wav: accept wav file uses waveformatextensible at fmt header that spe…

…cifies guid with KSDATAFORMAT_SUBTYPE_PCM. Maybe this also fixes issue faiface#2.

wav/decode.go

@@ -2,6 +2,7 @@ package wav
 
 import (
 	"encoding/binary"
+	"encoding/hex"
 	"fmt"
 	"io"
 	"time"
@@ -22,23 +23,118 @@ func Decode(rc io.ReadCloser) (s beep.StreamSeekCloser, format beep.Format, err
 			d.rc.Close()
 		}
 	}()
-	if err := binary.Read(rc, binary.LittleEndian, &d.h); err != nil {
+
+	// READ "RIFF" header
+	if err := binary.Read(rc, binary.LittleEndian, d.h.RiffMark[:]); err != nil {
 		return nil, beep.Format{}, errors.Wrap(err, "wav")
 	}
+
 	if string(d.h.RiffMark[:]) != "RIFF" {
-		return nil, beep.Format{}, errors.New("wav: missing RIFF at the beginning")
+		return nil, beep.Format{}, errors.New(fmt.Sprintf("wav: missing RIFF at the beginning > %s",string(d.h.RiffMark[:])))
+	}
+
+	// READ Total file size
+	if err := binary.Read(rc, binary.LittleEndian, &d.h.FileSize); err != nil {
+		return nil, beep.Format{}, errors.Wrap(err,"wav: missing RIFF file size")
+	}
+
+	if err := binary.Read(rc, binary.LittleEndian, d.h.WaveMark[:]); err != nil {
+		return nil, beep.Format{}, errors.Wrap(err,"wav: missing RIFF file type")
 	}
+
 	if string(d.h.WaveMark[:]) != "WAVE" {
 		return nil, beep.Format{}, errors.New("wav: unsupported file type")
 	}
+
+	//check each formtypes
+	ft := [4]byte {0,0,0,0}
+
+	var fs int32 = 0
+
+
+	for string(ft[:]) != "data" {
+
+		if err = binary.Read(rc,binary.LittleEndian,ft[:]); err != nil {
+			return nil, beep.Format{}, errors.Wrap(err, "wav: missing chunk type")
+		}
+
+		switch {
+			case string(ft[:]) == "fmt " : {
+				d.h.FmtMark = ft
+				if err := binary.Read(rc,binary.LittleEndian,&d.h.FormatSize); err != nil {
+					return nil, beep.Format{}, errors.New("wav: missing format chunk size")
+				}
+
+				if err := binary.Read(rc,binary.LittleEndian,&d.h.FormatType); err != nil {
+					return nil, beep.Format{}, errors.New("wav: missing format type")
+				}
+
+				//WAVEFORMATEXTENSIBLE
+				if d.h.FormatType == -2 {
+					fmtchunk := formatchunkextensible {0,0,0,0,0,0,0,0,[18]byte{
+					0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}}
+					if err := binary.Read(rc,binary.LittleEndian,&fmtchunk); err != nil {
+						return nil, beep.Format{}, errors.New("wav: missing format chunk body")
+					} else {
+						d.h.NumChans      = fmtchunk.NumChans
+						d.h.SampleRate    = fmtchunk.SampleRate
+						d.h.ByteRate      = fmtchunk.ByteRate
+						d.h.BytesPerFrame = fmtchunk.BytesPerFrame
+						d.h.BitsPerSample = fmtchunk.BitsPerSample
+					}
+					if fmtchunk.SubFormat != [18]byte{0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x10,0x00,0x80,0x00,0x00,0xaa,0x00,0x38,0x9b,0x71} {
+						return nil, beep.Format{}, errors.New(fmt.Sprintf("wav: unsupported sub format type - %s",hex.EncodeToString(fmtchunk.SubFormat[:])))
+					}
+				//WAVEFORMAT or WAVEFORMATEX
+				} else {
+					fmtchunk := formatchunk {0,0,0,0,0}
+					if err := binary.Read(rc,binary.LittleEndian,&fmtchunk); err != nil {
+						return nil, beep.Format{}, errors.New("wav: missing format chunk body")
+					} else {
+						d.h.NumChans      = fmtchunk.NumChans
+						d.h.SampleRate    = fmtchunk.SampleRate
+						d.h.ByteRate      = fmtchunk.ByteRate
+						d.h.BytesPerFrame = fmtchunk.BytesPerFrame
+						d.h.BitsPerSample = fmtchunk.BitsPerSample
+					}
+					//it would be skipping cbSize (WAVEFORMATEX's last member).
+					if d.h.FormatSize > 16 { 
+						trash := make([]byte,d.h.FormatSize - 16)
+						if err := binary.Read(rc,binary.LittleEndian,trash); err != nil {
+							return nil, beep.Format{}, errors.Wrap(err,"wav: missing extended format chunk body")
+						}
+					}
+				}
+
+			}
+
+			case string(ft[:]) == "data" : {
+				d.h.DataMark = ft
+				if err := binary.Read(rc,binary.LittleEndian,&d.h.DataSize); err != nil {
+					return nil, beep.Format{}, errors.Wrap(err,"wav: missing data chunk size")
+				}
+			}
+
+			default : {
+				if err := binary.Read(rc,binary.LittleEndian,&fs); err != nil {
+					return nil, beep.Format{}, errors.Wrap(err,"wav: missing unknown chunk size")
+				}
+				trash := make([]byte,fs)
+				if err := binary.Read(rc,binary.LittleEndian,trash); err != nil {
+					return nil, beep.Format{}, errors.Wrap(err,"wav: missing unknown chunk body")
+				}
+			}
+		}
+	}
+
 	if string(d.h.FmtMark[:]) != "fmt " {
 		return nil, beep.Format{}, errors.New("wav: missing format chunk marker")
 	}
 	if string(d.h.DataMark[:]) != "data" {
 		return nil, beep.Format{}, errors.New("wav: missing data chunk marker")
 	}
-	if d.h.FormatType != 1 {
-		return nil, beep.Format{}, errors.New("wav: unsupported format type")
+	if d.h.FormatType != 1 && d.h.FormatType != -2 {
+		return nil, beep.Format{}, errors.New(fmt.Sprintf("wav: unsupported format type - %d",d.h.FormatType))
 	}
 	if d.h.NumChans <= 0 {
 		return nil, beep.Format{}, errors.New("wav: invalid number of channels (less than 1)")
@@ -53,19 +149,42 @@ func Decode(rc io.ReadCloser) (s beep.StreamSeekCloser, format beep.Format, err
 	}
 	return &d, format, nil
 }
+type formatchunk struct {
+	NumChans      int16
+	SampleRate    int32
+	ByteRate      int32
+	BytesPerFrame int16
+	BitsPerSample int16
+}
+
+type formatchunkextensible struct {
+	NumChans      int16
+	SampleRate    int32
+	ByteRate      int32
+	BytesPerFrame int16
+	BitsPerSample int16
+	SubFormatSize int16
+	Samples int16
+	ChannelMask int16
+	SubFormat [18]byte
+}
 
 type header struct {
 	RiffMark      [4]byte
 	FileSize      int32
+
 	WaveMark      [4]byte
+
 	FmtMark       [4]byte
 	FormatSize    int32
 	FormatType    int16
+
 	NumChans      int16
 	SampleRate    int32
 	ByteRate      int32
 	BytesPerFrame int16
 	BitsPerSample int16
+
 	DataMark      [4]byte
 	DataSize      int32
 }