What is a DCP?

A DCP, or Digital Cinema Package, is the standard format cinemas use to play a film. If you are delivering to a festival, a single screen or a national release, your film needs to be a DCP before it can reach a projector.

Think of a DCP as the digital equivalent of a film print. It is not a single video file you can double-click. It is a folder of specialised files, built to a strict industry standard so that any compliant cinema server in the world can play it back exactly as intended.

What is inside a DCP?

A DCP keeps picture, sound and instructions as separate parts, then ties them together with metadata:

• Picture, stored as a JPEG 2000 image sequence rather than a compressed video file, which keeps every frame at cinema quality.
• Audio, stored as uncompressed tracks, commonly 5.1 or 7.1 surround, so nothing is lost.
• Subtitles or captions, when your film needs them, either open (always visible) or closed (switched on by the cinema).
• Metadata, the CPL, PKL and ASSETMAP files that tell the projector what to play, in what order, and confirm nothing is missing or corrupted.

Why do cinemas use DCPs instead of a video file?

Consistency and reliability. A DCP guarantees the same picture and sound on every screen, protects the image from the quality loss that comes with ordinary video compression, and can be encrypted so a film only plays where and when it is authorised. It is the format cinema projection is built around.

SMPTE or Interop, which do you need?

There are two DCP standards. Interop is the older one and plays on almost any cinema server, which makes it a safe choice for mixed or older venues. SMPTE is the modern standard, required for features such as closed captions and advanced audio formats. Many festivals and cinemas now expect SMPTE, but the right answer depends on where your film is screening. If you are unsure, we will confirm what your venue needs.

2K or 4K, and what about frame rate?

DCPs are mastered at 2K (roughly 2048 pixels wide) or 4K (roughly 4096 pixels wide). 2K is still extremely common and looks excellent on the vast majority of screens, while 4K suits large-format cinemas and future-proofing. A DCP also carries a fixed frame rate, most often 24 frames per second, though higher rates are supported for specific formats.

Encrypted DCPs and KDMs

An encrypted DCP cannot be played without a key. That key is a KDM (Key Delivery Message), and it is locked to a specific cinema and a specific date range. This is how distributors keep control of a film: the same DCP can go to many cinemas, but each one only plays during the window you allow. Festivals and screeners often use this to protect a film before release.

How is a DCP played?

The cinema copies, or ingests, your DCP onto its server, loads any KDM key, and builds a playlist. A badly made DCP that fails to ingest, or plays with wrong colour or dropped audio, is expensive and sometimes impossible to fix once the audience is seated. This is why every DCP should be tested before it is delivered, not after.

How do I get a DCP made?

You send a high quality master, such as ProRes, DPX or an image sequence, along with your final audio and any subtitle files, and a DCP is built and tested to the correct standard for your screening. That is exactly what we do at Pixel Storm Post, on our own Storm DCP Studio software, with every package quality-checked before it reaches the projection booth.

Want to master DCPs yourself? The same software we use is available to license: Storm DCP Studio.