24 Jul
2006
24 Jul
'06
7:54 p.m.
On Tue, 2006-07-25 at 01:43 +0200, Nicolas Pouillon wrote:
[Mon, 24 Jul 2006 17:09:02 -0400]
Lee Revell <rlrevell(a)joe-job.com> eut le bonheur d'_crire:
Ugh. All I need to do is snoop note on, note off, and the note number.
But you're saying that 0x81 is sometimes part of a timestamp, and other
times it means note off on channel 1?
So you are saying my driver needs to have full knowledge of the MIDI
state machine in order to snoop note on and note off?
Lee
Also, why doesn't every event have a
timestamp? For example "81 0C 90
30 5B 00 90 3C 79 81 70"? I guess multiple events can be scheduled in
one "tick"?
Actually delta times between events are encoded with a variable length
value. As long as bit 7 is 1, you must drop this very bit and add next
byte in the value decoding. Here; 81 0c is a variable length value:
delta 81 0c which is ((0x7f & 0x81) << 7) | 0x0c = 0x8c
event 90 30 5b
delta 00
event 90 3c 78
delta 81 70 which is 0xf0
hth