Question about multiple ouput buses

Hi everybody,

so I have a question about multi bus processing for an AU (VST also) sample player using Juce (5.4.7).
I’ve already searched in the Juce forum but can`t find an answer (may be that I just don’t understand…)

I have a AU synth (almost) perfectly running.
It sets up 8 stereo buses for output using the code snippets that you can see below.

The plug in validates fine and when opening the plug-in in Logic I can select between

  • Stereo and
  • Multi-Output “8x Stereo”
    which is in fact what I want (those 2 options). Everything fine until here.

At startup, the constructor of my AudioProcessor calls addBuses().
At this stage I’d like to see wheather the DAW tries to run a “Stereo” or a “Multi-Output 8xStereo” version of the plug-in, so I can set up the busses accordingly to the selection that I’ve made in the DAW. And it’s for a good reason because 1 bus cheaper to process than 8, right ?
Is this possible at all ?

While being in the constructor of SimpleSamplerComponentAudioProcessor (and in addBuses() ) i can’t see from where I could obtain this information.

May be that I am missing something here but i think the options that gives me the DAW (Stereo / Multi 8xStereo) must be good for something … ?

Thanks for any thoughts…


Code snippets:

( Everything still in an experimental stage…)

: AudioProcessor(addBuses())
// do things

static BusesProperties addBuses()

BusesProperties buses;
for (int i = 0; i < MAX_NR_OF_OUPUTBUSSES; i++) {
	std::stringstream busName;
	busName << "Output #" << (i + 1);
    bool activeByDefault = ((i == 0 ) || i == (MAX_NR_OF_OUPUTBUSSES - 1));
	buses = buses.withOutput(busName.str(), AudioChannelSet::stereo(), activeByDefault);
return buses;


bool SimpleSamplerComponentAudioProcessor::isBusesLayoutSupported(const BusesLayout& layouts) const
if (layouts.getMainInputChannels() != 0)
return false;
if (layouts.getMainOutputChannels() != 2)
return false;

int nOuts = layouts.outputBuses.size();
if( nOuts != 1 && nOuts != 8) {
    return false;

for (int i = 1; i < nOuts; i++) {
    if (layouts.getNumChannels(false, i) != 2) return false;

return true;