Why DVD+R(W) is superior to DVD-R(W)

This is the official thread associated with the article,
so feel free to post your comments and questions here.

–spath

Good work!

I posted about this here as well.

Somehow people are talking about this article at many places but only I am responding in this thread. :slight_smile:

http://www.dvdrhelp.com/forum/viewtopic.php?t=163147
http://www.dvdrhelp.com/forum/viewtopic.php?t=164824
http://www.cdrlabs.com/phpBB/viewtopic.php?t=11422
http://www.dvdplusrw.org/cgi/forum/ikonboard.cgi?;act=ST;f=3;t=6861

Thanks for your support Kenny :slight_smile:

Assuming that a disc is damaged and makes use of defect management (whenever drive manufacturers are going to implement it :wink: : Would it be readable in an older dvd-rom drive? This would require that sector relocation is defined in the original dvd-rom specs, wouldn’t it.

A fascinating article.

You mention data coded into the wobble with writable CD’s. I have seen it mentioned before, but never found details of exactly what is data is coded, where, and how.

Does anybody know of an article on the topic?

As far as I know these details are only available
in the orange book unfortunately.

Spath sigh… you are probably right.

I was wondering if it used 250 baud (4 milliseconds) pulses of 22.05khz wobble, as used by playstation copy protection.

I was also wondering if this coded wobble is actualy used at all. The writer doesn’t nead to be told about the character of the disk, as it makes its own tests. Nor does it need to be told where the head is in the disk, as it writes in sequence.

> I was wondering if it used 250 baud (4
> milliseconds) pulses of 22.05khz wobble, as
> used by playstation copy protection.

No, 1 ATIP bit is coded over 7 wobble periods
and one ATIP frame is 42 bits long.

> I was also wondering if this coded wobble is
> actualy used at all. The writer doesn’t nead
> to be told about the character of the disk,
> as it makes its own tests.

If you’re talking about the OPC, it uses as
start values the informations read from the
ATIP frames

> Nor does it need to be told where the head
> is in the disk, as it writes in sequence.

Even if you write your complete disc in
sequence, you still need to know where
to start writing, and this requires ATIP times
(mechanical measures of the PUH’s position
are not precise enough for this).

Spath

My thanks.

A bit rate of 3.15 khz, and a frame rate of 75hz.
That is one frame for every sector of recordable data. Is that how it’s used, with frames throughout the disk?

the +/- discussion reminds me about the one between vhs/betamax/video2000.

Sadly enough the best doesn’t always win.

When you look at www.vcdhelp.com and look in the list of standalone dvd drives…you can see that dvd-r is the most widly supported.

One ATIP frame per sector indeed. As for the list
on vcdhelp.com, I don’t see where it shows that
dvd-r is most supported.

when you scroll to all the drives you see that more support dvd-r then dvd+r

    • and + compatibility was not tested on the
      same amount of drives, not even the same
      players.
  1. were the + tests performed with compatibility
    bit settings or not ?

If someone of you has access to about 100 or 200 players, and has the time to check all of them with dvd-r, dvd+r and dvd+r with booktype set to dvd-rom, your results are welcome!

i wish i had

but till some one has time and that many drives…vcdhelps list is a good reference for normal users if they want to know what their drives supports

The question over which format has the most players is unimportant. By the time DVD rewriters replace CD rewriters as the norm (perhaps next year), these newer, faster, and very much cheaper drives will all support both standards.

There is no particular reason why DVD rewriters should not drop to near the price of CD rewriters. By the time one of the two formats wins, those few stuck with the wrong single standard drive will be able to upgrade for a small fraction of the cost of their original drive.

Given dual standard drives, this will be not so much a DVD drive war as a writeable DVD disk war. There is no particular reason why it should be more difficult to produce one disk rather than the other, nor any great difficult in changing production from one to the other. The relative quantities of disks produced in each format should follow demand.

Spath gives good arguments for the DVD+R(W) disk being superior at high speeds. The new Plextor dual format drive (Px-708A/UF) writes DVD+R at 8X, but DVD-R at only 4X. That is some proof that his arguments are correct in practice. It would, admittedly be better proof if 8X disks existed.

The only reasons I can imagine for DVD+ not being the ultimate winner would be excessive royalties demanded on the blank disks, or some sort of legal battle.

There is no particular reason why it should be more difficult to produce one disk rather than the other,
In theory, DVD- should be more expensive because pressing proper (!) pre-land-pits is difficult, and because dvd-r need to be pre-written in a certain region.
However, this appearently does not really affect the costs, because otherwise dvd+ media would be cheaper than dvd- and could knock out dvd- easily

Will the Plextor drive support DVD+MRW or defect management? If not, the DVD+ alliance continues to boast with non-existant features.

or some sort of legal battle
A hacked firmware might allow to produce CSS encrypted dvd+ discs.
So the RIAA might indeed decide to go for this…

The question over which format has the most players is unimportant

not totally true

most people buy a dvd burner conform the dvd’s the stand-alone player supports.

and the more are sold, the more support there will be at first

new standards are nothing when people don’t buy it

damiandimitri

Why should a stand alone dvd reader care if a disk is written in DVD+ rather than DVD- ? It ignores the atp data, so providing the are both written in the same format, they should appear the same.

Perhaps a lot of these early DVD readers can read DVD+ (booktype set to dvd rom), even though they are not listed as being able to.