move to new cspot

components/spotify/cspot/bell/main/audio-dsp/include/BiquadCombo.h

@@ -0,0 +1,85 @@
+#pragma once
+
+#include <vector>
+#include <memory>
+#include <cmath>
+#include <mutex>
+#include <map>
+
+#include "Biquad.h"
+#include "AudioTransform.h"
+
+namespace bell
+{
+    class BiquadCombo : public bell::AudioTransform
+    {
+    private:
+        std::vector<std::unique_ptr<bell::Biquad>> biquads;
+
+        // Calculates Q values for Nth order Butterworth / Linkwitz-Riley filters
+        std::vector<float> calculateBWQ(int order);
+        std::vector<float> calculateLRQ(int order);
+
+    public:
+        BiquadCombo();
+        ~BiquadCombo(){};
+        int channel;
+
+        std::map<std::string, float> paramCache = {
+            {"order", 0.0f},
+            {"frequency", 0.0f}
+        };
+
+        enum class FilterType
+        {
+            Highpass,
+            Lowpass
+        };
+
+        void linkwitzRiley(float freq, int order, FilterType type);
+        void butterworth(float freq, int order, FilterType type);
+
+        std::unique_ptr<StreamInfo> process(std::unique_ptr<StreamInfo> data) override;
+        void sampleRateChanged(uint32_t sampleRate) override;
+
+        void reconfigure() override
+        {
+            std::scoped_lock lock(this->accessMutex);
+
+            float freq = config->getFloat("frequency");
+            int order = config->getInt("order");
+
+            if (paramCache["frequency"] == freq && paramCache["order"] == order)
+            {
+                return;
+            } else {
+                paramCache["frequency"] = freq;
+                paramCache["order"] = order;
+            }
+
+            this->channel = config->getChannels()[0];
+            this->biquads = std::vector<std::unique_ptr<bell::Biquad>>();
+            auto type = config->getString("combo_type");
+            if (type == "lr_lowpass")
+            {
+                this->linkwitzRiley(freq, order, FilterType::Lowpass);
+            }
+            else if (type == "lr_highpass")
+            {
+                this->linkwitzRiley(freq, order, FilterType::Highpass);
+            }
+            else if (type == "bw_highpass")
+            {
+                this->butterworth(freq, order, FilterType::Highpass);
+            }
+            else if (type == "bw_lowpass")
+            {
+                this->butterworth(freq, order, FilterType::Highpass);
+            }
+            else
+            {
+                throw std::invalid_argument("Invalid combo filter type");
+            }
+        }
+    };
+};