g726.h File Reference

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Typedefs
typedef struct g726_state_s	g726_state_t
typedef int16_t(*	g726_decoder_func_t )(g726_state_t *s, uint8_t code)
typedef uint8_t(*	g726_encoder_func_t )(g726_state_t *s, int16_t amp)

Enumerations
enum	{ G726_ENCODING_LINEAR = 0, G726_ENCODING_ULAW, G726_ENCODING_ALAW }
enum	{ G726_PACKING_NONE = 0, G726_PACKING_LEFT = 1, G726_PACKING_RIGHT = 2 }

Functions
g726_state_t *	g726_init (g726_state_t *s, int bit_rate, int ext_coding, int packing)
int	g726_release (g726_state_t *s)
int	g726_free (g726_state_t *s)
int	g726_decode (g726_state_t *s, int16_t amp[], const uint8_t g726_data[], int g726_bytes)
int	g726_encode (g726_state_t *s, uint8_t g726_data[], const int16_t amp[], int len)

Detailed Description

Typedef Documentation

typedef struct g726_state_s g726_state_t

G.726 state

Function Documentation

int g726_decode	(	g726_state_t *	s,
		int16_t	amp[],
		const uint8_t	g726_data[],
		int	g726_bytes
	)

Decode a buffer of G.726 ADPCM data to linear PCM, a-law or u-law.

Parameters

s	The G.726 context.
amp	The audio sample buffer.
g726_data
g726_bytes

Returns

The number of samples returned.

int g726_encode	(	g726_state_t *	s,
		uint8_t	g726_data[],
		const int16_t	amp[],
		int	len
	)

Encode a buffer of linear PCM data to G.726 ADPCM.

Parameters

s	The G.726 context.
g726_data	The G.726 data produced.
amp	The audio sample buffer.
len	The number of samples in the buffer.

Returns

The number of bytes of G.726 data produced.

int g726_free

(

g726_state_t *

s

)

Free a G.726 encode or decode context.

Parameters

s	The G.726 context.

Returns

0 for OK.

g726_state_t* g726_init	(	g726_state_t *	s,
		int	bit_rate,
		int	ext_coding,
		int	packing
	)

Initialise a G.726 encode or decode context.

Parameters

s	The G.726 context.
bit_rate	The required bit rate for the ADPCM data. The valid rates are 16000, 24000, 32000 and 40000.
ext_coding	The coding used outside G.726.
packing	One of the G.726_PACKING_xxx options.

Returns

A pointer to the G.726 context, or NULL for error.

References bitstream_init().

int g726_release

(

g726_state_t *

s

)

Release a G.726 encode or decode context.

Parameters

s	The G.726 context.

Returns

0 for OK.