Disklavier

On Sun, 18 Jan 2004, Freehold Computer Training wrote:
> James,
> You will NOT need my CD. Burn ANY audio CD, even from MP3s. Use
> PianoSmart to record to floppy OR memory disk. Play back and observe
> what happens if you change the CD. The system 'knows' there is a
> DIFFERENT CD. No UPC/EAN since these not original CDs. I believe that
> even blank CDRs prior to burning have some identifier on the media (pre
> DRM debacle)! I doubt that Yamaha uses any algorithm similar to CDDB or
> Free DB. Bottom line: something is written to the floppy and that
> something is an identifier coming from the CD. The question in my mind
> is deciphering the identifier on the floppy as it relates to the CD. I
> am using FXEdit to read the MIDI data on the floppy.
>
> Fred

I think you missed my point - different areas of the world have slightly
different versions of commercial CD's. If I get a pianosmart disk that was
designed for the USA release of some CD, if I buy a European edition there
is a possibility that the tracks will be slightly different mixes, or have
a bonus track which screws up the algorithm. If you record a CD, unless I
have an exact copy of it here, I'm not going to be able to play around
with generating the hash/identifier/code myself from the CD and comparing
it with that present in the pianosmart file. Yamaha WILL use an algorithm
similar to CDDB - there is no other sensible way of doing it - but
deciphering exactly what the algorithm is may take some time

I'll take your word for the UPC/EAN code being ignored - not having a
working pianosmart system means that I'm unable to test with home recorded
CD's. Blank CDR's do have an identifier on them which describes the
manufacturer, write speed, dye type, manufacture date, etc., but I don't
believe there is a serial number present in any form. In any case, this
would be different from that present on a commercial CD.

If you were to make an exact copy of a pressed CD that had been used for a
pianosmart recording, what would happen when you played the copy? I would
expect the piano to not know the difference. Note this would have to be an
exact copy, with each track exactly the same number of sectors in length
etc.

Regards,

James