func readFile(filename string) []int16 {
file, err := os.Open(filename)
if err != nil {
log.Fatal(err)
}
// Create a decoder for the audio source
decoder, format, err := audio.NewDecoder(file)
if err != nil {
log.Fatal(err)
}
config := decoder.Config()
log.Printf("Decoding a %s file.\n", format)
log.Println(config)
// Create a buffer that can hold 3 second of audio samples
bufSize := duration * config.SampleRate * config.Channels
buf := make(audio.F64Samples, bufSize)
// Fill the buffer with as many audio samples as we can
read, err := decoder.Read(buf)
if err != nil {
log.Fatal(err)
}
readBuf := buf.Slice(0, read)
data := make([]int16, readBuf.Len())
for i := 0; i < readBuf.Len(); i++ {
data[i] = int16(audio.F64ToPCM16(readBuf.At(i)))
}
return data
}
func readFile(filename string) (data []audio.PCM16, duration float64, config audio.Config) {
file, err := os.Open(filename)
if err != nil {
log.Panic(err)
}
fi, err := file.Stat()
if err != nil {
log.Panic(err)
}
// Create a decoder for the audio source
decoder, format, err := audio.NewDecoder(file)
if err != nil {
log.Panic("err: %T %v %#v", err, err, err)
}
config = decoder.Config()
log.Printf("Decoding a %s file.\n", format)
log.Println(config)
// guess (mostly accurate for WAVs)
duration = float64(fi.Size()) / float64(config.SampleRate*config.Channels*16/8)
// Create a buffer that can hold 3 second of audio samples
bufSize := int(duration * float64(config.SampleRate*config.Channels)) // undersized for flac files
// Most WAVs are PCM16
samples := make(audio.PCM16Samples, 0, bufSize)
// Fill our samples slice
var read int
buf := make(audio.PCM16Samples, 1024*1000)
err = nil
for err != audio.EOS {
var r int
r, err = decoder.Read(buf)
if err != nil && err != audio.EOS {
panic(err)
}
read += r
samples = append(samples, buf[:r]...)
}
duration = 1 / float64(config.SampleRate) * float64(read)
return []audio.PCM16(samples)[:read], duration, config
}