/*============================================================================= // // This software has been released under the terms of the GNU General Public // license. See http://www.gnu.org/copyleft/gpl.html for details. // // Copyright 2002 Anders Johansson ajh@atri.curtin.edu.au // //============================================================================= */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <inttypes.h> #include <math.h> #include <limits.h> #include "af.h" // Data for specific instances of this filter typedef struct af_comp_s { int enable[AF_NCH]; // Enable/disable / channel float time[AF_NCH]; // Forgetting factor for power estimate float pow[AF_NCH]; // Estimated power level [dB] float tresh[AF_NCH]; // Threshold [dB] int attack[AF_NCH]; // Attack time [ms] int release[AF_NCH]; // Release time [ms] float ratio[AF_NCH]; // Compression ratio }af_comp_t; // Initialization and runtime control static int control(struct af_instance_s* af, int cmd, void* arg) { af_comp_t* s = (af_comp_t*)af->setup; int i; switch(cmd){ case AF_CONTROL_REINIT: // Sanity check if(!arg) return AF_ERROR; af->data->rate = ((af_data_t*)arg)->rate; af->data->nch = ((af_data_t*)arg)->nch; af->data->format = AF_FORMAT_FLOAT_NE; af->data->bps = 4; // Time constant set to 0.1s // s->alpha = (1.0/0.2)/(2.0*M_PI*(float)((af_data_t*)arg)->rate); return af_test_output(af,(af_data_t*)arg); case AF_CONTROL_COMMAND_LINE:{ /* float v=-10.0; */ /* float vol[AF_NCH]; */ /* float s=0.0; */ /* float clipp[AF_NCH]; */ /* int i; */ /* sscanf((char*)arg,"%f:%f", &v, &s); */ /* for(i=0;i<AF_NCH;i++){ */ /* vol[i]=v; */ /* clipp[i]=s; */ /* } */ /* if(AF_OK != control(af,AF_CONTROL_VOLUME_SOFTCLIP | AF_CONTROL_SET, clipp)) */ /* return AF_ERROR; */ /* return control(af,AF_CONTROL_VOLUME_LEVEL | AF_CONTROL_SET, vol); */ } case AF_CONTROL_COMP_ON_OFF | AF_CONTROL_SET: memcpy(s->enable,(int*)arg,AF_NCH*sizeof(int)); return AF_OK; case AF_CONTROL_COMP_ON_OFF | AF_CONTROL_GET: memcpy((int*)arg,s->enable,AF_NCH*sizeof(int)); return AF_OK; case AF_CONTROL_COMP_THRESH | AF_CONTROL_SET: return af_from_dB(AF_NCH,(float*)arg,s->tresh,20.0,-60.0,-1.0); case AF_CONTROL_COMP_THRESH | AF_CONTROL_GET: return af_to_dB(AF_NCH,s->tresh,(float*)arg,10.0); case AF_CONTROL_COMP_ATTACK | AF_CONTROL_SET: return af_from_ms(AF_NCH,(float*)arg,s->attack,af->data->rate,500.0,0.1); case AF_CONTROL_COMP_ATTACK | AF_CONTROL_GET: return af_to_ms(AF_NCH,s->attack,(float*)arg,af->data->rate); case AF_CONTROL_COMP_RELEASE | AF_CONTROL_SET: return af_from_ms(AF_NCH,(float*)arg,s->release,af->data->rate,3000.0,10.0); case AF_CONTROL_COMP_RELEASE | AF_CONTROL_GET: return af_to_ms(AF_NCH,s->release,(float*)arg,af->data->rate); case AF_CONTROL_COMP_RATIO | AF_CONTROL_SET: for(i=0;i<AF_NCH;i++) s->ratio[i] = clamp(((float*)arg)[i],1.0,10.0); return AF_OK; case AF_CONTROL_COMP_RATIO | AF_CONTROL_GET: for(i=0;i<AF_NCH;i++) ((float*)arg)[i] = s->ratio[i]; return AF_OK; } return AF_UNKNOWN; } // Deallocate memory static void uninit(struct af_instance_s* af) { if(af->data) free(af->data); if(af->setup) free(af->setup); } // Filter data through filter static af_data_t* play(struct af_instance_s* af, af_data_t* data) { af_data_t* c = data; // Current working data af_comp_t* s = (af_comp_t*)af->setup; // Setup for this instance float* a = (float*)c->audio; // Audio data int len = c->len/4; // Number of samples int ch = 0; // Channel counter register int nch = c->nch; // Number of channels register int i = 0; // Compress/expand for(ch = 0; ch < nch ; ch++){ if(s->enable[ch]){ float t = 1.0 - s->time[ch]; for(i=ch;i<len;i+=nch){ register float x = a[i]; register float pow = x*x; s->pow[ch] = t*s->pow[ch] + pow*s->time[ch]; // LP filter if(pow < s->pow[ch]){ ; } else{ ; } a[i] = x; } } } return c; } // Allocate memory and set function pointers static int open(af_instance_t* af){ af->control=control; af->uninit=uninit; af->play=play; af->mul.n=1; af->mul.d=1; af->data=calloc(1,sizeof(af_data_t)); af->setup=calloc(1,sizeof(af_comp_t)); if(af->data == NULL || af->setup == NULL) return AF_ERROR; return AF_OK; } // Description of this filter af_info_t af_info_comp = { "Compressor/expander audio filter", "comp", "Anders", "", AF_FLAGS_NOT_REENTRANT, open };