void AudioMixerSlave::addStreams(Node& listener, AudioMixerClientData& listenerData) {
auto& ignoredNodeIDs = listener.getIgnoredNodeIDs();
auto& ignoringNodeIDs = listenerData.getIgnoringNodeIDs();
auto& streams = listenerData.getStreams();
// add data for newly created streams to our vector
if (!listenerData.getHasReceivedFirstMix()) {
// when this listener is new, we need to fill its added streams object with all available streams
std::for_each(_begin, _end, [&](const SharedNodePointer& node) {
AudioMixerClientData* nodeData = static_cast<AudioMixerClientData*>(node->getLinkedData());
if (nodeData) {
for (auto& stream : nodeData->getAudioStreams()) {
bool ignoredByListener = contains(ignoredNodeIDs, node->getUUID());
bool ignoringListener = contains(ignoringNodeIDs, node->getUUID());
if (ignoredByListener || ignoringListener) {
streams.skipped.emplace_back(node->getUUID(), node->getLocalID(),
stream->getStreamIdentifier(), stream.get());
// pre-populate ignored and ignoring flags for this stream
streams.skipped.back().ignoredByListener = ignoredByListener;
streams.skipped.back().ignoringListener = ignoringListener;
} else {
streams.active.emplace_back(node->getUUID(), node->getLocalID(),
stream->getStreamIdentifier(), stream.get());
}
}
}
});
// flag this listener as having received their first mix so we know we don't need to enumerate all nodes again
listenerData.setHasReceivedFirstMix(true);
} else {
for (const auto& newStream : _sharedData.addedStreams) {
bool ignoredByListener = contains(ignoredNodeIDs, newStream.nodeIDStreamID.nodeID);
bool ignoringListener = contains(ignoringNodeIDs, newStream.nodeIDStreamID.nodeID);
if (ignoredByListener || ignoringListener) {
streams.skipped.emplace_back(newStream.nodeIDStreamID, newStream.positionalStream);
// pre-populate ignored and ignoring flags for this stream
streams.skipped.back().ignoredByListener = ignoredByListener;
streams.skipped.back().ignoringListener = ignoringListener;
} else {
streams.active.emplace_back(newStream.nodeIDStreamID, newStream.positionalStream);
}
}
}
}
bool AudioMixerSlave::prepareMix(const SharedNodePointer& listener) {
AvatarAudioStream* listenerAudioStream = static_cast<AudioMixerClientData*>(listener->getLinkedData())->getAvatarAudioStream();
AudioMixerClientData* listenerData = static_cast<AudioMixerClientData*>(listener->getLinkedData());
// zero out the mix for this listener
memset(_mixSamples, 0, sizeof(_mixSamples));
bool isThrottling = _numToRetain != -1;
bool isSoloing = !listenerData->getSoloedNodes().empty();
auto& streams = listenerData->getStreams();
addStreams(*listener, *listenerData);
// Process skipped streams
erase_if(streams.skipped, [&](MixableStream& stream) {
if (shouldBeRemoved(stream, _sharedData)) {
return true;
}
if (!shouldBeSkipped(stream, *listener, *listenerAudioStream, *listenerData)) {
if (shouldBeInactive(stream)) {
streams.inactive.push_back(move(stream));
++stats.skippedToInactive;
} else {
streams.active.push_back(move(stream));
++stats.skippedToActive;
}
return true;
}
if (!isThrottling) {
updateHRTFParameters(stream, *listenerAudioStream,
listenerData->getMasterAvatarGain());
}
return false;
});
// Process inactive streams
erase_if(streams.inactive, [&](MixableStream& stream) {
if (shouldBeRemoved(stream, _sharedData)) {
return true;
}
if (shouldBeSkipped(stream, *listener, *listenerAudioStream, *listenerData)) {
streams.skipped.push_back(move(stream));
++stats.inactiveToSkipped;
return true;
}
if (!shouldBeInactive(stream)) {
streams.active.push_back(move(stream));
++stats.inactiveToActive;
return true;
}
if (!isThrottling) {
updateHRTFParameters(stream, *listenerAudioStream,
listenerData->getMasterAvatarGain());
}
return false;
});
// Process active streams
