func BenchmarkFrameHash(b *testing.B) {
// The file 151185.flac is a 119.5 MB public domain FLAC file used to
// benchmark the flac library. Because of its size, it has not been included
// in the repository, but is available for download at
//
// http://freesound.org/people/jarfil/sounds/151185/
for i := 0; i < b.N; i++ {
stream, err := flac.Open("../testdata/benchmark/151185.flac")
if err != nil {
b.Fatal(err)
}
md5sum := md5.New()
for {
frame, err := stream.ParseNext()
if err != nil {
if err == io.EOF {
break
}
stream.Close()
b.Fatal(err)
}
frame.Hash(md5sum)
}
stream.Close()
want := stream.Info.MD5sum[:]
got := md5sum.Sum(nil)
// Verify the decoded audio samples by comparing the MD5 checksum that is
// stored in StreamInfo with the computed one.
if !bytes.Equal(got, want) {
b.Fatalf("MD5 checksum mismatch for decoded audio samples; expected %32x, got %32x", want, got)
}
}
}
func TestFrameHash(t *testing.T) {
for i, g := range golden {
stream, err := flac.Open(g.name)
if err != nil {
t.Fatal(err)
}
defer stream.Close()
md5sum := md5.New()
for frameNum := 0; ; frameNum++ {
frame, err := stream.ParseNext()
if err != nil {
if err == io.EOF {
break
}
t.Errorf("i=%d, frameNum=%d: error while parsing frame; %v", i, frameNum, err)
continue
}
frame.Hash(md5sum)
}
want := stream.Info.MD5sum[:]
got := md5sum.Sum(nil)
// Verify the decoded audio samples by comparing the MD5 checksum that is
// stored in StreamInfo with the computed one.
if !bytes.Equal(got, want) {
t.Errorf("i=%d: MD5 checksum mismatch for decoded audio samples; expected %32x, got %32x", i, want, got)
}
}
}
func BenchmarkFrameParse(b *testing.B) {
// The file 151185.flac is a 119.5 MB public domain FLAC file used to
// benchmark the flac library. Because of its size, it has not been included
// in the repository, but is available for download at
//
// http://freesound.org/people/jarfil/sounds/151185/
for i := 0; i < b.N; i++ {
stream, err := flac.Open("../testdata/benchmark/151185.flac")
if err != nil {
b.Fatal(err)
}
for {
_, err := stream.ParseNext()
if err != nil {
if err == io.EOF {
break
}
stream.Close()
b.Fatal(err)
}
}
stream.Close()
}
}
// flac2wav converts the provided FLAC file to a WAV file.
func flac2wav(path string) error {
// Open FLAC file.
stream, err := flac.Open(path)
if err != nil {
return err
}
defer stream.Close()
// Create WAV file.
wavPath := pathutil.TrimExt(path) + ".wav"
if !flagForce {
exists, err := osutil.Exists(wavPath)
if err != nil {
return err
}
if exists {
return fmt.Errorf("the file %q exists already", wavPath)
}
}
fw, err := os.Create(wavPath)
if err != nil {
return err
}
defer fw.Close()
// Create WAV encoder.
conf := audio.Config{
Channels: int(stream.Info.NChannels),
SampleRate: int(stream.Info.SampleRate),
}
enc, err := wav.NewEncoder(fw, conf)
if err != nil {
return err
}
defer enc.Close()
for {
// Decode FLAC audio samples.
frame, err := stream.ParseNext()
if err != nil {
if err == io.EOF {
break
}
return err
}
// Encode WAV audio samples.
samples := make(audio.Int16, 1)
for i := 0; i < int(frame.BlockSize); i++ {
for _, subframe := range frame.Subframes {
samples[0] = int16(subframe.Samples[i])
_, err = enc.Write(samples)
if err != nil {
return err
}
}
}
}
return nil
}
func ExampleOpen() {
// Open love.flac for audio streaming without parsing metadata.
stream, err := flac.Open("testdata/love.flac")
if err != nil {
log.Fatal(err)
}
defer stream.Close()
// Parse audio samples and verify the MD5 signature of the decoded audio
// samples.
md5sum := md5.New()
for {
// Parse one frame of audio samples at the time, each frame containing one
// subframe per audio channel.
frame, err := stream.ParseNext()
if err != nil {
if err == io.EOF {
break
}
log.Fatal(err)
}
frame.Hash(md5sum)
// Print first three samples from each channel of the first five frames.
if frame.Num < 5 {
fmt.Printf("frame %d\n", frame.Num)
for i, subframe := range frame.Subframes {
fmt.Printf(" subframe %d\n", i)
for j, sample := range subframe.Samples {
if j >= 3 {
break
}
fmt.Printf(" sample %d: %v\n", j, sample)
}
}
}
}
fmt.Println()
got, want := md5sum.Sum(nil), stream.Info.MD5sum[:]
fmt.Println("decoded audio md5sum valid:", bytes.Equal(got, want))
// Output:
// frame 0
// subframe 0
// sample 0: 126
// sample 1: 126
// sample 2: 126
// subframe 1
// sample 0: 126
// sample 1: 126
// sample 2: 126
// frame 1
// subframe 0
// sample 0: 126
// sample 1: 126
// sample 2: 126
// subframe 1
// sample 0: 126
// sample 1: 126
// sample 2: 126
// frame 2
// subframe 0
// sample 0: 121
// sample 1: 130
// sample 2: 137
// subframe 1
// sample 0: 121
// sample 1: 130
// sample 2: 137
// frame 3
// subframe 0
// sample 0: -9501
// sample 1: -6912
// sample 2: -3916
// subframe 1
// sample 0: -9501
// sample 1: -6912
// sample 2: -3916
// frame 4
// subframe 0
// sample 0: 513
// sample 1: 206
// sample 2: 152
// subframe 1
// sample 0: 513
// sample 1: 206
// sample 2: 152
//
// decoded audio md5sum valid: true
}