ai.h File Reference

#include <types.h>
#include <broadway.h>

Go to the source code of this file.

Enumerations
enum	ai_sample_rate_t { AI_SAMPLE_RATE_48000 = 0, AI_SAMPLE_RATE_32000 }
Functions
int	ai_initialize (void)
	Initialize the AI subsystem.
int	ai_shutdown (void)
	Shut down the AI subsystem.
void	ai_set_sample_rate (ai_sample_rate_t rate)
	Set the sample rate.
ai_sample_rate_t	ai_get_sample_rate (void)
	Get the sample rate.
void	ai_enable_irq (int on_sample, int(*exec)(u32 irq, void *data), void *data)
	Enable the sample-reached IRQ.
void	ai_disable_irq (void)
	Disable the sample-reached IRQ.
void	ai_set_volume (u8 left, u8 right)
	Sets the volume of the stereo output.
void	ai_get_volume (u8 *left, u8 *right)
	Gets the volume of the stereo output.
u32	ai_samples_played (void)
	Gets how many samples have been played.
void	ai_reset_sample_counter (void)
	Resets the sample played counter.
int	ai_is_playing (void)
	Returns whether AI is playing audio or not.
int	ai_play (int play)
	Starts or stops the AI from playing audio.

---

Detailed Description

An abstraction of the Audio Interface (AI). Controls various portions of the audio output (including volume and sample rate).

---

Enumeration Type Documentation

enum ai_sample_rate_t

The sample rates supported by AI

Enumerator:

AI_SAMPLE_RATE_48000	48kHz
AI_SAMPLE_RATE_32000	32kHz

---

Function Documentation

void ai_disable_irq

(

void

)

Disable the sample-reached IRQ.

Turns off the IRQ that fires when the AI plays a specific sample.

See also:

ai_enable_irq()

void ai_enable_irq	(	int	on_sample,
		int(*)(u32 irq, void *data)	exec,
		void *	data
	)

Enable the sample-reached IRQ.

Turns on the IRQ that fires when the AI plays a specified sample.

Parameters:

	on_sample	the sample that the IRQ fires on.
	exec	the callback that is called when the IRQ fires.
	data	data provided to the callback when it fires.

See also:

ai_disable_irq()

ai_sample_rate_t ai_get_sample_rate

(

void

)

Get the sample rate.

Returns:

The sample rate that AI was set to use. -1 if there was an error.

See also:

ai_set_sample_rate()

void ai_get_volume	(	u8 *	left,
		u8 *	right
	)

Gets the volume of the stereo output.

Parameters:

	left	a pointer to which the left volume is put. NULL if you don't want the output.
	right	a pointer to which the right volume is put. NULL if you don't want the output.

See also:

ai_set_volume()

int ai_initialize

(

void

)

Initialize the AI subsystem.

Initializes the AI subsystem, registers the handler for the AI interrupt and performs all other required initialization tasks.

Returns:

If initialization was successful, returns 1. Otherwise 0.

See also:

ai_shutdown()

int ai_is_playing

(

void

)

Returns whether AI is playing audio or not.

Returns:

Returns 1 if it was playing, 0 otherwise. -1 if an error occurred.

See also:

ai_play()

int ai_play

(

int

play

)

Starts or stops the AI from playing audio.

Parameters:

play

if 1 starts playing, or if 0 stops playing.

Returns:

Returns 1 if it was playing, 0 otherwise. -1 if an error occurred.

See also:

ai_is_playing()

u32 ai_samples_played

(

void

)

Gets how many samples have been played.

Gets the number of stereo samples that have been played since the counter was last reset (either by a system reset or a manual reset.)

Returns:

How many samples were played. 0xFFFFFFFF if an error occurred.

See also:

ai_reset_sample_counter

void ai_set_sample_rate

(

ai_sample_rate_t

rate

)

Set the sample rate.

Must only be called when the AI is not playing audio.

Parameters:

rate

a value from ai_sample_rate_t specifying the sample rate to use.

See also:

ai_get_sample_rate()

void ai_set_volume	(	u8	left,
		u8	right
	)

Sets the volume of the stereo output.

Sets the volume of the output sound, with the left and right speakers being changable independantly

Parameters:

	left	the volume on the left speaker. 0 is mute, 0xFF is maximum.
	right	the volume on the right speaker. 0 is mute, 0xFF is maximum.

See also:

ai_get_volume()

int ai_shutdown

(

void

)

Shut down the AI subsystem.

Shuts down the AI subsystem, unregisters the handler for the AI interrupt and performs all other required shut down tasks.

Returns:

If shut down was successful, returns 1. Otherwise 0.

See also:

ai_initialize()