DIGITAL PRESERVATION: AUDIOVISUAL EDITION PART 1downloads.alcts.ala.org/ce/Digital_Preservation_PartI_Slides.pdfDIGITAL PRESERVATION: AUDIOVISUAL EDITION PART 1 ALCTS Webinar Series

DIGITAL PRESERVATION:AUDIOVISUAL EDITION PART 1

ALCTS Webinar Series2/27/2019

FacilitatorStefan Elnabli (UC San Diego)

Hosted by ALCTS, Association for Library Collections and Technical Services

ABOUT ME

Stefan ElnabliUC San Diego

Media Curation Librarian \\Manager, Digital Reformatting Operations


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


CONTEXT OF PART 1


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:



“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:



“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:


DIGITIZATION

• Formats• Care and handling• Reformatting• Sustainability• Metadata• Access needs


POLL


• Is digitally preserving AV a priority at your institution?

• Do you digitize AV materials?

• Do you engage in digital preservation activities?

RESULTS


PROPERTIES AND CHARACTERISTICSOF ANALOG AV


ANALOG FILM CHARACTERISTICS

Film gauges:

Physical property of photographic or motion picture film stock which defines its width.



• 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



• 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)



• Soundtracks



• https://www.filmcare.org/visual_decay


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



• 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





Open reel(analog)

Cassette(analog)

Cassette(digital)





• Degradation• Hydrolysis (sticky shed

syndrome) • Loss of lubricant• Particle instabilities• Substrate deformation• Chemical breakdown• Tape deformation• Oxide flaking


INVENTORIES, DIGITIZATION, AND VIABLE WORKSTATIONS


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:


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






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




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



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



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



• 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







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




• 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)


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


Thank you!

Stefan ElnabliMedia Curation Librarian \\Manager, Digital Reformatting OperationsUC San Diego [email protected]


mailto:[email protected]

Documents

DIGITAL PRESERVATION: AUDIOVISUAL EDITION PART 1downloads.alcts.ala.org/ce/Digital_Preservation_PartI_Slides.pdfDIGITAL PRESERVATION: AUDIOVISUAL EDITION PART 1 ALCTS Webinar Series