libaf/af_pan.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 /* */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15
  16 #include <inttypes.h>
  17 #include <math.h>
  18 #include <limits.h>
  19
  20 #include "af.h"
  21
  22 // Data for specific instances of this filter
  23 typedef struct af_pan_s
  24 {
  25   int nch; // Number of output channels; zero means same as input
  26   float level[AF_NCH][AF_NCH];  // Gain level for each channel
  27 }af_pan_t;
  28
  29 // Initialization and runtime control
  30 static int control(struct af_instance_s* af, int cmd, void* arg)
  31 {
  32   af_pan_t* s = af->setup;
  33
  34   switch(cmd){
  35   case AF_CONTROL_REINIT:
  36     // Sanity check
  37     if(!arg) return AF_ERROR;
  38
  39     af->data->rate   = ((af_data_t*)arg)->rate;
  40     af->data->format = AF_FORMAT_FLOAT_NE;
  41     af->data->bps    = 4;
  42     af->data->nch    = s->nch ? s->nch: ((af_data_t*)arg)->nch;
  43     af->mul          = (double)af->data->nch / ((af_data_t*)arg)->nch;
  44
  45     if((af->data->format != ((af_data_t*)arg)->format) ||
  46        (af->data->bps != ((af_data_t*)arg)->bps)){
  47       ((af_data_t*)arg)->format = af->data->format;
  48       ((af_data_t*)arg)->bps = af->data->bps;
  49       return AF_FALSE;
  50     }
  51     return AF_OK;
  52   case AF_CONTROL_COMMAND_LINE:{
  53     int   nch = 0;
  54     int   n = 0;
  55     char* cp = NULL;
  56     int   j,k;
  57     // Read number of outputs
  58     sscanf((char*)arg,"%i%n", &nch,&n);
  59     if(AF_OK != control(af,AF_CONTROL_PAN_NOUT | AF_CONTROL_SET, &nch))
  60       return AF_ERROR;
  61
  62     // Read pan values
  63     cp = &((char*)arg)[n];
  64     j = 0; k = 0;
  65     while((*cp == ':') && (k < AF_NCH)){
  66       sscanf(cp, ":%f%n" , &s->level[j][k], &n);
  67       af_msg(AF_MSG_VERBOSE,"[pan] Pan level from channel %i to"
  68              " channel %i = %f\n",k,j,s->level[j][k]);
  69       cp =&cp[n];
  70       j++;
  71       if(j>=nch){
  72         j = 0;
  73         k++;
  74       }
  75     }
  76     return AF_OK;
  77   }
  78   case AF_CONTROL_PAN_LEVEL | AF_CONTROL_SET:{
  79     int    i;
  80     int    ch = ((af_control_ext_t*)arg)->ch;
  81     float* level = ((af_control_ext_t*)arg)->arg;
  82     if (ch >= AF_NCH)
  83       return AF_FALSE;
  84     for(i=0;i<AF_NCH;i++)
  85       s->level[ch][i] = level[i];
  86     return AF_OK;
  87   }
  88   case AF_CONTROL_PAN_LEVEL | AF_CONTROL_GET:{
  89     int    i;
  90     int ch = ((af_control_ext_t*)arg)->ch;
  91     float* level = ((af_control_ext_t*)arg)->arg;
  92     if (ch >= AF_NCH)
  93       return AF_FALSE;
  94     for(i=0;i<AF_NCH;i++)
  95       level[i] = s->level[ch][i];
  96     return AF_OK;
  97   }
  98   case AF_CONTROL_PAN_NOUT | AF_CONTROL_SET:
  99     // Reinit must be called after this function has been called
 100
 101     // Sanity check
 102     if(((int*)arg)[0] <= 0 || ((int*)arg)[0] > AF_NCH){
 103       af_msg(AF_MSG_ERROR,"[pan] The number of output channels must be"
 104              " between 1 and %i. Current value is %i\n",AF_NCH,((int*)arg)[0]);
 105       return AF_ERROR;
 106     }
 107     s->nch=((int*)arg)[0];
 108     return AF_OK;
 109   case AF_CONTROL_PAN_NOUT | AF_CONTROL_GET:
 110     *(int*)arg = af->data->nch;
 111     return AF_OK;
 112   case AF_CONTROL_PAN_BALANCE | AF_CONTROL_SET:{
 113     float val = *(float*)arg;
 114     if (s->nch)
 115       return AF_ERROR;
 116     if (af->data->nch >= 2) {
 117       s->level[0][0] = min(1.f, 1.f - val);
 118       s->level[0][1] = max(0.f, val);
 119       s->level[1][0] = max(0.f, -val);
 120       s->level[1][1] = min(1.f, 1.f + val);
 121     }
 122     return AF_OK;
 123   }
 124   case AF_CONTROL_PAN_BALANCE | AF_CONTROL_GET:
 125     if (s->nch)
 126       return AF_ERROR;
 127     *(float*)arg = s->level[0][1] - s->level[1][0];
 128     return AF_OK;
 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->audio);
 138   free(af->data);
 139   if(af->setup)
 140     free(af->setup);
 141 }
 142
 143 // Filter data through filter
 144 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
 145 {
 146   af_data_t*    c    = data;            // Current working data
 147   af_data_t*    l    = af->data;        // Local data
 148   af_pan_t*     s    = af->setup;       // Setup for this instance
 149   float*        in   = c->audio;        // Input audio data
 150   float*        out  = NULL;            // Output audio data
 151   float*        end  = in+c->len/4;     // End of loop
 152   int           nchi = c->nch;          // Number of input channels
 153   int           ncho = l->nch;          // Number of output channels
 154   register int  j,k;
 155
 156   if(AF_OK != RESIZE_LOCAL_BUFFER(af,data))
 157     return NULL;
 158
 159   out = l->audio;
 160   // Execute panning
 161   // FIXME: Too slow
 162   while(in < end){
 163     for(j=0;j<ncho;j++){
 164       register float  x   = 0.0;
 165       register float* tin = in;
 166       for(k=0;k<nchi;k++)
 167         x += tin[k] * s->level[j][k];
 168       out[j] = x;
 169     }
 170     out+= ncho;
 171     in+= nchi;
 172   }
 173
 174   // Set output data
 175   c->audio = l->audio;
 176   c->len   = c->len / c->nch * l->nch;
 177   c->nch   = l->nch;
 178
 179   return c;
 180 }
 181
 182 // Allocate memory and set function pointers
 183 static int af_open(af_instance_t* af){
 184   af->control=control;
 185   af->uninit=uninit;
 186   af->play=play;
 187   af->mul=1;
 188   af->data=calloc(1,sizeof(af_data_t));
 189   af->setup=calloc(1,sizeof(af_pan_t));
 190   if(af->data == NULL || af->setup == NULL)
 191     return AF_ERROR;
 192   return AF_OK;
 193 }
 194
 195 // Description of this filter
 196 af_info_t af_info_pan = {
 197     "Panning audio filter",
 198     "pan",
 199     "Anders",
 200     "",
 201     AF_FLAGS_REENTRANT,
 202     af_open
 203 };