AudioMerge basic framework - not working yet

AudioMerge_F32.h

@@ -0,0 +1,73 @@
+#ifndef _AudioMerge_I16toI32_h
+#define _AudioMerge_I16toI32_h
+
+#include <AudioStream_F32.h>
+
+// class AudioMerge_I16toI32 : public AudioStream_F32 //receive Int and transmits Float
+class AudioMerge_I16toI32 : public AudioStream //receive Int and transmits Float
+{
+  //GUI: inputs:2, outputs:1  //this line used for automatic generation of GUI node
+  public:
+    // AudioMerge_I16toI32(void) : AudioStream_F32(2, inputQueueArray_f32) { };  // specify two inputs here
+	  // AudioMerge_I16toI32(const AudioSettings_F32 &settings) : AudioStream_F32(2, inputQueueArray_f32) { };  // specify 2 inputs here
+  
+    AudioMerge_I16toI32(void) : AudioStream(2, inputQueueArray) { };  // specify two inputs here
+	  AudioMerge_I16toI32(const AudioSettings_F32 &settings) : AudioStream(2, inputQueueArray) { };  // specify 2 inputs here
+
+
+    void update(void) {	
+      //get the Int16 blocks
+      audio_block_t *int_block_1;
+      audio_block_t *int_block_2;
+      int_block_1 = AudioStream::receiveReadOnly(0);  // first int16 data block
+      int_block_2 = AudioStream::receiveReadOnly(1);  // second int16 data block
+      if (int_block_1 == NULL) return;
+      if (int_block_2 == NULL) {
+        AudioStream::release(int_block_1);
+        return;
+      }
+
+      // Allocate a single float block
+      audio_block_f32_t *float_block;
+      float_block = AudioStream_F32::allocate_f32(); 
+      if (float_block == NULL) {
+        AudioStream::release(int_block_1);
+        AudioStream::release(int_block_2);
+        return;
+      }
+      
+      // Merge two I16 streams into a single F32 stream
+      mergeAudio_I16toF32(int_block_1, int_block_2, float_block, float_block->length);
+
+      //transmit the audio and return it to the system
+      AudioStream_F32::transmit(float_block, 0);
+      AudioStream_F32::release(float_block);
+      AudioStream::transmit(int_block_1);
+      AudioStream::transmit(int_block_2);
+      AudioStream::release(int_block_1);
+      AudioStream::release(int_block_2);
+    };
+    
+    static void mergeAudio_I16toF32(audio_block_t *in_1, audio_block_t *in_2, audio_block_f32_t *out, int len) {
+      // const float MAX_INT_16 = 32768.0;
+      // const float MAX_INT_32 = 2147483648.0;
+
+      for (int i = 0; i < len; i++) {
+        // Convert to unsigned
+        uint16_t u1 = (uint16_t)in_1->data[i];
+        uint16_t u2 = (uint16_t)in_2->data[i];
+        uint32_t u_combined = (u1 << 16) | u2;
+        out->data[i] = (float)u_combined;  // this will have rounding errors
+      }
+      arm_scale_f32(out->data, 1./2147483648., out->data, out->length);  // this puts it between 0 and 2.0
+      arm_offset_f32(out->data, -1., out->data, out->length);  // this scales it to -1.0 and +1.0
+    }    
+    
+  private:
+    audio_block_f32_t *inputQueueArray_f32[2];
+    audio_block_t *inputQueueArray[2];
+
+};
+
+
+#endif

OpenAudio_ArduinoLibrary.h

@@ -18,6 +18,7 @@
 #include <AudioFilterFIR_F32.h>
 #include <AudioFilterIIR_F32.h>
 #include "AudioLMSDenoiseNotch_F32.h"
+#include "AudioMerge_F32.h"
 #include "AudioMixer_F32.h"
 #include "AudioMultiply_F32.h"
 #include "AudioSettings_F32.h"