BelaContext Struct Reference

Structure holding current audio and sensor settings and pointers to data buffers. More...

#include <Bela.h>

Public Attributes
const float *const	audioIn
	Buffer holding audio input samples. More...
float *const	audioOut
	Buffer holding audio output samples. More...
const float *const	analogIn
	Buffer holding analog input samples. More...
float *const	analogOut
	Buffer holding analog output samples. More...
uint32_t *const	digital
	Buffer holding digital input/output samples. More...
const uint32_t	audioFrames
	Number of audio frames per period.
const uint32_t	audioInChannels
	Number of input audio channels.
const uint32_t	audioOutChannels
	Number of output audio channels.
const float	audioSampleRate
	Audio sample rate in Hz (currently always 44100.0)
const uint32_t	analogFrames
	Number of analog frames per period. More...
const uint32_t	analogInChannels
	Number of input analog channels. More...
const uint32_t	analogOutChannels
	Number of output analog channels. More...
const float	analogSampleRate
	Analog sample rate in Hz. More...
const uint32_t	digitalFrames
	Number of digital frames per period.
const uint32_t	digitalChannels
	Number of digital channels. More...
const float	digitalSampleRate
	Digital sample rate in Hz (currently always 44100.0)
const uint64_t	audioFramesElapsed
	Number of elapsed audio frames since the start of rendering. More...
const uint32_t	flags
	Other audio/sensor settings. More...

Detailed Description

Structure holding current audio and sensor settings and pointers to data buffers.

This structure is passed to setup(), render() and cleanup(). It is initialised in Bela_initAudio() based on the contents of the BelaInitSettings structure.

Examples:

analog-input/render.cpp, analog-output/render.cpp, capacitive-touch/render.cpp, digital-input/render.cpp, digital-output/render.cpp, FFT-audio-in/render.cpp, FFT-phase-vocoder/render.cpp, filter-FIR/render.cpp, filter-IIR/render.cpp, logging-sensors/render.cpp, minimal/render.cpp, OSC/render.cpp, oscillator-bank/render.cpp, passthrough/render.cpp, samples/render.cpp, scope-analog/render.cpp, scope/render.cpp, sinetone/render.cpp, tremolo/render.cpp, userdata/render.cpp, and write-file/render.cpp.

Member Data Documentation

const float* const BelaContext::audioIn

Buffer holding audio input samples.

This buffer may be in either interleaved or non-interleaved format, depending on the contents of the BelaInitSettings structure. Note: this element is available in render() only.

Examples:

FFT-audio-in/render.cpp, and write-file/render.cpp.

float* const BelaContext::audioOut

Buffer holding audio output samples.

This buffer may be in either interleaved or non-interleaved format, depending on the contents of the BelaInitSettings structure. Note: this element is available in render() only.

Examples:

capacitive-touch/render.cpp, FFT-audio-in/render.cpp, FFT-phase-vocoder/render.cpp, filter-FIR/render.cpp, filter-IIR/render.cpp, oscillator-bank/render.cpp, and samples/render.cpp.

const float* const BelaContext::analogIn

Buffer holding analog input samples.

This buffer may be in either interleaved or non-interleaved format, depending on the contents of the BelaInitSettings structure. Note: this element is available in render() only.

Examples:

logging-sensors/render.cpp, and oscillator-bank/render.cpp.

float* const BelaContext::analogOut

Buffer holding analog output samples.

This buffer may be in either interleaved or non-interleaved format, depending on the contents of the BelaInitSettings structure. Note: this element is available in render() only.

uint32_t* const BelaContext::digital

Buffer holding digital input/output samples.

Note: this element is available in render() only.

const uint32_t BelaContext::analogFrames

Number of analog frames per period.

This will be 0 if analog I/O is disabled.

Examples:

analog-input/render.cpp, analog-output/render.cpp, logging-sensors/render.cpp, oscillator-bank/render.cpp, passthrough/render.cpp, scope-analog/render.cpp, and tremolo/render.cpp.

const uint32_t BelaContext::analogInChannels

Number of input analog channels.

This will be 0 if analog I/O is disabled.

Examples:

analog-input/render.cpp, analog-output/render.cpp, FFT-audio-in/render.cpp, FFT-phase-vocoder/render.cpp, filter-FIR/render.cpp, filter-IIR/render.cpp, passthrough/render.cpp, samples/render.cpp, scope-analog/render.cpp, and tremolo/render.cpp.

const uint32_t BelaContext::analogOutChannels

Number of output analog channels.

This will be 0 if analog I/O is disabled.

Examples:

analog-output/render.cpp, and tremolo/render.cpp.

const float BelaContext::analogSampleRate

Analog sample rate in Hz.

The analog sample rate depends on the number of analog channels used. If 8 channels are used, the sample rate is 22050. If 4 channels are used, the sample rate is 44100. If 2 channels are used, the sample rate is 88200. If analog I/O is disabled, the sample rate is 0.

Examples:

analog-output/render.cpp.

const uint32_t BelaContext::digitalChannels

Number of digital channels.

Currently this will always be 16, unless digital I/O is disabled, in which case it will be 0.

const uint64_t BelaContext::audioFramesElapsed

Number of elapsed audio frames since the start of rendering.

This holds the total number of audio frames as of the beginning of the current period. To find the current number of analog or digital frames elapsed, multiply by the ratio of the sample rates (e.g. half the number of analog frames will have elapsed if the analog sample rate is 22050).

const uint32_t BelaContext::flags

Other audio/sensor settings.

Binary combination of flags including:

BELA_FLAG_INTERLEAVED: indicates the audio and analog buffers are interleaved

BELA_FLAG_ANALOG_OUTPUTS_PERSIST: indicates that writes to the analog outputs will persist for future frames. If not set, writes affect one frame only.

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The documentation for this struct was generated from the following file:

• Bela.h