Digital Preservation Master

Overview

A digital preservation master (DPM) is the canonical archival bundle: high-quality image sequences (often 16-bit log DPX or TIFF), full-fidelity audio stems, subtitles/captions, and metadata (timing notes, color science, scanner reports). It is intentionally not a distribution encode; it is a durable source for any future deliverable—DCP, IMF, HDR streaming, or formats yet to emerge.

Composition and Structure

• Picture: Uncompressed or losslessly compressed frames in open formats; frame-accurate naming with reel/timecode.
• Audio: Poly-WAV stems (DX/MX/FX), M&E, and printmaster variants; documented sample rate and sync.
• Metadata: Color pipeline (OCIO/LUTs), scanner/camera details, QC reports, rights, and provenance.
• Checksums: Per-file hashes and a manifest for fixity.

Governance and Access

DPMs are write-once assets. Changes require versioned derivations and change logs. Access copies (ProRes/H.264 proxies) are generated separately to protect the master from casual handling.

Storage and Refresh

At least two geographically separated LTO copies plus an online replica for retrieval are standard. Institutions plan migration calendars so masters are re-written to new media generations before obsolescence.

Related Terms

• DPX sequence, TIFF sequence, redundant LTO, MD5/SHA-256.