void AudioMixerSlave::addStream(AudioMixerClientData::MixableStream& mixableStream,
AvatarAudioStream& listeningNodeStream,
float masterListenerGain, bool isSoloing) {
++stats.totalMixes;
auto streamToAdd = mixableStream.positionalStream;
// check if this is a server echo of a source back to itself
bool isEcho = (streamToAdd == &listeningNodeStream);
glm::vec3 relativePosition = streamToAdd->getPosition() - listeningNodeStream.getPosition();
float distance = glm::max(glm::length(relativePosition), EPSILON);
float azimuth = isEcho ? 0.0f : computeAzimuth(listeningNodeStream, listeningNodeStream, relativePosition);
float gain = masterListenerGain;
if (!isSoloing) {
gain = computeGain(masterListenerGain, listeningNodeStream, *streamToAdd, relativePosition, distance, isEcho);
}
const int HRTF_DATASET_INDEX = 1;
if (!streamToAdd->lastPopSucceeded()) {
bool forceSilentBlock = true;
if (!streamToAdd->getLastPopOutput().isNull()) {
bool isInjector = dynamic_cast<const InjectedAudioStream*>(streamToAdd);
// in an injector, just go silent - the injector has likely ended
// in other inputs (microphone, &c.), repeat with fade to avoid the harsh jump to silence
if (!isInjector) {
// calculate its fade factor, which depends on how many times it's already been repeated.
float fadeFactor = calculateRepeatedFrameFadeFactor(streamToAdd->getConsecutiveNotMixedCount() - 1);
if (fadeFactor > 0.0f) {
// apply the fadeFactor to the gain
gain *= fadeFactor;
forceSilentBlock = false;
}
}
}
if (forceSilentBlock) {
// call renderSilent with a forced silent block to reduce artifacts
// (this is not done for stereo streams since they do not go through the HRTF)
if (!streamToAdd->isStereo() && !isEcho) {
static int16_t silentMonoBlock[AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL] = {};
mixableStream.hrtf->render(silentMonoBlock, _mixSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
++stats.hrtfRenders;
}
return;
}
}
// grab the stream from the ring buffer
AudioRingBuffer::ConstIterator streamPopOutput = streamToAdd->getLastPopOutput();
// stereo sources are not passed through HRTF
if (streamToAdd->isStereo()) {
// apply the avatar gain adjustment
gain *= mixableStream.hrtf->getGainAdjustment();
const float scale = 1 / 32768.0f; // int16_t to float
for (int i = 0; i < AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL; i++) {
_mixSamples[2*i+0] += (float)streamPopOutput[2*i+0] * gain * scale;
_mixSamples[2*i+1] += (float)streamPopOutput[2*i+1] * gain * scale;
}
++stats.manualStereoMixes;
} else if (isEcho) {
// echo sources are not passed through HRTF
const float scale = 1/32768.0f; // int16_t to float
for (int i = 0; i < AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL; i++) {
float sample = (float)streamPopOutput[i] * gain * scale;
_mixSamples[2*i+0] += sample;
_mixSamples[2*i+1] += sample;
}
++stats.manualEchoMixes;
} else {
streamPopOutput.readSamples(_bufferSamples, AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
mixableStream.hrtf->render(_bufferSamples, _mixSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
++stats.hrtfRenders;
}
}
void AudioMixerSlave::addStream(AudioMixerClientData& listenerNodeData, const QUuid& sourceNodeID,
const AvatarAudioStream& listeningNodeStream, const PositionalAudioStream& streamToAdd,
bool throttle) {
++stats.totalMixes;
// to reduce artifacts we call the HRTF functor for every source, even if throttled or silent
// this ensures the correct tail from last mixed block and the correct spatialization of next first block
// check if this is a server echo of a source back to itself
bool isEcho = (&streamToAdd == &listeningNodeStream);
glm::vec3 relativePosition = streamToAdd.getPosition() - listeningNodeStream.getPosition();
float distance = glm::max(glm::length(relativePosition), EPSILON);
float gain = computeGain(listenerNodeData, listeningNodeStream, streamToAdd, relativePosition, isEcho);
float azimuth = isEcho ? 0.0f : computeAzimuth(listeningNodeStream, listeningNodeStream, relativePosition);
const int HRTF_DATASET_INDEX = 1;
if (!streamToAdd.lastPopSucceeded()) {
bool forceSilentBlock = true;
if (!streamToAdd.getLastPopOutput().isNull()) {
bool isInjector = dynamic_cast<const InjectedAudioStream*>(&streamToAdd);
// in an injector, just go silent - the injector has likely ended
// in other inputs (microphone, &c.), repeat with fade to avoid the harsh jump to silence
if (!isInjector) {
// calculate its fade factor, which depends on how many times it's already been repeated.
