Main Bela public API. More...

#include <stdint.h>
#include <unistd.h>
#include <stdbool.h>
#include <stdio.h>
#include <GPIOcontrol.h>
#include <time.h>
#include <Utilities.h>

Classes
struct	_BelaHwConfig
struct	BelaContext
	Structure holding audio and sensor settings and pointers to I/O data buffers. More...
struct	BelaChannelGain
struct	BelaChannelGainArray
struct	BelaInitSettings
	Structure containing initialisation parameters for the real-time audio control system. More...
struct	BelaCpuData

Macros
#define	BELA_MAJOR_VERSION 1
#define	BELA_MINOR_VERSION 13
#define	BELA_BUGFIX_VERSION 0
#define	BELA_AUDIO_PRIORITY 95
#define	DEFAULT_LINE_OUT_LEVEL 0.0
#define	DEFAULT_PGA_GAIN 16
#define	DEFAULT_HP_LEVEL -6.0
#define	BELA_FLAG_INTERLEAVED (1 << 0)
#define	BELA_FLAG_ANALOG_OUTPUTS_PERSIST (1 << 1)
#define	BELA_FLAG_DETECT_UNDERRUNS (1 << 2)
#define	BELA_FLAG_OFFLINE (1 << 3)

Typedefs
typedef struct _BelaHwConfig	BelaHwConfig
typedef void *	AuxiliaryTask

Enumerations
enum	BelaHw { BelaHw_NoHw = -1 , BelaHw_Bela , BelaHw_BelaMini , BelaHw_Salt , BelaHw_CtagFace , BelaHw_CtagBeast , BelaHw_CtagFaceBela , BelaHw_CtagBeastBela , BelaHw_BelaMiniMultiAudio , BelaHw_BelaMiniMultiTdm , BelaHw_BelaMultiTdm , BelaHw_BelaMiniMultiI2s , BelaHw_BelaEs9080 , BelaHw_BelaRevC , BelaHw_Batch }
enum	BelaHwDetectMode { BelaHwDetectMode_Scan , BelaHwDetectMode_Cache , BelaHwDetectMode_CacheOnly , BelaHwDetectMode_User , BelaHwDetectMode_UserOnly }
enum	{ INPUT = 0 , OUTPUT = 1 }

