[LAD] Fwd: Re: How can a LV2 plugin know on what host's MIDI Channel it's on?

Len Ovens len at ovenwerks.net
Thu Oct 16 19:29:02 UTC 2014

On Thu, 16 Oct 2014, Phil CM wrote:

> Wow, not even the very channel it's broadcasting on in readable? Does that
> mean that I have to implement a MIDI channel selection in my synth? There is
> no way to go around this?

A plugin, should take care of it's own midi channel setting/sensing in the 
same way as a HW synth does, or a hw control surface. Sensing channel is a 
one step deal and requires almost no cpu cycles (it is always the first 
byte of a midi event which has to be tested anyway). It would be normal 
for any one function to use the same channel for input/output unless 
the plugin itself was doing filtering or other MIDI manipulating. It would 
be possible to ignore channel and use any channel, but the host should not 
be expected to do filtering for the plugin.

Dispite what people have said about the posibility of the host filtering 
the MIDI channels, it is unlikey unless the user chooses that in which 
case they are also responsible for making sure your plugin is also set to 
the right channel. So you do need to expose a control to do that. That 
control could have an option to accept all channels too so that the host 
could do filtering.

Note I have written only one MIDI application so far. I do need to finish 
it and it is not a plugin, but standalone.

Len Ovens

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