-- import "github.com/zaf/g711"
Package g711 implements encoding and decoding of G711.0 compressed 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 (
// Alaw G711 encoded PCM data
Alaw = iota
// Ulaw G711 encoded PCM data
Ulaw
// Lpcm 16bit signed linear data
Lpcm
)func Alaw2Ulaw(pcm uint8) uint8Alaw2Ulaw performs direct A-law to u-law frame conversion
func DecodeAlaw(pcm uint8) int16DecodeAlaw decodes an A-law PCM frame to 16bit LPCM
func DecodeUlaw(pcm uint8) int16DecodeUlaw decodes a u-law PCM frame to 16bit LPCM
func EncodeAlaw(lpcm int16) uint8EncodeAlaw encodes a 16bit LPCM frame to G711 A-law PCM
func EncodeUlaw(lpcm int16) uint8EncodeUlaw encodes a 16bit LPCM frame to G711 u-law PCM
func Ulaw2Alaw(pcm uint8) uint8Ulaw2Alaw performs direct u-law to A-law frame conversion
type Reader struct {
}Reader reads G711 PCM data and decodes it to 16bit LPCM or directly transcodes between A-law and u-law
func NewAlawReader(reader io.Reader, output int) (*Reader, error)NewAlawReader returns a pointer to a Reader that decodes or trans-codes A-law data. It takes as input the source data Reader and the output encoding fomrat.
func NewUlawReader(reader io.Reader, output int) (*Reader, error)NewUlawReader returns a pointer to a Reader that decodes or trans-codes u-law data. It takes as input the source data Reader and the output encoding fomrat.
func (r *Reader) Read(p []byte) (int, 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 *Reader) Reset(reader io.Reader)Reset discards the Reader state. This permits reusing a Reader rather than allocating a new one.
type Writer struct {
}Writer encodes 16bit LPCM data to G711 PCM or directly transcodes between A-law and u-law
func NewAlawWriter(writer io.Writer, input int) (*Writer, error)NewAlawWriter returns a pointer to a Writer that encodes data to A-law. It takes as input the destination data Writer and the input encoding fomrat.
func NewUlawWriter(writer io.Writer, input int) (*Writer, error)NewUlawWriter returns a pointer to a Writer that encodes data to u-law. It takes as input the destination data Writer and the input encoding fomrat.
func (w *Writer) Flush() (err error)Flush flushes any pending data to the underlying writer.
func (w *Writer) Reset(writer io.Writer)Reset discards the Writer state. This permits reusing a Writer rather than allocating a new one.
func (w *Writer) Write(p []byte) (int, 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)/2 due to compression) and any error encountered that caused the write to stop early.