Magnetic Videotape Recordings: Preservation, Assessment, and Migration

MAGNETIC VIDEOTAPE
RECORDINGS:
Preservation, Assessment, and
Migration
Sarah Stauderman
Collections Care Manager
Smithsonian Institution Archives
1Digital Directions, August 18, 2010

Key Concepts for Video
Preservation
• Identify Collections
– Attributes
– Materials – technical issues and connoisseurship
– Content
• Identify Preservation Strategy
– Storage
– Selection through survey and assessment
• Implement Preservation Reformatting
– Documentation
– Collaboration
– Expertise

Attributes
• What is the videotape format?
– What are the known materials for this format type?
– Is the format considered a professional, consumer, or
“prosumer” format?
• What is the date of the videotape?
• What is the content of the videotape?
• What are the known storage needs for this
material?
• What is the obsolescence rating for this format?

Magnetic Media Cross-Section
Polyester
Polyurethane
Back-coat
with magnetic particles and
additives
2-5 m
10-40 m

Magnetic Component
• Gamma Ferric Oxide - stable
• Barium Ferrite (BaF) – very stable
• Chromium Dioxide (Cr02) – early forms
unstable; later forms stable
• Metal Particle (MP) – earliest form
unstable; later forms stable
• Metal Evaporated (ME) – unstable

Videotape Deterioration
• Physical Structure: Base, Binder, Pigment
• Binder Failure: “Sticky Shed Syndrome”
• Life Expectancy: 10 – 30 years
– “Magnetic Tape Storage and Handling” (1995)
Commission on Preservation and Access and
National Media Lab
R1-NH-C(=O)-O-R2

Agents of Deterioration
• Heat
• Light
• Excessive Moisture
• Extreme Mechanical Stress
• Dust

Appropriate Storage for Videotapes
ISO 18923 and 18933
• 10-year storage: 46°-73°F and 15-50% RH
• 50-year storage: 51°F and 50% RH and
pollution controls
• Never place magnetic media below 46°F

Basic Preservation Guidelines
from Magnetic Tape Storage and Handling
• Replace tapes every 10-
30 years (when 12% of
binder hydrolyzed)
• Store at 59°F (+/- 5°) and
40% RH
• Treatment such as
baking advocated for
damaged tapes
• Visual examination leads
to quality of playback
diagnosis
• When do you know that
12% has hydrolyzed?
• Why can’t tapes be
frozen? (lubricant)
• What are the long-term
effects of baking or
other?
• No conclusive methods to
show correlation of
physical state to sticky
shed

Basic Housekeeping
• Dust free
• Grounded metal shelves
• Upright, like books
• Wound (or rewound) position
• Remove record tab
• Find out what you have – and label it –
before it gets put on a shelf.

Format Proliferation
• Reel-to-reel
• Cartridge
• Cassette
Each requires specific
playback machinery
and has different
qualities

VR - 1000
The VR-1000 was the
first videotape recorder
ever sold. It achieved its
success by separating
the “writing speed” (the
speed at which
information is recorded
on the tape) from the tape
speed through the use of
spinning heads, a
principle that has
continued in every
videotape format to date.

Format Proliferation
~over 60 separate formats~

Format Identification Guides
http://videopreservation.stanford.edu/vid_id/index
.html Videotape Identification Guide produced
in 1998-99 to help curators, collections
managers, and conservators identify formats
http://www.arts.state.tx.us/video/pdf/video.pdf
Texas Commission of the Arts Videotape
Identification and Assessment Guide 2004
http://en.wikipedia.org/wiki/Videotape_recorder

OBSOLESCENCE
Extinct
Critically endangered
Endangered
Threatened
Vulnerable
Lower risk

SMPTE STANDARDS
Society of Motion Picture and
Television Engineers

NTSC
• National Television System Committee
– Established the specifications for resolution of display
of the video signal on the television picture tube in the
United States (used in Canada and Japan too)
– 525 horizontal lines per frame of video
– Frame rate is 30 frames per second
– ULTIMATE picture quality = 210,000 pixels
• Distinguished from SECAM or PAL
– 600 horizontal lines per frame of video
– Frame rate is 25 frames per second
– ULTIMATE picture quality = 300,000 pixels
– Much better color fidelity

NTSC Composite (or, how to broadcast
color on a black-and-white system)
• Color Video Signal (RGB Signal) consisting of
red, green, blue
• Color information generates a Luminance Signal
(“Y” or black and white) and phase-alternating
Chrominance Signal (“C” color information)
• Thus COMPOSITE indicates 2 signals coming
from 3 sources
• If information coming from “C” is out-of-phase,
can generate major image color shift, thus
“never the same color”

NTSC Component
• Color Component Video exists as three
separate electric signals (plus
synchronization): Red, Green, Blue.
• Each color signal is processed through its
own isolated path.
• Some systems use a Y, R-Y, B-Y
configuration in order to eliminate
unnecessary color information.

