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Re: [Dvdrtools-users] DVD+R/+RW support
From: |
Bryan J . Smith |
Subject: |
Re: [Dvdrtools-users] DVD+R/+RW support |
Date: |
Fri, 25 Mar 2005 15:15:31 -0800 |
All of this "speculation" is 100 percent, factually and technically
explained by the understanding of how "single-groove" media and
"pie-slice" media differ physically.
CD-RW, DVD-RW and DVD+RW are "pie-slice" MO and DVD+R is a hybrid
MO-WORM, but still "pie-slice" physically.
CD-R and DVD-R are "single-groove" WORM. Physically, how the laser
tracks is *no* different than CD-ROM or DVD-ROM. I.e., literally like
an analog record, a revolution does not return the laser where it
started.
This is not true of MO. When the disc does a revolution, the laser
starts *exactly* back where it was.
So for "pie-slice" MO to emulate "single-groove" WORM, additional logic
is required.
An additional issue in DVD+R/+RW v. DVD-RW/RAM is CAV v. CLV,
respectively.
CLV MO always has the same, relative layout.
CAV MO requires "gap fill-in" that is not consistent.
It's much, much easier to accomodate MO CLV than MO CAV.
Which is why official CD-RW MO standards *never* introduced CAV, they
were always CLV.
Even the 8x and higher Pioneer standards were CLV MO.
Sony/Philips introduced 10x and higher standards using CAV MO, which has
been attributed to shortening of drive lifespans and reduced
compatibility.
I used to refer to it as CD+RW.
At least there is no more confusion in the DVD arena.
But the issues with DVD+RW remain for non-DVD+RW consortium drives.
MO is already a support issue for players, but CAV MO is even worse.
Hence the problem with DVD+RW compatibility on even Sony/Philips
consumer drives.
Again, I'll show this in the fact I'm writing.
No I did mean computer dvdrom drives. If they're manufactured 2004 or
later they should always be able to read everything. Many dvdrom drives
manufactured in 2003 can also read everything, but there probably were
still some sold who couldn't read DVD+R or DVD+RW. "Read everything"
here means "meant to read everything", there are always some
combinations of dvdrom drive and media brand which don't work. And the
probability of some dvdrom drive failing to accept DVD+R media XYZ are
not higher than a failure with DVD-R media XYZ, for drives of 2004 or
later (and many earlier).
Consumer video players can usually read DVD+R(W) since about 2004, but
the packaging will say. Some players can also read some brands of media
types for which they aren't specified, so it's worth trying.
Burners aren't so much the issue, assuming you stick to the media
varieties which the burner can actually burn. And obviously assuming the
burner was designed to burn all formats.
This all from my relatively small sample size.
--
Bryan J. Smith mailto:address@hidden
Currently Mobile
Re: [Dvdrtools-users] DVD+R/+RW support, Volker Kuhlmann, 2005/03/24
Re: [Dvdrtools-users] DVD+R/+RW support, Bryan J . Smith, 2005/03/24
Re: [Dvdrtools-users] DVD+R/+RW support, Bryan J . Smith, 2005/03/24
Re: [Dvdrtools-users] DVD+R/+RW support,
Bryan J . Smith <=
Re: [Dvdrtools-users] DVD+R/+RW support, Bryan J . Smith, 2005/03/25