Merge pull request #2 from patrick-radius/multiply

Added a multiply in float format

AudioMultiply_F32.cpp

@@ -0,0 +1,20 @@
+#include "AudioMultiply_F32.h"
+
+void AudioMultiply_F32::update(void) {
+  audio_block_f32_t *block, *in;
+
+  block = AudioStream_F32::receiveWritable_f32(0);
+  if (!block) return;
+
+  in = AudioStream_F32::receiveReadOnly_f32(1);
+  if (!in) {
+    release(block);
+    return;
+  }
+
+  arm_mult_f32(block->data, in->data, block->data, AUDIO_BLOCK_SAMPLES);
+  release(in);
+
+  transmit(block);
+  release(block);
+}

AudioMultiply_F32.h

@@ -0,0 +1,28 @@
+/*
+ * AudioMultiply
+ * 
+ * Created: Patrick Radius, December 2016
+ * Purpose: Multiply two channels of audio data. Can be used for example as 'vca' or amplitude modulation.
+ * Assumes floating-point data.
+ *          
+ * This processes a single stream fo audio data (ie, it is mono)       
+ *          
+ * MIT License.  use at your own risk.
+*/
+#ifndef AUDIOMULTIPLYF32_H
+#define AUDIOMULTIPLYF32_H
+
+#include <arm_math.h>
+#include <AudioStream_F32.h>
+
+class AudioMultiply_F32 : public AudioStream_F32
+{
+  public:
+    AudioMultiply_F32(void) : AudioStream_F32(2, inputQueueArray_f32) {};
+    void update(void);
+    
+  private:
+    audio_block_f32_t *inputQueueArray_f32[2];
+};
+
+#endif