libaf/af_gate.c

   1 /*
   2  * Copyright (C) 2002 Anders Johansson ajh@atri.curtin.edu.au
   3  *
   4  * This file is part of MPlayer.
   5  *
   6  * MPlayer is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * MPlayer is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include <inttypes.h>
  26 #include <math.h>
  27 #include <limits.h>
  28
  29 #include "af.h"
  30
  31 // Data for specific instances of this filter
  32 typedef struct af_gate_s
  33 {
  34   int   enable[AF_NCH];         // Enable/disable / channel
  35   float time[AF_NCH];           // Forgetting factor for power estimate
  36   float pow[AF_NCH];            // Estimated power level [dB]
  37   float tresh[AF_NCH];          // Threshold [dB]
  38   int   attack[AF_NCH];         // Attack time [ms]
  39   int   release[AF_NCH];        // Release time [ms]
  40   float range[AF_NCH];          // Range level [dB]
  41 }af_gate_t;
  42
  43 // Initialization and runtime control
  44 static int control(struct af_instance_s* af, int cmd, void* arg)
  45 {
  46   af_gate_t* s   = (af_gate_t*)af->setup;
  47   switch(cmd){
  48   case AF_CONTROL_REINIT:
  49     // Sanity check
  50     if(!arg) return AF_ERROR;
  51
  52     af->data->rate   = ((af_data_t*)arg)->rate;
  53     af->data->nch    = ((af_data_t*)arg)->nch;
  54     af->data->format = AF_FORMAT_FLOAT_NE;
  55     af->data->bps    = 4;
  56
  57     // Time constant set to 0.1s
  58     //    s->alpha = (1.0/0.2)/(2.0*M_PI*(float)((af_data_t*)arg)->rate);
  59     return af_test_output(af,(af_data_t*)arg);
  60   case AF_CONTROL_COMMAND_LINE:{
  61 /*     float v=-10.0; */
  62 /*     float vol[AF_NCH]; */
  63 /*     float s=0.0; */
  64 /*     float clipp[AF_NCH]; */
  65 /*     int i; */
  66 /*     sscanf((char*)arg,"%f:%f", &v, &s); */
  67 /*     for(i=0;i<AF_NCH;i++){ */
  68 /*       vol[i]=v; */
  69 /*       clipp[i]=s; */
  70 /*     } */
  71 /*     if(AF_OK != control(af,AF_CONTROL_VOLUME_SOFTCLIP | AF_CONTROL_SET, clipp)) */
  72 /*       return AF_ERROR; */
  73 /*     return control(af,AF_CONTROL_VOLUME_LEVEL | AF_CONTROL_SET, vol); */
  74   }
  75
  76   case AF_CONTROL_GATE_ON_OFF | AF_CONTROL_SET:
  77     memcpy(s->enable,(int*)arg,AF_NCH*sizeof(int));
  78     return AF_OK;
  79   case AF_CONTROL_GATE_ON_OFF | AF_CONTROL_GET:
  80     memcpy((int*)arg,s->enable,AF_NCH*sizeof(int));
  81     return AF_OK;
  82   case AF_CONTROL_GATE_THRESH | AF_CONTROL_SET:
  83     return af_from_dB(AF_NCH,(float*)arg,s->tresh,20.0,-60.0,-1.0);
  84   case AF_CONTROL_GATE_THRESH | AF_CONTROL_GET:
  85     return af_to_dB(AF_NCH,s->tresh,(float*)arg,10.0);
  86   case AF_CONTROL_GATE_ATTACK | AF_CONTROL_SET:
  87     return af_from_ms(AF_NCH,(float*)arg,s->attack,af->data->rate,500.0,0.1);
  88   case AF_CONTROL_GATE_ATTACK | AF_CONTROL_GET:
  89     return af_to_ms(AF_NCH,s->attack,(float*)arg,af->data->rate);
  90   case AF_CONTROL_GATE_RELEASE | AF_CONTROL_SET:
  91     return af_from_ms(AF_NCH,(float*)arg,s->release,af->data->rate,3000.0,10.0);
  92   case AF_CONTROL_GATE_RELEASE | AF_CONTROL_GET:
  93     return af_to_ms(AF_NCH,s->release,(float*)arg,af->data->rate);
  94   case AF_CONTROL_GATE_RANGE | AF_CONTROL_SET:
  95     return af_from_dB(AF_NCH,(float*)arg,s->range,20.0,100.0,0.0);
  96   case AF_CONTROL_GATE_RANGE | AF_CONTROL_GET:
  97     return af_to_dB(AF_NCH,s->range,(float*)arg,10.0);
  98   }
  99   return AF_UNKNOWN;
 100 }
 101
 102 // Deallocate memory
 103 static void uninit(struct af_instance_s* af)
 104 {
 105     free(af->data);
 106     free(af->setup);
 107 }
 108
 109 // Filter data through filter
 110 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
 111 {
 112   af_data_t*    c   = data;                     // Current working data
 113   af_gate_t*    s   = (af_gate_t*)af->setup;    // Setup for this instance
 114   float*        a   = (float*)c->audio;         // Audio data
 115   int           len = c->len/4;                 // Number of samples
 116   int           ch  = 0;                        // Channel counter
 117   register int  nch = c->nch;                   // Number of channels
 118   register int  i   = 0;
 119
 120
 121   // Noise gate
 122   for(ch = 0; ch < nch ; ch++){
 123     if(s->enable[ch]){
 124       float     t   = 1.0 - s->time[ch];
 125       for(i=ch;i<len;i+=nch){
 126         register float x        = a[i];
 127         register float pow      = x*x;
 128         s->pow[ch] = t*s->pow[ch] +
 129           pow*s->time[ch]; // LP filter
 130         if(pow < s->pow[ch]){
 131           ;
 132         }
 133         else{
 134           ;
 135         }
 136         a[i] = x;
 137       }
 138     }
 139   }
 140   return c;
 141 }
 142
 143 // Allocate memory and set function pointers
 144 static int af_open(af_instance_t* af){
 145   af->control=control;
 146   af->uninit=uninit;
 147   af->play=play;
 148   af->mul=1;
 149   af->data=calloc(1,sizeof(af_data_t));
 150   af->setup=calloc(1,sizeof(af_gate_t));
 151   if(af->data == NULL || af->setup == NULL)
 152     return AF_ERROR;
 153   return AF_OK;
 154 }
 155
 156 // Description of this filter
 157 af_info_t af_info_gate = {
 158     "Noise gate audio filter",
 159     "gate",
 160     "Anders",
 161     "",
 162     AF_FLAGS_NOT_REENTRANT,
 163     af_open
 164 };