|
So we all make CD and DVD’s and most are perfect,
or so we think. It’s funny how some people have troubles, and others
never do.
My problems arose from some DVD's I made for someone, and most were absolutely
dreadful on her newish machine, freezing, jumping, blocking and have we
got something else? Of course they all played OK on mine didn’t
they.
Well the way to solve problems like this is to ask some
one who has done all the research for you already, who do you ask, well
Mr Google of course.
So start by going to
Quality
of CD and DVD Media
and you find half the answers to your problems,just browse through
the various sections and its there. But if you are not sure then read
on.
For information only I give the DVDInfo reading of some
of my DVD’s
Blue DataWrite……….RitekGO5……….
Middle 2nd Class
TraxData………………CMCMAG…….…See
List
Verbatim………………MCC03RG20…...
Almost THE best
PioData………………..RitekGO5……….
Middle 2nd Class
TaiyoYuden…………...TYG02……….…
Almost THE best
I don’t have trouble with Verbatim or Taiyo Yuden,
surprise surprise, but I did pay a lot for the Taiyo Yuden, look them
up on the Net.
Next read Quality
of CD and DVD Burning, when you have read that, think about
your own disk quality, do yours stand the test?
In the articles that I read on CD, the main errors are
C1 and C2, and for the best explanation go to this site, NOT for the faint
hearted
http://club.cdfreaks.com/f77/interpreting-c1-c2-error-scans-75573/
For those people who will do it all “Next week”
I give the test results that I had, so they can compare them.
The errors are on the left, the scale changes to suit, with C1 errors
shown in the upper graph, and C2 errors in yellow in the lower graph,
and speed is the green line which is graduated on the right.
Look at the header to see which drive is used for the test, they are:-
1)Lite On LTR-48125S
2)Lite-On DVDRW SHM165P6S
3)Lite-On COMBO SOHC5235K
Please also note that I have used two versions of Nero,
Nero Express 6.6.0.17 and Nero 6.0. This was because I have two computers
with different versions and I was curious as to how they compared.
Figure 1
This shows a pre-recorded CD on a CD player,
Note level of C1 errors, this is very reasonable, the C2 errors
are one bad blip, don't know why. Note scale of verticle reading,
peak at 10-20.
Figure 2
|
This shows a good recording, notice C1 errors
are high, certainly at the end of disk, with a maximum of 835, the
C2 errors are once again one bad blip, could be a problem with the
drive as its on all three of the figures.
Figure 3
|
This is totally bad, C1 peaks at 11686, total
of 4234006 errors(over 4 million) and C2 is 1784, BAD.This is another
copy of the same disc as above.
Just look at the scale on the left, its at 4000, not 200 as per
others. Notice that as errors increase then the speed also becomes
erratic, because it has to read the data several times.
Figure 4
|
This shows the same CD as Figure 2, But this
time in a DVD drive
|
Figure 5
Should you get a nice even response like this,
with the speed stuck at about 12.7, the answer normally is that
you have not got DMA enabled on your drive and its working in PIO
mode only.
Go to Start/Settings/Control Panel/System/Hardware/Device Manager/IDE
controller/Secondary IDE channel/ Right Click /Properties/Advanced
Setting.......Make sure DMA is enabled, and reboot. |
Figure 6
The same drive, same disk, but with DMA enabled.
Note still NO C2 errors. Notice speed is now 33.7!
Figure 7 |
 |
| Should this be what your disks are like then
you are in serious trouble, if you have just bought 300 cheap disks
from a computer fair, take them back, they are not worth anything.Of
course what I have not said yet is that if you copy a disk then it
becomes error corrected every time, up to a limit, but it can make
a bad disk good? |
The problems of DVD have been well documented and for
some people very,very frustating. The errors are similar to CD only this
time they are referrred to as PI and PIF, which is Parity Inner and Parity
Inner Failure. For a detailed example of errors, and testing see here
http://www.cdrinfo.com/Sections/Reviews/Specific.aspx?ArticleId=20622,
and follow the arrows, the conclusion is that most problems are in order-----
a combination of poor media, poor player, poor recorder, and of course
sods law.
For further help and understanding I would visit this
link http://club.cdfreaks.com/f96/cd-dvd-speed-user-guide-192563/
there's a lot to read and understand but if it helps to get reduce the
number of coasters that are produced then its worth the trouble.
I thought I would test a DVD that I had using Kprobe2, the result is below,
looks pretty good, don't just look at the pattern, look at the scale.
In the first figure the absolute peak is 120, whilst the second figure
is 1113, almost ten times as much. Regarding the PIF values, the first
figure is peak at 4, the second shows 124. It speaks for itself.
The test results are also dependant on the testing speed, I did these
using Maximum, but I have to point out that running these with speed at
*4 gave much worse results than are shown here, why I don't know?
What I did notice however was that by leaving the speed setting at Max,
then it would appear that the drive goes to a constant Max speed and therefore
the inner tracks (start) have a much slower data rate than the outer (finish),
which is why the errors seem to be greater for some disks?
|
Lastly using Kprobe2 (free)I thought I would look at
a BAD disk that did not play too well, now I know why.
My thanks to all the people on the Net for publishing
their hard work and enabling us all to make better recordings.
|
