func (vis *basic) Push(samples []float32) {
po := &spectral.PwelchOptions{
NFFT: 64,
}
powers, _ := spectral.Pwelch(float32To64(samples), vis.freq, po)
vis.Set(float64ToInt(powers, 10))
}
func findNextCandidate(samples []float64, sampleRate, min, max float64, c0 int) int {
sr := int(sampleRate)
for c := 0; c+sr < len(samples); c += sr {
pxx, freqs := spectral.Pwelch(samples[c:c+sr], sampleRate, pwOpts)
globalPeakPower, globalPeakFreq := findPeak(pxx, freqs, 32, 880)
localPeakPower, localPeakFreq := findPeak(pxx, freqs, min, max)
if !dsputils.Float64Equal(globalPeakPower, localPeakPower) {
if globalPeakFreq < localPeakFreq || !areHarmonic(globalPeakFreq, localPeakFreq) {
continue
}
}
if localPeakPower < purrMinPower {
continue
}
fmt.Printf("Candidate at %v (local peak: %f Hz (%.2f), global peak: %f Hz (%.2f))\n", fmtSeconds(float64(c+c0)/sampleRate), localPeakFreq, localPeakPower, globalPeakFreq, globalPeakPower)
findRepeats(samples[c:], sampleRate, localPeakFreq, true, true)
return c + c0
}
return -1
}
func findRepeats(samples []float64, sampleRate, baseFreq float64, lookBelow, lookAbove bool) {
if !lookBelow && !lookAbove {
fmt.Println("findRepeats: both lookBelow and lookAbove are false.")
}
win0 := int(2.9 * sampleRate)
if win0 >= len(samples) {
fmt.Println("findRepeats: reached the end of the samples.")
return
}
win1 := minInt(int(6.1*sampleRate), len(samples))
if win1-win0 < int(sampleRate) {
fmt.Println("findRepeats: reached near the end of the samples.")
return
}
freqBelow := baseFreq / 1.5
freqAbove := baseFreq * 1.5
pxx, freqs := spectral.Pwelch(samples[win0:win1], sampleRate, pwOpts)
peakPowerBelow, peakFreqBelow := findPeak(pxx, freqs, freqBelow/1.1, freqBelow*1.1)
peakPowerAbove, peakFreqAbove := findPeak(pxx, freqs, freqAbove/1.1, freqAbove*1.1)
var repeatPower float64 = 0
var repeatFreq float64 = 0
foundBelow := false
foundAbove := false
if lookBelow {
if lookAbove {
if peakPowerBelow > peakPowerAbove {
repeatPower = peakPowerBelow
repeatFreq = peakFreqBelow
foundBelow = true
} else {
repeatPower = peakPowerAbove
repeatFreq = peakFreqAbove
foundAbove = true
}
} else {
repeatPower = peakPowerBelow
repeatFreq = peakFreqBelow
foundBelow = true
}
} else {
repeatPower = peakPowerAbove
repeatFreq = peakFreqAbove
foundAbove = true
}
if repeatPower >= purrMinPower {
fmt.Printf("Repeat candidate: %f Hz (%.2f)\n", repeatFreq, repeatPower)
findRepeats(samples[int(4*sampleRate):], sampleRate, baseFreq, lookBelow && foundBelow, lookAbove && foundAbove)
} else {
fmt.Println("No further repeat candidates found.")
}
}
func getHits() ([]hit, error) {
w, err := wav.New(os.Stdin)
if err != nil {
return nil, err
}
log.Printf("format: %d, channels: %d, sample rate: %d, byte rate: %d, bps: %d, samples: %d, duration: %v\n",
w.Header.AudioFormat, w.Header.NumChannels, w.Header.SampleRate,
w.Header.ByteRate, w.Header.BitsPerSample, w.Samples, w.Duration)
winSize := int(w.Header.SampleRate * uint32(w.Header.NumChannels) / winDenom)
cursor := 0
hits := make([]hit, 0)
for {
rawSamples, err := w.ReadFloats(winSize)
if err != nil {
if err == io.EOF || err == io.ErrUnexpectedEOF {
break
} else {
return nil, err
}
}
if len(rawSamples) < winSize {
break
}
samples := flattenChannels(int(w.Header.NumChannels), rawSamples)
pxx, freqs := spectral.Pwelch(samples, float64(w.Header.SampleRate), &spectral.PwelchOptions{NFFT: 16384, Scale_off: true})
maxPower, maxPowerFreq := findPeak(pxx, freqs, 32, 880)
pMaxPower, pMaxPowerFreq := findPeak(pxx, freqs, 55, 170)
harmonic := true
if !dsputils.Float64Equal(maxPowerFreq, pMaxPowerFreq) {
if maxPowerFreq < pMaxPowerFreq || !areHarmonic(maxPower, pMaxPower) {
fmt.Printf("t = %v: %f !~ %f\n", fmtSeconds(float64(cursor)/float64(w.Header.SampleRate)), maxPowerFreq, pMaxPowerFreq)
harmonic = false
}
}
v1Freq := pMaxPowerFreq * 1.1
v1Pow := powerAtFreq(v1Freq, pxx, freqs)
p1Freq := pMaxPowerFreq * 1.2
p1Pow := powerAtFreq(p1Freq, pxx, freqs)
v2Freq := pMaxPowerFreq * 1.3
v2Pow := powerAtFreq(v2Freq, pxx, freqs)
p2Freq := pMaxPowerFreq * 1.4
p2Pow := powerAtFreq(p2Freq, pxx, freqs)
if harmonic && pMaxPower >= 0.00 && pMaxPowerFreq >= 55.0 && pMaxPowerFreq <= 160.0 && v1Pow < p1Pow && v2Pow < p2Pow {
hits = append(hits, hit{t: float64(cursor) / float64(w.Header.SampleRate), freq: pMaxPowerFreq, pow: pMaxPower})
}
cursor += len(rawSamples) / int(w.Header.NumChannels)
}
return hits, nil
}