Disklavier

Hi Mark / All

> > Where is the MTC or what controls the CD sync? 

Forgive me if I am way out, but surly the midi data comes from the CD 
as it is being played therefor it can never get out of sync.

Mark, those 0000 & 11111 you sent are not a lot of use.
Thinking about it to get an Audio/Midi CD to play from a PC you will 
need the sound card to decode the midi from the CD and also de-
multiplex the left channel back into stereo.
IMHO it can not be done without hardware. 



Midi Magic




--- In disklavier@yahoogroups.com, "Mark A. Fontana" <mfontana@f...> 
wrote:
> 
> 
> 
> On Wed, 31 Dec 2003, fkagel wrote:
> 
> > Is there anyone in the group that has dissected the MIDI data when
> > accompanying a CD? The system 'knows' which CD is supposed to be 
in
> > place and will indicate that the wrong one has been inserted if 
that
> > is the case.
> 
> 
> I would guess that the Disklavier identifies the CD based upon the
> UPC/EAN code read from the audio CD's table of contents.
> 
> If you manually read this code from a CD (a program like NERO will
> probably be able to do this) you could find it in the corresponding 
hex
> dump and figure out how to make a SYSEX message that checks for the
> correct CD.
> 
> 
> > I've noted 3 SYSEXs at the beginning:
> > F0 05 7E 7F 09 01 F7 - Turns on GM, but what is the 2nd Byte 05 
mean?
> > F0 08 43 10 4C 00 00 7E 00 F7 - XG on, but what does 2nd Byte 08 
mean?
> > F0 05 43 71 05 01 F7 - Don't know???
> 
> The second byte appears to be the length of the message that 
follows,
> including the terminating F7.
> 
> This size is probably coded as a variable-length quantity (in MIDI
> file lingo) so be prepared for this length to occupy more than one 
byte.
> 
> 
> > Where is the MTC or what controls the CD sync? What should I be
> > looking for in the hex dump?
> 
> As for the sync, no MIDI-specific time events are required in the 
MIDI
> file.
> 
> During playback against a CD, the MIDI timing is probably slaved to 
the
> 44.1 KHz CD sample rate, and MIDI playback is probably set to begin 
at a
> particular time marker (0:00:00?) in the CD subcode.  This only
> gets tricky when the user skips forward or backwards during 
playback;
> the playback engine would need to be coded very carefully to 
maintain
> sync.
> 
> Mark Fontana