Analog vs. Digital
ANALOG
• Continuous waveform
representing the size and
shape of picture
information
• Can be component or
composite
DIGITAL
• Video signal exists as a
set of numbers
representing analog
voltage values
• Quality of video is
determined by the
precision and frequency
of sampling of analog
values
• Can be component or
composite

Preservation Strategy
• What to Preserve:
– Preserve the object, migrate, emulate? Defer action?
– Selection
• Why Preserve: Documentary, Intrinsic, Artistic
Value?
• How to Preserve: For instance, if choose to
migrate In house or outside vendor? What
preservation “format”? How to incorporate
duplicates into collections?
• For whom: General public through the Internet;
lone scholars on-demand; to generate
programming?

Preservation Priority Surveys
• Host of new tools (see Audio Preservation
handouts)
• Needs diagnostic data points

Diagnostic Data Points
• Dust or dirt on container or on item
• Wind of the cassette (popping, spoking, etc.)
• Presence or absence of record tab (housekeeping)
• Anecdotal evidence that a tape brand is poor quality or
aging rapidly
• Degree of information on label
• Storage history
• No strict correlation between physical condition and
playability
• Playback issues (skew, tracking, balance)
• No easy diagnostic tool forthcoming

A Preservation Priority Worksheet
• Undergoing the exercise is as important as the
methodology
• Uses a matrix to determine priorities
• Emphasizes intellectual control and
obsolescence
• Based on “An ‘Angels Project’ of Dinosaur
Proportions”
http://aic.stanford.edu/sg/bpg/annual/v15/bp15-
18.html

Overview of Survey Tool
I. Identify the Collection – Don’t survey
unless content has been determined
II. Value Assessment – Ask multiple
colleagues about collections; don’t give
all collections a high value
III. Risk Assessment – Condition,
Obsolescence, Level of Risk,
Master/Element

CONDITION MATRIX Unstable
Materials
A
High
B
Mod
C
Low
A
High
A A B
B
Mod
A B C
Physical
Damage
C
Low
A B C

Materials
A
High
B
Mod
C
Low
A
High
A A B
B
Mod
A B C
Physical
Damage
C
Low
A B C

RESULTS of SURVEY at SI
ARCHIVES
• 10% NO NEED [received a low-priority score of
8 or 9 based solely on age of the collection ≤10
years]
• 80% SOME NEED [received a moderate priority
score of 4 to 7 based on a combination of age ≥
10 years and format obsolescence: ¾” U Matic]
• 10% URGENT NEED [received a high-priority
score of 1 to 3 based on a combination of age ≥
20 years and format obsolescence: ½” EIAJ
reel-to-reels and 1” SMPTE Type C]

Reformatting Video
• Preservation Formats
– Same or better quality than original
– Proven track record of use
– Seek the highest sampling and least
compression
– Choose reputable technologies and
machineries
– Consider purpose of reformatting (for
broadcast, digital asset management,
migration, etc.)

Analog vs. Digital
• Most analog formats are quickly becoming
obsolete
• Analog has unacceptable degree of
generational loss and poor quality
• Digital tape formats have capture and
compression issues
• Digital files have management and
expense issues

Digitization: Ideal Color Sampling
4:4:4
4 = Luna (brightness, darkness) sampled at every pixel
4 = Chroma (Red) sampled every pixel
4 = Chroma (Blue) sampled every pixel
1 hour of NTSC analog video 140 GB
1 hour of HD video 840 GB

REALISTIC COLOR SAMPLING
4 : 2 : 2
4 = Luna (brightness, darkness) sampled at every pixel
2 = Chroma (Red) sampled every other pixel
2 = Chroma (Blue) sampled every other pixel

DIGITAL TAPE FORMATS WITH
4:2:2 SAMPLING
• D1
• DCT
• DVC Pro
• D9
• Digital Betacam
• HD-Cam
• HD-D5
• D6

COMPRESSION RATIO
Lossy vs. Lossless
• No compression would be best but is difficult
and expensive
• Lossless compression is OK but also difficult
and expensive, not “robust” (yet)
• Most Videotape formats and Advanced
Television System Committee [ATSC] formats
employ compression that is LOSSY
• Compression ratios of 4:1 may be considered
OK for archival purposes