Functions
int	rt_printf (const char *format,...)
int	rt_fprintf (FILE stream, const char format,...)
int	rt_vprintf (const char *format, va_list ap)
int	rt_vfprintf (FILE stream, const char format, va_list ap)
BelaHwConfig *	Bela_HwConfig_new (BelaHw hw)
void	Bela_HwConfig_delete (BelaHwConfig *cfg)
bool	setup (BelaContext context, void userData)
	User-defined initialisation function which runs before audio rendering begins.
void	render (BelaContext context, void userData)
	User-defined callback function to process audio and sensor data.
void	cleanup (BelaContext context, void userData)
	User-defined cleanup function which runs when the program finishes.
BelaInitSettings *	Bela_InitSettings_alloc ()
	Allocate the data structure containing settings for Bela.
void	Bela_InitSettings_free (BelaInitSettings *settings)
	De-allocate the data structure containing settings for Bela.
void	Bela_defaultSettings (BelaInitSettings *settings)
	Initialise the data structure containing settings for Bela.
void	Bela_userSettings (BelaInitSettings *settings)
	Initialise the data structure containing settings for Bela.
int	Bela_getopt_long (int argc, char const argv[], const char customShortOptions, const struct option customLongOptions, BelaInitSettings settings)
	Get long options from command line argument list, including Bela standard options.
void	Bela_usage ()
	Print usage information for Bela standard options.
void	Bela_getVersion (int major, int minor, int *bugfix)
	Get the version of Bela you are running.
void	Bela_setVerboseLevel (int level)
	Set level of verbose (debugging) printing.
BelaHw	Bela_detectHw (BelaHwDetectMode mode)
	Detect what hardware we are running on.
int	Bela_initAudio (BelaInitSettings settings, void userData)
	Initialise audio and sensor rendering environment.
int	Bela_startAudio ()
	Begin processing audio and sensor data.
int	Bela_runInSameThread ()
	Begin processing audio and sensor data in the same thread as the caller.
void	Bela_stopAudio ()
	Stop processing audio and sensor data.
void	Bela_cleanupAudio ()
	Clean up resources from audio and sensor processing.
void	Bela_setUserData (void *newUserData)
	Set the userData variable, which is passed to setup(), render() and cleanup().
void	Bela_requestStop ()
	Tell the Bela program to stop.
int	Bela_stopRequested ()
	Check whether the program should stop.
int	Bela_cpuMonitoringInit (int count)
BelaCpuData *	Bela_cpuMonitoringGet ()
void	Bela_cpuTic (BelaCpuData *data)
void	Bela_cpuToc (BelaCpuData *data)
int	Bela_setLineOutLevel (int channel, float decibel)
	Set the level of the audio line out.
int	Bela_setDacLevel (int channel, float decibels)
	Set the level of the audio DAC.
int	Bela_setDACLevel (float decibels)
int	Bela_setAdcLevel (int channel, float decibels)
	Set the level of the audio ADC.
int	Bela_setADCLevel (float decibels)
int	Bela_setAudioInputGain (int channel, float decibels)
	Set the gain of the audio input preamplifier.
int	Bela_setPgaGain (float decibels, int channel)
int	Bela_setHpLevel (int channel, float decibels)
	Set the level of the onboard headphone amplifier.
int	Bela_setHeadphoneLevel (float decibels)
int	Bela_muteSpeakers (int mute)
	Mute or unmute the onboard speaker amplifiers.
AuxiliaryTask	Bela_createAuxiliaryTask (void(callback)(void ), int priority, const char name, void arg=NULL)
	Create a new auxiliary task.
int	Bela_scheduleAuxiliaryTask (AuxiliaryTask task)
	Run an auxiliary task which has previously been created.
AuxiliaryTask	Bela_runAuxiliaryTask (void(callback)(void ), int priority=0, void *arg=nullptr)
	Create and start an AuxiliaryTask.
int	Bela_startAuxiliaryTask (AuxiliaryTask task)
	Initialize an auxiliary task so that it can be scheduled.
int	Bela_startAllAuxiliaryTasks ()
void	Bela_stopAllAuxiliaryTasks ()
void	Bela_deleteAllAuxiliaryTasks ()

static float	audioRead (BelaContext *context, int frame, int channel)
	Read an audio input, specifying the frame number (when to read) and the channel.
static float	audioReadNI (BelaContext *context, int frame, int channel)
	Non-interleaved version of audioRead().
static void	audioWrite (BelaContext *context, int frame, int channel, float value)
	Write an audio output, specifying the frame number (when to write) and the channel.
static void	audioWriteNI (BelaContext *context, int frame, int channel, float value)
	Non-interleaved version of audioWrite().
static float	analogRead (BelaContext *context, int frame, int channel)
	Read an analog input, specifying the frame number (when to read) and the channel.
static float	analogReadNI (BelaContext *context, int frame, int channel)
	Non-interleaved version of analogRead().
static void	analogWrite (BelaContext *context, int frame, int channel, float value)
	Write an analog output, specifying the frame number (when to write) and the channel.
static void	analogWriteNI (BelaContext *context, int frame, int channel, float value)
	Non-interleaved version of analogWrite().
static void	analogWriteOnce (BelaContext *context, int frame, int channel, float value)
	Write an analog output, specifying the frame number (when to write) and the channel.
static void	analogWriteOnceNI (BelaContext *context, int frame, int channel, float value)
	Non-interleaved version of analogWriteNI().
static int	digitalRead (BelaContext *context, int frame, int channel)
	Read a digital input, specifying the frame number (when to read) and the pin.
static void	digitalWrite (BelaContext *context, int frame, int channel, int value)
	Write a digital output, specifying the frame number (when to write) and the pin.
static void	digitalWriteOnce (BelaContext *context, int frame, int channel, int value)
	Write a digital output, specifying the frame number (when to write) and the pin.
static void	pinMode (BelaContext *context, int frame, int channel, int mode)
	Set the direction of a digital pin to input or output.
static void	pinModeOnce (BelaContext *context, int frame, int channel, int mode)
	Set the direction of a digital pin to input or output.
static float	multiplexerAnalogRead (BelaContext *context, int input, int muxChannel)
	Read an audio input, specifying the frame number (when to read) and the channel.
static unsigned int	multiplexerChannelForFrame (BelaContext *context, int frame)
	Read an audio input, specifying the frame number (when to read) and the channel.

