func bitstream(stream string) []datatypes.Bit {
bits := make([]datatypes.Bit, 32)
for i, c := range stream {
if string(c) == "1" {
bits[i] = datatypes.Bit(true)
} else {
bits[i] = datatypes.Bit(false)
}
}
return bits
}
// StreamToBits converts samples to bits using the bitlength specified.
// Observe that POCSAG signifies a high bit with a low frequency.
func StreamToBits(stream []int16, bitlength int) []datatypes.Bit {
bits := make([]datatypes.Bit, (len(stream)/bitlength)+1)
b := 0
for a := 0; a < len(stream); a += bitlength {
sample := stream[a]
if a > 2 && a < len(stream)-2 {
// let the samples before and after influence our sample, to prevent spike errors
sample = (stream[a-1] / 2) + stream[a] + (stream[a+1] / 2)
}
bits[b] = datatypes.Bit((sample < 0))
b += 1
}
return bits
}