SignalProcessing Library API

API for using SignalProcessing. More...

Classes
class	IIRClass
	Biquad IIR filter class. More...

Macros
#define	ARM_MATH_CM4
#define	__FPU_PRESENT   1U

Typedefs
typedef enum e_filterType	filterType_t
typedef enum IIRClass::e_format	IIRClass::format_t
typedef enum IIRClass::e_error	IIRClass::error_t

Enumerations
enum	e_filterType { TYPE_LPF , TYPE_HPF , TYPE_BPF , TYPE_BEF }
enum	IIRClass::e_format { IIRClass::Interleave , IIRClass::Planar }
enum	IIRClass::e_error {   IIRClass::ERR_OK = 0 , IIRClass::ERR_CH_NUM = -1 , IIRClass::ERR_FORMAT = -2 , IIRClass::ERR_MEMORY = -3 ,   IIRClass::ERR_FILTER_TYPE = -4 , IIRClass::ERR_FRAME_SIZE = -5 , IIRClass::ERR_BUF_FULL = -6 , IIRClass::ERR_FS = -7 }

Functions
bool	IIRClass::begin (filterType_t type, int channel, int cutoff, float q, int sample=DEFAULT_FRAMESIZE, format_t output=Planar, int fs=48000)
	Initialize the IIR library. More...
bool	IIRClass::put (q15_t *pSrc, int size)
	Put input data into the IIR library. More...
int	IIRClass::get (q15_t *pDst, int channel)
	Get the execution data of each channel. More...
int	IIRClass::get (q15_t *pDsts)
	Get the execution data of all channels. More...
void	IIRClass::end ()
	Finalize the IIR library. More...
bool	IIRClass::empty (int channel)
	Is the buffer empty or not of each channel. More...
error_t	IIRClass::getErrorCause ()
	Get error information. More...

Variables
static const int	IIRClass::BITLEN = 16
static const int	IIRClass::DEFAULT_FRAMESIZE = 768
static const int	IIRClass::MIN_FRAMESIZE = 240
static const int	IIRClass::MAX_CHANNEL_NUM = 8
static const int	IIRClass::INPUT_BUFFER_SIZE = 4

Detailed Description

API for using SignalProcessing.

Enumeration Type Documentation

e_filterType

enum e_filterType

Enumerator
TYPE_LPF	Low Pass Filter.
TYPE_HPF	High Pass Filter.
TYPE_BPF	Band Pass Filter.
TYPE_BEF	Band Elimination Filter.

e_format

enum IIRClass::e_format

Enumerator
Interleave	the channel interleave format
Planar	the channel planar format

e_error

enum IIRClass::e_error

Enumerator
ERR_OK	No error.
ERR_CH_NUM	Wrong channel setting.
ERR_FORMAT	Wrong output format setting.
ERR_MEMORY	Lack of memory area.
ERR_FILTER_TYPE	Wrong filter type setting.
ERR_FRAME_SIZE	Wrong number of samples.
ERR_BUF_FULL	Failture of write as buffer is full.
ERR_FS	Wrong sampling rate.

Function Documentation

begin()

bool IIRClass::begin	(	filterType_t	type,
		int	channel,
		int	cutoff,
		float	q,
		int	sample = DEFAULT_FRAMESIZE,
		format_t	output = Planar,
		int	fs = 48000
	)

Initialize the IIR library.

Returns

OK(true) or Failure(false)

This function is called only once when using the IIR library.

Parameters

type	The execution filter type
channel	The number of channels
cutoff	The cutoff frequency(BPF/HPF) or the center frequency(BPF/BEF)
q	The Q value(BPF/HPF) or the bandwidthoctave
sample	The number of samples in an execution filter(default size is DEFAULT_FRAMESIZE)
output	The output format(default is Planar)
fs	The Sampling rate

put()

bool IIRClass::put	(	q15_t *	pSrc,
		int	size
	)

Put input data into the IIR library.

Returns

OK(true) or Failure(false)

Put input data into the IIR library. Multi-channel input data support interleave format.

Parameters

pSrc	The pointer of input data address
size	The number of input data sample

get() [1/2]

int IIRClass::get	(	q15_t *	pDst,
		int	channel
	)

Get the execution data of each channel.

Returns

The size of an execution data sample(Error code when negative numbers)

Get the execution data of each channel. This API can be called only for Planar format.

Parameters

pDst	The pointer of area that output data is written
channel	The each channel number of the execution data

get() [2/2]

int IIRClass::get

(

q15_t *

pDsts

)

Get the execution data of all channels.

Returns

The size of execution data sample(Error code when negative numbers)

Get the execution data of all channels. This API can be called only for Interleave format.

Parameters

pDsts

The pointer of area that output data is written

end()

void IIRClass::end

(

)

Finalize the IIR library.

This function is called when you want to exit the IIR library.

empty()

bool IIRClass::empty

(

int

channel

)

Is the buffer empty or not of each channel.

Returns

Empty(true) or Not empty(false)

Is the buffer empty or not of each channel.

Parameters

channel

The channel number that you want to check

getErrorCause()

error_t IIRClass::getErrorCause ( )

inline

Get error information.

Returns

Error code[IIRClass::error_t]

When an error occurs, you call this function and get error cause information.

Variable Documentation

BITLEN

const int IIRClass::BITLEN = 16

static

The bit length definition (Only Support 16bit)

DEFAULT_FRAMESIZE

const int IIRClass::DEFAULT_FRAMESIZE = 768

static

The default number of samples in an execution frame

MIN_FRAMESIZE

const int IIRClass::MIN_FRAMESIZE = 240

static

The minimum number of samples in an execution frame

MAX_CHANNEL_NUM

const int IIRClass::MAX_CHANNEL_NUM = 8

static

The Maximum number of channels

INPUT_BUFFER_SIZE

const int IIRClass::INPUT_BUFFER_SIZE = 4

static

The size of input buffer (Multiple of frame size)