Digital Cinema Mastering 101

I. Introduction

II. What is a DCP?

III. The Digital Cinema Mastering Workflow

IV. DCP Duplication and Distribution

Graef Allen

Dolby Laboratories, Burbank

Introduction

The future of film…

End of 2012:

Cinema screens in US: ~40,000 Digital screens in US: ~33,500 = 84%

Cinema screens WW: ~130,000 Digital screens WW: ~90,000 = 69%

Source: Screen Digest

Nearly all cinema screens worldwide expected to be converted by 2015.

Advantages

Broad Acceptance

Cinemas (mainstream, art house)

Film Festivals (Sundance, Cannes, Berlin, Telluride, SXSW…)

AMPAS (Submission for Academy Award consideration)

Financial

Media Integrity

Advantages

Broad Acceptance

Financial

Cost for a feature film print: $1500 - $2500 (Source: Wikipedia)

Cost for a copy of a feature DCP: $150 - $650

Media Integrity

Virtual Print Fees

Ted Hope raised this issue in the Q&A, and it is definitely an important financial

consideration.

In addition to the costs for mastering and media, your distributor may be charged

virtual print fees, or “VPFs,” by theatres that book your film on DCP. VPFs are

collected by theatres to cover the cost of the upgrade to digital projection equipment.

Depending on the specific terms of your booking, the VPF could be as much as $1000

for a week-long engagement, or as little as $25 for a single off-peak screening (e.g.

Tuesday night).

A theatre that paid for its own digital equipment up front may not charge VPFs.

Virtual print fees will eventually fade away as equipment loans are paid off. New VPF

agreements have mostly ceased.

The VPF business model was introduced to spread the cost of equipment upgrades

between both exhibitors and distributors. VPF agreements probably helped to

accelerate the transition to digital cinema.

Advantages

Broad Acceptance

Financial

Media Integrity

Perfect copies (hash check verification)

Robust media, less fragile than 35mm film or Blu-ray

Sound and picture as pristine on 100th screening as on 1st

35mm Film Print Damage

Photos courtesy of Brad Miller, film-tech.com

Digital Cinema Mastering 101

I. Introduction

II. What is a DCP?

III. The Digital Cinema Mastering Workflow

IV. Digital Cinema Duplication and Distribution

Graef Allen

Dolby Laboratories, Burbank

II. What is a DCP?

DCP is a standardized delivery format. It is not a single file,

but a collection of digital files.

DCPs are intended to match or surpass the quality of 35mm

film prints.

Standards set by DCI

Digital Cinema Initiatives, a studio consortium

Today’s DCPs: Interop

Tomorrow’s DCPs: SMPTE (Society of Motion Picture and Television Engineers)

DCP: Video Files

Uncompressed video files would be too large to duplicate and

distribute easily. File sizes reduced by compressing.

Digital cinema projectors able to reproduce a broader array of

colors than computer or television monitors.

Aspect Ratios = 1.85:1 or 2.39:1 (not 1.78:1)

Codec = JPEG 2000

Maximum Bitrate = 250 Mbps (about 10 x Blu-ray data rate)

Color Space = DCI P3, mapped to XYZ

File Container = MXF (.mxf)

DCP: Audio Files

Multi-channel audio on film required compression due to

physical space restrictions.

Digital audio files are so small relative to digital video files

that compression is not used.

Uncompressed

Sample rate = 48kHz

Bit depth = 24 bit

File Container = MXF (.mxf)

Information on Film vs. Information in a DCP

Audio (Analog)

Audio (Digital)

Picture/Subtitles

DCP: CPL

Sample CPL

Video

Audio

Subtitles

Digital Cinema Mastering 101

I. Introduction

II. What is a DCP?

III. The Digital Cinema Mastering Workflow

IV. DCP Duplication and Distribution

Graef Allen

Dolby Laboratories, Burbank

Video Source Files

DCDM

Digital Cinema Distribution Master

DSM

Digital Source Master

Other sources

Tape (HDCAM / HDCAM SR / D5)

ProRes or uncompressed QuickTime

Video Workflow

DSM Digital Source Master

DPX or TIFF RGB Color

DCDM Digital Cinema Distribution

Master

16bit TIFF XYZ Color

JPEG 2000

Tape or QuickTime

extract frames

resize to 2k or 4k, convert color to XYZ

JPEG 2000 compression

Audio Source Files

Uncompressed linear PCM (digital audio)

48kHz sample rate @ 24fps

Audio commonly delivered as 48kHz @ 23.98fps, which

requires a sample rate conversion to stay in sync at 24fps.

24bit

Audio Workflow

Stereo?

Wrong sample rate?

Wrong bit depth?

Wrong file type?

5.1 or 7.1 Mono .wav Files

24bit, 48kHz @ 24fps

5.1 or 7.1 Interleaved .wav File

Tape or QuickTime

capture or extract audio

bit depth conversion

sample rate conversion

upmix

interleave file type conversion

Subtitle and Caption Source Files

CineCanvas XML

Timed Text + Associated Font File (e.g. arial.ttf)

OR

Timed Subtitle Spots + Associated .png Images

(sometimes used for Japanese, Chinese, Hebrew)

Subtitle and Caption Source Files

Sample Timed Text

Subtitles

(Partial File - Japanese)

Encryption, MXF Wrapping

JPEG 2000

Encryption

(Optional),

MXF wrapping

audio.mxf

(enc.audio.mxf)

5.1 or 7.1 Interleaved .wav File

CineCanvas Subtitles (XML),

font.ttf

Folder: CineCanvas

Subtitles (XML), font.ttf

video.mxf (enc.video.mxf)

Encryption

Optional, but most distributors require features to be

encrypted

Encryption standard is AES, Advanced Encryption

Standard: Extremely secure

Additional layer of link encryption between server and

projector applied at playback

If content is encrypted, cinemas must be supplied with

playback keys to decrypt the content.

Key Delivery Messages (KDMs)

Small XML files, generally delivered zipped by email.

Three-way lock:

Content • KDM specific to exactly one CPL.

Server • KDM specific to exactly one server.

Timeframe

• KDM only valid between specified start and end times.

Common Post Production Issues

Non-cinema frame rate

HD aspect ratio

Misidentified color space or dynamic range

Highly compressed video source

Color graded on uncalibrated monitor (cinema projector is best)

Missing sync details (no 2-pop, no countdown leader)

Sound mixed in uncalibrated room (way too loud or way too quiet)

Mislabeled audio channels

Invalid subtitle XML

Mistimed subtitle XML

Missing font file

The Final Product!

Once the DCP is packaged, it needs to be watched start to finish to check for problems. After a full QC, duplication can begin.

Feature DCP Distribution Kit

Digital Cinema Mastering 101

I. Introduction

II. What is a DCP?

III. The Digital Cinema Mastering Workflow

IV. DCP Duplication and Distribution

Graef Allen

Dolby Laboratories, Burbank

Duplication

Duplication done in batches

Multiple identical copies created at once

The smaller the master DCP, the faster each

duplication run will be

Verification by hash check

Distribution

Feature distribution on CRU Dataport HDD

FedEx, UPS, DHL

KDMs (Key Delivery Messages) sent via email

Technical support should be made available, especially

if content encrypted.

DCP’s modular structure (separate file for each

component) allows single-inventory distribution to

multiple territories.

Distribution SNAFUs

Problems can include…

Lost shipments (uncommon)

Damaged hard drives (uncommon)

Misplaced hard drives (more

common)

Server upgrades, new KDMs

needed (very common)

Projector/server subtitle rendering

problems (uncommon)