Merge pull request #261 from birarda/mixer-crash

de-thread the audio mixer to hopefully resolve its constant restarts
This commit is contained in:
ZappoMan 2013-05-09 13:53:16 -07:00
commit a1a0bf320f
3 changed files with 211 additions and 272 deletions

View file

@ -71,23 +71,42 @@ void plateauAdditionOfSamples(int16_t &mixSample, int16_t sampleToAdd) {
mixSample = normalizedSample;
}
void *sendBuffer(void *args) {
int sentBytes;
void attachNewBufferToAgent(Agent *newAgent) {
if (!newAgent->getLinkedData()) {
newAgent->setLinkedData(new AudioRingBuffer(RING_BUFFER_SAMPLES, BUFFER_LENGTH_SAMPLES_PER_CHANNEL));
}
}
int main(int argc, const char* argv[]) {
setvbuf(stdout, NULL, _IOLBF, 0);
AgentList* agentList = AgentList::createInstance(AGENT_TYPE_AUDIO_MIXER, MIXER_LISTEN_PORT);
ssize_t receivedBytes = 0;
agentList->linkedDataCreateCallback = attachNewBufferToAgent;
agentList->startSilentAgentRemovalThread();
agentList->startDomainServerCheckInThread();
unsigned char* packetData = new unsigned char[MAX_PACKET_SIZE];
sockaddr* agentAddress = new sockaddr;
// make sure our agent socket is non-blocking
agentList->getAgentSocket().setBlocking(false);
int nextFrame = 0;
timeval startTime;
AgentList* agentList = AgentList::getInstance();
gettimeofday(&startTime, NULL);
while (true) {
sentBytes = 0;
// enumerate the agents, check if we can add audio from the agent to current mix
for (AgentList::iterator agent = agentList->begin(); agent != agentList->end(); agent++) {
AudioRingBuffer* agentBuffer = (AudioRingBuffer*) agent->getLinkedData();
if (agentBuffer && agentBuffer->getEndOfLastWrite() != NULL) {
if (agentBuffer->getEndOfLastWrite()) {
if (!agentBuffer->isStarted()
&& agentBuffer->diffLastWriteNextOutput() <= BUFFER_LENGTH_SAMPLES_PER_CHANNEL + JITTER_BUFFER_SAMPLES) {
printf("Held back buffer for agent with ID %d.\n", agent->getAgentId());
@ -107,132 +126,131 @@ void *sendBuffer(void *args) {
int numAgents = agentList->size();
float distanceCoefficients[numAgents][numAgents];
memset(distanceCoefficients, 0, sizeof(distanceCoefficients));
for (AgentList::iterator agent = agentList->begin(); agent != agentList->end(); agent++) {
AudioRingBuffer* agentRingBuffer = (AudioRingBuffer*) agent->getLinkedData();
int16_t clientMix[BUFFER_LENGTH_SAMPLES_PER_CHANNEL * 2] = {};
if (agentRingBuffer) {
int16_t clientMix[BUFFER_LENGTH_SAMPLES_PER_CHANNEL * 2] = {};
for (AgentList::iterator otherAgent = agentList->begin(); otherAgent != agentList->end(); otherAgent++) {
if (otherAgent != agent || (otherAgent == agent && agentRingBuffer->shouldLoopbackForAgent())) {
AudioRingBuffer* otherAgentBuffer = (AudioRingBuffer*) otherAgent->getLinkedData();
for (AgentList::iterator otherAgent = agentList->begin(); otherAgent != agentList->end(); otherAgent++) {
if (otherAgent != agent || (otherAgent == agent && agentRingBuffer->shouldLoopbackForAgent())) {
AudioRingBuffer* otherAgentBuffer = (AudioRingBuffer*) otherAgent->getLinkedData();
if (otherAgentBuffer->shouldBeAddedToMix()) {
if (otherAgentBuffer->shouldBeAddedToMix()) {
float bearingRelativeAngleToSource = 0.f;
float attenuationCoefficient = 1.f;
int numSamplesDelay = 0;
float weakChannelAmplitudeRatio = 1.f;
if (otherAgent != agent) {
Position agentPosition = agentRingBuffer->getPosition();
Position otherAgentPosition = otherAgentBuffer->getPosition();