float fadeFactor = calculateRepeatedFrameFadeFactor(streamToAdd.getConsecutiveNotMixedCount() - 1);
if (fadeFactor > 0.0f) {
// apply the fadeFactor to the gain
gain *= fadeFactor;
forceSilentBlock = false;
}
}
}
if (forceSilentBlock) {
// call renderSilent with a forced silent block to reduce artifacts
// (this is not done for stereo streams since they do not go through the HRTF)
if (!streamToAdd.isStereo() && !isEcho) {
// get the existing listener-source HRTF object, or create a new one
auto& hrtf = listenerNodeData.hrtfForStream(sourceNodeID, streamToAdd.getStreamIdentifier());
static int16_t silentMonoBlock[AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL] = {};
hrtf.renderSilent(silentMonoBlock, _mixSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
++stats.hrtfSilentRenders;
}
return;
}
}
// grab the stream from the ring buffer
AudioRingBuffer::ConstIterator streamPopOutput = streamToAdd.getLastPopOutput();
// stereo sources are not passed through HRTF
if (streamToAdd.isStereo()) {
for (int i = 0; i < AudioConstants::NETWORK_FRAME_SAMPLES_STEREO; ++i) {
_mixSamples[i] += float(streamPopOutput[i] * gain / AudioConstants::MAX_SAMPLE_VALUE);
}
++stats.manualStereoMixes;
return;
}
// echo sources are not passed through HRTF
if (isEcho) {
for (int i = 0; i < AudioConstants::NETWORK_FRAME_SAMPLES_STEREO; i += 2) {
auto monoSample = float(streamPopOutput[i / 2] * gain / AudioConstants::MAX_SAMPLE_VALUE);
_mixSamples[i] += monoSample;
_mixSamples[i + 1] += monoSample;
}
++stats.manualEchoMixes;
return;
}
// get the existing listener-source HRTF object, or create a new one
auto& hrtf = listenerNodeData.hrtfForStream(sourceNodeID, streamToAdd.getStreamIdentifier());
streamPopOutput.readSamples(_bufferSamples, AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
if (streamToAdd.getLastPopOutputLoudness() == 0.0f) {
// call renderSilent to reduce artifacts
hrtf.renderSilent(_bufferSamples, _mixSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
++stats.hrtfSilentRenders;
return;
}
if (throttle) {
// call renderSilent with actual frame data and a gain of 0.0f to reduce artifacts
hrtf.renderSilent(_bufferSamples, _mixSamples, HRTF_DATASET_INDEX, azimuth, distance, 0.0f,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
++stats.hrtfThrottleRenders;
return;
}
hrtf.render(_bufferSamples, _mixSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
++stats.hrtfRenders;
}
void AudioMixer::addStreamToMixForListeningNodeWithStream(AudioMixerClientData& listenerNodeData,
const PositionalAudioStream& streamToAdd,
const QUuid& sourceNodeID,
const AvatarAudioStream& listeningNodeStream) {
// to reduce artifacts we calculate the gain and azimuth for every source for this listener
// even if we are not going to end up mixing in this source
++_totalMixes;
// this ensures that the tail of any previously mixed audio or the first block of new audio sounds correct
// check if this is a server echo of a source back to itself
bool isEcho = (&streamToAdd == &listeningNodeStream);
glm::vec3 relativePosition = streamToAdd.getPosition() - listeningNodeStream.getPosition();
// figure out the distance between source and listener
float distance = glm::max(glm::length(relativePosition), EPSILON);
// figure out the gain for this source at the listener
float gain = gainForSource(streamToAdd, listeningNodeStream, relativePosition, isEcho);
// figure out the azimuth to this source at the listener
float azimuth = isEcho ? 0.0f : azimuthForSource(streamToAdd, listeningNodeStream, relativePosition);
float repeatedFrameFadeFactor = 1.0f;
static const int HRTF_DATASET_INDEX = 1;
if (!streamToAdd.lastPopSucceeded()) {
bool forceSilentBlock = true;
if (_streamSettings._repetitionWithFade && !streamToAdd.getLastPopOutput().isNull()) {
// reptition with fade is enabled, and we do have a valid previous frame to repeat
// so we mix the previously-mixed block
// this is preferable to not mixing it at all to avoid the harsh jump to silence
// we'll repeat the last block until it has a block to mix
// and we'll gradually fade that repeated block into silence.
