erikstmartin/skills/catalog/audio/juce-framework

Requires: audio-engineering-principles May use: dsp-algorithms, audio-systems

Purpose

Builds production-quality JUCE-based software: standalone apps, plugin targets (VST3/AU), shared DSP cores, parameter systems, UI wiring, and host/device interoperability.

This skill covers both:

• Full JUCE applications / plugins end-to-end
• Framework-specific glue needed to embed portable DSP and analysis modules into JUCE lifecycles

Core Areas

• AudioProcessor lifecycle
• prepareToPlay()
• processBlock()
• releaseResources()
• AudioProcessorValueTreeState
• Parameter smoothing
• Message thread vs audio thread separation
• JUCE DSP module usage when appropriate

Rules

• Use juce::ScopedNoDenormals
• Preallocate in prepareToPlay
• Smooth parameters
• Avoid heap in processBlock
• UI must never block audio thread

AudioProcessor Skeleton Example

class MyProcessor : public juce::AudioProcessor {
    void prepareToPlay(double sampleRate, int samplesPerBlock) override {
        // Preallocate here — NO allocation in processBlock
        filter.setLowpass(1000.0f, 0.707f, (float)sampleRate);
    }

    void processBlock(juce::AudioBuffer<float>& buffer, juce::MidiBuffer&) override {
        juce::ScopedNoDenormals noDenormals;
        for (int ch = 0; ch < buffer.getNumChannels(); ++ch) {
            auto* data = buffer.getWritePointer(ch);
            for (int i = 0; i < buffer.getNumSamples(); ++i)
                data[i] = filter.process(data[i]);
        }
    }
};

Plugin Considerations

• Automation compatibility
• Sample rate changes
• Block size changes
• Host tempo sync
• Parameter thread safety