From a7ecf41a426dab17fb2c5064477a7dd909b0cdc5 Mon Sep 17 00:00:00 2001
From: Zach Pomerantz <zmp@umich.edu>
Date: Sun, 8 Jan 2017 23:24:23 -0500
Subject: [PATCH] add audio limiting to device callback
---
libraries/audio-client/src/AudioClient.cpp | 44 ++++++++++++++++++----
libraries/audio-client/src/AudioClient.h | 5 +++
2 files changed, 42 insertions(+), 7 deletions(-)
diff --git a/libraries/audio-client/src/AudioClient.cpp b/libraries/audio-client/src/AudioClient.cpp
index 6477449366..1e97de8dca 100644
--- a/libraries/audio-client/src/AudioClient.cpp
+++ b/libraries/audio-client/src/AudioClient.cpp
@@ -1386,6 +1386,12 @@ bool AudioClient::switchOutputToAudioDevice(const QAudioDeviceInfo& outputDevice
_loopbackOutputDevice = NULL;
delete _loopbackAudioOutput;
_loopbackAudioOutput = NULL;
+
+ delete[] _limitMixBuffer;
+ _limitMixBuffer = NULL;
+
+ delete[] _limitScratchBuffer;
+ _limitScratchBuffer = NULL;
}
if (_networkToOutputResampler) {
@@ -1436,6 +1442,12 @@ bool AudioClient::switchOutputToAudioDevice(const QAudioDeviceInfo& outputDevice
_audioOutput->start(&_audioOutputIODevice);
lock.unlock();
+ int periodSampleSize = _audioOutput->periodSize() / AudioConstants::SAMPLE_SIZE;
+ // device callback is not restricted to periodSampleSize, so double the mix/scratch buffer sizes
+ _limitPeriod = periodSampleSize * 2;
+ _limitMixBuffer = new float[_limitPeriod];
+ _limitScratchBuffer = new int16_t[_limitPeriod];
+
qCDebug(audioclient) << "Output Buffer capacity in frames: " << _audioOutput->bufferSize() / AudioConstants::SAMPLE_SIZE / (float)deviceFrameSize <<
"requested bytes:" << requestedSize << "actual bytes:" << _audioOutput->bufferSize() <<
"os default:" << osDefaultBufferSize << "period size:" << _audioOutput->periodSize();
@@ -1545,6 +1557,8 @@ qint64 AudioClient::AudioOutputIODevice::readData(char * data, qint64 maxSize) {
// samples requested from OUTPUT_CHANNEL_COUNT
int deviceChannelCount = _audio->_outputFormat.channelCount();
int samplesRequested = (int)(maxSize / AudioConstants::SAMPLE_SIZE) * OUTPUT_CHANNEL_COUNT / deviceChannelCount;
+ // restrict samplesRequested to the size of our mix/scratch buffers
+ samplesRequested = std::min(samplesRequested, _audio->_limitPeriod);
int samplesPopped;
int bytesWritten;
@@ -1553,14 +1567,30 @@ qint64 AudioClient::AudioOutputIODevice::readData(char * data, qint64 maxSize) {
qCDebug(audiostream, "Read %d samples from buffer (%d available)", samplesPopped, _receivedAudioStream.getSamplesAvailable());
AudioRingBuffer::ConstIterator lastPopOutput = _receivedAudioStream.getLastPopOutput();
- // if required, upmix or downmix to deviceChannelCount
- if (deviceChannelCount == OUTPUT_CHANNEL_COUNT) {
- lastPopOutput.readSamples((int16_t*)data, samplesPopped);
- } else if (deviceChannelCount > OUTPUT_CHANNEL_COUNT) {
- lastPopOutput.readSamplesWithUpmix((int16_t*)data, samplesPopped, deviceChannelCount - OUTPUT_CHANNEL_COUNT);
- } else {
- lastPopOutput.readSamplesWithDownmix((int16_t*)data, samplesPopped);
+ int16_t* scratchBuffer = _audio->_limitScratchBuffer;
+ lastPopOutput.readSamples(scratchBuffer, samplesPopped);
+
+ float* mixBuffer = _audio->_limitMixBuffer;
+ for (int i = 0; i < samplesPopped; i++) {
+ mixBuffer[i] = (float)scratchBuffer[i] * (1/32768.0f);
}
+
+ int framesPopped = samplesPopped / AudioConstants::STEREO;
+ if (deviceChannelCount == OUTPUT_CHANNEL_COUNT) {
+ // limit the audio
+ _audio->_audioLimiter.render(mixBuffer, (int16_t*)data, framesPopped);
+ } else {
+ _audio->_audioLimiter.render(mixBuffer, scratchBuffer, framesPopped);
+
+ // upmix or downmix to deviceChannelCount
+ if (deviceChannelCount > OUTPUT_CHANNEL_COUNT) {
+ int extraChannels = deviceChannelCount - OUTPUT_CHANNEL_COUNT;
+ channelUpmix(scratchBuffer, (int16_t*)data, samplesPopped, extraChannels);
+ } else {
+ channelDownmix(scratchBuffer, (int16_t*)data, samplesPopped);
+ }
+ }
+
bytesWritten = (samplesPopped * AudioConstants::SAMPLE_SIZE) * deviceChannelCount / OUTPUT_CHANNEL_COUNT;
} else {
// nothing on network, don't grab anything from injectors, and just return 0s
diff --git a/libraries/audio-client/src/AudioClient.h b/libraries/audio-client/src/AudioClient.h
index 123da35319..0320b5db2b 100644
--- a/libraries/audio-client/src/AudioClient.h
+++ b/libraries/audio-client/src/AudioClient.h
@@ -300,6 +300,11 @@ private:
// for local hrtf-ing
float _mixBuffer[AudioConstants::NETWORK_FRAME_SAMPLES_STEREO];
int16_t _scratchBuffer[AudioConstants::NETWORK_FRAME_SAMPLES_AMBISONIC];
+
+ // for limiting
+ int _limitPeriod { 0 };
+ float* _limitMixBuffer { NULL };
+ int16_t* _limitScratchBuffer { NULL };
AudioLimiter _audioLimiter;
// Adds Reverb