float bearingRelativeAngleToSource = 0.f;
float attenuationCoefficient = 1.f;
int numSamplesDelay = 0;
float weakChannelAmplitudeRatio = 1.f;
// calculate the distance to the other agent
if (otherAgent != agent) {
float *agentPosition = agentRingBuffer->getPosition();
float *otherAgentPosition = otherAgentBuffer->getPosition();
// use the distance to the other agent to calculate the change in volume for this frame
int lowAgentIndex = std::min(agent.getAgentIndex(), otherAgent.getAgentIndex());
int highAgentIndex = std::max(agent.getAgentIndex(), otherAgent.getAgentIndex());
if (distanceCoefficients[lowAgentIndex][highAgentIndex] == 0) {
float distanceToAgent = sqrtf(powf(agentPosition.x - otherAgentPosition.x, 2) +
powf(agentPosition.y - otherAgentPosition.y, 2) +
powf(agentPosition.z - otherAgentPosition.z, 2));
// calculate the distance to the other agent
// use the distance to the other agent to calculate the change in volume for this frame
int lowAgentIndex = std::min(agent.getAgentIndex(), otherAgent.getAgentIndex());
int highAgentIndex = std::max(agent.getAgentIndex(), otherAgent.getAgentIndex());
if (distanceCoefficients[lowAgentIndex][highAgentIndex] == 0) {
float distanceToAgent = sqrtf(powf(agentPosition[0] - otherAgentPosition[0], 2) +
powf(agentPosition[1] - otherAgentPosition[1], 2) +
powf(agentPosition[2] - otherAgentPosition[2], 2));
float minCoefficient = std::min(1.0f,
powf(0.5,
(logf(DISTANCE_RATIO * distanceToAgent) / logf(3)) - 1));
distanceCoefficients[lowAgentIndex][highAgentIndex] = minCoefficient;
}
// get the angle from the right-angle triangle
float triangleAngle = atan2f(fabsf(agentPosition[2] - otherAgentPosition[2]),
fabsf(agentPosition[0] - otherAgentPosition[0])) * (180 / M_PI);
float absoluteAngleToSource = 0;
bearingRelativeAngleToSource = 0;
// find the angle we need for calculation based on the orientation of the triangle
if (otherAgentPosition[0] > agentPosition[0]) {
if (otherAgentPosition[2] > agentPosition[2]) {
absoluteAngleToSource = -90 + triangleAngle;
} else {
absoluteAngleToSource = -90 - triangleAngle;
}
} else {
if (otherAgentPosition[2] > agentPosition[2]) {
absoluteAngleToSource = 90 - triangleAngle;
} else {
absoluteAngleToSource = 90 + triangleAngle;
}
}
bearingRelativeAngleToSource = absoluteAngleToSource - agentRingBuffer->getBearing();
if (bearingRelativeAngleToSource > 180) {
bearingRelativeAngleToSource -= 360;
} else if (bearingRelativeAngleToSource < -180) {
bearingRelativeAngleToSource += 360;
}
float angleOfDelivery = absoluteAngleToSource - otherAgentBuffer->getBearing();
if (angleOfDelivery > 180) {
angleOfDelivery -= 360;
} else if (angleOfDelivery < -180) {
angleOfDelivery += 360;
}
float offAxisCoefficient = MAX_OFF_AXIS_ATTENUATION +
(OFF_AXIS_ATTENUATION_FORMULA_STEP * (fabsf(angleOfDelivery) / 90.0f));
attenuationCoefficient = distanceCoefficients[lowAgentIndex][highAgentIndex]
* otherAgentBuffer->getAttenuationRatio()
* offAxisCoefficient;
bearingRelativeAngleToSource *= (M_PI / 180);
float sinRatio = fabsf(sinf(bearingRelativeAngleToSource));
numSamplesDelay = PHASE_DELAY_AT_90 * sinRatio;
weakChannelAmplitudeRatio = 1 - (PHASE_AMPLITUDE_RATIO_AT_90 * sinRatio);
float minCoefficient = std::min(1.0f,
powf(0.5,
(logf(DISTANCE_RATIO * distanceToAgent) / logf(3)) - 1));
distanceCoefficients[lowAgentIndex][highAgentIndex] = minCoefficient;
}
