#include "iirfilter.h"
#include <complex.h>
#include <math.h>
Go to the source code of this file.
Data Structures | |
struct | FFIIRFilterCoeffs |
IIR filter global parameters. More... | |
struct | FFIIRFilterState |
IIR filter state. More... | |
Defines | |
#define | MAXORDER 30 |
maximum supported filter order | |
#define | FILTER(i0, i1, i2, i3) |
Functions | |
struct FFIIRFilterCoeffs * | ff_iir_filter_init_coeffs (enum IIRFilterType filt_type, enum IIRFilterMode filt_mode, int order, float cutoff_ratio, float stopband, float ripple) |
Initialize filter coefficients. | |
struct FFIIRFilterState * | ff_iir_filter_init_state (int order) |
Create new filter state. | |
void | ff_iir_filter (const struct FFIIRFilterCoeffs *c, struct FFIIRFilterState *s, int size, const int16_t *src, int sstep, int16_t *dst, int dstep) |
Perform lowpass filtering on input samples. | |
void | ff_iir_filter_free_state (struct FFIIRFilterState *state) |
Free filter state. | |
void | ff_iir_filter_free_coeffs (struct FFIIRFilterCoeffs *coeffs) |
Free filter coefficients. |
Definition in file iirfilter.c.
#define FILTER | ( | i0, | |||
i1, | |||||
i2, | |||||
i3 | ) |
Value:
in = *src * c->gain \ + c->cy[0]*s->x[i0] + c->cy[1]*s->x[i1] \ + c->cy[2]*s->x[i2] + c->cy[3]*s->x[i3]; \ res = (s->x[i0] + in )*1 \ + (s->x[i1] + s->x[i3])*4 \ + s->x[i2] *6; \ *dst = av_clip_int16(lrintf(res)); \ s->x[i0] = in; \ src += sstep; \ dst += dstep; \
Definition at line 106 of file iirfilter.c.
#define MAXORDER 30 |
maximum supported filter order
Definition at line 49 of file iirfilter.c.
Referenced by ff_iir_filter_init_coeffs().
void ff_iir_filter | ( | const struct FFIIRFilterCoeffs * | coeffs, | |
struct FFIIRFilterState * | state, | |||
int | size, | |||
const int16_t * | src, | |||
int | sstep, | |||
int16_t * | dst, | |||
int | dstep | |||
) |
Perform lowpass filtering on input samples.
coeffs | pointer to filter coefficients | |
state | pointer to filter state | |
size | input length | |
src | source samples | |
sstep | source stride | |
dst | filtered samples (destination may be the same as input) | |
dstep | destination stride |
Definition at line 118 of file iirfilter.c.
void ff_iir_filter_free_coeffs | ( | struct FFIIRFilterCoeffs * | coeffs | ) |
Free filter coefficients.
coeffs | pointer allocated with ff_iir_filter_init_coeffs() |
Definition at line 156 of file iirfilter.c.
void ff_iir_filter_free_state | ( | struct FFIIRFilterState * | state | ) |
Free filter state.
state | pointer allocated with ff_iir_filter_init_state() |
Definition at line 151 of file iirfilter.c.
struct FFIIRFilterCoeffs* ff_iir_filter_init_coeffs | ( | enum IIRFilterType | filt_type, | |
enum IIRFilterMode | filt_mode, | |||
int | order, | |||
float | cutoff_ratio, | |||
float | stopband, | |||
float | ripple | |||
) | [read] |
Initialize filter coefficients.
filt_type | filter type (e.g. Butterworth) | |
filt_mode | filter mode (e.g. lowpass) | |
order | filter order | |
cutoff_ratio | cutoff to input frequency ratio | |
stopband | stopband to input frequency ratio (used by bandpass and bandstop filter modes) | |
ripple | ripple factor (used only in Chebyshev filters) |
Definition at line 51 of file iirfilter.c.
struct FFIIRFilterState* ff_iir_filter_init_state | ( | int | order | ) | [read] |
Create new filter state.
order | filter order |
Definition at line 100 of file iirfilter.c.