qint64 AudioRingBuffer::writeData(const char* data, qint64 maxSize) {
// make sure we have enough bytes left for this to be the right amount of audio
// otherwise we should not copy that data, and leave the buffer pointers where they are
int samplesToCopy = std::min((quint64)(maxSize / sizeof(int16_t)), (quint64)_sampleCapacity);
std::less<int16_t*> less;
std::less_equal<int16_t*> lessEqual;
if (_hasStarted
&& (less(_endOfLastWrite, _nextOutput)
&& lessEqual(_nextOutput, shiftedPositionAccomodatingWrap(_endOfLastWrite, samplesToCopy)))) {
// this read will cross the next output, so call us starved and reset the buffer
qDebug() << "Filled the ring buffer. Resetting.";
_endOfLastWrite = _buffer;
_nextOutput = _buffer;
_isStarved = true;
}
if (_endOfLastWrite + samplesToCopy <= _buffer + _sampleCapacity) {
memcpy(_endOfLastWrite, data, samplesToCopy * sizeof(int16_t));
} else {
int numSamplesToEnd = (_buffer + _sampleCapacity) - _endOfLastWrite;
memcpy(_endOfLastWrite, data, numSamplesToEnd * sizeof(int16_t));
memcpy(_buffer, data + (numSamplesToEnd * sizeof(int16_t)), (samplesToCopy - numSamplesToEnd) * sizeof(int16_t));
}
_endOfLastWrite = shiftedPositionAccomodatingWrap(_endOfLastWrite, samplesToCopy);
return samplesToCopy * sizeof(int16_t);
}
int AudioRingBuffer::writeData(const char* data, int maxSize) {
// make sure we have enough bytes left for this to be the right amount of audio
// otherwise we should not copy that data, and leave the buffer pointers where they are
int samplesToCopy = std::min((int)(maxSize / sizeof(int16_t)), _sampleCapacity);
int samplesRoomFor = _sampleCapacity - samplesAvailable();
if (samplesToCopy > samplesRoomFor) {
// there's not enough room for this write. erase old data to make room for this new data
int samplesToDelete = samplesToCopy - samplesRoomFor;
_nextOutput = shiftedPositionAccomodatingWrap(_nextOutput, samplesToDelete);
_overflowCount++;
qCDebug(audio) << "Overflowed ring buffer! Overwriting old data";
}
if (_endOfLastWrite + samplesToCopy <= _buffer + _bufferLength) {
memcpy(_endOfLastWrite, data, samplesToCopy * sizeof(int16_t));
} else {
int numSamplesToEnd = (_buffer + _bufferLength) - _endOfLastWrite;
memcpy(_endOfLastWrite, data, numSamplesToEnd * sizeof(int16_t));
memcpy(_buffer, data + (numSamplesToEnd * sizeof(int16_t)), (samplesToCopy - numSamplesToEnd) * sizeof(int16_t));
}
_endOfLastWrite = shiftedPositionAccomodatingWrap(_endOfLastWrite, samplesToCopy);
return samplesToCopy * sizeof(int16_t);
}
int AudioRingBuffer::writeSamplesWithFade(ConstIterator source, int maxSamples, float fade) {
int samplesToCopy = std::min(maxSamples, _sampleCapacity);
int samplesRoomFor = _sampleCapacity - samplesAvailable();
if (samplesToCopy > samplesRoomFor) {
// there's not enough room for this write. erase old data to make room for this new data
int samplesToDelete = samplesToCopy - samplesRoomFor;
_nextOutput = shiftedPositionAccomodatingWrap(_nextOutput, samplesToDelete);
_overflowCount++;
qCDebug(audio) << "Overflowed ring buffer! Overwriting old data";
}
int16_t* bufferLast = _buffer + _bufferLength - 1;
for (int i = 0; i < samplesToCopy; i++) {
*_endOfLastWrite = (int16_t)((float)(*source) * fade);
_endOfLastWrite = (_endOfLastWrite == bufferLast) ? _buffer : _endOfLastWrite + 1;
++source;
}
return samplesToCopy;
}
qint64 AudioRingBuffer::readData(char *data, qint64 maxSize) {
// only copy up to the number of samples we have available
int numReadSamples = std::min((unsigned) (maxSize / sizeof(int16_t)), samplesAvailable());
