libaf/af_volume.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 /* This audio filter changes the volume of the sound, and can be used
  22    when the mixer doesn't support the PCM channel. It can handle
  23    between 1 and 6 channels. The volume can be adjusted between -60dB
  24    to +20dB and is set on a per channels basis. The is accessed through
  25    AF_CONTROL_VOLUME_LEVEL.
  26
  27    The filter has support for soft-clipping, it is enabled by
  28    AF_CONTROL_VOLUME_SOFTCLIPP. It has also a probing feature which
  29    can be used to measure the power in the audio stream, both an
  30    instantaneous value and the maximum value can be probed. The
  31    probing is enable by AF_CONTROL_VOLUME_PROBE_ON_OFF and is done on a
  32    per channel basis. The result from the probing is obtained using
  33    AF_CONTROL_VOLUME_PROBE_GET and AF_CONTROL_VOLUME_PROBE_GET_MAX. The
  34    probed values are calculated in dB.
  35 */
  36
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #include <inttypes.h>
  42 #include <math.h>
  43 #include <limits.h>
  44
  45 #include "af.h"
  46
  47 // Data for specific instances of this filter
  48 typedef struct af_volume_s
  49 {
  50   int   enable[AF_NCH];         // Enable/disable / channel
  51   float pow[AF_NCH];            // Estimated power level [dB]
  52   float max[AF_NCH];            // Max Power level [dB]
  53   float level[AF_NCH];          // Gain level for each channel
  54   float time;                   // Forgetting factor for power estimate
  55   int soft;                     // Enable/disable soft clipping
  56   int fast;                     // Use fix-point volume control
  57 }af_volume_t;
  58
  59 // Initialization and runtime control
  60 static int control(struct af_instance_s* af, int cmd, void* arg)
  61 {
  62   af_volume_t* s   = (af_volume_t*)af->setup;
  63
  64   switch(cmd){
  65   case AF_CONTROL_REINIT:
  66     // Sanity check
  67     if(!arg) return AF_ERROR;
  68
  69     af->data->rate   = ((af_data_t*)arg)->rate;
  70     af->data->nch    = ((af_data_t*)arg)->nch;
  71
  72     if(s->fast && (((af_data_t*)arg)->format != (AF_FORMAT_FLOAT_NE))){
  73       af->data->format = AF_FORMAT_S16_NE;
  74       af->data->bps    = 2;
  75     }
  76     else{
  77       // Cutoff set to 10Hz for forgetting factor
  78       float x = 2.0*M_PI*15.0/(float)af->data->rate;
  79       float t = 2.0-cos(x);
  80       s->time = 1.0 - (t - sqrt(t*t - 1));
  81       af_msg(AF_MSG_DEBUG0,"[volume] Forgetting factor = %0.5f\n",s->time);
  82       af->data->format = AF_FORMAT_FLOAT_NE;
  83       af->data->bps    = 4;
  84     }
  85     return af_test_output(af,(af_data_t*)arg);
  86   case AF_CONTROL_COMMAND_LINE:{
  87     float v=0.0;
  88     float vol[AF_NCH];
  89     int   i;
  90     sscanf((char*)arg,"%f:%i", &v, &s->soft);
  91     for(i=0;i<AF_NCH;i++) vol[i]=v;
  92     return control(af,AF_CONTROL_VOLUME_LEVEL | AF_CONTROL_SET, vol);
  93   }
  94   case AF_CONTROL_POST_CREATE:
  95     s->fast = ((((af_cfg_t*)arg)->force & AF_INIT_FORMAT_MASK) ==
  96       AF_INIT_FLOAT) ? 0 : 1;
  97     return AF_OK;
  98   case AF_CONTROL_VOLUME_ON_OFF | AF_CONTROL_SET:
  99     memcpy(s->enable,(int*)arg,AF_NCH*sizeof(int));
 100     return AF_OK;
 101   case AF_CONTROL_VOLUME_ON_OFF | AF_CONTROL_GET:
 102     memcpy((int*)arg,s->enable,AF_NCH*sizeof(int));
 103     return AF_OK;
 104   case AF_CONTROL_VOLUME_SOFTCLIP | AF_CONTROL_SET:
 105     s->soft = *(int*)arg;
 106     return AF_OK;
 107   case AF_CONTROL_VOLUME_SOFTCLIP | AF_CONTROL_GET:
 108     *(int*)arg = s->soft;
 109     return AF_OK;
 110   case AF_CONTROL_VOLUME_LEVEL | AF_CONTROL_SET:
 111     return af_from_dB(AF_NCH,(float*)arg,s->level,20.0,-200.0,60.0);
 112   case AF_CONTROL_VOLUME_LEVEL | AF_CONTROL_GET:
 113     return af_to_dB(AF_NCH,s->level,(float*)arg,20.0);
