How to Format a USB Drive for a Cinema

The ISDCF Specification

The ISDCF (Inter-Society Digital Cinema Forum) specifies a precise format for cinema delivery media: a single MBR partition, formatted in EXT2 or EXT3 (Linux file systems), with an inode size of 128 bytes. This is a Linux format. Your Windows computer cannot create it natively. Your Mac cannot either. Standard Linux systems default to an inode size of 256 — which older cinema servers will reject. To create a correctly specification-compliant drive, you need a Linux computer with the correct command-line tools to specify the inode size explicitly at format time.

What Cinemas Actually Prefer — NTFS

Here is where the specification and the real world diverge. Most modern cinema servers run Windows as their operating system. They handle NTFS drives natively and without difficulty. The majority of independent film screenings are delivered on NTFS formatted drives without problems. Some older servers — particularly certain Dolby systems — only accept EXT2. If you are delivering to a venue with older equipment, ask in advance.

Folder Structure

The DCP folder must sit at the root of the drive — immediately visible when the server mounts it. One folder deep, no more. The folder should be named correctly to the ISDCF convention so the server and projectionist can identify the film without opening any files.

Verify Before You Hand Over

After copying the DCP to the drive, run a checksum verification. Confirm every file on the drive matches its hash. A single corrupted byte — from a bad drive, a faulty USB port, or an interrupted copy — will cause ingest to fail with no further explanation. Discovering a checksum failure at the cinema projection booth on the day of a screening is an entirely avoidable experience.