Standards Reference

Standards used by the Media Curator framework for metadata, integrity, provenance, and interoperability.

Metadata Standards

ID3v2.4 (Audio - MP3)

• Specification: id3.org v2.4.0
• Usage: Tagging MP3 files with title, artist, album, artwork
• Key frames: TIT2 (title), TPE1 (artist), TALB (album), TRCK (track), TDRC (year), APIC (picture)

Vorbis Comments (Audio - Opus, FLAC, OGG)

• Specification: xiph.org Vorbis Comment
• Usage: Tagging Opus and FLAC files
• Key fields: TITLE, ARTIST, ALBUM, TRACKNUMBER, DATE, GENRE
• Tool: `opustags` for Opus files

MP4 Metadata (Video)

• Specification: ISO/IEC 14496-12 (MPEG-4 Part 12)
• Usage: Tagging MP4 video files via ffmpeg
• Key atoms: title, artist, album, year, description

Integrity Standards

SHA-256 (NIST FIPS 180-4)

• Specification: NIST Federal Information Processing Standard 180-4
• Usage: File integrity verification via CHECKSUMS.sha256
• Tool: `sha256sum` (GNU coreutils)
• Digest length: 256 bits (64 hex characters)

Self-Verifying Manifest

• Pattern: MANIFEST_HASH header containing SHA-256 of manifest content
• Verification: `tail -n +4 CHECKSUMS.sha256 | sha256sum`
• Purpose: Detect tampering of the manifest itself

Provenance Standards

W3C PROV-O (Provenance Ontology)

• Specification: W3C Recommendation 2013-04-30
• URI: http://www.w3.org/ns/prov#
• Core model: Entity-Activity-Agent
• Usage: Tracking derivation chains (source → download → transcode → tag)
• Serialization: JSON-LD in PROVENANCE.jsonld

PREMIS 3.0 (Preservation Metadata)

• Specification: Library of Congress PREMIS 3.0
• URI: http://www.loc.gov/premis/rdf/v3/
• Usage: Fixity metadata linking provenance to integrity verification
• Key properties: premis:hasFixity, premis:messageDigestAlgorithm

Dublin Core 1.1

• Specification: DCMI Metadata Terms
• URI: http://purl.org/dc/terms/
• Usage: Descriptive metadata (title, creator, date, format)

Data Sources

MusicBrainz

• API: https://musicbrainz.org/ws/2/
• Format: JSON (append `&fmt=json`)
• Rate limit: 1 request per second
• Usage: Canonical discography data, release verification, cover art
• Cover Art: https://coverartarchive.org/

Discogs

• API: https://api.discogs.com/
• Usage: Physical releases, variants, pressings
• Rate limit: 60 requests per minute (authenticated)

Internet Archive

• API: https://archive.org/advancedsearch.php
• Usage: Archival audio/video sources
• Format: JSON output with `&output=json`

fanart.tv

• API: https://webservice.fanart.tv/v3/music/
• Usage: Album artwork, artist images
• Requires: API key

Timestamp Standard

ISO 8601 with Nanosecond Precision

• Format: `YYYY-MM-DDTHH:MM:SS.NNNNNNNNNZ`
• Example: `2026-01-26T01:33:51.302755851Z`
• Command: `date -u +%Y-%m-%dT%H:%M:%S.%NZ`
• Rules:
• Always UTC (Z suffix)
• Never local timezone
• 9 decimal places (nanosecond precision)
• Used in PROVENANCE.jsonld, CHECKSUMS.sha256, manifest.json

File Format Preferences

Audio (ordered by preference)

1. FLAC - Lossless, archival quality 2. Opus - Best lossy codec, small files, excellent quality at 128kbps 3. M4A/AAC - Good compatibility, Apple ecosystem 4. MP3 - Maximum compatibility, larger files

Video (ordered by preference)

1. MKV - Best container for preservation, supports all codecs 2. MP4 - Best compatibility across players 3. WebM - Web-optimized, VP9/AV1 codecs

Image (for artwork)

1. JPEG - Universal compatibility, embedded in ID3 2. WebP - Smaller size, embedded via opustags 3. PNG - Lossless, for logos/graphics 4. SVG - Vector, for logos only