apps/plugins/pdbox/PDa/src/d_resample.c

   1 /* Copyright (c) 1997-1999 Miller Puckette.
   2  * For information on usage and redistribution, and for a DISCLAIMER OF ALL
   3  * WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */
   4
   5 /* upsampling/downsampling methods for inlet~/outlet~
   6  *
   7  * mfg.gfd.uil
   8  * IOhannes
   9  *
  10  * 2509:forum::für::umläute:2001
  11  */
  12
  13
  14
  15 #include "m_pd.h"
  16
  17 /* --------------------- up/down-sampling --------------------- */
  18 t_int *downsampling_perform_0(t_int *w)
  19 {
  20   t_sample *in  = (t_sample *)(w[1]); /* original signal     */
  21   t_sample *out = (t_sample *)(w[2]); /* downsampled signal  */
  22   int down     = (int)(w[3]);       /* downsampling factor */
  23   int parent   = (int)(w[4]);       /* original vectorsize */
  24
  25   int n=parent/down;
  26
  27   while(n--){
  28     *out++=*in;
  29     in+=down;
  30   }
  31
  32   return (w+5);
  33 }
  34
  35 t_int *upsampling_perform_0(t_int *w)
  36 {
  37   t_sample *in  = (t_sample *)(w[1]); /* original signal     */
  38   t_sample *out = (t_sample *)(w[2]); /* upsampled signal    */
  39   int up       = (int)(w[3]);       /* upsampling factor   */
  40   int parent   = (int)(w[4]);       /* original vectorsize */
  41
  42   int n=parent*up;
  43   t_sample *dummy = out;
  44
  45   while(n--)*out++=0;
  46
  47   n = parent;
  48   out = dummy;
  49   while(n--){
  50     *out=*in++;
  51     out+=up;
  52   }
  53
  54   return (w+5);
  55 }
  56
  57 t_int *upsampling_perform_hold(t_int *w)
  58 {
  59   t_sample *in  = (t_sample *)(w[1]); /* original signal     */
  60   t_sample *out = (t_sample *)(w[2]); /* upsampled signal    */
  61   int up       = (int)(w[3]);       /* upsampling factor   */
  62   int parent   = (int)(w[4]);       /* original vectorsize */
  63   int i=up;
  64
  65   int n=parent;
  66   t_sample *dum_out = out;
  67   t_sample *dum_in  = in;
  68
  69   while (i--) {
  70     n = parent;
  71     out = dum_out+i;
  72     in  = dum_in;
  73     while(n--){
  74       *out=*in++;
  75       out+=up;
  76     }
  77   }
  78   return (w+5);
  79 }
  80
  81 t_int *upsampling_perform_linear(t_int *w)
  82 {
  83   t_resample *x= (t_resample *)(w[1]);
  84   t_sample *in  = (t_sample *)(w[2]); /* original signal     */
  85   t_sample *out = (t_sample *)(w[3]); /* upsampled signal    */
  86   int up       = (int)(w[4]);       /* upsampling factor   */
  87   int parent   = (int)(w[5]);       /* original vectorsize */
  88   int length   = parent*up;
  89   int n;
  90   t_sample *fp;
  91   t_sample a=*x->buffer, b=*in;
  92
  93
  94   for (n=0; n<length; n++) {
  95     t_float findex = (t_float)(n+1)/up;
  96     int     index  = findex;
  97     t_sample frac=findex - index;
  98     if (frac==0.)frac=1.;
  99     *out++ = frac * b + (1.-frac) * a;
 100     fp = in+index;
 101     b=*fp;
 102     a=(index)?*(fp-1):a;
 103   }
 104
 105   *x->buffer = a;
 106   return (w+6);
 107 }
 108
 109 /* ----------------------- public -------------------------------- */
 110
 111 /* utils */
 112
 113 void resample_init(t_resample *x)
 114 {
 115   x->method=0;
 116
