import "github.com/zaf/g711"
Package g711 implements encoding and decoding of G711 PCM sound data. G.711 is an ITU-T standard for audio companding.
For usage details please see the code snippets in the cmd folder.
const (
// Input and output formats
Alaw = iota // Alaw G711 encoded PCM data
Ulaw // Ulaw G711 encoded PCM data
Lpcm // Lpcm 16bit signed linear data
)func Alaw2Ulaw(alaw []byte) []byteAlaw2Ulaw performs direct A-law to u-law data conversion
func Alaw2UlawFrame(frame uint8) uint8Alaw2UlawFrame directly converts an A-law frame to u-law
func DecodeAlaw(pcm []byte) []byteDecodeAlaw decodes A-law PCM data to 16bit LPCM
func DecodeAlawFrame(frame uint8) int16DecodeAlawFrame decodes an A-law PCM frame to 16bit LPCM
func DecodeUlaw(pcm []byte) []byteDecodeUlaw decodes u-law PCM data to 16bit LPCM
func DecodeUlawFrame(frame uint8) int16DecodeUlawFrame decodes a u-law PCM frame to 16bit LPCM
func EncodeAlaw(lpcm []byte) []byteEncodeAlaw encodes 16bit LPCM data to G711 A-law PCM
func EncodeAlawFrame(frame int16) uint8EncodeAlawFrame encodes a 16bit LPCM frame to G711 A-law PCM
func EncodeUlaw(lpcm []byte) []byteEncodeUlaw encodes 16bit LPCM data to G711 u-law PCM
func EncodeUlawFrame(frame int16) uint8EncodeUlawFrame encodes a 16bit LPCM frame to G711 u-law PCM
func Ulaw2Alaw(ulaw []byte) []byteUlaw2Alaw performs direct u-law to A-law data conversion
func Ulaw2AlawFrame(frame uint8) uint8Ulaw2AlawFrame directly converts a u-law frame to A-law
type Decoder struct {
}Decoder reads G711 PCM data and decodes it to 16bit 8000Hz LPCM
func NewAlawDecoder(reader io.Reader) (*Decoder, error)NewAlawDecoder returns a pointer to a Decoder that implements an io.Reader. It takes as input the source data Reader.
func NewUlawDecoder(reader io.Reader) (*Decoder, error)NewUlawDecoder returns a pointer to a Decoder that implements an io.Reader. It takes as input the source data Reader.
func (r *Decoder) Read(p []byte) (i int, err error)Read decodes G711 data. Reads up to len(p) bytes into p, returns the number of bytes read and any error encountered.
func (r *Decoder) Reset(reader io.Reader) errorReset discards the Decoder state. This permits reusing a Decoder rather than allocating a new one.
type Encoder struct {
}Encoder encodes 16bit 8000Hz LPCM data to G711 PCM or directly transcodes between A-law and u-law
func NewAlawEncoder(writer io.Writer, input int) (*Encoder, error)NewAlawEncoder returns a pointer to an Encoder that implements an io.Writer. It takes as input the destination data Writer and the input encoding format.
func NewUlawEncoder(writer io.Writer, input int) (*Encoder, error)NewUlawEncoder returns a pointer to an Encoder that implements an io.Writer. It takes as input the destination data Writer and the input encoding format.
func (w *Encoder) Reset(writer io.Writer) errorReset discards the Encoder state. This permits reusing an Encoder rather than allocating a new one.
func (w *Encoder) Write(p []byte) (i int, err error)Write encodes G711 Data. Writes len(p) bytes from p to the underlying data stream, returns the number of bytes written from p (0 <= n <= len(p)) and any error encountered that caused the write to stop early.