 114   case AF_CONTROL_VOLUME_PROBE | AF_CONTROL_GET:
 115     return af_to_dB(AF_NCH,s->pow,(float*)arg,10.0);
 116   case AF_CONTROL_VOLUME_PROBE_MAX | AF_CONTROL_GET:
 117     return af_to_dB(AF_NCH,s->max,(float*)arg,10.0);
 118   case AF_CONTROL_PRE_DESTROY:{
 119     float m = 0.0;
 120     int i;
 121     if(!s->fast){
 122       for(i=0;i<AF_NCH;i++)
 123         m=max(m,s->max[i]);
 124         af_to_dB(1, &m, &m, 10.0);
 125         af_msg(AF_MSG_INFO,"[volume] The maximum volume was %0.2fdB \n", m);
 126     }
 127     return AF_OK;
 128   }
 129   }
 130   return AF_UNKNOWN;
 131 }
 132
 133 // Deallocate memory
 134 static void uninit(struct af_instance_s* af)
 135 {
 136   if(af->data)
 137     free(af->data);
 138   if(af->setup)
 139     free(af->setup);
 140 }
 141
 142 // Filter data through filter
 143 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
 144 {
 145   af_data_t*    c   = data;                     // Current working data
 146   af_volume_t*  s   = (af_volume_t*)af->setup;  // Setup for this instance
 147   int           ch  = 0;                        // Channel counter
 148   register int  nch = c->nch;                   // Number of channels
 149   register int  i   = 0;
 150
 151   // Basic operation volume control only (used on slow machines)
 152   if(af->data->format == (AF_FORMAT_S16_NE)){
 153     int16_t*    a   = (int16_t*)c->audio;       // Audio data
 154     int         len = c->len/2;                 // Number of samples
 155     for(ch = 0; ch < nch ; ch++){
 156       if(s->enable[ch]){
 157         register int vol = (int)(255.0 * s->level[ch]);
 158         for(i=ch;i<len;i+=nch){
 159           register int x = (a[i] * vol) >> 8;
 160           a[i]=clamp(x,SHRT_MIN,SHRT_MAX);
 161         }
 162       }
 163     }
 164   }
 165   // Machine is fast and data is floating point
 166   else if(af->data->format == (AF_FORMAT_FLOAT_NE)){
 167     float*      a       = (float*)c->audio;     // Audio data
 168     int         len     = c->len/4;             // Number of samples
 169     for(ch = 0; ch < nch ; ch++){
 170       // Volume control (fader)
 171       if(s->enable[ch]){
 172         float   t   = 1.0 - s->time;
 173         for(i=ch;i<len;i+=nch){
 174           register float x      = a[i];
 175           register float pow    = x*x;
 176           // Check maximum power value
 177           if(pow > s->max[ch])
 178             s->max[ch] = pow;
 179           // Set volume
 180           x *= s->level[ch];
 181           // Peak meter
 182           pow   = x*x;
 183           if(pow > s->pow[ch])
 184             s->pow[ch] = pow;
 185           else
 186             s->pow[ch] = t*s->pow[ch] + pow*s->time; // LP filter
 187           /* Soft clipping, the sound of a dream, thanks to Jon Wattes
 188              post to Musicdsp.org */
 189           if(s->soft)
 190             x=af_softclip(x);
 191           // Hard clipping
 192           else
 193             x=clamp(x,-1.0,1.0);
 194           a[i] = x;
 195         }
 196       }
 197     }
 198   }
 199   return c;
 200 }
 201
 202 // Allocate memory and set function pointers
 203 static int af_open(af_instance_t* af){
 204   int i = 0;
 205   af->control=control;
 206   af->uninit=uninit;
 207   af->play=play;
 208   af->mul=1;
 209   af->data=calloc(1,sizeof(af_data_t));
 210   af->setup=calloc(1,sizeof(af_volume_t));
 211   if(af->data == NULL || af->setup == NULL)
 212     return AF_ERROR;
 213   // Enable volume control and set initial volume to 0dB.
 214   for(i=0;i<AF_NCH;i++){
 215     ((af_volume_t*)af->setup)->enable[i] = 1;
 216     ((af_volume_t*)af->setup)->level[i]  = 1.0;
 217   }
 218   return AF_OK;
 219 }
 220
 221 // Description of this filter
 222 af_info_t af_info_volume = {
 223     "Volume control audio filter",
 224     "volume",
 225     "Anders",
 226     "",
 227     AF_FLAGS_NOT_REENTRANT,
 228     af_open
 229 };