Add wyoming module

pkg/pcm/pcm.go

@@ -185,3 +185,23 @@ func Transcode(dst, src *core.Codec) func([]byte) []byte {
 		return writer(samples)
 	}
 }
+
+func ConsumerCodecs() []*core.Codec {
+	return []*core.Codec{
+		{Name: core.CodecPCML},
+		{Name: core.CodecPCM},
+		{Name: core.CodecPCMA},
+		{Name: core.CodecPCMU},
+	}
+}
+
+func ProducerCodecs() []*core.Codec {
+	return []*core.Codec{
+		{Name: core.CodecPCML, ClockRate: 16000},
+		{Name: core.CodecPCM, ClockRate: 16000},
+		{Name: core.CodecPCML, ClockRate: 8000},
+		{Name: core.CodecPCM, ClockRate: 8000},
+		{Name: core.CodecPCMA, ClockRate: 8000},
+		{Name: core.CodecPCMU, ClockRate: 8000},
+	}
+}

pkg/pcm/s16le/s16le.go

@@ -0,0 +1,42 @@
+package s16le
+
+func PeaksRMS(b []byte) int16 {
+	// RMS of sine wave = peak / sqrt2
+	// https://en.wikipedia.org/wiki/Root_mean_square
+	// https://www.youtube.com/watch?v=MUDkL4KZi0I
+	var peaks int32
+	var peaksSum int32
+	var prevSample int16
+	var prevUp bool
+
+	var i int
+	for n := len(b); i < n; {
+		lo := b[i]
+		i++
+		hi := b[i]
+		i++
+
+		sample := int16(hi)<<8 | int16(lo)
+		up := sample >= prevSample
+
+		if i >= 4 {
+			if up != prevUp {
+				if prevSample >= 0 {
+					peaksSum += int32(prevSample)
+				} else {
+					peaksSum -= int32(prevSample)
+				}
+				peaks++
+			}
+		}
+
+		prevSample = sample
+		prevUp = up
+	}
+
+	if peaks == 0 {
+		return 0
+	}
+
+	return int16(peaksSum / peaks)
+}