add AudioNoiseGate to Agent

assignment-client/src/Agent.cpp

@@ -371,25 +371,39 @@ void Agent::executeScript() {
     using namespace recording;
     static const FrameType AUDIO_FRAME_TYPE = Frame::registerFrameType(AudioConstants::getAudioFrameName());
     Frame::registerFrameHandler(AUDIO_FRAME_TYPE, [this, &scriptedAvatar](Frame::ConstPointer frame) {
-        const QByteArray& audio = frame->data;
         static quint16 audioSequenceNumber{ 0 };
-        Transform audioTransform;
 
+        QByteArray audio(frame->data);
+
+        if (_isNoiseGateEnabled) {
+            static int numSamples = AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL;
+            _noiseGate.gateSamples(reinterpret_cast<int16_t*>(audio.data()), numSamples);
+        }
+
+        computeLoudness(&audio, scriptedAvatar);
+
+        // the codec needs a flush frame before sending silent packets, so
+        // do not send one if the gate closed in this block (eventually this can be crossfaded).
+        auto packetType = PacketType::MicrophoneAudioNoEcho;
+        if (scriptedAvatar->getAudioLoudness() == 0.0f && !_noiseGate.closedInLastBlock()) {
+            packetType = PacketType::SilentAudioFrame;
+        }
+
+        Transform audioTransform;
         auto headOrientation = scriptedAvatar->getHeadOrientation();
         audioTransform.setTranslation(scriptedAvatar->getPosition());
         audioTransform.setRotation(headOrientation);
 
-        computeLoudness(&audio, scriptedAvatar);
-
         QByteArray encodedBuffer;
         if (_encoder) {
             _encoder->encode(audio, encodedBuffer);
         } else {
             encodedBuffer = audio;
         }
+
         AbstractAudioInterface::emitAudioPacket(encodedBuffer.data(), encodedBuffer.size(), audioSequenceNumber,
             audioTransform, scriptedAvatar->getPosition(), glm::vec3(0),
-            PacketType::MicrophoneAudioNoEcho, _selectedCodecName);
+            packetType, _selectedCodecName);
     });
 
     auto avatarHashMap = DependencyManager::set<AvatarHashMap>();

assignment-client/src/Agent.h

@@ -29,6 +29,7 @@
 
 #include <plugins/CodecPlugin.h>
 
+#include "AudioNoiseGate.h"
 #include "MixedAudioStream.h"
 #include "avatars/ScriptableAvatar.h"
 
@@ -110,6 +111,7 @@ private:
     QTimer* _avatarIdentityTimer = nullptr;
     QHash<QUuid, quint16> _outgoingScriptAudioSequenceNumbers;
 
+    AudioNoiseGate _noiseGate;
     bool _isNoiseGateEnabled { false };
 
     CodecPluginPointer _codec;