int16_t* goodChannel = bearingRelativeAngleToSource > 0.0f
? clientMix + BUFFER_LENGTH_SAMPLES_PER_CHANNEL
: clientMix;
int16_t* delayedChannel = bearingRelativeAngleToSource > 0.0f
? clientMix
: clientMix + BUFFER_LENGTH_SAMPLES_PER_CHANNEL;
int16_t* delaySamplePointer = otherAgentBuffer->getNextOutput() == otherAgentBuffer->getBuffer()
// get the angle from the right-angle triangle
float triangleAngle = atan2f(fabsf(agentPosition.z - otherAgentPosition.z),
fabsf(agentPosition.x - otherAgentPosition.x)) * (180 / M_PI);
float absoluteAngleToSource = 0;
bearingRelativeAngleToSource = 0;
// find the angle we need for calculation based on the orientation of the triangle
if (otherAgentPosition.x > agentPosition.x) {
if (otherAgentPosition.z > agentPosition.z) {
absoluteAngleToSource = -90 + triangleAngle;
} else {
absoluteAngleToSource = -90 - triangleAngle;
}
} else {
if (otherAgentPosition.z > agentPosition.z) {
absoluteAngleToSource = 90 - triangleAngle;
} else {
absoluteAngleToSource = 90 + triangleAngle;
}
}
bearingRelativeAngleToSource = absoluteAngleToSource - agentRingBuffer->getBearing();
if (bearingRelativeAngleToSource > 180) {
bearingRelativeAngleToSource -= 360;
} else if (bearingRelativeAngleToSource < -180) {
bearingRelativeAngleToSource += 360;
}
float angleOfDelivery = absoluteAngleToSource - otherAgentBuffer->getBearing();
if (angleOfDelivery > 180) {
angleOfDelivery -= 360;
} else if (angleOfDelivery < -180) {
angleOfDelivery += 360;
}
float offAxisCoefficient = MAX_OFF_AXIS_ATTENUATION +
(OFF_AXIS_ATTENUATION_FORMULA_STEP * (fabsf(angleOfDelivery) / 90.0f));
attenuationCoefficient = distanceCoefficients[lowAgentIndex][highAgentIndex]
* otherAgentBuffer->getAttenuationRatio()
* offAxisCoefficient;
bearingRelativeAngleToSource *= (M_PI / 180);
float sinRatio = fabsf(sinf(bearingRelativeAngleToSource));
numSamplesDelay = PHASE_DELAY_AT_90 * sinRatio;
weakChannelAmplitudeRatio = 1 - (PHASE_AMPLITUDE_RATIO_AT_90 * sinRatio);
}
int16_t* goodChannel = bearingRelativeAngleToSource > 0.0f
? clientMix + BUFFER_LENGTH_SAMPLES_PER_CHANNEL
: clientMix;
int16_t* delayedChannel = bearingRelativeAngleToSource > 0.0f
? clientMix
: clientMix + BUFFER_LENGTH_SAMPLES_PER_CHANNEL;
int16_t* delaySamplePointer = otherAgentBuffer->getNextOutput() == otherAgentBuffer->getBuffer()
? otherAgentBuffer->getBuffer() + RING_BUFFER_SAMPLES - numSamplesDelay
: otherAgentBuffer->getNextOutput() - numSamplesDelay;
for (int s = 0; s < BUFFER_LENGTH_SAMPLES_PER_CHANNEL; s++) {
for (int s = 0; s < BUFFER_LENGTH_SAMPLES_PER_CHANNEL; s++) {
if (s < numSamplesDelay) {
// pull the earlier sample for the delayed channel
int earlierSample = delaySamplePointer[s] * attenuationCoefficient;
plateauAdditionOfSamples(delayedChannel[s], earlierSample * weakChannelAmplitudeRatio);
}
int16_t currentSample = (otherAgentBuffer->getNextOutput()[s] * attenuationCoefficient);
plateauAdditionOfSamples(goodChannel[s], currentSample);
if (s + numSamplesDelay < BUFFER_LENGTH_SAMPLES_PER_CHANNEL) {
plateauAdditionOfSamples(delayedChannel[s + numSamplesDelay],
currentSample * weakChannelAmplitudeRatio);
}
if (s < numSamplesDelay) {
// pull the earlier sample for the delayed channel
int earlierSample = delaySamplePointer[s] * attenuationCoefficient;
plateauAdditionOfSamples(delayedChannel[s], earlierSample * weakChannelAmplitudeRatio);
}
