libaf/af_comp.c

   1 /*=============================================================================
   2 //
   3 //  This software has been released under the terms of the GNU General Public
   4 //  license. See http://www.gnu.org/copyleft/gpl.html for details.
   5 //
   6 //  Copyright 2002 Anders Johansson ajh@atri.curtin.edu.au
   7 //
   8 //=============================================================================
   9 */
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14
  15 #include <inttypes.h>
  16 #include <math.h>
  17 #include <limits.h>
  18
  19 #include "af.h"
  20
  21 // Data for specific instances of this filter
  22 typedef struct af_comp_s
  23 {
  24   int   enable[AF_NCH];         // Enable/disable / channel
  25   float time[AF_NCH];           // Forgetting factor for power estimate
  26   float pow[AF_NCH];            // Estimated power level [dB]
  27   float tresh[AF_NCH];          // Threshold [dB]
  28   int   attack[AF_NCH];         // Attack time [ms]
  29   int   release[AF_NCH];        // Release time [ms]
  30   float ratio[AF_NCH];          // Compression ratio
  31 }af_comp_t;
  32
  33 // Initialization and runtime control
  34 static int control(struct af_instance_s* af, int cmd, void* arg)
  35 {
  36   af_comp_t* s   = (af_comp_t*)af->setup;
  37   int i;
  38
  39   switch(cmd){
  40   case AF_CONTROL_REINIT:
  41     // Sanity check
  42     if(!arg) return AF_ERROR;
  43
  44     af->data->rate   = ((af_data_t*)arg)->rate;
  45     af->data->nch    = ((af_data_t*)arg)->nch;
  46     af->data->format = AF_FORMAT_FLOAT_NE;
  47     af->data->bps    = 4;
  48
  49     // Time constant set to 0.1s
  50     //    s->alpha = (1.0/0.2)/(2.0*M_PI*(float)((af_data_t*)arg)->rate);
  51     return af_test_output(af,(af_data_t*)arg);
  52   case AF_CONTROL_COMMAND_LINE:{
  53 /*     float v=-10.0; */
  54 /*     float vol[AF_NCH]; */
  55 /*     float s=0.0; */
  56 /*     float clipp[AF_NCH]; */
  57 /*     int i; */
  58 /*     sscanf((char*)arg,"%f:%f", &v, &s); */
  59 /*     for(i=0;i<AF_NCH;i++){ */
  60 /*       vol[i]=v; */
  61 /*       clipp[i]=s; */
  62 /*     } */
  63 /*     if(AF_OK != control(af,AF_CONTROL_VOLUME_SOFTCLIP | AF_CONTROL_SET, clipp)) */
  64 /*       return AF_ERROR; */
  65 /*     return control(af,AF_CONTROL_VOLUME_LEVEL | AF_CONTROL_SET, vol); */
  66   }
  67   case AF_CONTROL_COMP_ON_OFF | AF_CONTROL_SET:
  68     memcpy(s->enable,(int*)arg,AF_NCH*sizeof(int));
  69     return AF_OK;
  70   case AF_CONTROL_COMP_ON_OFF | AF_CONTROL_GET:
  71     memcpy((int*)arg,s->enable,AF_NCH*sizeof(int));
  72     return AF_OK;
  73   case AF_CONTROL_COMP_THRESH | AF_CONTROL_SET:
  74     return af_from_dB(AF_NCH,(float*)arg,s->tresh,20.0,-60.0,-1.0);
  75   case AF_CONTROL_COMP_THRESH | AF_CONTROL_GET:
  76     return af_to_dB(AF_NCH,s->tresh,(float*)arg,10.0);
  77   case AF_CONTROL_COMP_ATTACK | AF_CONTROL_SET:
  78     return af_from_ms(AF_NCH,(float*)arg,s->attack,af->data->rate,500.0,0.1);
  79   case AF_CONTROL_COMP_ATTACK | AF_CONTROL_GET:
  80     return af_to_ms(AF_NCH,s->attack,(float*)arg,af->data->rate);
  81   case AF_CONTROL_COMP_RELEASE | AF_CONTROL_SET:
  82     return af_from_ms(AF_NCH,(float*)arg,s->release,af->data->rate,3000.0,10.0);
  83   case AF_CONTROL_COMP_RELEASE | AF_CONTROL_GET:
  84     return af_to_ms(AF_NCH,s->release,(float*)arg,af->data->rate);
  85   case AF_CONTROL_COMP_RATIO | AF_CONTROL_SET:
  86     for(i=0;i<AF_NCH;i++)
  87       s->ratio[i] = clamp(((float*)arg)[i],1.0,10.0);
  88     return AF_OK;
  89   case AF_CONTROL_COMP_RATIO | AF_CONTROL_GET:
  90     for(i=0;i<AF_NCH;i++)
  91       ((float*)arg)[i] = s->ratio[i];
  92     return AF_OK;
  93   }
  94   return AF_UNKNOWN;
  95 }
  96
  97 // Deallocate memory
  98 static void uninit(struct af_instance_s* af)
  99 {
 100   if(af->data)
 101     free(af->data);
 102   if(af->setup)
 103     free(af->setup);
 104 }
 105
 106 // Filter data through filter
 107 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
 108 {
 109   af_data_t*    c   = data;                     // Current working data
 110   af_comp_t*    s   = (af_comp_t*)af->setup;    // Setup for this instance
 111   float*        a   = (float*)c->audio;         // Audio data
 112   int           len = c->len/4;                 // Number of samples
 113   int           ch  = 0;                        // Channel counter
 114   register int  nch = c->nch;                   // Number of channels
 115   register int  i   = 0;
 116
 117   // Compress/expand
 118   for(ch = 0; ch < nch ; ch++){
 119     if(s->enable[ch]){
 120       float     t   = 1.0 - s->time[ch];
 121       for(i=ch;i<len;i+=nch){
 122         register float x        = a[i];
 123         register float pow      = x*x;
 124         s->pow[ch] = t*s->pow[ch] +
 125           pow*s->time[ch]; // LP filter
 126         if(pow < s->pow[ch]){
 127           ;
 128         }
 129         else{
 130           ;
 131         }
 132         a[i] = x;
 133       }
 134     }
 135   }
 136   return c;
 137 }
 138
 139 // Allocate memory and set function pointers
 140 static int af_open(af_instance_t* af){
 141   af->control=control;
 142   af->uninit=uninit;
 143   af->play=play;
 144   af->mul=1;
 145   af->data=calloc(1,sizeof(af_data_t));
 146   af->setup=calloc(1,sizeof(af_comp_t));
 147   if(af->data == NULL || af->setup == NULL)
 148     return AF_ERROR;
 149   return AF_OK;
 150 }
 151
 152 // Description of this filter
 153 af_info_t af_info_comp = {
 154     "Compressor/expander audio filter",
 155     "comp",
 156     "Anders",
 157     "",
 158     AF_FLAGS_NOT_REENTRANT,
 159     af_open
 160 };