DVD and CD
Testing is not just for manufacturers anymore. If you
are involved with the creation, duplication, replication or
distribution of DVD's or CD's, you can save money and prevent problems by
being able to measure disc quality.
Why
Test Discs?
Data
comparison does not measure disc quality.
Just
because you can read it doesn’t mean it’s good.
Poor
disc quality can cause unreliable operation and short lifetime.
All
optical discs incorporate very powerful error detection and
correction. This error correction is extremely
effective, and DVD's & CD's could not work without it, as there would be
far too many errors.
However,
the error correction also hides a multitude of sins. In
principle, it is possible to drill a 2mm hole through a CD,
and still recover every single bit! But even though this
disc is readable, you could not consider it a "good"
disc. It will be slow and unreliable. The data could
become unrecoverable at any time.
The
only way to judge the quality of the disc is to make sure it
conforms to Red Book or DVD specifications. Measuring error rates
also shows the location and severity of defects.
Who Should Test
Discs?
Duplicators
Evaluate
and Qualify CD & DVD Media.
Identify
burners that are failing or about to fail.
Discover
if the problem is the media or the writer.
Make
sure the masters are good.
Replicators
Quality
Assurance
Production
line screening
Conformance
with standards & License Agreement
Distributors
Manage
quality variations from suppliers.
Generate
confidence in products.
Avoid
returns & unhappy customers.
Get
what you pay for.
Mastering Studios
Make sure your pre-masters can be
mastered.
Avoid delays due to re-mastering.
End
Users
Increased
reliability for critical applications.
Archiving
- High quality discs have longer lifetime.
Avoid
long access times.