// If we're in random access mode, then we consider our number of available read samples slightly
// differently. Namely, if anything has been written, we say we have as many samples as they ask for
// otherwise we say we have nothing available
if (_randomAccessMode) {
numReadSamples = _endOfLastWrite ? (maxSize / sizeof(int16_t)) : 0;
}
if (_nextOutput + numReadSamples > _buffer + _sampleCapacity) {
// we're going to need to do two reads to get this data, it wraps around the edge
// read to the end of the buffer
int numSamplesToEnd = (_buffer + _sampleCapacity) - _nextOutput;
memcpy(data, _nextOutput, numSamplesToEnd * sizeof(int16_t));
if (_randomAccessMode) {
memset(_nextOutput, 0, numSamplesToEnd * sizeof(int16_t)); // clear it
}
// read the rest from the beginning of the buffer
memcpy(data + (numSamplesToEnd * sizeof(int16_t)), _buffer, (numReadSamples - numSamplesToEnd) * sizeof(int16_t));
if (_randomAccessMode) {
memset(_buffer, 0, (numReadSamples - numSamplesToEnd) * sizeof(int16_t)); // clear it
}
} else {
// read the data
memcpy(data, _nextOutput, numReadSamples * sizeof(int16_t));
if (_randomAccessMode) {
memset(_nextOutput, 0, numReadSamples * sizeof(int16_t)); // clear it
}
}
// push the position of _nextOutput by the number of samples read
_nextOutput = shiftedPositionAccomodatingWrap(_nextOutput, numReadSamples);
return numReadSamples * sizeof(int16_t);
}
int AudioRingBuffer::addSilentSamples(int silentSamples) {
int samplesRoomFor = _sampleCapacity - samplesAvailable();
if (silentSamples > samplesRoomFor) {
// there's not enough room for this write. write as many silent samples as we have room for
silentSamples = samplesRoomFor;
qCDebug(audio) << "Dropping some silent samples to prevent ring buffer overflow";
}
// memset zeroes into the buffer, accomodate a wrap around the end
// push the _endOfLastWrite to the correct spot
if (_endOfLastWrite + silentSamples <= _buffer + _bufferLength) {
memset(_endOfLastWrite, 0, silentSamples * sizeof(int16_t));
} else {
int numSamplesToEnd = (_buffer + _bufferLength) - _endOfLastWrite;
memset(_endOfLastWrite, 0, numSamplesToEnd * sizeof(int16_t));
memset(_buffer, 0, (silentSamples - numSamplesToEnd) * sizeof(int16_t));
}
_endOfLastWrite = shiftedPositionAccomodatingWrap(_endOfLastWrite, silentSamples);
return silentSamples;
}
qint64 AudioRingBuffer::readData(char *data, qint64 maxSize) {
// only copy up to the number of samples we have available
int numReadSamples = std::min((unsigned) (maxSize / sizeof(int16_t)), samplesAvailable());
if (_nextOutput + numReadSamples > _buffer + _sampleCapacity) {
// we're going to need to do two reads to get this data, it wraps around the edge
// read to the end of the buffer
int numSamplesToEnd = (_buffer + _sampleCapacity) - _nextOutput;
memcpy(data, _nextOutput, numSamplesToEnd * sizeof(int16_t));
// read the rest from the beginning of the buffer
memcpy(data + (numSamplesToEnd * sizeof(int16_t)), _buffer, (numReadSamples - numSamplesToEnd) * sizeof(int16_t));
} else {
// read the data
memcpy(data, _nextOutput, numReadSamples * sizeof(int16_t));
}
// push the position of _nextOutput by the number of samples read
_nextOutput = shiftedPositionAccomodatingWrap(_nextOutput, numReadSamples);
return numReadSamples * sizeof(int16_t);
}
void AudioRingBuffer::shiftReadPosition(unsigned int numSamples) {
_nextOutput = shiftedPositionAccomodatingWrap(_nextOutput, numSamples);
}
const int16_t& AudioRingBuffer::operator[] (const int index) const {
return *shiftedPositionAccomodatingWrap(_nextOutput, index);
}