perf(audio): adjust audio processing presets and limiters

app/src/main/cpp/radio.cpp

@@ -110,6 +110,7 @@ struct alignas(16) BassFilter {
         float y = x * a0 + z1;
         z1 = x * a1 + z2 - b1 * y + DENORMAL_OFFSET;
         z2 = x * a2 - b2 * y;
+        y = bassSafeClip(y);
         if(y > 1.2f) y = 1.2f;
         else if(y < -1.2f) y = -1.2f;
         return y;
@@ -139,6 +140,13 @@ struct alignas(16) BassFilter {
 #endif
     }
 
+    static inline float bassSafeClip(float x) {
+        const float maxGain = 1.0f;
+        if (x > maxGain) return maxGain - (maxGain - x) * 0.5f;
+        if (x < -maxGain) return -maxGain - (-maxGain - x) * 0.5f;
+        return x;
+    }
+
     void setLowShelf(float sr,float f,float g,float q){
         active=std::abs(g)>0.01f;
         if(!active) return;
@@ -232,8 +240,8 @@ class CompressorOptimized {
 public:
     float threshold = 0.3f;
     float ratio = 4.0f;
-    float attack = 0.01f;
+    float attack = 0.08f;
-    float release = 0.2f;
+    float release = 0.8f;
     float sampleRate = 44100.0f;
 
 private:
@@ -385,6 +393,16 @@ inline void applyAutoGain(float* buffer, int count){
     }
 }
 
+inline void applyRMSLimit(float* buffer, int count){
+    float sumSq = 0.0f;
+    for(int i=0;i<count;i++) sumSq += buffer[i]*buffer[i];
+    float rms = sqrtf(sumSq / float(count));
+    if(rms > 0.8f){
+        float scale = 0.8f / rms;
+        for(int i=0;i<count;i++) buffer[i] *= scale;
+    }
+}
+
 // Main processing function - heavily optimized
 extern "C" {
 
@@ -468,6 +486,9 @@ JNIEXPORT void JNICALL Java_com_michatec_radio_helpers_NativeAudioProcessor_proc
     if (gBassBoostEnabled) {
         gBassL.processNEON(gLeftBuf.data(), numFrames);
         gBassR.processNEON(gRightBuf.data(), numFrames);
+
+        applyRMSLimit(gLeftBuf.data(), numFrames);
+        applyRMSLimit(gRightBuf.data(), numFrames);
     }
 
     // Reverb

app/src/main/java/com/michatec/radio/helpers/NativeAudioProcessor.kt

@@ -75,17 +75,17 @@ class NativeAudioProcessor : BaseAudioProcessor() {
     // ===== Presets =====
     fun setPresetRock() {
         enableDrc(true)
-        setReverb(0.2f)
+        setReverb(0.10f)
         setWidth(1.1f)
         setEqAll(floatArrayOf(2f, 1f, 0f, -1f, -1f, 0f, 1f, 2f, 2f, 3f))
-        enableBassBoost(0.8f)
+        enableBassBoost(0.6f)
     }
 
     fun setPresetPop() {
         enableDrc(true)
         setReverb(0.15f)
         setWidth(1.05f)
-        setEqAll(floatArrayOf(1f, 1f, 0f, 0f, 0f, 0f, 1f, 2f, 2f, 1f))
+        setEqAll(floatArrayOf(0f, 1f, 1f, 1f, 0f, 0f, 1f, 2f, 2f, 1f))
         enableBassBoost(0.5f)
     }
 

app/src/main/java/com/michatec/radio/helpers/PreferencesHelper.kt

@@ -257,13 +257,13 @@ object PreferencesHelper {
 
     /* Loads Bass Boost gain */
     fun loadBassBoost(): Float {
-        return if (sharedPreferences.getBoolean(Keys.PREF_BASS_BOOST, false)) 0.6f else 0.0f
+        return if (sharedPreferences.getBoolean(Keys.PREF_BASS_BOOST, false)) 0.4f else 0.0f
     }
 
 
     /* Loads Reverb mix */
     fun loadReverb(): Float {
-        return if (sharedPreferences.getBoolean(Keys.PREF_REVERB, false)) 0.3f else 0.0f
+        return if (sharedPreferences.getBoolean(Keys.PREF_REVERB, false)) 0.2f else 0.0f
     }