Assets, representations, resources, and locators

An asset is a logical production object. It is not a pathname.

A representation is one concrete realization of an asset, such as a camera original, editorial proxy, mezzanine transcode, or render sequence. A representation is not necessarily one file. It has an explicit content structure describing how storage resources form usable media.

A resource identifies a storage-level component. A single-file movie uses one resource, while spanned recordings and packages use several. A regular image sequence uses one compact patterned resource instead of creating one database object per frame. File facts and storage-level fingerprints belong to resources.

A representation fingerprint combines the content structure with its resource-fingerprint evidence. It excludes PostProject object IDs and locators, preserves order for spanned media, treats package member order as irrelevant, and hashes an image sequence’s compact descriptor without visiting every frame during representation aggregation. The sequence resource contributes deterministically sampled member-content evidence. Its confidence cannot exceed the resource evidence it aggregates: a sampled resource fingerprint does not become a full-content identity claim.

A locator describes where or how a resource can currently be accessed. One resource may have several locators, such as paths through different mounts. Moving content changes its locator rather than its resource, representation, or asset identity.

Content structures distinguish:

  • one resource;

  • a compact image sequence with a pattern, frame domain, and exact rate;

  • ordered resources, such as a spanned recording; and

  • a package whose required and optional members have extensible roles.

Availability is evaluated for the complete representation. All required content being resolvable is online; some required content being available is partial; none being available is offline; and multiple plausible resolutions are ambiguous. Missing optional package members can be reported without making otherwise usable media partial.

This separation is why PostProject can retain an asset’s identity and metadata when storage paths change, and why one missing image-sequence frame is not mistaken for a fully online representation.