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/*****************************************
EQ10 library version 1.0
Copyright (C)2002 4Front Technologies
Written by George Yohng
http://www.opensound.com
Proprietary software.
*****************************************/
#ifndef EQ10DSP_H_INCLUDED
#define EQ10DSP_H_INCLUDED
#ifdef __cplusplus
extern "C" {
#endif
/* used for volume detectors. for instance, if you want to plot
frequency response, you can use "detect" variable of needed
subband to query level of that frequency band.
release time - is the time in seconds in which detector falls back
to zero, if no peaks detected */
// #define EQ10_DETECTOR_CODE /* uncomment this to */
// #define EQ10_DETECTOR_RELEASE 1.0f /* enable band detector */
/* Dynamic limiter, which prevents EQ from distortion. In no case you
can overflow EQ and cause it to clip */
#define EQ10_TRIM_CODE 0.930 /* trim at -0.6dB */
#define EQ10_TRIM_RELEASE 0.700 /* trim release, in seconds */
#define EQ10_NOFBANDS 10 /* want more bands? not a problem */
#define EQ10_Q 1.41 /* global `Q' factor */
/* if you want separate Q per each band, comment global Q and uncomment
the following array */
//#define EQ10_DQ {1.4,1.4,1.4,1.4,1.4,1.4,1.4,1.4,1.4,1.4}
/* frequency table compatible to Q10 standard */
typedef
struct eq10band_s
{
double gain; /* gain of current band. Do not use this value,
use eq10_setgain instead */
#ifdef EQ10_DETECTOR_CODE
double detect; /* band detector value, do not use.
use eq10_detect to read detector value in dB */
double detectdecay; /* internal - do not use */
#endif
double ua0,ub1,ub2; /* internal - do not use */
double da0,db1,db2; /* internal - do not use */
double x1,x2,y1,y2; /* internal - do not use */
} eq10band_t;
typedef
struct eq10_s
{
double rate; /* sample rate; do not modify */
/* use eq10_setup to change */
eq10band_t band[EQ10_NOFBANDS]; /* bands of equalizer */
double detect; /* global detector value. do not use */
double detectdecay; /* internal - do not use */
} eq10_t;
double eq10_db2gain(double gain_dB); /* converts decibels to internal gain value*/
double eq10_gain2db(double gain); /* converts internal gain value to decibels*/
/* prepare eq array for processing,
eq - pointer to array,
eqs - number of elements in array (number of audio channels)
rate - sample rate
WARNING! this function resets all data in eq and sets all gains to 0dB
*/
void eq10_setup(eq10_t *eq, int eqs, double rate);
/* set band gain */
/*
eq - pointer to array,
eqs - number of elements in array (number of audio channels)
bandnr - # of band (0...EQ_NOFBANDS-1)
*/
void eq10_setgain(eq10_t *eq,int eqs,int bandnr,double gain_dB);
/* get current band gain */
/* eq - pointer to element, possible to read gain on each channel
separately */
double eq10_getgain(eq10_t *eq,int bandnr);
/* get detector value */
/* eq - pointer to element, possible to read detector value on
each channel separately */
double eq10_detect(eq10_t *eq,int bandnr);
/* process function
eq - pointer to eq structure, corresponding to wanted channel
buf - input buffer (interleaved multichannel)
outbuf - output buffer
sz - number of samples in input buffer
idx - index of processed channel (0...N-1)
step - total number of channels in interleaved stream (N)
*/
void eq10_processf(eq10_t *eq,float *buf,float *outbuf,int sz,int idx,int step);
/*
Example:
#define NCHAN 6
...
eq10_t eq[NCHAN]; // we process 5.1 data, thus 6 channels
int t;
eq10_t *peq;
...
eq10_setup(eq,NCHAN,44100); // initialize
...
eq10_setgain(eq,NCHAN, 5, -10.0f ); // set -10dB for gain6 (nr's from zero)
...
while (bla bla bla) // inner loop
{
for(t=0, peq=eq; t<NCHAN; t++, peq++)
{
eq10_processf(peq, input_buf, output_buf, cSamples, t, NCHAN);
}
}
...
*/
#ifdef __cplusplus
}
#endif
#endif //EQ10DSP_H_INCLUDED
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