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completed code for dynamicly resizing jitter buffer

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wangyix 2014-06-20 17:13:42 -07:00
parent a5457eb86b
commit cb6681f6f8
2 changed files with 60 additions and 23 deletions
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2
libraries/audio/src/AudioRingBuffer.cpp
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@ -158,7 +158,7 @@ const int16_t& AudioRingBuffer::operator[] (const int index) const {
void AudioRingBuffer::shiftReadPosition(unsigned int numSamples) {
_nextOutput = shiftedPositionAccomodatingWrap(_nextOutput, numSamples);
printf("\n mixed. %d samples remaining\n", samplesAvailable());
//printf("\nmixed. %d samples remaining\n", samplesAvailable());
}
unsigned int AudioRingBuffer::samplesAvailable() const {

81
libraries/audio/src/PositionalAudioRingBuffer.cpp
View file

@ -33,8 +33,7 @@ InterframeTimeGapHistory::InterframeTimeGapHistory()
}
void InterframeTimeGapHistory::frameReceived() {
static QQueue<quint64> gaps;
static quint64 gapsSum = 0;
quint64 now = usecTimestampNow();
@ -46,6 +45,14 @@ void InterframeTimeGapHistory::frameReceived() {
// update the current interval max
if (gap > _currentIntervalMaxGap) {
_currentIntervalMaxGap = gap;
// keep the window max gap at least as large as the current interval max
// this allows the window max gap to respond immediately to a sudden spike in gap times
// also, this prevents the window max gap from staying at 0 until the first interval of samples filled up
if (_currentIntervalMaxGap > _windowMaxGap) {
_windowMaxGap = _currentIntervalMaxGap;
_newWindowMaxGapAvailable = true;
}
}
_numSamplesInCurrentInterval++;
@ -116,17 +123,35 @@ int PositionalAudioRingBuffer::parseData(const QByteArray& packet) {
readBytes += sizeof(int16_t);
if (numSilentSamples > 0) {
addSilentFrame(numSilentSamples);
if (_currentJitterBufferFrames > _desiredJitterBufferFrames) {
// our current jitter buffer size exceeds its desired value, so ignore some silent
// frames to get that size as close to desired as possible
int samplesPerFrame = getSamplesPerFrame();
int numSilentFrames = numSilentSamples / samplesPerFrame;
int numFramesToDropDesired = _currentJitterBufferFrames - _desiredJitterBufferFrames;
if (numSilentFrames > numFramesToDropDesired) {
// we have more than enough frames to drop to get the jitter buffer to its desired length
int numSilentFramesToAdd = numSilentFrames - numFramesToDropDesired;
addSilentFrame(numSilentFramesToAdd * samplesPerFrame);
_currentJitterBufferFrames = _desiredJitterBufferFrames;
} else {
// we need to drop all frames to get the jitter buffer close as possible to its desired length
_currentJitterBufferFrames -= numSilentFrames;
printf("dropped silent packet! jbuffer size is now %d ###############", _currentJitterBufferFrames);
}
} else {
addSilentFrame(numSilentSamples);
}
}
printf("\nparsed silent packet of %d samples\n", numSilentSamples);
} else {
// there is audio data to read
int dataBytes = writeData(packet.data() + readBytes, packet.size() - readBytes);
readBytes += dataBytes;
printf("\nparsed packet of %d data bytes\n", dataBytes);
}
printf("%d samples available\n", samplesAvailable());
//printf("parsed packet. %d samples available\n", samplesAvailable());
return readBytes;
}
@ -174,16 +199,18 @@ void PositionalAudioRingBuffer::updateNextOutputTrailingLoudness() {
}
bool PositionalAudioRingBuffer::shouldBeAddedToMix() {
int samplesPerFrame = getSamplesPerFrame();
int currentJitterBufferSamples = 3 * samplesPerFrame; //_currentJitterBufferFrames * samplesPerFrame;
int desiredJitterBufferSamples = _desiredJitterBufferFrames * samplesPerFrame;
//printf("\nsamples available: %d frames available: %d\n", samplesAvailable(), samplesAvailable() / samplesPerFrame);
if (!isNotStarvedOrHasMinimumSamples(samplesPerFrame + currentJitterBufferSamples)) {
if (!isNotStarvedOrHasMinimumSamples(samplesPerFrame + _desiredJitterBufferFrames)) {
printf("\nMIXING DELAYED! waiting for jitter buffer to fill after being starved\n");
printf("samples available: %d frames available: %d\n", samplesAvailable(), samplesAvailable() / samplesPerFrame);
// if the buffer was starved, allow it to accrue at least the desired number of
// jitter buffer frames before we start taking frames from it for mixing
//printf("\nMIXING DELAYED! waiting for jitter buffer to fill after being starved\n");
//printf("samples available: %d frames available: %d\n", samplesAvailable(), samplesAvailable() / samplesPerFrame);
// if the buffer was starved and hasn't filled back up all the way, don't mix yet
if (_shouldOutputStarveDebug) {
_shouldOutputStarveDebug = false;
}
@ -192,26 +219,34 @@ bool PositionalAudioRingBuffer::shouldBeAddedToMix() {
} else if (samplesAvailable() < samplesPerFrame) {
//printf("\nMIXING DELAYED! jitter buffer is starved!!!\n");
//printf("samples available: %d frames available: %d\n", samplesAvailable(), samplesAvailable() / samplesPerFrame);
// if the buffer doesn't have a full frame of samples for mixing, it is starved
printf("\nMIXING DELAYED! jitter buffer is starved!!!\n");
printf("samples available: %d frames available: %d\n", samplesAvailable(), samplesAvailable() / samplesPerFrame);
// if the buffer doesn't have a full frame of samples to take for mixing, it is starved
_isStarved = true;
// set to 0 to indicate the jitter buffer is starved
_currentJitterBufferFrames = 0;
// reset our _shouldOutputStarveDebug to true so the next is printed
_shouldOutputStarveDebug = true;
// if buffer was starved, we've effectively increased the jitter buffer by one frame
// by "holding back" this ring buffer's contents until the next client frame is prepared.
_currentJitterBufferFrames++;
//printf("jbuffer size increased: new size: %d\n", _currentJitterBufferFrames);
return false;
}
//printf("WILL MIX\n");
// good buffer, add this to the mix
_isStarved = false;
if (_isStarved) {
// if this buffer was just finished replenishing after being starved, the number of frames in it now
// is the length of the jitter buffer
_currentJitterBufferFrames = samplesAvailable() / samplesPerFrame;
printf("jitter buffer length is now %d; desired: %d --------\n", _currentJitterBufferFrames, _desiredJitterBufferFrames);
_isStarved = false;
}
// since we've read data from ring buffer at least once - we've started
_hasStarted = true;
@ -228,5 +263,7 @@ void PositionalAudioRingBuffer::updateDesiredJitterBufferFrames() {
if (_desiredJitterBufferFrames < 1) {
_desiredJitterBufferFrames = 1;
}
printf(" desired jbuffer size is now %d --------------------------------\n", _desiredJitterBufferFrames);
}
}