Re: dual layer DVDs

From: Philip Hood (email suppressed)
Date: Tue May 15 2007 - 08:52:17 PDT

On Tue, 15 May 2007, gyoungblood wrote:

> I'm thinking to purchase a dual layer DVD read-write drive on the
> assumption that it will allow me to copy DVDs with less compression than
> single layer. Am I right? If so, what does "less compression" mean? If I
> copy a dual layer disc to another dual layer disc, will there be no
> compression? Are there any other problems with dual layer copying? Can
> anyone recommend a website that explains all this?

hi gene,

here's a short page of some dvd bit rate calculations
that you can use to give you an idea.

In short, as the page says, the 2 controlling factors are
the bit rate that the data is moving at, and the limit of
how much data the disc holds. the single sided dual layer DVD
discs on the market can hold 8.5 gigs of data. The highest
possible data rate for a DVD is 9.8 mbps.

You will be able to play back
image streams compressed into a certain bit rate - the higher
the bit rate, the more information is coming to you (less
compressed) - the lower, the more compressed, and usually
the worse the image looks.

Do note that Dual Layer discs are a bit more expensive,
costing around $2 to $3 a piece. Most dvd burners I've
seen on the market seem to be able to burn Dual Layer.


For info on FrameWorks, contact Pip Chodorov at <email suppressed>.