Digital cinema: movie distribution

I wrote about digital cinema earlier. I want to focus now on the distribution of movies to theatres.


The movie’s video signal is compressed and encrypted into a bitrate of max 250 Mbps, which translates in 31.25 MB/second or 112.50 GB/hour footage. So a ‘short’ 90-minute movie is something like 170GB, and a 2h30 movie, with some audio thrown in, is more like 300 GB. The estimates from the DCI specification are even higher: around 140 GB per hour running length (video, audio and subtitles together) or around 38 MB/s.
movie storage requirements


Kinepolis currently has 21 theatres that are equiped for digital cinema. So if a new movie comes out they need to transport 21 copies of 300GB to each of those. Imagine somewhere in the future a large distributor has to distribute 500 copies, preferably in less than a day. What are the options?
Start situation: 1 compressed file in DCDM format (compressed and encrypted – so safe to send)

External hard disk

Low-budget: send a LaCie Big Disk drive (500 euro/600GB – 1,5kg). Although, they are not exactly 100% reliable.

Mid-budget: send 2 drives in RAID-1 configuration (mirrored), such as the Lacie Two Big (1000 euro/500GB mirrored S-ATA – 2,5kg) or the Netgear/Zetera Storage Central SC101 (700 euro/400GB mirrored ATA)

These disks are USB2.0 (max 216 GB/h), Firewire (max 160 or 320 GB/h) or Gigabit Ethernet (max 450GB/h). Actual throughput speeds will be 25 to 75% of these theoretical values. So copying the whole data onto the local movie theatre network will take 1 to 2 hours, and then it’s ready for projection.

Backup tape

DLT tape: Super DLTape II can store 300GB onto a 0,225kg tape, with speeds up to 32MB/s

LTO tape: LTO 3 can store 400GB and has speeds up to 80 Mbps.

Reading speed can go up to 32 MB/s (115 GB/h), so a bit slower than the hard disks.


HD-DVD has a capacity of 15GB/disk, BluRay 25GB/disk. This means a 200GB movie translates 8 to 14 disks. Might be a way to distibute the content, but I’m not too convinced it’s a handy one.

Broadband (Cable/ADSL)

Imagine transport via network instead of magnetic carrier. Every theatre has a broadband connection. Max speeds in Belgium are around 10Mbps download (4,5GB/h). So downloading a 200GB movie file would take 2 full days. That’s too slow.

Fast Ethernet

If every theatre had 100Mbps download speed, would that make network download feasible? That adds up to 45GB/h, download a full movie in 5 hours, or -let’s be realistic- 8 hours. That’s OK. Actually, if there was only 1 theatre, that would be OK. But if 21 deliveries have to be made at the same time, and they all download from one location, that adds up to 21 x 100 Mbps or 2,1 Gbps. That’s more bandwidth than most hosts can handle. Let alone 500 simultaneous downloads.

Fast Ethernet + BitTorrent

But if the source host only serves as a BitTorrent seeder, and the other downloaders can serve as peers for each other, it should be possible to deliver the same content to each theatre within 8 hours. Looking at how close Hollywood is looking at BitTorrent, this should be an evident choice.

Since current movie distribution (printing on 35mm film) costs between $1500 and $3000 per copy, any of the above methods is way cheaper.

3 thoughts on “Digital cinema: movie distribution”

  1. I’m very interested in the development of this film as I’m considering the rivitalization of a classic cinema retrofitted with digital cinema presentation. Do you know where one would go for information on securing theatrical release rights & distribution rights in this digital format (particularly for classic films and sporting events)?

    Thanks for the already posted info; I’ve added some more bookmarks.


  2. Hello,

    I am greatly interested by the informations you gave.
    I am the founder of Real Reality in Brussels.
    We are doing six minutes shortfilms and they are showed in theatre here in Belgium.
    Since they are computer graphics animations and that they are already existing on hard disks, I would like to convert them so that thy conform to DCI specifications.

    A question : You meant that if I deliver the material on a external disk with USB 2 or Firewire all theatre will be able to read the material ?

    Another question : The film exists as a targa sequence for now. Do you know a tool or method or people who/which can convert this sequence as a complete file compliant to the DCI specs ?

    Thank you very much to answer me
    Luc Petitot

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