void ProcessCommon(AudioReader reader, ref float[] impulse)
{
int targetLen = QMath.Base2Ceil((int)reader.Length) << 1;
Complex[] commonSpectrum = new Complex[targetLen];
FFTCache cache = new FFTCache(targetLen);
for (int ch = 0; ch < reader.ChannelCount; ++ch)
{
float[] channel = new float[targetLen];
WaveformUtils.ExtractChannel(impulse, channel, ch, reader.ChannelCount);
Complex[] spectrum = Measurements.FFT(channel, cache);
for (int band = 0; band < spectrum.Length; ++band)
{
commonSpectrum[band] += spectrum[band];
}
}
float mul = 1f / reader.ChannelCount;
for (int band = 0; band < commonSpectrum.Length; ++band)
{
commonSpectrum[band] = (commonSpectrum[band] * mul).Invert();
}
Array.Resize(ref impulse, impulse.Length << 1);
for (int ch = 0; ch < reader.ChannelCount; ++ch)
{
Convolver filter = GetFilter(commonSpectrum, 1, reader.SampleRate);
filter.Process(impulse, ch, reader.ChannelCount);
}
}
void ProcessPerChannel(AudioReader reader, ref float[] impulse)
{
int targetLen = QMath.Base2Ceil((int)reader.Length) << 1;
Convolver[] filters = new Convolver[reader.ChannelCount];
FFTCache cache = new FFTCache(targetLen);
for (int ch = 0; ch < reader.ChannelCount; ++ch)
{
float[] channel = new float[targetLen];
WaveformUtils.ExtractChannel(impulse, channel, ch, reader.ChannelCount);
Complex[] spectrum = Measurements.FFT(channel, cache);
for (int band = 0; band < spectrum.Length; ++band)
{
spectrum[band] = spectrum[band].Invert();
}
filters[ch] = GetFilter(spectrum, WaveformUtils.GetRMS(channel), reader.SampleRate);
}
Array.Resize(ref impulse, impulse.Length << 1);
for (int ch = 0; ch < reader.ChannelCount; ++ch)
{
filters[ch].Process(impulse, ch, reader.ChannelCount);
}
}
