fork from github

src/AudioOutputBuffer.cpp

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+/*
+  AudioOutputBuffer
+  Adds additional bufferspace to the output chain
+  
+  Copyright (C) 2017  Earle F. Philhower, III
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <Arduino.h>
+#include "AudioOutputBuffer.h"
+
+AudioOutputBuffer::AudioOutputBuffer(int buffSizeSamples, AudioOutput *dest)
+{
+  buffSize = buffSizeSamples;
+  leftSample = (int16_t*)malloc(sizeof(int16_t) * buffSize);
+  rightSample = (int16_t*)malloc(sizeof(int16_t) * buffSize);
+  writePtr = 0;
+  readPtr = 0;
+  sink = dest;
+}
+
+AudioOutputBuffer::~AudioOutputBuffer()
+{
+  free(leftSample);
+  free(rightSample);
+}
+
+bool AudioOutputBuffer::SetRate(int hz)
+{
+  return sink->SetRate(hz);
+}
+
+bool AudioOutputBuffer::SetBitsPerSample(int bits)
+{
+  return sink->SetBitsPerSample(bits);
+}
+
+bool AudioOutputBuffer::SetChannels(int channels)
+{
+  return sink->SetChannels(channels);
+}
+
+bool AudioOutputBuffer::begin()
+{
+  filled = false;
+  return sink->begin();
+}
+
+bool AudioOutputBuffer::ConsumeSample(int16_t sample[2])
+{
+  // First, try and fill I2S...
+  if (filled) {
+    while (readPtr != writePtr) {
+      int16_t s[2] = {leftSample[readPtr], rightSample[readPtr]};
+      if (!sink->ConsumeSample(s)) break; // Can't stuff any more in I2S...
+      readPtr = (readPtr + 1) % buffSize;
+    }
+  }
+
+  // Now, do we have space for a new sample?
+  int nextWritePtr = (writePtr + 1) % buffSize;
+  if (nextWritePtr == readPtr) {
+    filled = true;
+    return false;
+  }
+  leftSample[writePtr] = sample[LEFTCHANNEL];
+  rightSample[writePtr] = sample[RIGHTCHANNEL];
+  writePtr = nextWritePtr;
+  return true;
+}
+
+bool AudioOutputBuffer::stop()
+{
+  return sink->stop();
+}
+
+