workbench/devs/AHI/Device/dspechofuncs.c

   1 /*
   2      AHI - Hardware independent audio subsystem
   3      Copyright (C) 1996-2005 Martin Blom <martin@blom.org>
   4
   5      This library is free software; you can redistribute it and/or
   6      modify it under the terms of the GNU Library General Public
   7      License as published by the Free Software Foundation; either
   8      version 2 of the License, or (at your option) any later version.
   9
  10      This library is distributed in the hope that it will be useful,
  11      but WITHOUT ANY WARRANTY; without even the implied warranty of
  12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13      Library General Public License for more details.
  14
  15      You should have received a copy of the GNU Library General Public
  16      License along with this library; if not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330, Cambridge,
  18      MA 02139, USA.
  19 */
  20
  21 #include <config.h>
  22
  23 #include "ahi_def.h"
  24 #include "dspecho.h"
  25 #include "dspechofuncs.h"
  26
  27 /**************
  28 * Inputs: ahiede_Delay, ahiede_Feedback, ahiede_Mix, ahiede_Cross
  29 *
  30 * Delay      = ahide_Delay
  31 * MixN       = 1-ahide_Mix
  32 * MixD       = ahide_Mix
  33 * FeedbackDO = ahide_Feedback*ahide_Cross
  34 * FeedbackDS = ahide_Feedback*(1-ahide_Cross)
  35 * FeedbackNO = (1-ahide_Feedback)*ahide_Cross
  36 * FeedbackNS = (1-ahide_Feedback)*(1-ahide_Cross)
  37 *
  38 *                                               |\
  39 * left in ->---+----------+---------------------| >---->(+)----> left out
  40 *              |          |                MixN |/       ^
  41 *  FeedbackNO \¯/        \¯/ FeedbackNS                  |
  42 *              v          v                              |
  43 *              |          |                              |
  44 *              |          v    |¯¯¯|            |\       |
  45 *              |    +--->(+)-->| T |----+-------| >------+
  46 *              |    |     ^    |___|    |  MixD |/
  47 *              |    |     |    Delay    |
  48 *              |    |     |             |
  49 *              |    |     |      /|     |
  50 *              |    |     +-----< |-----+
  51 *              |    | FeedbackDS \|     |
  52 *              |    |                   |
  53 *              |    |            /|     |
  54 *             (+)<--(-----------< |-----+
  55 *              |    |            \| FeedbackDO
  56 *              |    |
  57 *              |    |
  58 *              |    |
  59 *              |    |            /| FeedbackDO
  60 *              |   (+)<---------< |-----+
  61 *              |    |            \|     |
  62 *              |    |                   |
  63 *              |    | FeedbackDS /|     |
  64 *              |    |     +-----< |-----+
  65 *              |    |     |      \|     |
  66 *              |    |     |             |
  67 *              |    |     v    |¯¯¯|    |       |\
  68 *              +----(--->(+)-->| T |----+-------| >------+
  69 *                   |     ^    |___|       MixD |/       |
  70 *                   |     |    Delay                     |
  71 *                   ^     ^                              |
  72 *       FeedbackNO /_\   /_\ FeedbackNS                  |
  73 *                   |     |                     |\       v
  74 * right in ->-------+-----+---------------------| >---->(+)----> right out
  75 *                                          MixN |/
  76 */
  77
  78
  79 void
  80 EchoMono16( LONG          loops,
  81             struct Echo  *es,
  82             void        **buffer,
  83             void        **srcptr,
  84             void        **dstptr)
  85 {
  86   WORD *buf;
  87   WORD *src, *dst;
  88   LONG sample, delaysample;
  89
  90   buf = *buffer;
  91   src = *srcptr;
  92   dst = *dstptr;
  93
  94   while(loops > 0)
  95   {
  96     sample      = *buf;
  97     delaysample = *src++;
  98
  99     *buf++ = ( es->ahiecho_MixN * sample + es->ahiecho_MixD * delaysample ) >> 16;
 100
 101     sample = es->ahiecho_FeedbackNS * sample +
 102              es->ahiecho_FeedbackDS * (delaysample + 1);
 103
 104     *dst++ = sample >> 16;
 105
 106     loops--;
 107   }
 108
 109   *buffer = buf;
 110   *srcptr = src;
 111   *dstptr = dst;
 112 }
 113
 114
 115 void
 116 EchoStereo16( LONG          loops,
 117               struct Echo  *es,
 118               void        **buffer,
 119               void        **srcptr,
 120               void        **dstptr)
 121 {
 122   WORD *buf;
 123   WORD *src, *dst;
 124   LONG sample, sampleL, sampleR, delaysampleL, delaysampleR;
 125
 126   buf = *buffer;
 127   src = *srcptr;
 128   dst = *dstptr;
 129
