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DCP delivery spec

Purpose of a delivery spec

If you're delivering a Digital Cinema Package (DCP) to us for screening at a festival, we need to ensure it's going to play correctly and represent your film at its best.

Making a DCP correctly is a fairly complex process, and not all software does a very good job of it, so it's more of a minefield than it may appear on the surface.

A DCP which adheres to the spec below will be compatible with the wide range of DCP projectors currently in use in cinemas. If it doesn't, it risks failing playback in random ways on some equipment. It is an upsetting experience for filmmakers to see their film mangled in front of a packed auditorium, so it's a scenario we are committed to avoid.

Therefore all DCPs delivered to us will be carefully checked prior to the festival, and we won't be able to accept DCPs which are incorrectly made.

This isn't an exercise in academia or nit-picking! It's about ensuring your film screens exactly as you intended at the festival.

The basics

It's advisable to have a DCP made professionally, to ensure your film is represented on screen exactly as the filmmakers intended.

If the DCP is "home-made", it is vital that the director and/or other key crew members watch through the DCP in full themselves, and ensure they're completely happy with it, before sending it out to festivals/screenings.

Please do not send us DCPs which have not already been viewed in full. We do check everything we're sent, but it's not feasible to watch every film through start-to-finish. Our checks are purely a "last line of defence" - we can't catch everything.

If you do not have a DCP already, we also offer a DCP-creation service, which includes a full QC prior to dispatch. Our prices are the lowest in the industry for a professional service, and many festivals also arrange a further discount for their filmmakers. If you'd like the peace of mind of knowing that your film will screen perfectly, please consider this option.

QC

Ideally DCPs will have already received a full QC (quality control viewing) before sending to us.

The term "QC" is much over-used, so to clarify:

"QC" means a skilled technician watching through the film from start to finish with a close eye. They will typically rewind over any points of possible concern or step through sections of the film frame-by-frame, to spot any glitches. The DCP will also be put through an automated technical analysis and validation.

A QC is not:

  1. Briefly putting the film on screen and making sure the first minute plays.
  2. Non-technical crew watching through the film.
  3. A watch-through without also a technical validation.

(when festival says a DCP "passes QC", they often mean something like the first of these)

Specification

SMPTE/Interop

DCPs can be either SMPTE or Interop standard.

If Interop, frame rate MUST be 24fps. All other frame rates require SMPTE. DCP must comply with the relevant Interop standards.

If SMPTE, DCP must be compliant with the SMPTE Bv2.1 profile. This profile is well-understood among DCP-creators, and most will adhere to it. The full text is available here.

SMPTE Bv2.1 is designed for exactly the same purpose as this specification overall - to constrain the DCP standard to only features which have support on a wide variety of projectors and servers (working around known bugs etc).

Much of the remainder of this specification is a summary of some of the most salient points from these standards. However, please note that it is not exhaustive.

Container

DCPs must be in one of these formats:

We do not accept "Full" container DCPs (1.90 ratio). "Full" is intended for technical tests only, and most cinemas will NOT be able to present it correctly.

Aspect ratio

Your film should fill the chosen container entirely, or be letterboxed/pillarboxed.

Avoid combining both letterboxing and pillarboxing (i.e. film floating in a black box in middle of the screen), unless this is an intentional artistic decision.

Image must not be stretched or squashed, and there should be no unintentional masking (black bars which appear on only some shots).

DCP naming

DCP (or rather the CPLs which comprise it) must be named according to the DCP naming convention.

Ensure all parts of the DCP name are accurate (especially the aspect ratio, container and audio language).

Frame rate

Frame rate must be one of:

NB: 30 fps is not supported on all projectors. Only use 30 fps if that is the original frame rate your film was produced in.

There is no need to "conform" your film to 24 fps, if it was shot 25 fps.

Audio

DCPs must contain a minimum of 6 audio channels.

For films mixed in stereo only, stereo signal should be in the first 2 channels, with the remaining 4 channels containing silence.

If more than 6 channels, the number of channels must be 8 or 16.

Audio description (if present) must be on Ch 8.

Subtitles

Format

Subtitles may be either burned in to picture, or included "soft" in a separate track in the DCP.

Size

Positioning

Subtitles must be entirely within a 5% "safe area", to ensure they are not cropped off.

Please see our templates.

Timing

Titles and credits

All titles, credits and production logos must be within the safe area to ensure they are not cropped in projection.

Image quality

DCPs should be created from the highest quality master of the film available. ProResHQ or ProRes4444 are good choices for a mastering format. H264 is good for the web, but not suitable for being blown up to cinema size.

Questions?

Should you have any questions or concerns, our team is here to help. Please contact us.

Thank you for entrusting us with your film. We look forward to showcasing your work looking and sounding its very best.