Crossfade/Mix signal exp?

Development
1

Hi,

I want to mix two signal in a exp way.
Usually I’ll crossfade this way on other app (linearly):

return a + (b - a) * p;

Is there any “out-of-the-box” helpers on Juce to do this exponentially? Giving a non-linear slope on mixing two signals?

Thanks for any tips.

2

check out the dsp::DryWetMixer class

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3

Tried, but it seems do nothing:

void AudioPluginAudioProcessor::processBlock(juce::AudioBuffer<float> &buffer, juce::MidiBuffer &midiMessages)
{
	juce::ignoreUnused(midiMessages);
	auto *left = buffer.getWritePointer(0);
	auto *right = buffer.getWritePointer(1);

	mixer.pushDrySamples(buffer);
    mixer.setWetMixProportion(0.5f);
	
	for (int i = 0; i < buffer.getNumSamples(); i++) {
		// process left[i]...
	}
	
	mixer.mixWetSamples(buffer);
}

Am I wrong?

4

Maybe do I need to clone the buffer? And use it for wet one?

I only see example that use context and process, not processBlock.

Any tips please?

5

Yes, you need to clone the buffer before processing it with your effect. Create another buffer as a member of your processor and initialize it in prepareToPlay. In processBlock, before your for loop, just do dryBuffer.copyFrom(buffer), so you’ll have a copy of your incoming and unprocessed signal.

If you want a mix that’s not linear, look for “equal power crossfade”. This one works great for uncorrelated signals.

Cheers,
Luca

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