(almost) One loop to rule all the samples

Avoid looping over and over the samples. One

FM.cpp

@@ -31,7 +31,6 @@ q15_t FILTER_COEFFS[] = {
 
 const uint16_t FILTER_COEFFS_LEN = 101U;
 
-const uint16_t OUTPUT_BUFFER_SIZE = 1000U;
 
 CFM::CFM() :
 m_filter(),
@@ -50,8 +49,7 @@ m_holdoffTimer(),
 m_kerchunkTimer(),
 m_ackMinTimer(),
 m_ackDelayTimer(),
-m_hangTimer(),
-m_ringBuffer(OUTPUT_BUFFER_SIZE)
+m_hangTimer()
 {
   ::memset(m_filterState, 0x00U, 230U * sizeof(q15_t));
 
@@ -69,50 +67,31 @@ void CFM::samples(bool cos, q15_t* samples, uint8_t length)
   if (m_modemState != STATE_FM)
     return;
 
+  q15_t currentSample;
+  for(uint8_t i = 0U; i < length; i++) {
     // Only let audio through when relaying audio
-  // if (m_state != FS_RELAYING && m_state != FS_KERCHUNK) {
-  //   for (uint8_t i = 0U; i < length; i++)
-  //     samples[i] = 0;
-  // }
+    currentSample = samples[i];//save to a local variable to avoid indirection on every access
+    if (m_state != FS_RELAYING && m_state != FS_KERCHUNK) {
+      currentSample = 0U;
+    }
 
-  /*if (!m_callsign.isRunning())
-    m_rfAck.getAudio(samples, length);
+    if(!m_callsign.isRunning())
+      currentSample = m_rfAck.getAudio(currentSample);
     
-  if (!m_rfAck.isRunning())
-    m_callsign.getAudio(samples, length);
+    if(!m_rfAck.isRunning())
+      currentSample = m_rfAck.getAudio(currentSample);
 
     if (!m_callsign.isRunning() && !m_rfAck.isRunning())
-    m_timeoutTone.getAudio(samples, length);
+      currentSample = m_timeoutTone.getAudio(currentSample);
 
-  q15_t output[RX_BLOCK_SIZE];
-  ::arm_fir_fast_q15(&m_filter, samples, output, length);
-
-  m_ctcssTX.getAudio(output, length);*/
+    samples[i] = currentSample;
+  }
 
   io.write(STATE_FM, samples, length);
-
-  // for (uint8_t i = 0U; i < length; i++) {
-  //   bool ret = m_ringBuffer.put(output[i]);
-  //   if (!ret) {
-  //     DEBUG1("Overflow in the FM ring buffer");
-  //     break;
-  //   }
-  // }
 }
 
 void CFM::process()
 {
-  // uint16_t space = io.getSpace();
-  // uint16_t data  = m_ringBuffer.getData();
-  // if (data < space)
-  //   space = data;
-
-  // for (uint16_t i = 0U; i < space; i++) {
-  //   q15_t sample;
-  //   m_ringBuffer.get(sample);
-
-  //   io.write(STATE_FM, &sample, 1U);
-  // }
 }
 
 void CFM::reset()

FM.h

@@ -70,7 +70,6 @@ private:
   CFMTimer             m_ackMinTimer;
   CFMTimer             m_ackDelayTimer;
   CFMTimer             m_hangTimer;
-  CFMRB                m_ringBuffer;
 
   void stateMachine(bool validSignal, uint8_t length);
   void listeningState(bool validSignal);

FMCTCSSRX.cpp

@@ -109,9 +109,6 @@ uint8_t CFMCTCSSRX::setParams(uint8_t frequency, uint8_t threshold)
 
 bool CFMCTCSSRX::process(q15_t* samples, uint8_t length)
 {
-  //float32_t data[RX_BLOCK_SIZE];
-  //::arm_q15_to_float(samples, data, length);
-
   for (unsigned int i = 0U; i < length; i++) {
     float32_t q2 = m_q1;
     m_q1 = m_q0;
@@ -121,7 +118,7 @@ bool CFMCTCSSRX::process(q15_t* samples, uint8_t length)
     if (m_count == N) {
       float32_t value = m_q0 * m_q0 + m_q1 * m_q1 - m_q0 * m_q1 * m_coeff;
       m_result = value >= m_threshold;
-      DEBUG4("CTCSS value / threshold / result", value, m_threshold, m_result);
+      //DEBUG4("CTCSS value / threshold / result", value, m_threshold, m_result);
       m_count = 0U;
       m_q0 = 0.0F;
       m_q1 = 0.0F;

FMCTCSSTX.cpp

@@ -125,3 +125,12 @@ void CFMCTCSSTX::getAudio(q15_t* samples, uint8_t length)
       m_n = 0U;
   }
 }
+
+q15_t CFMCTCSSTX::getAudio(q15_t sample)
+{
+  sample += m_values[m_n++];
+  if(m_n >= m_length)
+    m_n = 0U;
+  
+  return sample;
+}

FMCTCSSTX.h

@@ -28,6 +28,7 @@ public:
   uint8_t setParams(uint8_t frequency, uint8_t level);
 
   void getAudio(q15_t* samples, uint8_t length);
+  inline q15_t getAudio(q15_t sample);
 
 private:
   q15_t*   m_values;

FMKeyer.cpp

@@ -152,6 +152,32 @@ void CFMKeyer::getAudio(q15_t* samples, uint8_t length)
   }
 }
 
+q15_t CFMKeyer::getAudio(q15_t sample)
+{
+  if (!m_wanted)
+    return 0U; //TODO F4FXL, not sure what to do here
+
+  q15_t output;
+  bool b = READ_BIT(m_poBuffer, m_poPos);
+  if (b)
+    output = sample + m_audio[m_audioPos];
+
+  m_audioPos++;
+  if (m_audioPos >= m_audioLen)
+    m_audioPos = 0U;
+  m_dotPos++;
+  if (m_dotPos >= m_dotLen) {
+    m_dotPos = 0U;
+    m_poPos++;
+    if (m_poPos >= m_poLen) {
+      stop();
+      return sample;
+    }
+  }
+
+  return output;
+}
+
 void CFMKeyer::start()
 {
   if (isRunning())

FMKeyer.h

@@ -29,6 +29,8 @@ public:
 
   void getAudio(q15_t* samples, uint8_t length);
 
+  q15_t getAudio(q15_t sample);
+
   void start();
   void stop();
 

FMTimeout.cpp

@@ -62,6 +62,26 @@ void CFMTimeout::getAudio(q15_t* samples, uint8_t length)
   }
 }
 
+q15_t CFMTimeout::getAudio(q15_t sample)
+{
+  if (m_pos > 12000U) {
+    q31_t sample = BUSY_AUDIO[m_n] * m_level;
+    sample = q15_t(__SSAT((sample >> 15), 16));
+
+    m_n++;
+    if (m_n >= BUSY_AUDIO_LEN)
+      m_n = 0U;
+  } else {
+    sample = 0U;
+  }
+
+  m_pos++;
+  if (m_pos >= 24000U)
+    m_pos = 0U;
+
+    return sample;
+}
+
 void CFMTimeout::start()
 {
   m_running = true;

FMTimeout.h

@@ -32,6 +32,8 @@ public:
 
   void getAudio(q15_t* samples, uint8_t length);
 
+  q15_t getAudio(q15_t sample);
+
 private:
   q15_t    m_level;
   bool     m_running;