HDV and dropout protection at DVinfo.net
DV Info Net

Go Back   DV Info Net > High Definition Video Acquisition > General HD (720 / 1080) Acquisition

General HD (720 / 1080) Acquisition
Topics about HD production.

Thread Tools Search this Thread
Old March 16th, 2006, 12:12 AM   #1
Join Date: Aug 2003
Location: Vancouver BC Canada
Posts: 1,315
HDV and dropout protection

In regards to HDV being higher risk at digital dropouts:

Clipped this from digitalproducer.com

"Walton(JVC rep): In the HDV progressive system we are using the same track layout as the DV format. There are 10 tracks per frame on DV and each track has an area for video data, audio, and subcode. With HDV, the tape speed is the same, but frames are grouped in to groups of six. Since it’s a six frame GOP, instead of using 10 tracks per frame we’re using 60 tracks per GOP. Critical data is interleaved throughout the entire GOP, so if you had a dropout somewhere—a defect in the tape or piece of dust—the recovery data is more likely not to be affected, and therefore you won’t see a defect in the recording. So, the actual dropout performance of HDV is superior to DV. It’s more robust"

This of course is representing the JVC 6GOP system. How the 15GOP sytems hold up is not mentioned.
Damnit Jim, I'm a film maker not a sysytems tech.
Ken Hodson is offline   Reply With Quote
Old March 16th, 2006, 08:29 AM   #2
Join Date: Jan 2004
Location: Stockton, UT
Posts: 5,648
HDV is indeed more robust, however no one's format is better than the other for or against it. Sony and Canon use one error correction unit across 16 tracks, with a wider physical area of the tape used, rather than using the DV footprint. By the math you're using, Sony and Canon offer 240 tracks per GOP, offering even greater protection. Additionally, 1080 offers scan tracks (x8/x24) which 720 doesn't offer, so you have a "protection" track there as well.
None of that matters in the grand scheme of things. It's 80% hype and 20% reality. If you have an across head dropout, with one format you're out for 1/6 of a second, the other, you're out for .5 of a second at the max, depending on whether the dropout hit an I frame or not (slim chance of that). I've had one dropout in hundreds of hours of tapes at this point, and it was forced to see what a dropout caused I don't recommend mounting your HDV cam on the handlebars and front fender of a motocross bike that is jumping fairly long distances.
Douglas Spotted Eagle/Spot
Author, producer, composer
Certified Sony Vegas Trainer
Douglas Spotted Eagle is offline   Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

B&H Photo Video
(866) 521-7381
New York, NY USA

Scan Computers Int. Ltd.
+44 0871-472-4747
Bolton, Lancashire UK

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > High Definition Video Acquisition > General HD (720 / 1080) Acquisition

Thread Tools Search this Thread
Search this Thread:

Advanced Search


All times are GMT -6. The time now is 01:04 PM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2021 The Digital Video Information Network