Group_adpcm

---

Functions
void	dsp_adpcm_ima_decode (int16_t *out, void *in, int size, int16_t *step_index, int16_t *predicted_value)
	IMA/DVI ADPCM decoder. More...
int16_t	dsp_adpcm_ima_decode_nibble (int8_t nibble, int16_t *step_index, int16_t *predicted_value)
	IMA/DVI ADPCM sample decoder. More...
void	dsp_adpcm_ima_encode (void *out, int16_t *in, int size, int16_t *step_index, int16_t *predicted_value)
	IMA/DVI ADPCM encoder. More...
int8_t	dsp_adpcm_ima_encode_nibble (int16_t nibble, int16_t *step_index, int16_t *predicted_value)
	IMA/DVI ADPCM sample encoder. More...

void dsp_adpcm_ima_decode	(	int16_t *	out,
		void *	in,
		int	size,
		int16_t *	step_index,
		int16_t *	predicted_value
	)

IMA/DVI ADPCM decoder.

Parameters

out	A 16-bit data vector that will contain the decoded data.
in	A 4-bit data vector that contains the IMA/DVI ADPCM encoded data to decode.
size	The number of data to decode.
step_index	A pointer on a 16 bits data which contain the current step index of the ADPCM algorithm.
predicted_value	A pointer on a 16 bits data which contain the current predicted value of the ADPCM algorithm.

int16_t dsp_adpcm_ima_decode_nibble	(	int8_t	nibble,
		int16_t *	step_index,
		int16_t *	predicted_value
	)

IMA/DVI ADPCM sample decoder.

Parameters

nibble	The sample to decode. It must be a 4-bit data.
step_index	A pointer on a 16 bits data which contain the previous step index of the ADPCM algorithm.
predicted_value	A pointer on a 16 bits data which contain the previous predicted value of the ADPCM algorithm.

Returns

A 16-bit data that corresponds to the sample decoded.

void dsp_adpcm_ima_encode	(	void *	out,
		int16_t *	in,
		int	size,
		int16_t *	step_index,
		int16_t *	predicted_value
	)

IMA/DVI ADPCM encoder.

Parameters

out	A 4-bit data vector that will contain the encoded data.
in	A 16-bit data vector that contains the data to encode.
size	The number of data to encode.
step_index	A pointer on a 16 bits data which contain the current step index of the ADPCM algorithm.
predicted_value	A pointer on a 16 bits data which contain the current predicted value of the ADPCM algorithm.

Note

Can be performed "in-place".

int8_t dsp_adpcm_ima_encode_nibble	(	int16_t	nibble,
		int16_t *	step_index,
		int16_t *	predicted_value
	)

IMA/DVI ADPCM sample encoder.

Parameters

nibble	The sample to encode.
step_index	A pointer on a 16 bits data which contain the current step index of the ADPCM algorithm.
predicted_value	A pointer on a 16 bits data which contain the current predicted value of the ADPCM algorithm.

Returns

A 4-bit data that corresponds to the sample encoded.