DSPLIB - IMA/DVI ADPCM

All the IMA/DVI ADPCM functions implemented in the DSP advanced library.

---

Functions
void	dsp_adpcm_ima_decode (S16 *out, void *in, int size, S16 *step_index, S16 *predicted_value)
	IMA/DVI ADPCM decoder. More...
S16	dsp_adpcm_ima_decode_nibble (S8 nibble, S16 *step_index, S16 *predicted_value)
	IMA/DVI ADPCM sample decoder. More...
void	dsp_adpcm_ima_encode (void *out, S16 *in, int size, S16 *step_index, S16 *predicted_value)
	IMA/DVI ADPCM encoder. More...
S8	dsp_adpcm_ima_encode_nibble (S16 nibble, S16 *step_index, S16 *predicted_value)
	IMA/DVI ADPCM sample encoder. More...

void dsp_adpcm_ima_decode	(	S16 *	out,
		void *	in,
		int	size,
		S16 *	step_index,
		S16 *	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.

References ADPCM_IMA_DECODE_NIBBLE, predicted_value, and step_index.

S16 dsp_adpcm_ima_decode_nibble	(	S8	nibble,
		S16 *	step_index,
		S16 *	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.

References ADPCM_IMA_DECODE_NIBBLE.

Referenced by main().

void dsp_adpcm_ima_encode	(	void *	out,
		S16 *	in,
		int	size,
		S16 *	step_index,
		S16 *	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".

References ADPCM_IMA_ENCODE_NIBBLE, predicted_value, and step_index.

S8 dsp_adpcm_ima_encode_nibble	(	S16	nibble,
		S16 *	step_index,
		S16 *	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.

References ADPCM_IMA_ENCODE_NIBBLE.