int16_t currentSample = (otherAgentBuffer->getNextOutput()[s] * attenuationCoefficient);
plateauAdditionOfSamples(goodChannel[s], currentSample);
if (s + numSamplesDelay < BUFFER_LENGTH_SAMPLES_PER_CHANNEL) {
plateauAdditionOfSamples(delayedChannel[s + numSamplesDelay],
currentSample * weakChannelAmplitudeRatio);
}
}
}
}
agentList->getAgentSocket().send(agent->getPublicSocket(), clientMix, BUFFER_LENGTH_BYTES);
}
}
agentList->getAgentSocket().send(agent->getPublicSocket(), clientMix, BUFFER_LENGTH_BYTES);
}
// push forward the next output pointers for any audio buffers we used
for (AgentList::iterator agent = agentList->begin(); agent != agentList->end(); agent++) {
AudioRingBuffer* agentBuffer = (AudioRingBuffer*) agent->getLinkedData();
if (agentBuffer && agentBuffer->shouldBeAddedToMix()) {
@ -246,45 +264,8 @@ void *sendBuffer(void *args) {
}
}
double usecToSleep = usecTimestamp(&startTime) + (++nextFrame * BUFFER_SEND_INTERVAL_USECS) - usecTimestampNow();
if (usecToSleep > 0) {
usleep(usecToSleep);
} else {
std::cout << "Took too much time, not sleeping!\n";
}
}
pthread_exit(0);
}
void attachNewBufferToAgent(Agent *newAgent) {
if (newAgent->getLinkedData() == NULL) {
newAgent->setLinkedData(new AudioRingBuffer(RING_BUFFER_SAMPLES, BUFFER_LENGTH_SAMPLES_PER_CHANNEL));
}
}
int main(int argc, const char* argv[]) {
setvbuf(stdout, NULL, _IOLBF, 0);
AgentList* agentList = AgentList::createInstance(AGENT_TYPE_AUDIO_MIXER, MIXER_LISTEN_PORT);
ssize_t receivedBytes = 0;
agentList->linkedDataCreateCallback = attachNewBufferToAgent;
agentList->startSilentAgentRemovalThread();
agentList->startDomainServerCheckInThread();
unsigned char *packetData = new unsigned char[MAX_PACKET_SIZE];
pthread_t sendBufferThread;
pthread_create(&sendBufferThread, NULL, sendBuffer, NULL);
sockaddr *agentAddress = new sockaddr;
while (true) {
if(agentList->getAgentSocket().receive(agentAddress, packetData, &receivedBytes)) {
// pull any new audio data from agents off of the network stack
while (agentList->getAgentSocket().receive(agentAddress, packetData, &receivedBytes)) {
if (packetData[0] == PACKET_HEADER_INJECT_AUDIO) {
if (agentList->addOrUpdateAgent(agentAddress, agentAddress, packetData[0], agentList->getLastAgentID())) {
@ -294,9 +275,15 @@ int main(int argc, const char* argv[]) {
agentList->updateAgentWithData(agentAddress, packetData, receivedBytes);
}
}
double usecToSleep = usecTimestamp(&startTime) + (++nextFrame * BUFFER_SEND_INTERVAL_USECS) - usecTimestampNow();
if (usecToSleep > 0) {
usleep(usecToSleep);
} else {
std::cout << "Took too much time, not sleeping!\n";
}
}
pthread_join(sendBufferThread, NULL);
return 0;
}

View file

@ -10,118 +10,63 @@
#include "AudioRingBuffer.h"
AudioRingBuffer::AudioRingBuffer(int ringSamples, int bufferSamples) :
ringBufferLengthSamples(ringSamples),
bufferLengthSamples(bufferSamples),
endOfLastWrite(NULL),
started(false),
_ringBufferLengthSamples(ringSamples),
_bufferLengthSamples(bufferSamples),
_endOfLastWrite(NULL),
_started(false),
_shouldBeAddedToMix(false),
_shouldLoopbackForAgent(false) {
buffer = new int16_t[ringBufferLengthSamples];
nextOutput = buffer;
_buffer = new int16_t[_ringBufferLengthSamples];
_nextOutput = _buffer;
};
AudioRingBuffer::AudioRingBuffer(const AudioRingBuffer &otherRingBuffer) {
ringBufferLengthSamples = otherRingBuffer.ringBufferLengthSamples;
bufferLengthSamples = otherRingBuffer.bufferLengthSamples;