erase_if(streams.active, [&](MixableStream& stream) {
if (shouldBeRemoved(stream, _sharedData)) {
return true;
}
if (isThrottling) {
// we're throttling, so we need to update the approximate volume for any un-skipped streams
// unless this is simply for an echo (in which case the approx volume is 1.0)
stream.approximateVolume = approximateVolume(stream, listenerAudioStream);
} else {
if (shouldBeSkipped(stream, *listener, *listenerAudioStream, *listenerData)) {
addStream(stream, *listenerAudioStream, 0.0f, isSoloing);
streams.skipped.push_back(move(stream));
++stats.activeToSkipped;
return true;
}
addStream(stream, *listenerAudioStream, listenerData->getMasterAvatarGain(),
isSoloing);
if (shouldBeInactive(stream)) {
// To reduce artifacts we still call render to flush the HRTF for every silent
// sources on the first frame where the source becomes silent
// this ensures the correct tail from last mixed block
streams.inactive.push_back(move(stream));
++stats.activeToInactive;
return true;
}
}
return false;
});
if (isThrottling) {
// since we're throttling, we need to partition the mixable into throttled and unthrottled streams
int numToRetain = min(_numToRetain, (int)streams.active.size()); // Make sure we don't overflow
auto throttlePoint = begin(streams.active) + numToRetain;
std::nth_element(streams.active.begin(), throttlePoint, streams.active.end(),
[](const auto& a, const auto& b)
{
return a.approximateVolume > b.approximateVolume;
});
SegmentedEraseIf<MixableStreamsVector> erase(streams.active);
erase.iterateTo(throttlePoint, [&](MixableStream& stream) {
if (shouldBeSkipped(stream, *listener, *listenerAudioStream, *listenerData)) {
resetHRTFState(stream);
streams.skipped.push_back(move(stream));
++stats.activeToSkipped;
return true;
}
addStream(stream, *listenerAudioStream, listenerData->getMasterAvatarGain(),
isSoloing);
if (shouldBeInactive(stream)) {
// To reduce artifacts we still call render to flush the HRTF for every silent
// sources on the first frame where the source becomes silent
// this ensures the correct tail from last mixed block
streams.inactive.push_back(move(stream));
++stats.activeToInactive;
return true;
}
return false;
});
erase.iterateTo(end(streams.active), [&](MixableStream& stream) {
// To reduce artifacts we reset the HRTF state for every throttled
// sources on the first frame where the source becomes throttled
// this ensures at least remove the tail from last mixed block
// preventing excessive artifacts on the next first block
resetHRTFState(stream);
if (shouldBeSkipped(stream, *listener, *listenerAudioStream, *listenerData)) {
streams.skipped.push_back(move(stream));
++stats.activeToSkipped;
return true;
}
if (shouldBeInactive(stream)) {
streams.inactive.push_back(move(stream));
++stats.activeToInactive;
return true;
}
return false;
});
}
stats.skipped += (int)streams.skipped.size();
stats.inactive += (int)streams.inactive.size();
stats.active += (int)streams.active.size();
// clear the newly ignored, un-ignored, ignoring, and un-ignoring streams now that we've processed them
listenerData->clearStagedIgnoreChanges();
#ifdef HIFI_AUDIO_MIXER_DEBUG
auto mixEnd = p_high_resolution_clock::now();
auto mixTime = std::chrono::duration_cast<std::chrono::nanoseconds>(mixEnd - mixStart);
stats.mixTime += mixTime.count();
#endif
// check for silent audio before limiting
// limiting uses a dither and can only guarantee abs(sample) <= 1
bool hasAudio = false;
for (int i = 0; i < AudioConstants::NETWORK_FRAME_SAMPLES_STEREO; ++i) {
if (_mixSamples[i] != 0.0f) {
hasAudio = true;
break;
}
}
// use the per listener AudioLimiter to render the mixed data
listenerData->audioLimiter.render(_mixSamples, _bufferSamples, AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
return hasAudio;
}
