have the AudioMixer handle silent audio, send silence from Interface when gate closed

interface/src/Audio.cpp

@@ -436,9 +436,8 @@ void Audio::handleAudioInput() {
                     }
                 }
                 if (!_noiseGateOpen) {
-                    for (int i = 0; i < NETWORK_BUFFER_LENGTH_SAMPLES_PER_CHANNEL; i++) {
+                    memset(monoAudioSamples, 0, NETWORK_BUFFER_LENGTH_SAMPLES_PER_CHANNEL);
-                        monoAudioSamples[i] = 0;
+                    _lastInputLoudness = 0;
-                    }
                 }
             }
 
@@ -482,9 +481,26 @@ void Audio::handleAudioInput() {
 
             // we need the amount of bytes in the buffer + 1 for type
             // + 12 for 3 floats for position + float for bearing + 1 attenuation byte
-
+            
-            PacketType packetType = Menu::getInstance()->isOptionChecked(MenuOption::EchoServerAudio)
+            int numAudioBytes = 0;
-                ? PacketTypeMicrophoneAudioWithEcho : PacketTypeMicrophoneAudioNoEcho;
+            
+            PacketType packetType;
+            if (_lastInputLoudness == 0) {
+                packetType = PacketTypeSilentAudioListener;
+                
+                // we need to indicate how many silent samples this is to the audio mixer
+                monoAudioSamples[0] = NETWORK_BUFFER_LENGTH_SAMPLES_PER_CHANNEL;
+                numAudioBytes = sizeof(int16_t);
+                
+            } else {
+                numAudioBytes = NETWORK_BUFFER_LENGTH_BYTES_PER_CHANNEL;
+                
+                if (Menu::getInstance()->isOptionChecked(MenuOption::EchoServerAudio)) {
+                    packetType = PacketTypeMicrophoneAudioWithEcho;
+                } else {
+                    packetType = PacketTypeMicrophoneAudioNoEcho;
+                }
+            }
 
             char* currentPacketPtr = monoAudioDataPacket + populatePacketHeader(monoAudioDataPacket, packetType);
 
@@ -495,10 +511,8 @@ void Audio::handleAudioInput() {
             // memcpy our orientation
             memcpy(currentPacketPtr, &headOrientation, sizeof(headOrientation));
             currentPacketPtr += sizeof(headOrientation);
-
+            
-            nodeList->writeDatagram(monoAudioDataPacket,
+            nodeList->writeDatagram(monoAudioDataPacket, numAudioBytes + leadingBytes, audioMixer);
-                                    NETWORK_BUFFER_LENGTH_BYTES_PER_CHANNEL + leadingBytes,
-                                    audioMixer);
 
             Application::getInstance()->getBandwidthMeter()->outputStream(BandwidthMeter::AUDIO)
                 .updateValue(NETWORK_BUFFER_LENGTH_BYTES_PER_CHANNEL + leadingBytes);
@@ -638,7 +652,14 @@ void Audio::addProceduralSounds(int16_t* monoInput, int numSamples) {
 
             int16_t collisionSample = (int16_t) sample;
 
+            _lastInputLoudness = 0;
+            
             monoInput[i] = glm::clamp(monoInput[i] + collisionSample, MIN_SAMPLE_VALUE, MAX_SAMPLE_VALUE);
+            
+            _lastInputLoudness += fabsf(monoInput[i]);
+            _lastInputLoudness /= numSamples;
+            _lastInputLoudness /= MAX_SAMPLE_VALUE;
+            
             _localProceduralSamples[i] = glm::clamp(_localProceduralSamples[i] + collisionSample,
                                                   MIN_SAMPLE_VALUE, MAX_SAMPLE_VALUE);
 
@@ -662,7 +683,14 @@ void Audio::addProceduralSounds(int16_t* monoInput, int numSamples) {
 
             int16_t collisionSample = (int16_t) sample;
 
+            _lastInputLoudness = 0;
+            
             monoInput[i] = glm::clamp(monoInput[i] + collisionSample, MIN_SAMPLE_VALUE, MAX_SAMPLE_VALUE);
+            
+            _lastInputLoudness += fabsf(monoInput[i]);
+            _lastInputLoudness /= numSamples;
+            _lastInputLoudness /= MAX_SAMPLE_VALUE;
+            
             _localProceduralSamples[i] = glm::clamp(_localProceduralSamples[i] + collisionSample,
                                                   MIN_SAMPLE_VALUE, MAX_SAMPLE_VALUE);
 

libraries/audio/src/AudioRingBuffer.cpp

@@ -156,6 +156,19 @@ unsigned int AudioRingBuffer::samplesAvailable() const {
     }
 }
 
+void AudioRingBuffer::addSilentFrame(int numSilentSamples) {
+    // setup the silent frame
+    int numSilentBytes = numSilentSamples * sizeof(int16_t);
+    char* silentFrame = new char[numSilentBytes];
+    memset(silentFrame, 0, numSilentBytes);
+    
+    // write it
+    writeData(silentFrame, numSilentBytes);
+    
+    // delete the temporary silent frame
+    delete[] silentFrame;
+}
+
 bool AudioRingBuffer::isNotStarvedOrHasMinimumSamples(unsigned int numRequiredSamples) const {
     if (!_isStarved) {
         return true;

libraries/audio/src/AudioRingBuffer.h

@@ -70,6 +70,8 @@ public:
     void setIsStarved(bool isStarved) { _isStarved = isStarved; }
     
     bool hasStarted() const { return _hasStarted; }
+    
+    void addSilentFrame(int numSilentSamples);
 protected:
     // disallow copying of AudioRingBuffer objects
     AudioRingBuffer(const AudioRingBuffer&);

libraries/audio/src/PositionalAudioRingBuffer.cpp

@@ -44,8 +44,19 @@ int PositionalAudioRingBuffer::parseData(const QByteArray& packet) {
     packetStream.skipRawData(numBytesForPacketHeader(packet));
     
     packetStream.skipRawData(parsePositionalData(packet.mid(packetStream.device()->pos())));
-    packetStream.skipRawData(writeData(packet.data() + packetStream.device()->pos(),
+   
-                                       packet.size() - packetStream.device()->pos()));
+    if (packetTypeForPacket(packet) == PacketTypeSilentAudioListener) {
+        // this source had no audio to send us, but this counts as a packet
+        // write silence equivalent to the number of silent samples they just sent us
+        int16_t numSilentSamples;
+        packetStream >> numSilentSamples;
+        addSilentFrame(numSilentSamples);
+    } else {
+        // there is audio data to read
+        packetStream.skipRawData(writeData(packet.data() + packetStream.device()->pos(),
+                                           packet.size() - packetStream.device()->pos()));
+    }
+    
 
     return packetStream.device()->pos();
 }

libraries/shared/src/PacketHeaders.h

@@ -32,7 +32,7 @@ enum PacketType {
     PacketTypeMicrophoneAudioNoEcho,
     PacketTypeMicrophoneAudioWithEcho,
     PacketTypeBulkAvatarData,
-    PacketTypeTransmitterData, // usable
+    PacketTypeSilentAudioListener,
     PacketTypeEnvironmentData,
     PacketTypeDomainListRequest,
     PacketTypeRequestAssignment,