> -----Original Message----- > From: Association for Recorded Sound Discussion List > [mailto:[log in to unmask]] On Behalf Of Mike Richter > Sent: Thursday, June 02, 2005 9:22 PM > To: [log in to unmask] > Subject: Re: [ARSCLIST] Testing DVDs > > At 08:02 PM 6/2/2005 -0400, Jerome Hartke wrote: > >Based on testing for our clients, I believe that you are pursuing the > wrong > >quality indicators. "Too cumbersome and time-consuming" suggests that you > >wish an easy answer to a complex question. Such answers invariably lead > to > >misguided efforts, a false sense of security, and unsatisfactory results. > > May I suggest that we need to define the outcome we hope for from such > tests before examining procedures? For example, we might want to begin by > saying that we require a set of measures of quality of recording and of > accuracy of retrieval over time. If such measures can be defined, then a > methodology for their assessment is needed; we should then be ready to > charge the manufacturers with making and publishing those measurements. > > Over all of this, we need to face the limitations of time and cost. They > are related in that the measurements need to be made available before the > medium has become obsolete. Thus, if one postulates a methodology for > measuring CD-R failure rate over time which requires a decade of test, the > discs in question can be expected to have vanished by the time their > performance is known. > > On a trivial level, it is not even clear that anyone has enumerated the > failure modes of interest or a fitting measure of "failure", given that > bit-level errors are expected in DVD recording. > > Mike > -- > [log in to unmask] > http://www.mrichter.com/ Well put. A key issue is the absence of any standards for drives. The only standards are for media. Interchange failure is a probability, not a pass/fail issue. Non-conformance to media standards means that the disc is at fault when an interchange failure occurs, even when the disc is readable in some systems. Conformance to media standards means that the drive is at fault when interchange failure occurs. Jerry Media Sciences, Inc.