ADPCM Decoder (rm_adpcm_decoder)

Functions
fsp_err_t	RM_ADPCM_DECODER_Open (adpcm_decoder_ctrl_t *p_ctrl, adpcm_decoder_cfg_t const *const p_cfg)
fsp_err_t	RM_ADPCM_DECODER_Decode (adpcm_decoder_ctrl_t *const p_ctrl, void const *p_src, void *p_dest, uint32_t src_len_bytes)
fsp_err_t	RM_ADPCM_DECODER_Reset (adpcm_decoder_ctrl_t *p_ctrl)
fsp_err_t	RM_ADPCM_DECODER_Close (adpcm_decoder_ctrl_t *p_ctrl)

Detailed Description

Middleware to implement the ADPCM Audio Decoder. This module implements the ADPCM Decoder Interface.

Overview

Features

The ADPCM Audio Decoder has the following key features:

• Decodes 4-bit ADPCM input to 16-bit PCM output

Configuration

Build Time Configurations for rm_adpcm_decoder

The following build time configurations are defined in fsp_cfg/rm_adpcm_decoder_cfg.h:

Configuration	Options	Default	Description
Parameter Checking	Default (BSP) Enabled Disabled	Default (BSP)	If selected code for parameter checking is included in the build.

Configurations for Audio > ADPCM Decoder (rm_adpcm_decoder)

This module can be added to the Stacks tab via New Stack > Audio > ADPCM Decoder (rm_adpcm_decoder).

Configuration	Options	Default	Description
Name	Name must be a valid C symbol	g_adpcm_decoder0	Module name.

Clock Configuration

This module has no required clock configurations.

Pin Configuration

This module does not use I/O pins.

Examples

Basic Example

This is a basic example of minimal use of the ADPCM Audio Decoder implementation in an application.

void rm_adpcm_decoder_example ()
{
    /* Open the ADPCM audio decoder instance. */
    fsp_err_t err = RM_ADPCM_DECODER_Open(&g_adpcmdec_ctrl, &g_adpcmdec_cfg);

    /* Handle any errors. This function should be defined by the user. */
    assert(FSP_SUCCESS == err);

    /* Decode the data */
    err = RM_ADPCM_DECODER_Decode(&g_adpcmdec_ctrl, g_adpcm_stream1, g_pcm_stream, ADPCM_BUFFER_SIZE_BYTES);
    assert(FSP_SUCCESS == err);

    /* Reset the ADPCM audio decoder instance before decoding a new stream. */
    err = RM_ADPCM_DECODER_Reset(&g_adpcmdec_ctrl);
    assert(FSP_SUCCESS == err);

    /* Decode the first chunk of ADPCM data */
    err = RM_ADPCM_DECODER_Decode(&g_adpcmdec_ctrl, g_adpcm_stream2, g_pcm_stream, (ADPCM_BUFFER_SIZE_BYTES/2));
    assert(FSP_SUCCESS == err);

    /* Decode the second chunk of ADPCM data */
    err = RM_ADPCM_DECODER_Decode(&g_adpcmdec_ctrl, &g_adpcm_stream2[ADPCM_BUFFER_SIZE_BYTES/2],
                                  g_pcm_stream, (ADPCM_BUFFER_SIZE_BYTES/2));
    assert(FSP_SUCCESS == err);

}

Data Structures
struct	adpcm_decoder_instance_ctrl_t

---

Data Structure Documentation

adpcm_decoder_instance_ctrl_t

struct adpcm_decoder_instance_ctrl_t

RM_ADPCM_DECODER instance control block. DO NOT INITIALIZE. Initialized in adpcm_decoder_api_t::open().

Function Documentation

RM_ADPCM_DECODER_Open()

fsp_err_t RM_ADPCM_DECODER_Open	(	adpcm_decoder_ctrl_t *	p_ctrl,
		adpcm_decoder_cfg_t const *const	p_cfg
	)

Initializes ADPCM audio decoder device.

Implements adpcm_decoder_api_t::open().

Return values

FSP_SUCCESS	Module is ready for use.
FSP_ERR_ASSERTION	An input argument is invalid.
FSP_ERR_ALREADY_OPEN	The instance control structure has already been opened.

RM_ADPCM_DECODER_Decode()

fsp_err_t RM_ADPCM_DECODER_Decode	(	adpcm_decoder_ctrl_t *const	p_ctrl,
		void const *	p_src,
		void *	p_dest,
		uint32_t	src_len_bytes
	)

Decodes 4bit ADPCM data to 16bit PCM data. It reads ADPCM data from area pointed by inputAddr pointer, decodes the number of samples specified and stores the decoded data in buffer pointed with outputAddr pointer.

Implements adpcm_decoder_api_t::decode().

Return values

FSP_SUCCESS	Decode operation successfully completed.
FSP_ERR_ASSERTION	An input argument is invalid.
FSP_ERR_NOT_OPEN	Unit is not open.

RM_ADPCM_DECODER_Reset()

fsp_err_t RM_ADPCM_DECODER_Reset

(

adpcm_decoder_ctrl_t *

p_ctrl

)

This function resets the ADPCM decoder device.

Implements adpcm_decoder_api_t::reset().

Return values

FSP_SUCCESS	Module closed.
FSP_ERR_ASSERTION	An input argument is invalid.
FSP_ERR_NOT_OPEN	Unit is not open.

RM_ADPCM_DECODER_Close()

fsp_err_t RM_ADPCM_DECODER_Close

(

adpcm_decoder_ctrl_t *

p_ctrl

)

This function closes the ADPCM decoder device.

Implements adpcm_decoder_api_t::close().

Return values

FSP_SUCCESS	Module closed.
FSP_ERR_ASSERTION	An input argument is invalid.
FSP_ERR_NOT_OPEN	Unit is not open.