Challenges of Digital Media Preservation Karen Cariani, Director - - PowerPoint PPT Presentation

SLIDE 1

Challenges of Digital Media Preservation

Karen Cariani, Director Media Library and Archives

SLIDE 2

Who we are: WGBH Media Library and Archives

2

SLIDE 3

Challenges § Challenges for Born Digital Media

— Access vs Preservation re: file size — New and Many Capture Formats — New Workflows for Metadata Capture — Given these challenges: how best to store

3

SLIDE 4

Digital Content formats

4

HD Acquisition Codecs

1080p Container Mbps 960 1280 1280 1440 1920 1920 Sample # Bits DCT HDCam [1] 140 √ 3:1:1 4 20

Tape

DVCProHD@24p 40 √ 4:2:2 √ 8 16

DV-AVI, DV-DIF , MXF , QuickTime & Tape

DVCProHD-720p 100 √ 4:2:2 8 16

DV-AVI, DV-DIF , MXF , QuickTime & Tape

DVCProHD-1080i 100 √ 4:2:2 8 16

DV-AVI, DV-DIF , MXF , QuickTime & Tape

Avid DNxHD 145 √ √ √ 4:2:2 4 16

MXF & QuickTime

Avid DNxHD 220 √ √ √ 4:2:2 √ 4 16

MXF & QuickTime

Apple ProRes 145 √ √ √ 4:2:2 √ 8 24

QuickTime

Apple ProRes HQ 220 √ √ √ 4:2:2 √ 8 24

QuickTime

Wavelet Red 224-336 √ √ RGB or 4:2:2 12 4 24

REDCODE & QuickTime

MPEG2 Long GOP HDV 25 √ √ 4:2:0 2 MP1

M2T , MXF , QuickTime & Tape

XDCamHD 18-35 √ 4:2:0 4 16

DV-AVI, MP4, MXF & QuickTime

XDCam422 50 √ √ 4:2:2 8 24

DV-AVI, MP4, MXF & QuickTime

XDCamEX 25 √ 4:2:0 2 16

DV-AVI, MP4, MXF & QuickTime

XDCamEX 35 √ √ 4:2:0 2 16

DV-AVI, MP4, MXF & QuickTime

GFCam 50 √ √ 4:2:2 4 16

MXF

Canon C300 50 √ √ √ 4:2:2 2 16

MXF

MPEG2 I-frame GFCam 100 √ √ 4:2:2 4 16

MXF

H.264 AVCHD PS 28 √ 4:2:2* 2 AC3

MTS, MP4

AVCHD 24 √ √ 4:2:0 2 AC3

MTS, MP4 & QuickTime

AVCHD@24 24 √ 4:2:0 2 AC3

MTS, MP4 & QuickTime

Canon 5DMKII 38 √ 4:2:0 2 16

QuickTime

Nikon D800 24 √ √ 4:2:0** 2 16

QuickTime

H.264 I-frame AVCIntra 50 √ √ 4:2:0 √ 2 16

MXF

AVCIntra 100 √ √ 4:2:2 √ 2 16

MXF

HDCamSR [2] 440 √ √ 4:2:2/4:4:4 √ 12 24

DPX, Tape

HDCamSR-HQ [2] 880 √ √ √ 4:2:2/4:4:4 √ 12 24

DPX, Tape *Sony FS100 HDMI output ** 4:2:2 HDMI output [1] Tape format for comparison [2] Tape with DPX file out

• D. MacCarn, WGBH

720p 1080i 10 Bit Audio Video Sample MPEG4 Studio Profile

SLIDE 5

For Access: Data organizational Issues § Technical Metadata

— Characterize files

§ Descriptive metadata

— Need description for video to be useful, findable — How to capture that — How to make sure it is linked to video files

5

SLIDE 6

Original Footage

6

SLIDE 7

§ In-camera - encourage tagging files with data. § User-generated clip naming

• -- (Health001, Health002)

§ Card Labeling § Content Labeling through folder structures

Metadata Entry in the Field:

7

SLIDE 8

Folder Structure § Create folders by card

— Assign unique number — Continue numbers — Add description — Place ENTIRE card

contents into this folder!!

8

SLIDE 9

Video, Video, Where for art thou video?

9

SLIDE 10

Storage and retrieval How do we:

§ Capture the audio and video generated by myriad cameras § Store the project information to allow potential re-edit § Store files with rich, meaningful metadata § Store born-digital materials § Display and retrieve born-digital materials

10

SLIDE 11

Proposed tapeless workflow § Create a mapping document between filemaker and DAM § Used to generate an xml stylesheet § Video is ingested simultaneously with the metadata from filemaker using the xml stylesheet § Technical metadata is ingested simultaneously with the video and production data using the xml generated by the source digital files

11

SLIDE 12

Challenges of preservation and access § For preservation

— Want to capture as close to original as possible

— Originals may be many different formats — Will need to make sure you can export — File format issues – playback in future — Fixity check big files

§ For access

— Want one consistent proxy format for playback/access

— Needs to be easy to migrate, use

12

SLIDE 13

Challenges - again

§ Access issues

— File size — Formats – to playback — Useable - — Search/findable > Metadata > Organize files

§ Preservation issues

— Copies — Formats – for migration — Being able to play again later — Speed of access (big file size) – to use/process — Migration ease

13

SLIDE 14

Insert graphic § Blacklight Hydra heads § Hydra mgmt layer § Fedora repository § HSM storage system

14

SLIDE 15

Preservation Needs

§ Multiple Copies § Validity – check sum § Regular storage migration § Persistence § File format issues

— Migration ease — Future playback

§ Fixity check big files § Big files

— Speed of access of

preservation files for reuse/

— Processing speed

15

SLIDE 16

Access

§ File size – need proxies

— Speed of access

§ Formats

— Want consistency for

playback § Reuse

— Retrieval of original files/

preservation files § Search/findable

— Metadata

— Organize files

16

SLIDE 17

What makes video different?

§ Preservation files are large

— Uncompressed — Slow to move around

§ Need proxy files for viewing

— Smaller size for quick transport

• ver network

§ Complicated formats

— Not just one file type — Codecs, wrappers, frame speed,

etc

17

SLIDE 18

Q & A

§ Karen: karen_carinani@wgbh.org

18