Why do i observe a change of Midi channel from 0 to 1 with VST3 on linux?

Audio Plugins
1

Hello,
i wrote two VST3 plugins with JUCE v7.0.5 and use them in series with Juce HOST.
Plugin 1: midi → midi
Plugin 2 : midi → audio is a synthesizer

Curiously when Plugin 1 sends “note on” on channel 0 then Plugin 2 receives the note on channel 1, as i if Juce or the host changes the channel number?
( But no similar problem for channels 1 to 15.)
Why is it so?
Thanks,
Frederic.

2

JUCE uses indices 1-16 not 0-15 as programers might expect to refer to the midi channels. So a channel index of 0 is invalid in JUCE. Might this be the cause for the confusion?

3

Thanks very much, this was indeed my mistake.

4

By the way i wonder why JUCE has chosen to code the midi channels from 1 to 16 and not 0 to 15?
This shift creates non necessary complications in the code.
We could have reserved the +1 shift only for display.