COMPRESSION RATES OF
SOME VIDEOTAPE FORMATS
• D1 (no compression; obsolete)
• DCT (2:1)
• DVC Pro (5:1)
• D9 (3.3:1)
• Digital Betacam (2.3:1)
• HD-Cam (7.1:1)
• HD-D5 (4:1)
• D6 (no compression; obsolete)

A Word about DVDs
• Sampling and compression rate uses
MPEG-2 or MPEG-4 sampling and
compression [encoding]
• 4:2:2 or 4:2:0 sampling
• 10:1 or greater approximate compression
ratio
• In a VOB container format
• About 4.7 GB

Good-enough Formats
• Preservation of Video in the Conservation
Laboratory (PPT)
Tim Vitale, June 2005
http://aic.stanford.edu/sg/emg/library/
• Any digital videotape format’s “resolution” is better than
your average analog videotape collection and can
capture all the information necessary
• Systems using ITU-R.BT601 standard are able to
capture on a computer at high resolution and low
compression (using MPEG4 compression and .mov
codec [Quicktime])
• Cost of loaded system $50-60K

Some Video File Formats
• .mj2
• .mov
• .avi
• .wmv
• .vob
• .mpg

What about PERFECT video
duplication?
• Preservation-Worthy Digital Video; or,
How to Drive your Library into Chapter 11
(PDF)
Jerome McDonough, June 2004
http://cool.conservation-
us.org/coolaic/sg/emg/library/pdf/mcdonou
gh/McDonough-EMG2004.pdf
• Placing video onto hard drives or robotic-
type systems at the highest sampling rate

Motion JPEG 2000?
• Lossless Video Compression for Archives: Motion
JPEG2k and Other Options
Ian Gilmour, Media Consultant, National Film and Sound
Archive, Australia and R. Justin Dávila, Technology
Consultant, Media Matters LLC January 2006
http://www.media-
matters.net/docs/WhitePapers/WPMJ2k.pdf
• An Evaluation of Motion JPEG 2000 for Video
Archiving
Glenn Pearson and Michael Gill, National Library of
Medicine 2005
http://archive.nlm.nih.gov/pubs/pearson/MJ2_video_arch
iving.pdf

A Practical Solution for the
Smithsonian Archives (SIA)
• Digital Betacam as a preservation medium
• DVDs or VHS as a use copy
• Most duplication done by vendor using
specifications written by SIA
• Experimenting with SAMMA solo
machinery that places video content onto
LTO-3 tapes in JPEG 2000 format

Reformatting Guidelines
• Document your actions including strategy
• Ideally, tapes should be cleaned prior to transfer using a
“buffer-winder” system. Excessive cleaning should be
avoided.
• Baking should be avoided as a routine operation, but
may be necessary for tapes that show “sticky shed.”
• Tape machines should be immaculately maintained.
• Slates, color bars*, and sound tones* should be placed
on new copies to identify the videotape and calibrate it.
*indicating calibration occurred prior to transfer

Reformatting Vendors
Resources
• Independent Media Arts Preservation
http://www.imappreserve.org/info_res/services/treatment
.html
• Association of Moving Image Archivists (listserv)
http://www.amianet.org/
• Local post-production companies

Reformatting Vendors
• Bay Area Video Coalition http://www.bavc.org/
• Crawford Communications, Inc.
http://www.crawford.com
• Safe Sound Archive
http://www.safesoundarchive.com/
• Scene Savers http://www.scenesavers.com
• Specs Brothers http://www.specsbros.com/
• SAMMA http://www.media-
matters.net/aboutus.html

An In-House Duplication Rack

$40,000 +/-
• Equipment rack and shelves $ 2,000
• Matrix router for dubbing and monitoring $ 1,500
• Audio monitor panel $ 500
• Sync Generator $ 500
• Hardware, cables, connectors $ 500
• Waveform monitor and vectorscope $ 1,500
• Timebase Corrector $ 1,000
• Betacam SP deck $ 8,000
• 13” Color Monitor $ 1,000
• Digital Betacam deck (used) $17,000
• Original videotape decks $ 1,000
• Engineer to design and put it together $ 2,500

Plus
Tape stock @ $20 per tape
Cleaning machine(s)
Qualified staff person(s)
NYU Film Preservation Program
http://cinema.tisch.nyu.edu/page/miap.html
Selznick School of Film Preservation
http://www.eastmanhouse.org/inc/education/selznick_sc
hool.php

Thank you!
Sarah Stauderman
Collections Care Manager
Smithsonian Institution Archives
staudermans@si.edu

Magnetic Videotape Recordings: Preservation, Assessment, and Migration

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