daisy::AudioHandle¶

Module: LIBDAISY / HUMAN_INTERFACE / AUDIO

Audio Engine Handle. More...

#include <audio.h>

Public Classes¶

	Name
struct	Config

Public Types¶

	Name
enum class	Result
typedef const float const	InputBuffer
typedef float **	OutputBuffer
typedef void(*)(InputBuffer in, OutputBuffer out, size_t size)	AudioCallback
typedef const float *	InterleavingInputBuffer
typedef float *	InterleavingOutputBuffer
typedef void(*)(InterleavingInputBuffer in, InterleavingOutputBuffer out, size_t size)	InterleavingAudioCallback

Public Functions¶

	Name
	AudioHandle()
	~AudioHandle()
	AudioHandle(const AudioHandle & other) =default
AudioHandle &	operator=(const AudioHandle & other) =default
Result	Init(const Config & config, SaiHandle sai)
Result	Init(const Config & config, SaiHandle sai1, SaiHandle sai2)
Result	DeInit()
const Config &	GetConfig() const
size_t	GetChannels() const
float	GetSampleRate()
Result	SetSampleRate(SaiHandle::Config::SampleRate samplerate)
Result	SetBlockSize(size_t size)
Result	SetPostGain(float val)
Result	SetOutputCompensation(float val)
Result	Start(AudioCallback callback)
Result	Start(InterleavingAudioCallback callback)
Result	Stop()
Result	ChangeCallback(AudioCallback callback)
Result	ChangeCallback(InterleavingAudioCallback callback)

Detailed Description¶

class daisy::AudioHandle;

Audio Engine Handle.

This class allows for higher level access to an audio engine. If you're using a SOM like the DaisySeed or DaisyPatchSM (or any board that includes one of those objects) then the intialization is already taken care of. If you're setting up your own custom hardware, or need to make changes you will have to take the following steps:

Create and Initialize an SaiHandle or two depending on your requirements
Initialize the Audio Handle with the desired settings and the Initialized SaiHandle
If the connected codec requires special configuration or initialization, do so
Write a callback method using either the AudioCallback or the InterleavingAudioCallback format
Start the Audio using one of the StartAudio function

Public Types Documentation¶

enum Result¶

Enumerator	Value	Description
OK
ERR

typedef InputBuffer¶

typedef const float* const* daisy::AudioHandle::InputBuffer;

Non-Interleaving input buffer Buffer arranged by float[chn][sample] const so that the user can't modify the input

typedef OutputBuffer¶

typedef float** daisy::AudioHandle::OutputBuffer;

Non-Interleaving output buffer Arranged by float[chn][sample]

typedef AudioCallback¶

typedef void(* daisy::AudioHandle::AudioCallback) (InputBuffer in, OutputBuffer out, size_t size);

Type for a Non-Interleaving audio callback Non-Interleaving audio callbacks in daisy will be of this type

typedef InterleavingInputBuffer¶

typedef const float* daisy::AudioHandle::InterleavingInputBuffer;

Interleaving Input buffer audio is prepared as { L0, R0, L1, R1, . . . LN, RN }] this is const, as the user shouldn't modify it

typedef InterleavingOutputBuffer¶

typedef float* daisy::AudioHandle::InterleavingOutputBuffer;

Interleaving Output buffer audio is prepared as { L0, R0, L1, R1, . . . LN, RN }

typedef InterleavingAudioCallback¶

typedef void(* daisy::AudioHandle::InterleavingAudioCallback) (InterleavingInputBuffer in, InterleavingOutputBuffer out, size_t size);

Interleaving Audio Callback Interleaving audio callbacks in daisy must be of this type

Public Functions Documentation¶

function AudioHandle¶

inline AudioHandle()

function ~AudioHandle¶

inline ~AudioHandle()

function AudioHandle¶

AudioHandle(
    const AudioHandle & other
) =default

function operator=¶

AudioHandle & operator=(
    const AudioHandle & other
) =default

function Init¶

Result Init(
    const Config & config,
    SaiHandle sai
)

Initializes audio to run using a single SAI configured in Stereo I2S mode.

function Init¶

Result Init(
    const Config & config,
    SaiHandle sai1,
    SaiHandle sai2
)

Initializes audio to run using two SAI, each configured in Stereo I2S mode.

function DeInit¶

Result DeInit()

Stops and deinitializes audio.

function GetConfig¶

const Config & GetConfig() const

Returns the Global Configuration struct for the Audio

function GetChannels¶

size_t GetChannels() const

Returns the number of channels of audio. When using a single SAI this returns 2, when using two SAI it returns 4 If no SAI is initialized this returns 0

Eventually when we add non-standard I2S for each SAI this will be work differently

function GetSampleRate¶

float GetSampleRate()

Returns the Samplerate as a float

function SetSampleRate¶

Result SetSampleRate(
    SaiHandle::Config::SampleRate samplerate
)

Sets the samplerate, and reinitializes the sai as needed.

function SetBlockSize¶

Result SetBlockSize(
    size_t size
)

Sets the block size after initialization, and updates the internal configuration struct. Get BlockSize and other details via the GetConfig

function SetPostGain¶

Result SetPostGain(
    float val
)

Parameters:

val Gain adjustment amount. The hardware will clip at the reciprical of this value.

Sets the amount of gain adjustment to perform before and after callback. useful if the hardware has additional headroom, and the nominal value shouldn't be 1.0

function SetOutputCompensation¶

Result SetOutputCompensation(
    float val
)

Parameters:

val To calcuate the value, measure the input signal, then measure the output signal (with this set to default value of 1.0). Then calculate val as: val = 1 / (vout / vin);

Sets an additional amount of gain compensation to perform at the end of the callback Useful if the hardware input/output levels are not equal.

function Start¶

Result Start(
    AudioCallback callback
)

Starts the Audio using the non-interleaving callback.

function Start¶

Result Start(
    InterleavingAudioCallback callback
)

Starts the Audio using the interleaving callback. For now only two channels are supported via this method.

function Stop¶

Result Stop()

Stop the Audio

function ChangeCallback¶

Result ChangeCallback(
    AudioCallback callback
)

Immediatley changes the audio callback to the non-interleaving callback passed in.

function ChangeCallback¶

Result ChangeCallback(
    InterleavingAudioCallback callback
)

Immediatley changes the audio callback to the interleaving callback passed in.

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Updated on 2024-01-03 at 19:41:01 +0000