started = otherRingBuffer.started;
_ringBufferLengthSamples = otherRingBuffer._ringBufferLengthSamples;
_bufferLengthSamples = otherRingBuffer._bufferLengthSamples;
_started = otherRingBuffer._started;
_shouldBeAddedToMix = otherRingBuffer._shouldBeAddedToMix;
_shouldLoopbackForAgent = otherRingBuffer._shouldLoopbackForAgent;
buffer = new int16_t[ringBufferLengthSamples];
memcpy(buffer, otherRingBuffer.buffer, sizeof(int16_t) * ringBufferLengthSamples);
_buffer = new int16_t[_ringBufferLengthSamples];
memcpy(_buffer, otherRingBuffer._buffer, sizeof(int16_t) * _ringBufferLengthSamples);
nextOutput = buffer + (otherRingBuffer.nextOutput - otherRingBuffer.buffer);
endOfLastWrite = buffer + (otherRingBuffer.endOfLastWrite - otherRingBuffer.buffer);
_nextOutput = _buffer + (otherRingBuffer._nextOutput - otherRingBuffer._buffer);
_endOfLastWrite = _buffer + (otherRingBuffer._endOfLastWrite - otherRingBuffer._buffer);
}
AudioRingBuffer::~AudioRingBuffer() {
delete[] buffer;
delete[] _buffer;
};
AudioRingBuffer* AudioRingBuffer::clone() const {
return new AudioRingBuffer(*this);
}
int16_t* AudioRingBuffer::getNextOutput() {
return nextOutput;
}
void AudioRingBuffer::setNextOutput(int16_t *newPointer) {
nextOutput = newPointer;
}
int16_t* AudioRingBuffer::getEndOfLastWrite() {
return endOfLastWrite;
}
void AudioRingBuffer::setEndOfLastWrite(int16_t *newPointer) {
endOfLastWrite = newPointer;
}
int16_t* AudioRingBuffer::getBuffer() {
return buffer;
}
bool AudioRingBuffer::isStarted() {
return started;
}
void AudioRingBuffer::setStarted(bool status) {
started = status;
}
float* AudioRingBuffer::getPosition() {
return position;
}
void AudioRingBuffer::setPosition(float *newPosition) {
position[0] = newPosition[0];
position[1] = newPosition[1];
position[2] = newPosition[2];
}
float AudioRingBuffer::getAttenuationRatio() {
return attenuationRatio;
}
void AudioRingBuffer::setAttenuationRatio(float newAttenuation) {
attenuationRatio = newAttenuation;
}
float AudioRingBuffer::getBearing() {
return bearing;
}
void AudioRingBuffer::setBearing(float newBearing) {
bearing = newBearing;
}
const int AGENT_LOOPBACK_MODIFIER = 307;
int AudioRingBuffer::parseData(unsigned char* sourceBuffer, int numBytes) {
if (numBytes > (bufferLengthSamples * sizeof(int16_t))) {
if (numBytes > (_bufferLengthSamples * sizeof(int16_t))) {
unsigned char *dataPtr = sourceBuffer + 1;
for (int p = 0; p < 3; p ++) {
memcpy(&position[p], dataPtr, sizeof(float));
dataPtr += sizeof(float);
}
memcpy(&_position, dataPtr, sizeof(_position));
dataPtr += (sizeof(_position));
unsigned int attenuationByte = *(dataPtr++);
attenuationRatio = attenuationByte / 255.0f;
_attenuationRatio = attenuationByte / 255.0f;
memcpy(&bearing, dataPtr, sizeof(float));
dataPtr += sizeof(bearing);
memcpy(&_bearing, dataPtr, sizeof(float));
dataPtr += sizeof(_bearing);
if (bearing > 180 || bearing < -180) {
if (_bearing > 180 || _bearing < -180) {
// we were passed an invalid bearing because this agent wants loopback (pressed the H key)
_shouldLoopbackForAgent = true;
// correct the bearing
bearing = bearing > 0
? bearing - AGENT_LOOPBACK_MODIFIER
: bearing + AGENT_LOOPBACK_MODIFIER;
_bearing = _bearing > 0
? _bearing - AGENT_LOOPBACK_MODIFIER
: _bearing + AGENT_LOOPBACK_MODIFIER;
} else {
_shouldLoopbackForAgent = false;
}