 117   x->downsample=x->upsample=1;
 118
 119   x->s_n = x->coefsize = x->bufsize = 0;
 120   x->s_vec = x->coeffs = x->buffer  = 0;
 121 }
 122
 123 void resample_free(t_resample *x)
 124 {
 125   if (x->s_n) t_freebytes(x->s_vec, x->s_n*sizeof(*x->s_vec));
 126   if (x->coefsize) t_freebytes(x->coeffs, x->coefsize*sizeof(*x->coeffs));
 127   if (x->bufsize) t_freebytes(x->buffer, x->bufsize*sizeof(*x->buffer));
 128
 129   x->s_n = x->coefsize = x->bufsize = 0;
 130   x->s_vec = x->coeffs = x->buffer  = 0;
 131 }
 132
 133
 134 /* dsp-adding */
 135
 136 void resample_dsp(t_resample *x,
 137                   t_sample* in,  int insize,
 138                   t_sample* out, int outsize,
 139                   int method)
 140 {
 141   if (insize == outsize){
 142     bug("nothing to be done");
 143     return;
 144   }
 145
 146   if (insize > outsize) { /* downsampling */
 147     if (insize % outsize) {
 148       error("bad downsampling factor");
 149       return;
 150     }
 151     switch (method) {
 152     default:
 153       dsp_add(downsampling_perform_0, 4, in, out, insize/outsize, insize);
 154     }
 155
 156
 157   } else { /* upsampling */
 158     if (outsize % insize) {
 159       error("bad upsampling factor");
 160       return;
 161     }
 162     switch (method) {
 163     case 1:
 164       dsp_add(upsampling_perform_hold, 4, in, out, outsize/insize, insize);
 165       break;
 166     case 2:
 167       if (x->bufsize != 1) {
 168         t_freebytes(x->buffer, x->bufsize*sizeof(*x->buffer));
 169         x->bufsize = 1;
 170         x->buffer = t_getbytes(x->bufsize*sizeof(*x->buffer));
 171       }
 172       dsp_add(upsampling_perform_linear, 5, x, in, out, outsize/insize, insize);
 173       break;
 174     default:
 175       dsp_add(upsampling_perform_0, 4, in, out, outsize/insize, insize);
 176     }
 177   }
 178 }
 179
 180 void resamplefrom_dsp(t_resample *x,
 181                            t_sample *in,
 182                            int insize, int outsize, int method)
 183 {
 184   if (insize==outsize) {
 185    t_freebytes(x->s_vec, x->s_n * sizeof(*x->s_vec));
 186     x->s_n = 0;
 187     x->s_vec = in;
 188     return;
 189   }
 190
 191   if (x->s_n != outsize) {
 192     t_sample *buf=x->s_vec;
 193     t_freebytes(buf, x->s_n * sizeof(*buf));
 194     buf = (t_sample *)t_getbytes(outsize * sizeof(*buf));
 195     x->s_vec = buf;
 196     x->s_n   = outsize;
 197   }
 198
 199   resample_dsp(x, in, insize, x->s_vec, x->s_n, method);
 200   return;
 201 }
 202
 203 void resampleto_dsp(t_resample *x,
 204                          t_sample *out,
 205                          int insize, int outsize, int method)
 206 {
 207   if (insize==outsize) {
 208     if (x->s_n)t_freebytes(x->s_vec, x->s_n * sizeof(*x->s_vec));
 209     x->s_n = 0;
 210     x->s_vec = out;
 211     return;
 212   }
 213
 214   if (x->s_n != insize) {
 215     t_sample *buf=x->s_vec;
 216     t_freebytes(buf, x->s_n * sizeof(*buf));
 217     buf = (t_sample *)t_getbytes(insize * sizeof(*buf));
 218     x->s_vec = buf;
 219     x->s_n   = insize;
 220   }
 221
 222   resample_dsp(x, x->s_vec, x->s_n, out, outsize, method);
 223
 224   return;
 225 }
 226