some cleanup

interface/src/Audio.cpp

@@ -92,7 +92,7 @@ Audio::Audio(int16_t initialJitterBufferSamples, QObject* parent) :
     _processSpatialAudio(false),
     _spatialAudioStart(0),
     _spatialAudioFinish(0),
-    _spatialAudioRingBuffer(NETWORK_BUFFER_LENGTH_BYTES_PER_CHANNEL)
+    _spatialAudioRingBuffer(NETWORK_BUFFER_LENGTH_BYTES_PER_CHANNEL, true) // random access mode
 {
     // clear the array of locally injected samples
     memset(_localProceduralSamples, 0, NETWORK_BUFFER_LENGTH_BYTES_PER_CHANNEL);

libraries/audio/src/AudioRingBuffer.cpp

@@ -18,16 +18,19 @@
 
 #include "AudioRingBuffer.h"
 
-AudioRingBuffer::AudioRingBuffer(int numFrameSamples) :
+AudioRingBuffer::AudioRingBuffer(int numFrameSamples, bool randomAccessMode) :
     NodeData(),
     _sampleCapacity(numFrameSamples * RING_BUFFER_LENGTH_FRAMES),
     _numFrameSamples(numFrameSamples),
     _isStarved(true),
-    _hasStarted(false)
+    _hasStarted(false),
+    _randomAccessMode(randomAccessMode)
 {
     if (numFrameSamples) {
         _buffer = new int16_t[_sampleCapacity];
-        memset(_buffer, 0, _sampleCapacity * sizeof(int16_t));
+        if (_randomAccessMode) {
+            memset(_buffer, 0, _sampleCapacity * sizeof(int16_t));
+        }
         _nextOutput = _buffer;
         _endOfLastWrite = _buffer;
     } else {
@@ -51,7 +54,9 @@ void AudioRingBuffer::resizeForFrameSize(qint64 numFrameSamples) {
     delete[] _buffer;
     _sampleCapacity = numFrameSamples * RING_BUFFER_LENGTH_FRAMES;
     _buffer = new int16_t[_sampleCapacity];
-    memset(_buffer, 0, _sampleCapacity * sizeof(int16_t));
+    if (_randomAccessMode) {
+        memset(_buffer, 0, _sampleCapacity * sizeof(int16_t));
+    }
     _nextOutput = _buffer;
     _endOfLastWrite = _buffer;
 }
@@ -68,8 +73,14 @@ qint64 AudioRingBuffer::readSamples(int16_t* destination, qint64 maxSamples) {
 qint64 AudioRingBuffer::readData(char *data, qint64 maxSize) {
 
     // only copy up to the number of samples we have available
-    //int numReadSamples = std::min((unsigned) (maxSize / sizeof(int16_t)), samplesAvailable());
+    int numReadSamples = std::min((unsigned) (maxSize / sizeof(int16_t)), samplesAvailable());
-    int numReadSamples = _endOfLastWrite ? (maxSize / sizeof(int16_t)) : samplesAvailable();
+
+    // If we're in random access mode, then we consider our number of available read samples slightly
+    // differently. Namely, if anything has been written, we say we have as many samples as they ask for
+    // otherwise we say we have nothing available
+    if (_randomAccessMode) {
+        numReadSamples = _endOfLastWrite ? (maxSize / sizeof(int16_t)) : 0;
+    }
 
     if (_nextOutput + numReadSamples > _buffer + _sampleCapacity) {
         // we're going to need to do two reads to get this data, it wraps around the edge
@@ -77,15 +88,21 @@ qint64 AudioRingBuffer::readData(char *data, qint64 maxSize) {
         // read to the end of the buffer
         int numSamplesToEnd = (_buffer + _sampleCapacity) - _nextOutput;
         memcpy(data, _nextOutput, numSamplesToEnd * sizeof(int16_t));
-        memset(_nextOutput, 0, numSamplesToEnd * sizeof(int16_t)); // clear it
+        if (_randomAccessMode) {
+            memset(_nextOutput, 0, numSamplesToEnd * sizeof(int16_t)); // clear it
+        }
         
         // read the rest from the beginning of the buffer
         memcpy(data + (numSamplesToEnd * sizeof(int16_t)), _buffer, (numReadSamples - numSamplesToEnd) * sizeof(int16_t));
-        memset(_buffer, 0, (numReadSamples - numSamplesToEnd) * sizeof(int16_t)); // clear it
+        if (_randomAccessMode) {
+            memset(_buffer, 0, (numReadSamples - numSamplesToEnd) * sizeof(int16_t)); // clear it
+        }
     } else {
         // read the data
         memcpy(data, _nextOutput, numReadSamples * sizeof(int16_t));
-        memset(_nextOutput, 0, numReadSamples * sizeof(int16_t)); // clear it
+        if (_randomAccessMode) {
+            memset(_nextOutput, 0, numReadSamples * sizeof(int16_t)); // clear it
+        }
     }
 
     // push the position of _nextOutput by the number of samples read
@@ -111,7 +128,7 @@ qint64 AudioRingBuffer::writeData(const char* data, qint64 maxSize) {
         && (less(_endOfLastWrite, _nextOutput)
             && lessEqual(_nextOutput, shiftedPositionAccomodatingWrap(_endOfLastWrite, samplesToCopy)))) {
         // this read will cross the next output, so call us starved and reset the buffer
-        qDebug() << "Filled the ring buffer. Resetting. <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<";
+        qDebug() << "Filled the ring buffer. Resetting.";
         _endOfLastWrite = _buffer;
         _nextOutput = _buffer;
         _isStarved = true;
@@ -151,13 +168,6 @@ unsigned int AudioRingBuffer::samplesAvailable() const {
         if (sampleDifference < 0) {
             sampleDifference += _sampleCapacity;
         }
-        
-        if (sampleDifference == 0) {
-            qDebug() << "ran dry!!! _endOfLastWrite=" << _endOfLastWrite
-                << "_nextOutput=" << _nextOutput 
-                << "_buffer + _sampleCapacity=" << (_buffer + _sampleCapacity)
-                << " samplesAvailable() == 0!!!!!!!!!!!!!!!!!!!!";
-        }
 
         return sampleDifference;
     }

libraries/audio/src/AudioRingBuffer.h

@@ -39,7 +39,7 @@ const int MIN_SAMPLE_VALUE = std::numeric_limits<int16_t>::min();
 class AudioRingBuffer : public NodeData {
     Q_OBJECT
 public:
-    AudioRingBuffer(int numFrameSamples);
+    AudioRingBuffer(int numFrameSamples, bool randomAccessMode = false);
     ~AudioRingBuffer();
 
     void reset();
@@ -88,6 +88,7 @@ protected:
     int16_t* _buffer;
     bool _isStarved;
     bool _hasStarted;
+    bool _randomAccessMode; /// will this ringbuffer be used for random access? if so, do some special processing
 };
 
 #endif // hifi_AudioRingBuffer_h