applied platformio structure

lib/spotify/cspot/bell/main/audio-dsp/Gain.cpp

@@ -0,0 +1,29 @@
+#include "Gain.h"
+
+#include <cmath>   // for pow
+#include <string>  // for string
+
+using namespace bell;
+
+Gain::Gain() : AudioTransform() {
+  this->gainFactor = 1.0f;
+  this->filterType = "gain";
+}
+
+void Gain::configure(std::vector<int> channels, float gainDB) {
+  this->channels = channels;
+  this->gainDb = gainDB;
+  this->gainFactor = std::pow(10.0f, gainDB / 20.0f);
+}
+
+std::unique_ptr<StreamInfo> Gain::process(std::unique_ptr<StreamInfo> data) {
+  std::scoped_lock lock(this->accessMutex);
+  for (int i = 0; i < data->numSamples; i++) {
+    // Apply gain to all channels
+    for (auto& channel : channels) {
+      data->data[channel][i] *= gainFactor;
+    }
+  }
+
+  return data;
+}