Midi output questions

[digdugger]

I'm new to Ableton. In fact I'm not a musician. I'm using Ableton to control some custom led lighting effects that I have designed for a band. I pretty much have the control scheme figured out except for two anomalies that I don't understand.

1) When I play a clip Ableton seems to send the note on message before the note off. This is the output from my looped back serial monitor:

Note OFF: 84 64
Note ON: 84 100

Since the velocities are the correct default values for off and on I can't see that I've mixed up the messages somewhere or have I? I watch the progress of the clip in ableton and I definitely see the note off being echoed before the note on. I just need to know if this is expected behaviour or not so that I don't go digging in code if I don't have to. If it is expected then can I change this behaviour or what should I think about?

2) When I send a program change message (program 2) at the start of a clip I get 2 messages not one like this:

Program Change: 1
Program Change: 64

Playing around with bank and sub bank it seems that the second program change message is always follows the sub bank except if its not set then it defaults to 64. I could filter this second message. Essentially make it an invalid program number.

In general I've noticed that if any value (control change, program change) etc does not change from clip to clip then Ableton will not send that data again. This makes sense from a music point of view, but not if your trying to control something other than sound. What I have to do is set default values for all my control changes which control parameters of the lighting and remember the last values when a new clip or message comes in and only update them if they change. Doable, but it doesn't make a clip a stand-alone program. The "program" is possibly the sum of all the clips that played before.

Lastly but this is just a pie in the sky thing. Is there any way to send more than just velocity with a note? I'm using envelopes to control global parameters but would like to have 2 per note parameters not one. Any advice welcome. Thanks.

[digdugger]

As to anomaly #1 it seems it was a code error Still not sure about point 2. Also I noticed that Ableton sends 2 control change message when the program is closed.