Reset I/O processor if NaNs are detected in the audio buffer

src/BYOD.cpp

@@ -83,7 +83,8 @@ void BYOD::processBlock (AudioBuffer<float>& buffer, MidiBuffer& midi)
     // real processing here!
     procs->processAudio (buffer, midi);
 
-    chowdsp::BufferMath::sanitizeBuffer<AudioBuffer<float>, float> (buffer);
+    if (! chowdsp::BufferMath::sanitizeBuffer<AudioBuffer<float>, float> (buffer))
+        procs->reset();
 }
 
 void BYOD::processBlockBypassed (AudioBuffer<float>& buffer, MidiBuffer&)

src/headless/CMakeLists.txt

@@ -18,6 +18,7 @@ target_sources(BYOD_headless PRIVATE
 
     tests/AmpIRsSaveLoadTest.cpp
     tests/BadModulationTest.cpp
+    tests/NaNResetTest.cpp
     tests/ParameterSmoothTest.cpp
     tests/PreBufferTest.cpp
     tests/PresetsTest.cpp

src/headless/tests/NaNResetTest.cpp

@@ -0,0 +1,40 @@
+#include "UnitTests.h"
+
+class NaNResetTest : public UnitTest
+{
+public:
+    NaNResetTest() : UnitTest ("NaN Reset Test")
+    {
+    }
+
+    void runTest() override
+    {
+        beginTest ("NaN Reset Test");
+
+        static constexpr int blockSize = 512;
+
+        BYOD byod;
+        byod.prepareToPlay (48000.0, blockSize);
+
+        MidiBuffer midi;
+        AudioBuffer<float> buffer { 2, blockSize };
+
+        {
+            for (auto [_, data] : chowdsp::buffer_iters::channels (buffer))
+                std::fill (data.begin(), data.end(), std::numeric_limits<float>::quiet_NaN());
+            byod.processBlock (buffer, midi);
+            const auto mag = chowdsp::BufferMath::getMagnitude (buffer);
+            expectEquals (mag, 0.0f);
+        }
+
+        {
+            for (auto [_, data] : chowdsp::buffer_iters::channels (buffer))
+                std::fill (data.begin(), data.end(), 1.0f);
+            byod.processBlock (buffer, midi);
+            const auto mag = chowdsp::BufferMath::getMagnitude (buffer);
+            expectGreaterOrEqual (mag, 1.0f);
+        }
+    }
+};
+
+static NaNResetTest nanResetTest;

src/processors/chain/ChainIOProcessor.cpp

@@ -55,6 +55,17 @@ void ChainIOProcessor::prepare (double sampleRate, int samplesPerBlock)
     isPrepared = true;
 }
 
+void ChainIOProcessor::reset() noexcept
+{
+    oversampling.reset();
+
+    inGain.reset();
+    outGain.reset();
+
+    ioBuffer.clear();
+    dryWetMixer.reset();
+}
+
 int ChainIOProcessor::getOversamplingFactor() const
 {
     if (! isPrepared)

src/processors/chain/ChainIOProcessor.h

@@ -17,6 +17,7 @@ class ChainIOProcessor
 
     static void createParameters (Parameters& params);
     void prepare (double sampleRate, int samplesPerBlock);
+    void reset() noexcept;
 
     int getOversamplingFactor() const;
     dsp::AudioBlock<float> processAudioInput (const AudioBuffer<float>& buffer, bool& sampleRateChanged);

src/processors/chain/ProcessorChain.cpp

@@ -89,6 +89,11 @@ void ProcessorChain::prepare (double sampleRate, int samplesPerBlock)
     initializeProcessors();
 }
 
+void ProcessorChain::reset() noexcept
+{
+    ioProcessor.reset();
+}
+
 void ProcessorChain::runProcessor (BaseProcessor* proc, AudioBuffer<float>& buffer, bool& outProcessed)
 {
     TRACE_DSP();

src/processors/chain/ProcessorChain.h

@@ -24,6 +24,7 @@ class ProcessorChain : private AudioProcessorValueTreeState::Listener
     static void createParameters (Parameters& params);
     void prepare (double sampleRate, int samplesPerBlock);
     void processAudio (AudioBuffer<float>& buffer, const MidiBuffer& hostMidiBuffer);
+    void reset() noexcept;
 
     auto& getProcessors() { return procs; }
     const auto& getProcessors() const { return procs; }