very noob question

[Donnie]

Can someone please xplain why commercial DVDs contain 7gb and over data, and why DVD-R only accept 4.7 Gb ?
Are they physicaly different ?

[sfheath]

Basically your commercial 7Gb disk is either dual layer (if you don't need to turn it over half way) or double sided.
At the moment, writable media is only single layer, hence 4.7Gb capacity.
Commercial media is also pressed rather than burned in DVD writers.
Hence the black art of splitting, compressing etc.
Hope this helps

[Donnie]

Txs Sfheath, a little more clear to me now

[atifsh]

Originally posted by sfheath
Commercial media is also pressed rather than burned in DVD writers.

what u mean by pressed? also i realy wanted to know if 7gb dvd's not available how some dvd's i got are of 7 gb's and i mean the other dvd's hope u understand....

[sfheath]

Atifish:
Pressed as in stamped rather than 'recorded'. They are basically foil pressings laminated with a clear protective layer.

When you mention 7Gb, are we talking writables? Dual layer is on it's way I read but not for a while yet, hence 4.7Gb single layer limit. .... OR .... the 'flippables' double sided which I've not seen yet here in UK.

[Amey]

What I know here is that DVD-Rs are available in capacities of 4.7 and 9.4 GB and can be read in DVD players and drives on computers. DVD-R discs are available in two versions DVD-R(A), for professional authoring and DVD-R(G) for general consumers. The major difference between the two is that the professional supports Mastering and Copy protection.

[atifsh]

Originally posted by Amey
What I know here is that DVD-Rs are available in capacities of 4.7 and 9.4 GB.

yes i know that but frankly i hav'nt seen any dual sided 9.4 gb dvd yet, only dual sided disks i saw were old LD's
also dual layer 8.xGB dvdr is on way, so i dont think we'll see dual sided dvd's a lot in future.