AUDIO PLAYBACK Interface

Detailed Description

Interface for the Audio Playback.

Defines the API and data structures for the Audio Playback implementation.

Summary

This module provides common interface for Audio Playback.

Data Structures
struct	audio_playback_callback_args_t
struct	audio_playback_cfg_t
struct	audio_playback_api_t
struct	audio_playback_instance_t

Typedefs
typedef void	audio_playback_ctrl_t

Enumerations
enum	audio_playback_event_t

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Data Structure Documentation

audio_playback_callback_args_t

struct audio_playback_callback_args_t

Callback function parameter data

Data Fields
void *	p_context	Placeholder for user data.
audio_playback_event_t	event	Event that triggered the callback.

audio_playback_cfg_t

struct audio_playback_cfg_t

Audio Playback configuration parameters.

Data Fields
void const *	p_extend
	Hardware dependent configuration.
void(*	p_callback )(audio_playback_callback_args_t *p_args)
void *	p_context

Field Documentation

p_callback

void(* audio_playback_cfg_t::p_callback) (audio_playback_callback_args_t *p_args)

Callback called when play is complete.

p_context

void* audio_playback_cfg_t::p_context

Placeholder for user data. Passed to the user callback in audio_playback_callback_args_t.

audio_playback_api_t

struct audio_playback_api_t

Audio Playback functions implemented by the Audio Playback drivers will follow this API.

Data Fields
fsp_err_t(*	open )(audio_playback_ctrl_t *const p_ctrl, audio_playback_cfg_t const *const p_cfg)
fsp_err_t(*	start )(audio_playback_ctrl_t *const p_ctrl)
fsp_err_t(*	stop )(audio_playback_ctrl_t *const p_ctrl)
fsp_err_t(*	play )(audio_playback_ctrl_t *const p_ctrl, void const *const p_buffer, uint32_t length)
fsp_err_t(*	close )(audio_playback_ctrl_t *const p_ctrl)

Field Documentation

open

fsp_err_t(* audio_playback_api_t::open) (audio_playback_ctrl_t *const p_ctrl, audio_playback_cfg_t const *const p_cfg)

Open a audio playback module.

Parameters

[in]	p_ctrl	Pointer to memory allocated for control block.
[in]	p_cfg	Pointer to the hardware configurations.

start

fsp_err_t(* audio_playback_api_t::start) (audio_playback_ctrl_t *const p_ctrl)

Start audio playback hardware.

Parameters

[in]

p_ctrl

Pointer to control block.

stop

fsp_err_t(* audio_playback_api_t::stop) (audio_playback_ctrl_t *const p_ctrl)

Stop audio playback hardware.

Parameters

[in]

p_ctrl

Pointer to control block.

play

fsp_err_t(* audio_playback_api_t::play) (audio_playback_ctrl_t *const p_ctrl, void const *const p_buffer, uint32_t length)

Play audio buffer.

Parameters

[in]	p_ctrl	Pointer to control block.
[in]	p_buffer	Pointer to buffer with PCM samples to play. Data must be scaled for audio playback hardware.
[in]	length	Length of data in p_buffer.

close

fsp_err_t(* audio_playback_api_t::close) (audio_playback_ctrl_t *const p_ctrl)

Close the audio driver.

Parameters

[in]

p_ctrl

Pointer to control block initialized in audio_playback_api_t::open.

audio_playback_instance_t

struct audio_playback_instance_t

This structure encompasses everything that is needed to use an instance of this interface.

Data Fields
audio_playback_ctrl_t *	p_ctrl	Pointer to the control structure for this instance.
audio_playback_cfg_t const *	p_cfg	Pointer to the configuration structure for this instance.
audio_playback_api_t const *	p_api	Pointer to the API structure for this instance.

Typedef Documentation

audio_playback_ctrl_t

typedef void audio_playback_ctrl_t

Audio Playback control block. Allocate an instance specific control block to pass into the AUDIO_PLAYBACK API calls.

Enumeration Type Documentation

audio_playback_event_t

enum audio_playback_event_t

Callback event types.

Enumerator
AUDIO_PLAYBACK_EVENT_PLAYBACK_COMPLETE	Audio playback complete event.