with a 2.39:1 ("scope") aspect ratio could be supplied having 2048 x 858 pixels. A 2K image with a 1.85:1 ("flat") aspect ratio could be supplied having 1998 x 1080 pixels.
Sony, Christie, and some other manufacturers are also developing 4K projectors. A 4K image with a 2.39:1 ("scope") aspect ratio could be supplied having 4096 x 1714 pixels. A 4K image with a 1.85:1 ("flat") aspect ratio could be supplied having 3996 x 2160 pixels.

In terms of delivery and storage of content, the company I work for is installing 1.8 meter VSAT dishes on a bunch of major theater chains so that the movies can be downloaded over a satellite network and stored on Dell rack servers. At the theaters that dont have the dishes installed, but the digital projection systems are installed, they are using SCSI swappable HDD.

I thought they use the whole panel resolution of the projector for scope movies by using an anamorphic lens?

I saw a Sony 4K projector in action at ILM as part of AES 2006. It looked better than the best film projection I've ever seen. It was unbelievably detailed with no film grain, no jitter from frame to frame, and the pixels were completely invisible. They also used a 2k projector on the same screen for part of the demo; it looked fantastic, but the 4k was noticeably better.
Research done at a college recently (for the life of me I cant think of it) determined that 8K resolution is the threshold for the human brain being able to determine if the object being projected is "fake" or "real". They are developing them and should have prototypes in the next couple years...

I thought they use the whole panel resolution of the projector for scope movies by using an anamorphic lens?
Thats definitely possible but the lens is an option on a per customer basis.