 130   while(loops > 0)
 131   {
 132     sampleL      = *buf;
 133     delaysampleL = *src++;
 134
 135     *buf++ = ( es->ahiecho_MixN * sampleL + es->ahiecho_MixD * delaysampleL ) >> 16;
 136
 137     sampleR      = *buf;
 138     delaysampleR = *src++;
 139
 140     *buf++ = ( es->ahiecho_MixN * sampleR + es->ahiecho_MixD * delaysampleR ) >> 16;
 141
 142     sample = es->ahiecho_FeedbackDS * (delaysampleL + 1) +
 143              es->ahiecho_FeedbackDO * (delaysampleR + 1) +
 144              es->ahiecho_FeedbackNS * sampleL +
 145              es->ahiecho_FeedbackNO * sampleR;
 146
 147     *dst++ = sample >> 16;
 148
 149     sample = es->ahiecho_FeedbackDO * (delaysampleL + 1) +
 150              es->ahiecho_FeedbackDS * (delaysampleR + 1) +
 151              es->ahiecho_FeedbackNO * sampleL +
 152              es->ahiecho_FeedbackNS * sampleR;
 153
 154     *dst++ = sample >> 16;
 155
 156     loops--;
 157   }
 158
 159   *buffer = buf;
 160   *srcptr = src;
 161   *dstptr = dst;
 162 }
 163
 164
 165 void
 166 EchoMono32 ( LONG          loops,
 167              struct Echo  *es,
 168              void        **buffer,
 169              void        **srcptr,
 170              void        **dstptr)
 171 {
 172   LONG *buf;
 173   WORD *src, *dst;
 174   LONG sample, delaysample;
 175
 176   buf = *buffer;
 177   src = *srcptr;
 178   dst = *dstptr;
 179
 180   while(loops > 0)
 181   {
 182     sample      = *buf >> 16;
 183     delaysample = *src++;
 184
 185     *buf++ = es->ahiecho_MixN * sample + es->ahiecho_MixD * delaysample;
 186
 187     sample = es->ahiecho_FeedbackNS * sample +
 188              es->ahiecho_FeedbackDS * (delaysample + 1);
 189
 190     *dst++ = sample >> 16;
 191
 192     loops--;
 193   }
 194
 195   *buffer = buf;
 196   *srcptr = src;
 197   *dstptr = dst;
 198 }
 199
 200
 201 void
 202 EchoStereo32 ( LONG          loops,
 203                struct Echo  *es,
 204                void        **buffer,
 205                void        **srcptr,
 206                void        **dstptr)
 207 {
 208   LONG *buf;
 209   WORD *src, *dst;
 210   LONG sample, sampleL, sampleR, delaysampleL, delaysampleR;
 211
 212   buf = *buffer;
 213   src = *srcptr;
 214   dst = *dstptr;
 215
 216   while(loops > 0)
 217   {
 218     sampleL      = *buf >> 16;
 219     delaysampleL = *src++;
 220
 221     *buf++ = es->ahiecho_MixN * sampleL + es->ahiecho_MixD * delaysampleL;
 222
 223     sampleR      = *buf >> 16;
 224     delaysampleR = *src++;
 225
 226     *buf++ = es->ahiecho_MixN * sampleR + es->ahiecho_MixD * delaysampleR;
 227
 228     sample = es->ahiecho_FeedbackDS * (delaysampleL + 1) +
 229              es->ahiecho_FeedbackDO * (delaysampleR + 1) +
 230              es->ahiecho_FeedbackNS * sampleL +
 231              es->ahiecho_FeedbackNO * sampleR;
 232
 233     *dst++ = sample >> 16;
 234
 235     sample = es->ahiecho_FeedbackDO * (delaysampleL + 1) +
 236              es->ahiecho_FeedbackDS * (delaysampleR + 1) +
 237              es->ahiecho_FeedbackNO * sampleL +
 238              es->ahiecho_FeedbackNS * sampleR;
 239
 240     *dst++ = sample >> 16;
 241
 242     loops--;
 243   }
 244
 245   *buffer = buf;
 246   *srcptr = src;
 247   *dstptr = dst;
 248 }
 249
 250
 251 void
 252 EchoMulti32 ( LONG          loops,
 253               struct Echo  *es,
 254               void        **buffer,
 255               void        **srcptr,
 256               void        **dstptr)
 257 {
 258   LONG *buf;
 259   WORD *src, *dst;
 260   LONG sample, sampleL, sampleR, delaysampleL, delaysampleR;
 261
 262   buf = *buffer;
 263   src = *srcptr;
 264   dst = *dstptr;
 265
 266   while(loops > 0)
 267   {
 268     sampleL      = *buf >> 16;
 269     delaysampleL = *src++;
 270
 271     *buf++ = es->ahiecho_MixN * sampleL + es->ahiecho_MixD * delaysampleL;
 272
 273     sampleR      = *buf >> 16;
 274     delaysampleR = *src++;
 275
 276     *buf++ = es->ahiecho_MixN * sampleR + es->ahiecho_MixD * delaysampleR;
 277
 278     sample = es->ahiecho_FeedbackDS * (delaysampleL + 1) +
 279              es->ahiecho_FeedbackDO * (delaysampleR + 1) +
 280              es->ahiecho_FeedbackNS * sampleL +
 281              es->ahiecho_FeedbackNO * sampleR;
 282
 283     *dst++ = sample >> 16;
 284
 285     sample = es->ahiecho_FeedbackDO * (delaysampleL + 1) +
 286              es->ahiecho_FeedbackDS * (delaysampleR + 1) +
 287              es->ahiecho_FeedbackNO * sampleL +
 288              es->ahiecho_FeedbackNS * sampleR;
 289
 290     *dst++ = sample >> 16;
 291
 292     // Skip unused channels
 293     buf += 6;
 294     src += 6;
 295     dst += 6;
 296
 297     loops--;
 298   }
 299
 300   *buffer = buf;
 301   *srcptr = src;
 302   *dstptr = dst;
 303 }