bsnes/higan/audio/stream.cpp

36 lines
1.1 KiB
C++

auto Stream::reset(uint channels_, double inputFrequency, double outputFrequency) -> void {
channels.reset();
channels.resize(channels_);
for(auto& channel : channels) {
if(outputFrequency / inputFrequency <= 0.5) {
channel.iir.resize(order / 2);
for(auto phase : range(order / 2)) {
double q = DSP::IIR::Biquad::butterworth(order, phase);
channel.iir[phase].reset(DSP::IIR::Biquad::Type::LowPass, 20000.0 / inputFrequency, q);
}
}
channel.resampler.reset(inputFrequency, outputFrequency);
}
}
auto Stream::pending() const -> bool {
return channels && channels[0].resampler.pending();
}
auto Stream::read(double* samples) -> uint {
for(auto c : range(channels)) samples[c] = channels[c].resampler.read();
return channels.size();
}
auto Stream::write(const double* samples) -> void {
for(auto c : range(channels)) {
double sample = samples[c] + 1e-25; //constant offset used to suppress denormals
for(auto& iir : channels[c].iir) sample = iir.process(sample);
channels[c].resampler.write(sample);
}
audio.process();
}