Re: [Jsynthlib-devel] Fwd: [Jsynthlib-cvs] SF.net SVN: jsynthlib:[1104] trunk/JSynthLib/core/Actions.java

[Joe E. <jo...@em...>]

On 9/9/2011 7:17 AM, frankster wrote:
> On 09/09/11 15:03, Joe Emenaker wrote:
>> On 9/9/2011 1:56 AM, William Zwicky wrote:
>>> I think my example above matches that last case. Once the message 
>>> for widget A has started sending, other messages can be queued, but 
>>> they can't be sent until widget A says 'handshake complete'! 
>> My initial reaction to this is that this isn't an issue with the rate of
>> data sent by the MIDI layer, so the MIDI layer shouldn't be involved.
>> I'm thinking that the synthdriver should be able to manage all of this
>> itself. The only reason we'd need to trouble the MIDI layer with this is
>> if your synthdriver either needed special transfer-rate limits *or* if
>> your synthdriver needed to block all traffic for *other* synths on that
>> interface while the communication were happening. Otherwise, this should
>> be able to be managed by the synthdriver.
> I think it does concern the midi layer because transmitting data to one
> synth could overload a different synth on the same port. Although we can
> expect a synth driver to know how much traffic its device can handle, we
> can't expect a synth driver to care or know about other synths.
Well, that's a different case (but it's one that we've still discussed, 
and I think there does need to be a way for a synthdriver to tell the 
MIDI layer "I can't handle more than X bytes per second... no matter 
*what* synth it's for, so don't let any data onto the wires faster than 
that"). What *Bill* seems to be referring to is that there seems to be a 
synth which requires an orchestrated series of messages for updating 
synth settings. For example:

Where I imagine most synths use self-contained messages, like:
Msg: Update parameter 27 to value 10
Msg: Update parameter 27 to value 12
Msg: Update parameter 27 to value 14

Bill seems to have a synth which requires something like:

Msg: Begin messing with parameter 27
Msg: Set parameter to value 10
Msg: Set parameter to value 12
Msg: Set parameter to value 14
Msg: Done messing with parameter 27

You can see how things would get messed up if there was a second "begin" 
message before the "end" message for the first.

So, my point was that this kind of awareness of the *context* (not the 
data-rate) of the messages is probably best kept in the synthdrivers.

- Joe