Variables
int volatile	gShouldStop

Detailed Description

Main Bela public API.

Central control code for hard real-time audio on BeagleBone Black using PRU and Xenomai Linux extensions. This code began as part of the Hackable Instruments project (EPSRC) at Queen Mary University of London, 2013-14.

Macro Definition Documentation

◆ BELA_FLAG_INTERLEAVED

#define BELA_FLAG_INTERLEAVED (1 << 0)

Flag for BelaContext. If set, indicates the audio and analog buffers are interleaved.

Examples: Communication/logging-sensors/render.cpp.

◆ BELA_FLAG_ANALOG_OUTPUTS_PERSIST

#define BELA_FLAG_ANALOG_OUTPUTS_PERSIST (1 << 1)

Flag for BelaContext. If set, indicates analog outputs persist for future frames.

◆ BELA_FLAG_DETECT_UNDERRUNS

#define BELA_FLAG_DETECT_UNDERRUNS (1 << 2)

Flag for BelaContext. If set, indicates the user will be warned if an underrun occurs

◆ BELA_FLAG_OFFLINE

#define BELA_FLAG_OFFLINE (1 << 3)

Flag for BelaContext. If set, it means that render() is called offline, i.e.: the audio time does not correspond to wall clock time.

Enumeration Type Documentation

◆ BelaHw

enum BelaHw

A type of Bela hardware.

Enumerator
BelaHw_NoHw	No hardware.
BelaHw_Bela	Bela.
BelaHw_BelaMini	Bela Mini.
BelaHw_Salt	Salt.
BelaHw_CtagFace	Ctag Face.
BelaHw_CtagBeast	Ctag Beast.
BelaHw_CtagFaceBela	Ctag Face and Bela cape.
BelaHw_CtagBeastBela	Ctag Beast and Bela cape.
BelaHw_BelaMiniMultiAudio	Bela Mini with extra codecs.
BelaHw_BelaMiniMultiTdm	Bela Mini with extra codecs and/or tdm devices.
BelaHw_BelaMultiTdm	Bela with extra codecs and/or tdm devices.
BelaHw_BelaMiniMultiI2s	Bela Mini with extra rx and tx I2S data lines.
BelaHw_BelaEs9080	A Bela cape with Es9080 EVB on top, all as audio.
BelaHw_BelaRevC	A Bela cape rev C: Es9080 is used for analog outs.
BelaHw_Batch	Dummy offline.

◆ BelaHwDetectMode

enum BelaHwDetectMode

Arguments to be passed to Bela_detectHw()

Enumerator
BelaHwDetectMode_Scan	perform an automatic detection by scanning the peripherals and busses available, and cache value in /run/bela/belaconfig
BelaHwDetectMode_Cache	read cached value from /run/bela/belaconfig first. If it does not exist, fall back to BelaHwDetectMode_Scan
BelaHwDetectMode_CacheOnly	read cached value from /run/bela/belaconfig. If it does not exist, return BelaHw_NoHw
BelaHwDetectMode_User	read user-specified value from ~/.bela/belaconfig. If it does not exist, fall back to BelaHwDetectMode_Cache
BelaHwDetectMode_UserOnly	read user-specified value from ~/.bela/belaconfig. If it does not exist, return BelaHw_NoHw

Function Documentation

◆ Bela_HwConfig_new()

BelaHwConfig * Bela_HwConfig_new ( BelaHw hw )

Returns the configuration for a given BelaHw or nullptr if hw is invalid.

The returned pointer has to be deleted with Bela_HwConfig_delete().

◆ Bela_HwConfig_delete()

void Bela_HwConfig_delete ( BelaHwConfig * cfg )

Use this to delete a pointer returned by Bela_HwConfig_new()

Classes

Macros

Typedefs

Enumerations

Functions

Variables