I want to ask a design to play multiple note at same time from an audio file.
I checked Synthesiser, SoundSampler, VoiceSampler: Please give me more explaination about them. And what do they handle ? How to do multiple Voice/Sound/Synthe ?
Its all in the Synthesiser Class i think, you can see its implementation within AudioSynthesiserDemo.cpp from the demo, im sure thats the most hassle free way of doing it.
If you wanted to take the time rolling your own, youd need to determine all the metrics required to feed a buffer the correct number of samples for the voices pitch ratio, and then interpolate to fit into the callback buffer, every voice, every callback. Doable but not easy to perfect quickly.