Introduction

HDV is a high-definition variation of the DV video encoding specification that uses MPEG-2 compression to achieve the same data rate as the DV, DVCAM, and DVCPRO video encoding specifications. It was developed by Sony, Canon, JVC and Sharp and was introduced to the consumer market in 2003. HDV video can be captured in 720p, 1080i, and 1080p and can be recorded using MiniDV or Standard DVC cassettes. 

Physical Characteristics

Technical Characteristics

Techical standards

1. The HDV specification has not been standardized but it is based on the DV specification and uses MPEG-2 encoding, which is standardized in ISO/IEC 13818:2015 generic coding of motion pictures and associated audio information.

Storage

Types of damage and deterioration

Binder deterioration

Description

Commonly known as "sticky shed syndrome." Affected records will have a visible gummy or powdery residue on the surface of the tape. This can damage both the recorded material and playback equipment. Back-coated tapes are most affected by this type of deterioration. 

Cause

Polyester urethane is prone to moisture absorption which can cause the molecular structure of the binder to break down. This process is accelerated by high temperature and high humidity.

Remedy

Environmental conditioning: Moving the tape to a controlled storage environment (40°C / 20 to 25% Relative Humidity) may reverse the affects of hydrolysis over time.

Baking: Holding the tape at an elevated temperature (45°C to 55°C) for a brief period of time (up to 36 hours) can temporarily remove moisture and allow normal playback for a period of one to two weeks. Tapes should not be rewound before baking. 

Drop-out

https://www.musiikkiarkisto.fi/audio/audio113.html

Description

A brief signal loss caused by a tape head clog, missing magnetic oxide particles, tape defect, or debris on the tape or machine. These factors can reduce head-to-tape spacing and result in the appearance of white spots or streaks on playback. Multiple drop-outs per frame will result in a snowy appearance. 

Cause

Tapes kept in dusty conditions will accumulate particulate matter, increasing the risk of drop-out. 

Remedy

Flaking/missing magnetic oxide particles are an indication of tape deterioration. This type of drop-out cannot be corrected physically. 

Mould

Description

Active mould is generally moist while dormant mould is dry and dusty. Mould growths may be white, black, brown or mustard-coloured and usually have a pattered, fuzzy, or thread-like appearance. Mould can cause permanent damage to tapes over time if not removed. Fungus and mould is also a significant health hazard and affected materials should be handled using gloves and masks. 

Cause

Storing tapes at high temperature and relative humidity levels can facilitate the growth of mould. 

Remedy

Mouldy tapes should be isolated from unaffected materials to prevent cross contamination. Store tapes at a temperature of 24°C in an environment with effective air circulation and less than 50% Relative Humidity. Loose mold can be vacuumed from the tape pack and then the tape should be treated with an appropriate fungicide.  

Stretching and breaking

Cause

Stretching and breaking of video tape usually results from improper handling or use of playback equipment.  

Remedy

Stretching can distort the tape signal however data can usually be recovered (with a decrease in signal quality). 

Accidental recording

Description

Camera operators can accidentally record over pre-existing footage

Cause 

Tape is set to "record mode" when it is inserted into camera or deck

Remedy

Ensure tape is set to "safe mode" before inserting into camera or deck.

Risk assessment

HIGH RISK

1. Digital video material stored on magnetic videotape is considered to be at high-risk of loss or degradation.
   
   

   1. Polyester base film used in videotape is considered very stable.

   2. Other components of the videotape, including the binder, are considerably less stable and are more likely to be the cause of degradation.

   3. Format obsolesce, including lack of well-functioning playback equipment poses an equal or even greater risk than degradation, even with higher quality formats such as Digital Betacam
      
      

2. Archivists should appraise or reappraise digital video material stored on magnetic tape to determine the nature and significance of video elements contained on the tape. See Section 5 of the University Archives Procedure Manual for guidance on appraising sound recordings and moving images.
   
   

3. The archival appraisal should determine whether the video elements have sufficient archival value to justify reformatting and long-term preservation as digital video files.

Related resources

Digitization Handbook:

• Section 9.0 - Outsourced digitization of audiovisual items
• Appendix C - Technical specifications for moving images

University Archives Procedure Manual

• Section 5 - Archival Appraisal - Archival appraisal of sound recordings and moving images

Technology Watch

• Technical overview of digital video systems

Further Reading

Visit the /wiki/spaces/ALC/overview for further reading on /wiki/spaces/ALC/pages/1891631115. 

References

AMIA. "Video Preservation Factsheets." Accessed December 10, 2020. 

Avid. "Working With HDV." Accessed February 3, 2021. 

Bensinger, Charles. "Chapter 6: All about videotape." In The Video Guide, Second Edition, 71-75. Santa Barbara, California: Video-Info Publications, 1981. 

Bogart, John Van. "What Can Go Wrong With Magnetic Media?" In Magnetic Tape Storage and Handling: A Guide for Libraries and Archives. Washington, DC: The Commission on Preservation and Access, 1995. 

Casey, Mike. "FACET: Format characteristics and preservation problems." Bloomington, IN: Indiana University, 2007. 

Gibson, Gerald. D. "Magnetic tape deterioration: recognition, recovery and prevention." Paper presented at the IASA Conference, Perugia, August 26, 1996.

MediaCollege.com. "The HDV Video Format." Accessed February 3, 2021. 

Museum of Obsolete Media. "HDV (2003 – 2011)." Accessed February 3, 2021. 

Preservation Self Assessment Program. "Videotape: HDV." University of Illinois at Urbana-Champaign. Accessed February 3, 2021

Wheeler, Jim. "Videotape preservation handbook." 2002. 

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