Optimized SineFromTable

Author: pschatzmann

examples/tests/performance/sine/sine.ino

@@ -0,0 +1,44 @@
+
+#include "AudioTools.h"
+
+SineWaveGenerator<int16_t> sine_wave(32000);      // subclass of SoundGenerator with max amplitude of 32000
+SineFromTable<int16_t> sine_table(32000);         // subclass of SoundGenerator with max amplitude of 32000
+FastSineGenerator<int16_t> sine_fast(32000);  
+int sec = 5;
+
+size_t measure(int sec, SoundGenerator<int16_t> *gen){
+    uint64_t end = millis()+(1000*sec); // 10 seconds
+    size_t count;
+    while(millis()<end){
+        int16_t s = gen->readSample();
+        count++;
+    }
+    return count;
+}
+
+const char* resultStr(const char* name, size_t count){
+    static char msg[160];
+    sprintf(msg, "%s: %ld", name, count);
+    return msg;
+}
+
+void setup(){
+    Serial.begin(115200);
+    Serial.print("Number of call in ");
+    Serial.print(sec);
+    Serial.println(" seconds:");
+    Serial.println();
+}
+
+void loop(){
+    size_t result1 = measure(sec, &sine_wave);
+    size_t result2 = measure(sec, &sine_table);
+    size_t result3 = measure(sec, &sine_fast);
+
+    Serial.print(resultStr("SineWaveGenerator", result1));
+    Serial.print(" - ");
+    Serial.print(resultStr("SineFromTable", result2));
+    Serial.print(" - ");
+    Serial.print(resultStr("FastSineGenerator", result3));
+    Serial.println();
+}

src/AudioConfig.h

@@ -45,9 +45,9 @@
 // cheange USE_CHECK_MEMORY to 1 to activate memory checks
 #define USE_CHECK_MEMORY 0
 #if USE_CHECK_MEMORY
-#  define CHECK_MEMORY() 
-#else
 #  define CHECK_MEMORY() checkMemory(true)
+#else
+#  define CHECK_MEMORY() 
 #endif
 
 // Change USE_INLINE_VARS to 0 if inline variables are not supported

src/AudioEffects/SoundGenerator.h

@@ -612,7 +612,7 @@ class SineFromTable  : public SoundGenerator<T> {
                updateAmplitudeInSteps();
                //amplitude = amplitude_to_be;
             }
-            return amplitude * interpolate(angle);
+            return interpolate(angle);
         }
 
         bool begin() {
@@ -656,19 +656,19 @@ class SineFromTable  : public SoundGenerator<T> {
         //122.5 hz (at 44100); 61 hz (at 22050)
         const float values[181] = {0, 0.0174524, 0.0348995, 0.052336, 0.0697565, 0.0871557, 0.104528, 0.121869, 0.139173, 0.156434, 0.173648, 0.190809, 0.207912, 0.224951, 0.241922, 0.258819, 0.275637, 0.292372, 0.309017, 0.325568, 0.34202, 0.358368, 0.374607, 0.390731, 0.406737, 0.422618, 0.438371, 0.45399, 0.469472, 0.48481, 0.5, 0.515038, 0.529919, 0.544639, 0.559193, 0.573576, 0.587785, 0.601815, 0.615661, 0.62932, 0.642788, 0.656059, 0.669131, 0.681998, 0.694658, 0.707107, 0.71934, 0.731354, 0.743145, 0.75471, 0.766044, 0.777146, 0.788011, 0.798636, 0.809017, 0.819152, 0.829038, 0.838671, 0.848048, 0.857167, 0.866025, 0.87462, 0.882948, 0.891007, 0.898794, 0.906308, 0.913545, 0.920505, 0.927184, 0.93358, 0.939693, 0.945519, 0.951057, 0.956305, 0.961262, 0.965926, 0.970296, 0.97437, 0.978148, 0.981627, 0.984808, 0.987688, 0.990268, 0.992546, 0.994522, 0.996195, 0.997564, 0.99863, 0.999391, 0.999848, 1, 0.999848, 0.999391, 0.99863, 0.997564, 0.996195, 0.994522, 0.992546, 0.990268, 0.987688, 0.984808, 0.981627, 0.978148, 0.97437, 0.970296, 0.965926, 0.961262, 0.956305, 0.951057, 0.945519, 0.939693, 0.93358, 0.927184, 0.920505, 0.913545, 0.906308, 0.898794, 0.891007, 0.882948, 0.87462, 0.866025, 0.857167, 0.848048, 0.838671, 0.829038, 0.819152, 0.809017, 0.798636, 0.788011, 0.777146, 0.766044, 0.75471, 0.743145, 0.731354, 0.71934, 0.707107, 0.694658, 0.681998, 0.669131, 0.656059, 0.642788, 0.62932, 0.615661, 0.601815, 0.587785, 0.573576, 0.559193, 0.544639, 0.529919, 0.515038, 0.5, 0.48481, 0.469472, 0.45399, 0.438371, 0.422618, 0.406737, 0.390731, 0.374607, 0.358368, 0.34202, 0.325568, 0.309017, 0.292372, 0.275637, 0.258819, 0.241922, 0.224951, 0.207912, 0.190809, 0.173648, 0.156434, 0.139173, 0.121869, 0.104528, 0.0871557, 0.0697565, 0.052336, 0.0348995, 0.0174524, 0}; 
 
-        float interpolate(float angle){
+        T interpolate(float angle){
             bool positive = (angle<=180);
             float angle_positive = positive ? angle : angle - 180.0f;
             int angle_int1 = angle_positive;
             int angle_int2 = angle_int1+1;
-            float v1 = values[angle_int1];
-            float v2 = values[angle_int2];
-            float result = v1 < v2 ? map(angle_positive,angle_int1,angle_int2,v1, v2) : map(angle_positive,angle_int1,angle_int2,v2, v1)  ;
+            T v1 = values[angle_int1] * amplitude;
+            T v2 = values[angle_int2] * amplitude;
+            T result = v1 < v2 ? map(angle_positive,angle_int1,angle_int2,v1, v2) : map(angle_positive,angle_int1,angle_int2,v2, v1)  ;
             //float result = v1;
             return positive ? result : -result;
         }
 
-        float map(float x, float in_min, float in_max, float out_min, float out_max) {
+        T map(T x, T in_min, T in_max, T out_min, T out_max) {
           return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
         }