src/g726.c File Reference

#include <inttypes.h>
#include <memory.h>
#include <stdlib.h>
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/dc_restore.h"
#include "spandsp/bitstream.h"
#include "spandsp/bit_operations.h"
#include "spandsp/g711.h"
#include "spandsp/g726.h"

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_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

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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
	g726_data
	g726_bytes

Returns:

The number of samples returned.

References g726_state_s::bits_per_sample, bitstream_state_t::bitstream, g726_state_s::bs, g726_state_s::dec_func, g726_state_s::ext_coding, g726_state_s::in_bits, g726_state_s::in_buffer, g726_state_s::packing, and bitstream_state_t::residue.

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

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

Parameters:

	s	The G.726 context.
	g726_data
	amp
	samples

Returns:

The number of bytes of G.726 data produced.

References g726_state_s::bits_per_sample, bitstream_state_t::bitstream, g726_state_s::bs, g726_state_s::enc_func, g726_state_s::ext_coding, g726_state_s::out_bits, g726_state_s::out_buffer, g726_state_s::packing, and bitstream_state_t::residue.

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 g726_state_s::a, g726_state_s::ap, g726_state_s::b, g726_state_s::bits_per_sample, bitstream_init(), g726_state_s::bs, g726_state_s::dec_func, g726_state_s::dml, g726_state_s::dms, g726_state_s::dq, g726_state_s::enc_func, g726_state_s::ext_coding, g726_state_s::in_bits, g726_state_s::in_buffer, g726_state_s::out_bits, g726_state_s::out_buffer, g726_state_s::packing, g726_state_s::pk, g726_state_s::rate, g726_state_s::sr, g726_state_s::td, g726_state_s::yl, and g726_state_s::yu.

int g726_release

(

g726_state_t *

s

)

Free a G.726 encode or decode context.

Parameters:

s

The G.726 context.

Returns:

0 for OK.