oki_adpcm.c File Reference

#include <stdlib.h>
#include <inttypes.h>
#include <string.h>
#include "spandsp/telephony.h"
#include "spandsp/oki_adpcm.h"

Functions
oki_adpcm_state_t *	oki_adpcm_init (oki_adpcm_state_t *s, int bit_rate)
int	oki_adpcm_release (oki_adpcm_state_t *s)
int	oki_adpcm_decode (oki_adpcm_state_t *s, int16_t amp[], const uint8_t oki_data[], int oki_bytes)
int	oki_adpcm_encode (oki_adpcm_state_t *s, uint8_t oki_data[], const int16_t amp[], int len)

---

Detailed Description

---

Function Documentation

int oki_adpcm_decode	(	oki_adpcm_state_t *	s,
		int16_t	amp[],
		const uint8_t	oki_data[],
		int	oki_bytes
	)

Decode a buffer of Oki ADPCM data to linear PCM.

Parameters:

	s	The Oki ADPCM context.
	amp	The audio sample buffer.
	oki_data
	oki_bytes

Returns:

The number of samples returned.

References oki_adpcm_state_t::bit_rate, oki_adpcm_state_t::history, oki_adpcm_state_t::phase, and oki_adpcm_state_t::ptr.

int oki_adpcm_encode	(	oki_adpcm_state_t *	s,
		uint8_t	oki_data[],
		const int16_t	amp[],
		int	len
	)

Encode a buffer of linear PCM data to Oki ADPCM.

Parameters:

	s	The Oki ADPCM context.
	oki_data	The Oki ADPCM data produced
	amp	The audio sample buffer.
	len	The number of samples in the buffer.

Returns:

The number of bytes of Oki ADPCM data produced.

References oki_adpcm_state_t::bit_rate, oki_adpcm_state_t::history, oki_adpcm_state_t::mark, oki_adpcm_state_t::oki_byte, oki_adpcm_state_t::phase, and oki_adpcm_state_t::ptr.

oki_adpcm_state_t* oki_adpcm_init	(	oki_adpcm_state_t *	s,
		int	bit_rate
	)

Initialise an Oki ADPCM encode or decode context.

Parameters:

	s	The Oki ADPCM context.
	bit_rate	The required bit rate for the ADPCM data. The valid rates are 24000 and 32000.

Returns:

A pointer to the Oki ADPCM context, or NULL for error.

References oki_adpcm_state_t::bit_rate.

int oki_adpcm_release

(

oki_adpcm_state_t *

s

)

Free an Oki ADPCM encode or decode context.

Parameters:

s

The Oki ADPCM context.

Returns:

0 for OK.