[MacDV] Re: CDs to use for VCDs

[Ric Perrott]

On Wednesday, February 12, 2003, at 09:48  AM, Michael Winter wrote:

>> As far as computers are concerned, they don't care one way or the 
>> other. However it is my experience that most Music or Audio CDRs use 
>> a better grade of dye in order to ensure a successful burn. make of 
>> this what you will when deciding if the added cost of these CDRs is 
>> worth it. In many cases it is not and regular data grade CDRs will 
>> fit the bill just fine.
>
> I'm not saying your wrong about this, I've heard the same from many 
> places, but it just doesn't make sense to me. If you're talking about 
> consumer/home use a "soft" bit or two on an audio CD is no problem. 
> The same on a data CD can render a file or even entire disk 
> unreadable. For that reason, it just doesn't make sense to me that 
> audio CDs would require a better grade of dye. Am I missing something?

Not true. Data CDRs (orange Book) have a much more robust error 
correction mechanism than audio CDRs (Red book). A Data CDR can 
withstand a much greater error threshold than an Audio disc can. 
Remember also that Data CDs are read at a much faster rate than real 
time. This allows the computer to buffer the data, apply error 
correction, and even re-read a section of the disc before you can 
blink. Contrarily, Audio CDs are only read at 1x. This means all error 
correction is done real time, so any defects in the disc will become 
immediately apparent as an audible artifact.

  Also, the audio CDRs need to have the ability to be written in real 
time, meaning that you can hook up audio inputs to the CD Deck, hit 
record and record 74 minutes directly onto a CDR with no breaks. This 
requires that the disc be designed as stable as possible and that the 
grade of dye used be able to provide a clean and stable burn at 1x, 
which is actually much more difficult than buffering and writing the 
entire CDR at speeds like 12x or higher.

Data CDRs on the other hand are buffered before being written, and a 
much more robust error correction mechanism is used. You can get 
coasters with data CDRs for sure, but the likelihood is lessened by the 
different standard used.

Additionally, most of the users of these consumer decks are not 
computer folks and don't want to have to be versed in technology to 
record a CD. So it stands to reason that to reduce the number of 
complaints and returns of product, that the Audio CDRs are made to be 
as robust as possible. You don't really see Audio CDRs being sold in 
cake packs of 100 or more as a commodity item like Data CDRs. They 
exist, but most sales of Audio CDRs are in packs of 10 or 20 to general 
consumers that will not hesitate to return them to best buy or circuit 
city if they fail to work in their deck based CD Recorder.

-------------------------------
Ric Perrott
Writer, Poet, Pot-Stirrer
Visit http://www.ricperrott.com