wavio

Package wavio is for reading from and writing to wav audio files

Waveform Audio File Format

 RIFF('WAVE'
      <fmt-ck>            // Format
      [<fact-ck>]         // Fact chunk
      [<cue-ck>]          // Cue points
      [<playlist-ck>]     // Playlist
      [<assoc-data-list>] // Associated data list
      <wave-data> )       // Wave data

 <wave-data> → data( <bSampleData:Byte> ... )

Types

type File

type File struct {
	Format        Format // format type 1:PCM, 3:FLOAT
	Channels      uint16 // number of channels
	SampleRate    uint32 // sample rate (fs)
	ByteRate      uint32 // byte rate = fs * channels * bitspersample / 8
	BlockAlign    uint16 // block align = channels * bitspersample / 8
	BitsPerSample uint16 // 8, 16, 32 or 64 bits
	Data          []byte // samples
}

File contains the raw data for the wav file

Constants

const (
	// PCM indicates wav file format is PCM
	PCM Format = 1
	// Float indicates wav file format is IEEE floating point
	Float Format = 3
	// ALaw indicates wav file format is A-law companding algorithm
	ALaw Format = 6
	// MuLaw indicates wav file format is μ-law companding algorithm
	MuLaw Format = 7
)

const FmtSize = 16

FmtSize is the minimum length of RIFF fmt chunk

Functions

func NewFile(format Format, channels uint16, sampleRate uint32,
             bitsPerSample uint16, samples int) *File

NewFile creates and initializes a new wav file

func ReadFile(filename string) (wf *File, err error)

ReadFile reads a wav file into memory

func ReadFloat32

func ReadFloat32(filename string) (data []float32, rate uint32, err error)

ReadFloat32 reads a wav file and returns the samples as float32

func ReadFloat64

func ReadFloat64(filename string) (data []float64, rate uint32, err error)

ReadFloat64 reads a wav file and returns the samples as float64

func ReadInt16

func ReadInt16(filename string) (data []int16, rate uint32, err error)

ReadInt16 reads a wav file and returns the samples as int16

func Write

func Write(fname string, format Format, rate uint32, slice interface{}) error

Write writes slice to a wav file in the specified format and sample rate

Methods

func (wf *File) RIFFSize() int

RIFFSize computes the RIFF length field of the wav file

func (wf *File) Samples() int

Samples computes the total number of samples in each channel

func (wf *File) String() string

String formats the header information in the wav file as a string

func (wf *File) Summary() string

Summary formats the header information in the wav file as a string but more terse so it fits on one line

func (wf *File) ToFloat32(start, stop int) (data []float32, err error)

ToFloat32 converts Data to float32
start: start index of slice
stop: one more than the last index of slice
if start and stop are both zero, convert the entire slice
if start is zero and stop > total samples, convert the entire slice. Otherwise slice the samples before conversion.

func (wf *File) ToFloat64(start, stop int) (data []float64, err error)

ToFloat64 converts Data to float64 start: start index of slice
stop: one more than the last index of slice
if start and stop are both zero, convert the entire slice
if start is zero and stop > total samples, convert the entire slice. Otherwise slice the samples before conversion.

func (wf *File) ToInt16(start, stop int) (data []int16, err error)
ToInt16 converts Data to int16
start: start index of slice  
stop: one more than the last index of slice  
if start and stop are both zero, convert the entire slice  
if start is zero and stop > total samples, convert the
entire slice. Otherwise slice the samples before conversion.

func (wf *File) Write(filename string) error

Write writes wavio.File struct to a wav file

func (f Format) String() string

String converts the Format number to a human readable string

# README