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Preservation of Video Assets

Preservation of Video Assets. Linda Tadic lindatadic@optonline.net ltadic@archivenetwork.org. Analog Video. Videotape invented 1956 (2” Quad) Not intended as a preservation medium. LE: 35-50 years for larger formats; 5-10 for consumer tapes, thin cassettes, and ME tapes. Open reel formats.

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Preservation of Video Assets

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  1. Preservation of Video Assets Linda Tadic lindatadic@optonline.net ltadic@archivenetwork.org

  2. Analog Video Videotape invented 1956 (2” Quad) • Not intended as a preservation medium. LE: 35-50 years for larger formats; 5-10 for consumer tapes, thin cassettes, and ME tapes

  3. Open reel formats 2” Quad (1956-1978) 1” (1977-1990s) ½” portapaks (1965-1973)

  4. Cassette formats ¾” U-matic (1971-2008) VHS (1978-now) Betacam (+SP) (1982-2009) Video8 (1984- ) (MP) Hi8 (1989- ) (MP and ME)

  5. Digital Video Formats • Digital Betacam (1993- ) MP tape • DVCam (1995- ) ME tape • MiniDV (1995-) ME tape • DVCPro (1995-) MP tape • Digital8 (1999-) ME and MP

  6. Videotape Properties binder lubricant Magnetic particle Top coat substrate Back coat

  7. Inherent Problems • Binder holds magnetic particles. Weak link in preservation - hydrolysis (sticky shed) impacts binder, resulting in particle loss. Caused by high humidity • Lubrication decreases over time (especially when played)

  8. Inherent Problems • Metal particles: - iron oxide most stable (lasts longest) - MP & CrO2 tape: better signal quality, but doesn’t last as long. Used in VHS, Hi8, some digital video cassettes - ME: no binder. Metal particles directly on substrate. “5 play rule;” no freeze-frame. Used in 8mm video, some digital video cassettes

  9. Inherent Problems • Substrate (tape backing) deformation - Polyester since 1960s - Excessive tape pack stresses, age, poor wind quality results in distortion and mistracking • Format obsolescence!

  10. Human Contributions • Poor tape pack (tape pop-ups) - warped/bent edges destroy control track on edge of tape • Not rewound to head or tail (opening for hydrolysis) • Left in pause/freeze-frame (stretches tape) • Poor storage environment

  11. Preservation Actions • Macro environment: - 50 - 68° F / 30-45 % RH - DO NOT STORE: * under 46° F (binder breakdown) * over 74° F increases tape pack tightness (will cause dropouts) * over 65% RH (mold) - shelving (don’t use wood)

  12. Preservation Actions Micro environment: - DO NOT STORE in tape stock boxes - remove paper from containers - use inert polypropylene cans - upright storage position - wind to heads or tails with firm tape pack

  13. Preservation Actions • Baking to stabilize sticky shed tapes (use a professional) - 122° F for 48 hours - transfer within 24 hours (some say up to a week)

  14. Reformatting • Must digitize • Consider age, format, MP/ME • Triage: (1) ¾ Umatics created 1971-1990 (35y LE) (2) MiniDV, DVCAM Video8 shot before 2005 (ME tape) (5y LE) (3) BetaSP created before 1995 (25-45v LE)

  15. Digital File States • Preservation (highest resolution; store offline) • Mezzanine (“copy master;” store so have access) • Access (streaming, DVD, etc.)

  16. Digital Preservation File Formats • Depends on source format • Don’t use a target format with higher resolution than original • Open (not proprietary) formats recommended

  17. Digital Preservation File Formats (SD) BetaSP and ¾” Umatic: Uncompressed 10-bit (SD): 63 GB/hr JPEG2000 (color): 50 GB/hr DV50: 25 GB/hr DigiBeta (10-bit, 90Mbps): 90 GB/hr

  18. Digital Preservation File Formats(SD) Poor ¾” Umatic, VHS, and DV SD: DV50 (50 Mbps): 25 GB/hr DV25 (25 Mbps): 13 GB/hr

  19. Digital Preservation File Formats(HD) 10-bit, 1280 x 720 (HD 720): 250 GB/hr 10-bit, 1920 x 1080 (HD 1080) : 500 GB/hr XDCAM (MPEG2 35 Mbps): 15 GB/hr DVCPRO-HD (720p50Mbps): 44 GB/hr DVCPRO-HD (1080i/50p25 (100 Mbps). : 60 GB/hr

  20. Mezzanine File Format H.264: 1 hr. = 200-420 MB

  21. Filenaming Conventions • Each file state should share a unique identifier to help link them • UID can be based on Work or Shoot • No illegal characters • Don’t let your DAMS assign filenames.

  22. Digital Preservation • File format verification (exact format and version) • Checksums • Two copies geographically dispersed • Format obsolescence checks • Re-validate and migrate forward within 5-year cycle

  23. Digital Preservation and Metadata • Track all actions through metadata • How was digital file created (technical metadata) • Characteristics of the file (filesize, format) • Metadata that does not change should be embedded in file

  24. Metadata in File • Descriptive (who created, when, title at the time, subjects, original rights) - Add through DAMS (if enabled) or NLE system • Technical: also extract from file to add to DAMS

  25. Metadata in File • Wrappers: - QuickTime (if Final Cut Pro end-to-end environment; FCP doesn’t support MXF) - MXF (SMPTE standard; used in broadcasting (XDCAM), digital cinema, archives) • XMP: only in Adobe Premiere

  26. Metadata • Descriptive (what is it about) • Technical (how was the file created) • Preservation (track actions) • Rights (no standards)

  27. Metadata Standards Data structure: Commonly a list of fields or data elements Data schema: shows relationship between fields/elements Data rules: rules for how data in the fields should be constructed (content standards) Data values: controlled vocabularies for what can be entered in specific fields

  28. Data structures Best to be as granular as possible. Far easier to migrate/map data from one database/structure to another if the data is broken into discrete fields. … And the data WILL migrate to other systems during its existence!

  29. MERGED DATA FIELD Physical description: DB714: 1 DigiBeta (23 minutes) GRANULAR DATA FIELDS TapeID: DB00714 Format: DigiBeta Units: 1 Running time: 00:23:00 Why Granularity?

  30. BUT… Granular data is expensive to produce. If you increase the amount of data that is captured, you increase the number of skilled human hours required to create it. Economic reality for many: apply simpler data structure, and automate capture as much as possible

  31. Data Structure Standards : Descriptive (1) LIBRARIES • MARC21 • Dublin Core (15 basic elements) • MODS (schema; 19 basic elements): simpler, XML version of MARC21

  32. Data Structure Standards :Descriptive (2) Archives • FIAT (International Federation of Television Archives) (22 fields) • MIC (Moving Image Collections)

  33. Data Structure Standards : Descriptive (3) Broadcasting Industry • SMPTE DMS-1 • PBCore (48 elements and sub-elements) • EBU Core (European Broadcasting Union) • International Press Telecommunications Council (IPTC)

  34. Technical Metadata • SMPTE Metadata Dictionary RP210 (2,000 fields)

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