complete piping of stereo audio through mixer

assignment-client/src/audio/AudioMixer.cpp

@@ -174,12 +174,15 @@ void AudioMixer::addBufferToMixForListeningNodeWithBuffer(PositionalAudioRingBuf
         }
     }
     
+    const int16_t* nextOutputStart = bufferToAdd->getNextOutput();
+    
+    if (!bufferToAdd->isStereo()) {
+        // this is a mono buffer, which means it gets full attenuation and spatialization
+        
         // if the bearing relative angle to source is > 0 then the delayed channel is the right one
         int delayedChannelOffset = (bearingRelativeAngleToSource > 0.0f) ? 1 : 0;
         int goodChannelOffset = delayedChannelOffset == 0 ? 1 : 0;
         
-    const int16_t* nextOutputStart = bufferToAdd->getNextOutput();
-   
         const int16_t* bufferStart = bufferToAdd->getBuffer();
         int ringBufferSampleCapacity = bufferToAdd->getSampleCapacity();
         
@@ -303,6 +306,29 @@ void AudioMixer::addBufferToMixForListeningNodeWithBuffer(PositionalAudioRingBuf
                 _clientSamples[parentIndex + delayedChannelOffset] = shortResults[3];
             }
         }
+    } else {
+        // stereo buffer - do attenuation but no sample delay for spatialization
+        qDebug() << "Adding a stereo buffer";
+        
+        for (int s = 0; s < NETWORK_BUFFER_LENGTH_SAMPLES_STEREO; s += 4) {
+            // use MMX to clamp four additions at a time
+            
+            __m64 bufferSamples = _mm_set_pi16(_clientSamples[s], _clientSamples[s + 1],
+                                               _clientSamples[s + 2], _clientSamples[s + 3]);
+            __m64 addSamples = _mm_set_pi16(nextOutputStart[s] * attenuationCoefficient,
+                                            nextOutputStart[s + 1] * attenuationCoefficient,
+                                            nextOutputStart[s + 2] * attenuationCoefficient,
+                                            nextOutputStart[s + 3] * attenuationCoefficient);
+            
+            __m64 mmxResult = _mm_adds_pi16(bufferSamples, addSamples);
+            int16_t* shortResults = reinterpret_cast<int16_t*>(&mmxResult);
+            
+            _clientSamples[s] = shortResults[3];
+            _clientSamples[s + 1] = shortResults[2];
+            _clientSamples[s + 2] = shortResults[1];
+            _clientSamples[s + 3] = shortResults[0];
+        }
+    }
 }
 
 void AudioMixer::prepareMixForListeningNode(Node* node) {

assignment-client/src/audio/AudioMixerClientData.cpp

@@ -51,9 +51,21 @@ int AudioMixerClientData::parseData(const QByteArray& packet) {
         // grab the AvatarAudioRingBuffer from the vector (or create it if it doesn't exist)
         AvatarAudioRingBuffer* avatarRingBuffer = getAvatarAudioRingBuffer();
         
+        // read the first byte after the header to see if this is a stereo or mono buffer
+        quint8 channelFlag = packet.at(numBytesForPacketHeader(packet));
+        bool isStereo = channelFlag == 1;
+        
+        if (avatarRingBuffer && avatarRingBuffer->isStereo() != isStereo) {
+            // there's a mismatch in the buffer channels for the incoming and current buffer
+            // so delete our current buffer and create a new one
+            _ringBuffers.removeOne(avatarRingBuffer);
+            avatarRingBuffer->deleteLater();
+            avatarRingBuffer = NULL;
+        }
+
         if (!avatarRingBuffer) {
             // we don't have an AvatarAudioRingBuffer yet, so add it
-            avatarRingBuffer = new AvatarAudioRingBuffer();
+            avatarRingBuffer = new AvatarAudioRingBuffer(isStereo);
             _ringBuffers.push_back(avatarRingBuffer);
         }
 

assignment-client/src/audio/AudioMixerClientData.h

@@ -24,14 +24,14 @@ public:
     AudioMixerClientData();
     ~AudioMixerClientData();
     
