Now that you have digitised your audio and video, how to you keep the files -- forever?

1. Digital Preservation Strategy
Choices when moving
analogue to digital
Choices in the digital
world
Supporting choices with
good cost estimates
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2. Roadmap

Where am I, where do I go next

Audio: only one answer: uncompressed to .wav
file; some options

16-bit bit depth, or could go for “24”

CD sampling rate= 44.1 kHz; or 48 kHz or 96 kHz

BWF = Broadcast Wave Format version of .wav
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3. Video Roadmap

The basic problem: uncompressed video is 200
megabits per second = 100 gigabytes per hour

VHS quality is roughly 1 megabit/sec (AVC =
H.264 = MPEG-4)

DVD quality is roughly 5 megabits/sec (MPEG-
2)

So: hard to justify saving poor-quality video as
uncompressed video at 200 Mb/s

Compromise: “temporary archiving” in a
compressed format “for a few years”
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4. Video Roadmap
http://wiki.prestospace.org/pmwiki.php?n=Main.Roadmap
Clear statement for archived standard definition video
Input: Low, Medium and High Quality originals
Output: Access copy or Preservation copy

Access: DVD disc or MPEG-4 file
Preservation Roadmap:
Low: VHS, compressed digital DV file, 25 Mb/s
Middle: U-Matic, DV DV file
High: BetaSP, Digibeta, other pro formats uncompressed or
lossless compressed (JPEG2000)
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5. Video Roadmap

Much less clear for high definition video

Many production formats

Various kinds of “HD”

But:

Interlaced video should be saved as interlaced

Saving the 'native format' is ALWAYS good

Saving uncompressed remains a problem

BBC is promoting VC-2 codec (simpler than J2K)
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6. Too Many Video Formats !
The following are supported by one file converter (Total
Movie Converter):
Audio Video Interleaved (.AVI)
Windows Media Video (.WMV)
DivX Video (.DIVX)
XviD Video (.XVID)
DVD Video (.VOB)
Digital Video (.DV, .DIF)
Apple QuickTime Video (.MOV)
MPEG Video (.MPG, .MPEG, .MPE, .M1V, M2V, .MPV)
MPEG4 Video (.MPEG4, .M4V, .MP4)
Advanced Streaming Format (.ASF)
AVS Video (.AVS)
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7. More !
Intel Indeo Video (.IVF)
Matroska Video Stream (.MKV)
Mobile Phone Video (.3GP, .3G2)
HD Video (.H261, .H264)
JVC Digital Video (.MOD)
WinAmp3 Video (.NSV)
MythTV Video (.NUV, .NUT)
Flash video (.FLI, .FLC, .FLX, .FLV, .FFM,
.SWF)
Sony high definition video (.MTS and .M2TS)
RealMedia Variable Bitrate (RMVB)
Telesync (TS) Vietnam Film Institute Workshops
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8. Recommended for Video

Professional: MXF; does everything

Alternatives: MOV (Quicktime), AVI

But: AVI does not support timecode
And then: how do you store your files:

Hard drives

Data tape (LTO and a few others)

Optical media: CD, DVD
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9. File Formats for Film

DPX uncompressed, very flexible

DCI DCDM = Digital Cinema Distribution Master:
2048x1080 (or 4096x2160) only

DCP = Digital Cinema Packaging = lossy compressed
JPEG200; (not for master)

JPEG2000 (lossless); 2:1 data reduction

Various lossy compression formats (avoid!)

And … various wrappers: MXF, AVI ...
MXF (same as used in broadcasting – except there are
many versions of MXF)
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10. Migration of File Formats
(1 ) S TA R T H E R E
Is th e fo r m a t a
( 2 ) p r o b le m ?
Y E S
A r c h iv e fo r a
fe w y e a r s N O
(3 ) (4 )
(5 c ) W h a t c o s t/q u a lity /r is k
o p tio n c a n y o u a ffo r d
C o m p re s s
lo s s y
(5 b ) (5 a )
C o m p re s s U n c o m p re s s
lo s s le s s
E N D H E R E
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11. Preservation Strategy

Keep what you have as long as it works

Migrate to a new format when the old format
has a problem (usually, obsolete)

Examples: Real Audio, MPEG-1 Video

OR – maybe you can emulate the software
needed to use the file, even after standard
software no longer works

University of Liverpool: Multivalent Browser
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12. Strategy with Emulation
STAR T H ER E
Is th e fo r m a t a t
r is k ?
YES
A r c h iv e fo r a
fe w y e a rs N O
W h a t c o s t/
q u a lity / r is k c a n
y o u a ffo rd ?
C o m p re s s
lo s s y
C o m p re s s
U n c o m p re s s
lo s s le s s
M u ltiv a le n t EN D H ER E
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13. Storage Options
PrestoPRIME has lots of white papers

And tools for 'what-if' analysis of storage systems:
− How many copies do I need?
− Should I buy more discs, or use data tape backup?
− How often should I check the files?

Will give more detail on storage tomorrow
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14. A Preservation Model
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15. Demonstration: Tools for
Understanding Storage
PrestoPRIME Online Tools
http://prestoprime.it-innovation.soton.ac.uk/
http://prestoprime.it-innovation.soton.ac.uk/
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16. End of Day One !

Thank you all

Tomorrow:

Storage and storage systems

Software for a file-based archive

Access
− All the problems
− All the opportunities

General Summary and Discussion
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