func writeHeader(w io.Writer, f *audio.File) {
writeString(w, "RIFF")
writeUint32(w, uint32(36+f.Length()*int(f.ByteDepth())*f.NumChannels()))
writeString(w, "WAVE")
writeString(w, "fmt ")
writeUint32(w, 16)
writeUint16(w, 1)
writeUint16(w, uint16(f.NumChannels()))
writeUint32(w, uint32(f.SampleRate))
writeUint32(w, uint32(int(f.SampleRate)*f.NumChannels()*int(f.ByteDepth())))
writeUint16(w, uint16(int(f.ByteDepth())*f.NumChannels()))
writeUint16(w, uint16(f.Depth))
}
func Encode(w io.Writer, f *audio.File) error {
writeHeader(w, f)
writeString(w, "data")
writeUint32(w, uint32(f.Length()*int(f.ByteDepth())*f.NumChannels()))
for sample := range f.Data[0] {
for channel := range f.Data {
value := f.Data[channel][sample]
switch f.ByteDepth() {
case 1:
writeUint8(w, uint8(value))
case 2:
writeUint16(w, uint16(value))
default:
return ErrUnsupportedDepth
}
}
}
return nil
}
func EstimateFileSize(f *audio.File) uint64 {
return 44 + uint64(f.Length()*int(f.ByteDepth())*f.NumChannels())
}