-    const std::vector<PositionalAudioRingBuffer*> getRingBuffers() const { return _ringBuffers; }
+    const QList<PositionalAudioRingBuffer*> getRingBuffers() const { return _ringBuffers; }
     AvatarAudioRingBuffer* getAvatarAudioRingBuffer() const;
     
     int parseData(const QByteArray& packet);
     void checkBuffersBeforeFrameSend(int jitterBufferLengthSamples);
     void pushBuffersAfterFrameSend();
 private:
-    std::vector<PositionalAudioRingBuffer*> _ringBuffers;
+    QList<PositionalAudioRingBuffer*> _ringBuffers;
 };
 
 #endif // hifi_AudioMixerClientData_h

assignment-client/src/audio/AvatarAudioRingBuffer.cpp

@@ -13,8 +13,8 @@
 
 #include "AvatarAudioRingBuffer.h"
 
-AvatarAudioRingBuffer::AvatarAudioRingBuffer() :
+AvatarAudioRingBuffer::AvatarAudioRingBuffer(bool isStereo) :
-    PositionalAudioRingBuffer(PositionalAudioRingBuffer::Microphone) {
+    PositionalAudioRingBuffer(PositionalAudioRingBuffer::Microphone, isStereo) {
     
 }
 

assignment-client/src/audio/AvatarAudioRingBuffer.h

@@ -18,7 +18,7 @@
 
 class AvatarAudioRingBuffer : public PositionalAudioRingBuffer {
 public:
-    AvatarAudioRingBuffer();
+    AvatarAudioRingBuffer(bool isStereo = false);
     
     int parseData(const QByteArray& packet);
 private:

interface/src/Audio.cpp

@@ -641,6 +641,9 @@ void Audio::handleAudioInput() {
 
             char* currentPacketPtr = audioDataPacket + populatePacketHeader(audioDataPacket, packetType);
             
+            // set the mono/stereo byte
+            *currentPacketPtr++ = isStereo;
+
             // memcpy the three float positions
             memcpy(currentPacketPtr, &headPosition, sizeof(headPosition));
             currentPacketPtr += (sizeof(headPosition));
@@ -649,9 +652,6 @@ void Audio::handleAudioInput() {
             memcpy(currentPacketPtr, &headOrientation, sizeof(headOrientation));
             currentPacketPtr += sizeof(headOrientation);
             
-            // set the mono/stereo byte
-            *currentPacketPtr++ = isStereo;
-            
             nodeList->writeDatagram(audioDataPacket, numAudioBytes + leadingBytes, audioMixer);
 
             Application::getInstance()->getBandwidthMeter()->outputStream(BandwidthMeter::AUDIO)

libraries/audio/src/PositionalAudioRingBuffer.cpp

@@ -41,6 +41,9 @@ int PositionalAudioRingBuffer::parseData(const QByteArray& packet) {
     // skip the packet header (includes the source UUID)
     int readBytes = numBytesForPacketHeader(packet);
     
+    // hop over the channel flag that has already been read in AudioMixerClientData
+    readBytes += sizeof(quint8);
+    // read the positional data
     readBytes += parsePositionalData(packet.mid(readBytes));
    
     if (packetTypeForPacket(packet) == PacketTypeSilentAudioFrame) {

libraries/audio/src/PositionalAudioRingBuffer.h

@@ -41,6 +41,8 @@ public:
     
     bool shouldLoopbackForNode() const { return _shouldLoopbackForNode; }
     
+    bool isStereo() const { return _isStereo; }
+    
     PositionalAudioRingBuffer::Type getType() const { return _type; }
     const glm::vec3& getPosition() const { return _position; }
     const glm::quat& getOrientation() const { return _orientation; }