// calculate its fade factor, which depends on how many times it's already been repeated.
repeatedFrameFadeFactor = calculateRepeatedFrameFadeFactor(streamToAdd.getConsecutiveNotMixedCount() - 1);
if (repeatedFrameFadeFactor > 0.0f) {
// apply the repeatedFrameFadeFactor to the gain
gain *= repeatedFrameFadeFactor;
forceSilentBlock = false;
}
}
if (forceSilentBlock) {
// we're deciding not to repeat either since we've already done it enough times or repetition with fade is disabled
// in this case we will call renderSilent with a forced silent block
// this ensures the correct tail from the previously mixed block and the correct spatialization of first block
// of any upcoming audio
if (!streamToAdd.isStereo() && !isEcho) {
// get the existing listener-source HRTF object, or create a new one
auto& hrtf = listenerNodeData.hrtfForStream(sourceNodeID, streamToAdd.getStreamIdentifier());
// this is not done for stereo streams since they do not go through the HRTF
static int16_t silentMonoBlock[AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL] = {};
hrtf.renderSilent(silentMonoBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
++_hrtfSilentRenders;;
}
return;
}
}
// grab the stream from the ring buffer
AudioRingBuffer::ConstIterator streamPopOutput = streamToAdd.getLastPopOutput();
if (streamToAdd.isStereo() || isEcho) {
// this is a stereo source or server echo so we do not pass it through the HRTF
// simply apply our calculated gain to each sample
if (streamToAdd.isStereo()) {
for (int i = 0; i < AudioConstants::NETWORK_FRAME_SAMPLES_STEREO; ++i) {
_mixedSamples[i] += float(streamPopOutput[i] * gain / AudioConstants::MAX_SAMPLE_VALUE);
}
++_manualStereoMixes;
} else {
for (int i = 0; i < AudioConstants::NETWORK_FRAME_SAMPLES_STEREO; i += 2) {
auto monoSample = float(streamPopOutput[i / 2] * gain / AudioConstants::MAX_SAMPLE_VALUE);
_mixedSamples[i] += monoSample;
_mixedSamples[i + 1] += monoSample;
}
++_manualEchoMixes;
}
return;
}
// get the existing listener-source HRTF object, or create a new one
auto& hrtf = listenerNodeData.hrtfForStream(sourceNodeID, streamToAdd.getStreamIdentifier());
static int16_t streamBlock[AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL];
streamPopOutput.readSamples(streamBlock, AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
// if the frame we're about to mix is silent, simply call render silent and move on
if (streamToAdd.getLastPopOutputLoudness() == 0.0f) {
// silent frame from source
// we still need to call renderSilent via the HRTF for mono source
hrtf.renderSilent(streamBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
++_hrtfSilentRenders;
return;
}
if (_performanceThrottlingRatio > 0.0f
&& streamToAdd.getLastPopOutputTrailingLoudness() / glm::length(relativePosition) <= _minAudibilityThreshold) {
// the mixer is struggling so we're going to drop off some streams
// we call renderSilent via the HRTF with the actual frame data and a gain of 0.0
hrtf.renderSilent(streamBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, distance, 0.0f,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
++_hrtfStruggleRenders;
return;
}
++_hrtfRenders;
// mono stream, call the HRTF with our block and calculated azimuth and gain
hrtf.render(streamBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
}
