Skip to end of metadata
Go to start of metadata

You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 35 Next »

Introduction


DVCPRO is a professional-quality variation of the DV video recording specification introduced by Panasonic in 1995. DVCPRO also refers to video tape recorders and videocassettes that are designed to support these video recording specifications.

DVCPRO was used for professional and broadcast purposes such as electronic news gathering and producing cable television. This format uses the same compression scheme as DV but improves on colour rendition and robustness, employs “locked audio” tracks, and is better suited for linear editing environments. DVCPRO bit streams can also be carried in the MPEG-2 transport stream. 

In 1997, an enhanced version of DVCPRO was brought to market. DVCPRO50 used two parallel DV codecs and featured a bitrate of 50 Mbps and a colour-sampling resolution of 4:2:2. This increased data rate reduced the recording time of DVCPRO50 by half, compared to standard DVCPRO. Panasonic also marketed a high definition DV format, which was made available in 2000. DVCPRO HD combined four parallel DV codecs, which increased the bitrate to 100 Mbps. A progressive scan version (DVCPRO P) was also developed to respond to the need for 525p images. Panasonic stopped selling videotape equipment in 2013. 

Physical Characteristics


Tape width1/4 inch
Tape compositionMetal particulate
Cassette dimensions

Large cassettes: 4 7/8" x 3" x 9/16"

Medium cassettes: 3 13/16" x 2 1/2" x 9/16"

Container dimensions

Large cases: 5 1/4" x 3 5/16" x 3/4"

Medium cases: 4 1/8" x 2 3/4" x 3/4"

Identifying features

Yellow anti-static cover: DVCPRO tapes

Blue anti-static cover: DVCPRO50 tapes

Red anti-static cover: DVCPRO HD tapes 

DVCPRO logo: upper right hand corner

Tape length: left hand corner 

Common manufacturers/brandsPanasonic, Maxell, Fuji
Playback

DVCPRO tapes can be played using DVCPRO and DVCAM VTRs

DVCPRO VTRs can play DV, DVCAM and DVCPRO tapes

Technical Characteristics


VersionDVCPRODVCPRO50DVCPRO HD
Record time

Large cassettes: up to 126 minutes

Medium cassettes: up to 66 minutes

Large cassettes: up to 63 minutes

Medium cassettes: up to 33 minutes

Large cassettes: up to 31 minutes

Medium Cassettes: up to 16 minutes 

Track pitch18 microns18 microns

Long play: 18 microns 

Short play: 9 microns

Track width18 microns 18 microns18 microns 
Record/playback speed33.82 mm/sec (1x)

67.63 mm/sec (2x)

135.28 mm/sec (4x) 

Bitrate25 Mbit/s50 Mbit/s100 Mbit/s
Bit depth8 bit8 bit8 bit
Colour sampling4:1:14:2:24:2:2
Resolution

NTSC: 720x480

PAL: 720x576

NTSC: 720x480

PAL: 720x576

Uses downsampling:

  • 1280x720 becomes 960x720
  • 1920x1080 becomes 1280x1080 (59.94i)
  • 1920x1080 becomes 1440x1080 (50i)
Compression5:1 DCT compression3.3:1 DCT compression6.7:1 DCT compression 


Panasonic DVCPRO TapeDVCPRODVCPRO50DVCPROHDDVCPROHD-LPTape Length
ModelRecording and playback times(metres)
AJ0P12M (Medium Cassette)12 minutes6 minutes3 minutes6 minutes27 m
AJ-P24M (Medium Cassette)24 minutes12 minutes6 minutes12 minutes51 m
AJ-P33M (Medium Cassette)33 minutes16.5 minutes8 minutes16.5 minutes70 m
AJ-P46M (Medium Cassette)46 minutes23 minutes11.5 minutes23 minutes96 m
AJ-P66M (Medium Cassette)66 minutes33 minutes16.5 minutes33 minutes137 m
AJ-P34L (Large Cassette)32 minutes17 minutes8.5 minutes17 minutes72 m
AJ-P66L (Large Cassette)66 minutes33 minutes16.5 minutes33 minutes137 m
AJ-P94L (Large Cassette)94 minutes47 minutes23.5 minutes47 minutes194 m
AJ-P126L (Large Cassette)126 minutes63 minutes 31.5 minutes63 minutes259 m


Technical standards


FormatStandards
DVCPRO, DVCPRO 50
  1. Society for Motion Picture Technical Engineers (SMPTE) standard for television 314M Data structure for DV-based audio, data and compressed video – 25 and 50 MB/s. The differences between IEC 61834-5 and SMPTE 314M are shown in Annex A of SMPTE 314M.
DVCPRO HD
  1. Society for Motion Picture Technical Engineers (SMPTE) standard for television 370M:2006 Data structure for DV-based audio, data and compressed video at 100 Mb/s 1080/60i, 1080/50i, 720/60p, 720/50p.


Storage


Storage environment: temperature

Ideal: 40–54°F (4.5–12°C)

Acceptable: 55–60°F (13–15.5°C)

Storage environment: humidity30–50% RH
Container

DVCPRO containers should pass the Photographic Activity Test (PAT) as specified ISO Standard 18916:2007

  • Plastic: Polyethylene, polypropylene, or polyester (a.k.a. Mylar D or Melinex 516). No PVC or acetate
  • Paper/Paperboard: If paper containers are necessary, they should be constructed from lignin-free, neutral pH paper/paperboard

Containers are acceptable if they:

  • Are clean and free of mould
  • Protect the media from dust and other contaminants
  • Are not introducing contaminants through degradation

Unacceptable containers must be replaced with clean, inert containers.

Orientation of tape in storageVertical on its end (like books)

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:

University Archives Procedure Manual

Technology Watch

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. 

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. 

DigiMad. "Digital Video DV." Accessed February 2, 2021. 

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

MediaCollege.com. "The DVCPRO Video format." Accessed January 10, 2021.

MediaCollege.com. "The DVCPRO50 format." Accessed January 10, 2021. 

MediaCollege.com. "The DVCPRO HD format." Accessed January 10, 2021. 

Museum of Obsolete Media. "DVCPRO (1995 – early 2010s)." Accessed January 10, 2021. 

Museum of Obsolete Media. "DVCPRO HD (2000 – early 2010s)." Accessed January 10, 2021.

Museum of Obsolete Media. "DVCPRO50 (1997 – early 2010s)." Accessed January 10, 2021.

Panasonic Canada Inc. "AJHD150 DVCPRO HD Studio VTR." Accessed January 10, 2021. 

TapeOnline. "DVCPRO FAQ." January 10, 2021. 

Jimenez, Mona and Liss Platt. "Videotape Identification and Assessment Guide." Texas Commission on the Arts. 2004. 

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

Wilt, Adam J. "The DV, DVCAM & DVCPRO Formats: The DV formats tabulated." August 28, 2005. 

Version history


VersionDateAuthor(s)Version Notes




  • No labels