I’ve been playing with the dynamic audio library standingwave 3. Almost the first thing one notices is that if one tries out the code samples in the developer’s guide, namely this code:
// Create a chord of three simultaneous sine tones: A3, E4, A4.
var sequence:ListPerformance = new ListPerformance();
sequence.addSourceAt(0, new SineSource(new AudioDescriptor(), 0.1, 440));
sequence.addSourceAt(0, new SineSource(new AudioDescriptor(), 0.1, 660));
sequence.addSourceAt(0, new SineSource(new AudioDescriptor(), 0.2, 880));
// Play it back.
var source:IAudioSource = new AudioPerformer(sequence);
player.play(source);
then one gets a really unpleasant sound and trace messages that read “AUDIO CLIPPING”. The developer explains in one of the issue reports on github that you need to reduce the gain of samples when you mix them together to avoid this, and that there’s no easy way to know dynamically how much reduction is needed.
My question is, how is it that stangingwave2 seems to have dealt with this automatically? For instance, the code quoted above did not clip in SW2. Likewise consider this SW2 example demo – if you increase the sustain and hold (the S/H sliders) and press one of the sequence buttons, multiple tones will overlap without clipping, even though the source doesn’t show any apparent sign of changing the gain or the volume of the sin tones, they just get mixed together.
What’s going on here – did SW2 have some way of dealing with this automagically, or is there some robust way of generally overlaying arbitrary numbers of sounds dynamically without causing clipping? Thanks!
As no activity seems likely here, I’ll note for the ages that apparently SW2 simply returns sine sources at much less than full scale, but it turns out that if you combine enough sources you do get clipping. SW3 returns the sources at full scale so the clipping becomes apparent with fewer sources.