digital preservation: audiovisual edition part...
TRANSCRIPT
DIGITAL PRESERVATION:AUDIOVISUAL EDITION PART 1
ALCTS Webinar Series2/27/2019
FacilitatorStefan Elnabli (UC San Diego)
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ABOUT ME
Stefan ElnabliUC San Diego
Media Curation Librarian \\Manager, Digital Reformatting Operations
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SCHEDULE AT A GLANCE
10 mins Introduction and Context of Part 1
10 mins Properties and Considerations of Analog AV
10 mins Inventories, Digitization, Viable Workstations
10 mins Properties and Considerations of Digital AV
5 mins Context in Digital Preservation and Conclusion
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CONTEXT OF PART 1
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INTRODUCTION TO PART I
“Audiovisual materials are the fastest growing segment of our nation’s archives and special collections.”
- Library of Congress National Recording Preservation Plan, page 6
Happy Quote:
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INTRODUCTION TO PART I
“Experts… rank the lack of appropriate archival storage and conservation facilities…as their most challenging
management issue, followed closely by the need to digitize”
-Library of Congress National Recording Preservation Plan, page 6
Alarming Quote:
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INTRODUCTION TO PART I
“In the mid- to long-term there is a major risk that carrier degradation combined with playback obsolescence will
defeat the efforts of archivists…”
- International Association of Sound and Audiovisual Archives
Call-to-Action Quote:
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DIGITIZATION
• Formats• Care and handling• Reformatting• Sustainability• Metadata• Access needs
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POLL
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• Is digitally preserving AV a priority at your institution?
• Do you digitize AV materials?
• Do you engage in digital preservation activities?
RESULTS
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PROPERTIES AND CHARACTERISTICSOF ANALOG AV
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ANALOG FILM CHARACTERISTICS
Film gauges:
Physical property of photographic or motion picture film stock which defines its width.
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ANALOG FILM CHARACTERISTICS
• Black and white• Made from silver metal particles• Highly stable and unlikely to fade
• Color• Typically made from three layers of dye (yellow, magenta, cyan)• Yellow is the least stable, so when it fades, film turns pink/magenta
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ANALOG FILM CHARACTERISTICS
• Reversal vs. Print vs. Negative• Vast majority of films that are
amateur/independently produced are reversal stock (and virtually all 8mm/s8mm)
• If it has black edges, likely reversal stock (unique)
• Normal image without black edges, likely a print (duplicate)
• If image seems like it has an orange hue or colors are inverted then negative (likely camera original)
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ANALOG FILM CHARACTERISTICS
• Soundtracks
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ANALOG FILM CHARACTERISTICS
• https://www.filmcare.org/visual_decay
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ANALOG VIDEO CHARACTERISTICS
• There is a visible spectrum of light
• Analog visual input is recorded electronically and fixed in a magnetic medium
• The signal that is captured can then be reproduced for visual output
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ANALOG VIDEO CHARACTERISTICS
• Thin layer capable of recording a magnetic signal
• Magnetic pigment is suspended within a polymer binder
• To reproduce the image, tape is read by a rotating magnetic drum and displayed on a monitor
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Hosted by ALCTS, Association for Library Collections and Technical Services
Hosted by ALCTS, Association for Library Collections and Technical Services
ANALOG VIDEO CHARACTERISTICS
Open reel(analog)
Cassette(analog)
Cassette(digital)
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ANALOG VIDEO CHARACTERISTICS
• Degradation• Hydrolysis (sticky shed
syndrome) • Loss of lubricant• Particle instabilities• Substrate deformation• Chemical breakdown• Tape deformation• Oxide flaking
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INVENTORIES, DIGITIZATION, AND VIABLE WORKSTATIONS
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SETTING THE SCENE
“Another misleading perception about digital preservation investments is that… choices are binary: either we
implement intensive preservation… immediately and forever; or we do nothing… A relatively small investment may be enough to preserve the option of making larger
commitments in the future.”
- Blue Ribbon Task Force, Sustainable Economics for a Digital Planet
Practical Quote:
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INVENTORY
• Enable consistent inventory creation in preparation for digitization
• If item level inventories do not exist, then creating one is useful for:• Gathering digitization quotes• Performing quality control on
deliverables• Organizing metadata
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Hosted by ALCTS, Association for Library Collections and Technical Services
Hosted by ALCTS, Association for Library Collections and Technical Services
Hosted by ALCTS, Association for Library Collections and Technical Services
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PROCESS AND INVENTORY
• Key film characteristics• Gauge• Emulsion/Color• Stock/Generation• Length (feet)• Speed• Sound• Edge Code
• Key video characteristics• Format• Reel Size• Running time• Recording standard
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Hosted by ALCTS, Association for Library Collections and Technical Services
DIGITIZATION AND VIABLE WORKSTATIONS
Types of film digitization:• Film off a wall/screen• Film chain• Flying spot scanner (CRT)• Line array CCD• Frame by frame scanning• Pulsed LED/triggered
system• Scanners Müller HM Data Framescanner
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DIGITIZATION AND VIABLE WORKSTATIONS
Video digitization components:• Computer• Video decks• Analog-to-digital converter• Time Base Corrector• Capture software• Quality control software
Great Resource! - https://github.com/XFRCollective/WorkflowDocumentationHosted by ALCTS, Association for Library Collections and Technical Services
DIGITIZATION AND VIABLE WORKSTATIONS
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PROPERTIES/CONSIDERATIONS OF DIGITAL VIDEO
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DIGITIZATION AND VIABLE WORKSTATIONS
PROPERTIES/CONSIDERATIONS OF DIGITAL VIDEO
• Codec – a portmanteau of coder-decoder
• For playback, must have proper codec to decode the data so it can be converted to audio and visual output
• Examples• Video - h.264, mpeg-2, divx,
ProRes• PCM, FLAC, RealAudio
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PROPERTIES/CONSIDERATIONS OF DIGITAL VIDEO
• A file format is a standard way that information is encoded for storage in a computer file.
• Some file formats associated with audiovisual data are called containers because they can hold separate streams of audio, video, and metadata
• Video examples: .mov, .avi, .mp4, .flv, .rm, .wmv, .mkv
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PROPERTIES/CONSIDERATIONS OF DIGITAL VIDEO
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PROPERTIES/CONSIDERATIONS OF DIGITAL VIDEO
Video• Video length• Frames per second• Video dimensions• Bit-rate• Associated metadata• File size
Audio• Bit-rate• Sampling frequency• Number of channels
For both, know the formats and codecs present
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PROPERTIES/CONSIDERATIONS OF DIGITAL VIDEO
• Operating system• Microsoft Windows, Apple OS, and Linux
• Media players• Common ones include Apple Quicktime Player,
Windows Media Player, and VLC Player• Codec libraries
• Collection of codecs that your media player can access to decode video for playback
• libavcodec library comes free with VLC playerHosted by ALCTS, Association for Library Collections and Technical Services
SELECTING FILE FORMATS FOR PRESERVATION
• Faithfully reproduce the original• Lossy• Lossless• Uncompressed
• Seek to create files that are either lossless or uncompressed• v210 codec, 8-10bit, uncompressed (video)• FFV1 lossless codec (video)• 2k DPX file sequences (film)
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CONCLUSION OF PART 1
• Properties of analog AV that influence the digitization process
• Properties of digital AV that influence the digital preservation process
• Part 2, we will look closer at recommended file formats, the digital preservation process for AV, and common scenarios that all libraries face• e.g. VHS collections
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Thank you!
Stefan ElnabliMedia Curation Librarian \\Manager, Digital Reformatting OperationsUC San Diego [email protected]
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