@ -129,33 +74,33 @@ int AudioRingBuffer::parseData(unsigned char* sourceBuffer, int numBytes) {
sourceBuffer = dataPtr;
}
if (endOfLastWrite == NULL) {
endOfLastWrite = buffer;
} else if (diffLastWriteNextOutput() > ringBufferLengthSamples - bufferLengthSamples) {
endOfLastWrite = buffer;
nextOutput = buffer;
started = false;
if (!_endOfLastWrite) {
_endOfLastWrite = _buffer;
} else if (diffLastWriteNextOutput() > _ringBufferLengthSamples - _bufferLengthSamples) {
_endOfLastWrite = _buffer;
_nextOutput = _buffer;
_started = false;
}
memcpy(endOfLastWrite, sourceBuffer, bufferLengthSamples * sizeof(int16_t));
memcpy(_endOfLastWrite, sourceBuffer, _bufferLengthSamples * sizeof(int16_t));
endOfLastWrite += bufferLengthSamples;
_endOfLastWrite += _bufferLengthSamples;
if (endOfLastWrite >= buffer + ringBufferLengthSamples) {
endOfLastWrite = buffer;
if (_endOfLastWrite >= _buffer + _ringBufferLengthSamples) {
_endOfLastWrite = _buffer;
}
return numBytes;
}
short AudioRingBuffer::diffLastWriteNextOutput() {
if (endOfLastWrite == NULL) {
if (!_endOfLastWrite) {
return 0;
} else {
short sampleDifference = endOfLastWrite - nextOutput;
short sampleDifference = _endOfLastWrite - _nextOutput;
if (sampleDifference < 0) {
sampleDifference += ringBufferLengthSamples;
sampleDifference += _ringBufferLengthSamples;
}
return sampleDifference;

View file

@ -12,6 +12,12 @@
#include <stdint.h>
#include "AgentData.h"
struct Position {
float x;
float y;
float z;
};
class AudioRingBuffer : public AgentData {
public:
AudioRingBuffer(int ringSamples, int bufferSamples);
@ -21,35 +27,36 @@ public:
int parseData(unsigned char* sourceBuffer, int numBytes);
AudioRingBuffer* clone() const;
int16_t* getNextOutput();
void setNextOutput(int16_t *newPointer);
int16_t* getEndOfLastWrite();
void setEndOfLastWrite(int16_t *newPointer);
int16_t* getBuffer();
bool isStarted();
void setStarted(bool status);
int16_t* getNextOutput() const { return _nextOutput; }
void setNextOutput(int16_t* nextOutput) { _nextOutput = nextOutput; }
int16_t* getEndOfLastWrite() const { return _endOfLastWrite; }
void setEndOfLastWrite(int16_t* endOfLastWrite) { _endOfLastWrite = endOfLastWrite; }
int16_t* getBuffer() const { return _buffer; }
bool isStarted() const { return _started; }
void setStarted(bool started) { _started = started; }
bool shouldBeAddedToMix() const { return _shouldBeAddedToMix; }
void setShouldBeAddedToMix(bool shouldBeAddedToMix) { _shouldBeAddedToMix = shouldBeAddedToMix; }
float* getPosition();
void setPosition(float newPosition[]);
float getAttenuationRatio();
void setAttenuationRatio(float newAttenuation);
float getBearing();
void setBearing(float newBearing);
const Position& getPosition() const { return _position; }
float getAttenuationRatio() const { return _attenuationRatio; }
float getBearing() const { return _bearing; }
bool shouldLoopbackForAgent() const { return _shouldLoopbackForAgent; }
short diffLastWriteNextOutput();
private:
int ringBufferLengthSamples;
int bufferLengthSamples;
float position[3];
float attenuationRatio;
float bearing;
int16_t *nextOutput;
int16_t *endOfLastWrite;
int16_t *buffer;
bool started;
int _ringBufferLengthSamples;
int _bufferLengthSamples;
Position _position;
float _attenuationRatio;
float _bearing;
int16_t* _nextOutput;
int16_t* _endOfLastWrite;
int16_t* _buffer;
bool _started;
bool _shouldBeAddedToMix;
bool _shouldLoopbackForAgent;
};