Commit | Line | Data |
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ef79bbde P |
1 | /***************************************************************************\r |
2 | reverb.c - description\r | |
3 | -------------------\r | |
4 | begin : Wed May 15 2002\r | |
5 | copyright : (C) 2002 by Pete Bernert\r | |
6 | email : BlackDove@addcom.de\r | |
1775933a | 7 | \r |
8 | Portions (C) GraÅžvydas "notaz" Ignotas, 2010-2011\r | |
9 | Portions (C) SPU2-X, gigaherz, Pcsx2 Development Team\r | |
10 | \r | |
ef79bbde P |
11 | ***************************************************************************/\r |
12 | /***************************************************************************\r | |
13 | * *\r | |
14 | * This program is free software; you can redistribute it and/or modify *\r | |
15 | * it under the terms of the GNU General Public License as published by *\r | |
16 | * the Free Software Foundation; either version 2 of the License, or *\r | |
17 | * (at your option) any later version. See also the license.txt file for *\r | |
18 | * additional informations. *\r | |
19 | * *\r | |
20 | ***************************************************************************/\r | |
21 | \r | |
22 | #include "stdafx.h"\r | |
b71a957f | 23 | #include "spu.h"\r |
ef79bbde P |
24 | \r |
25 | #define _IN_REVERB\r | |
26 | \r | |
27 | // will be included from spu.c\r | |
28 | #ifdef _IN_SPU\r | |
29 | \r | |
ef79bbde P |
30 | ////////////////////////////////////////////////////////////////////////\r |
31 | // START REVERB\r | |
32 | ////////////////////////////////////////////////////////////////////////\r | |
33 | \r | |
34 | INLINE void StartREVERB(int ch)\r | |
35 | {\r | |
5514a050 | 36 | if(spu.s_chan[ch].bReverb && (spu.spuCtrl&0x80)) // reverb possible?\r |
ef79bbde | 37 | {\r |
5514a050 | 38 | spu.s_chan[ch].bRVBActive=!!spu_config.iUseReverb;\r |
ef79bbde | 39 | }\r |
5514a050 | 40 | else spu.s_chan[ch].bRVBActive=0; // else -> no reverb\r |
ef79bbde P |
41 | }\r |
42 | \r | |
ef79bbde P |
43 | ////////////////////////////////////////////////////////////////////////\r |
44 | \r | |
1775933a | 45 | INLINE int rvb2ram_offs(int curr, int space, int iOff)\r |
ef79bbde | 46 | {\r |
1775933a | 47 | iOff += curr;\r |
48 | if (iOff >= 0x40000) iOff -= space;\r | |
49 | return iOff;\r | |
ef79bbde P |
50 | }\r |
51 | \r | |
1775933a | 52 | // get_buffer content helper: takes care about wraps\r |
53 | #define g_buffer(var) \\r | |
b71a957f | 54 | ((int)(signed short)LE16TOH(spu.spuMem[rvb2ram_offs(curr_addr, space, rvb->var)]))\r |
ef79bbde | 55 | \r |
1775933a | 56 | // saturate iVal and store it as var\r |
57 | #define s_buffer(var, iVal) \\r | |
58 | ssat32_to_16(iVal); \\r | |
b71a957f | 59 | spu.spuMem[rvb2ram_offs(curr_addr, space, rvb->var)] = HTOLE16(iVal)\r |
ef79bbde | 60 | \r |
1775933a | 61 | #define s_buffer1(var, iVal) \\r |
62 | ssat32_to_16(iVal); \\r | |
b71a957f | 63 | spu.spuMem[rvb2ram_offs(curr_addr, space, rvb->var + 1)] = HTOLE16(iVal)\r |
ef79bbde P |
64 | \r |
65 | ////////////////////////////////////////////////////////////////////////\r | |
66 | \r | |
1775933a | 67 | // portions based on spu2-x from PCSX2\r |
05c7cec7 | 68 | static void MixREVERB(int *SSumLR, int *RVB, int ns_to, int curr_addr)\r |
ef79bbde | 69 | {\r |
05c7cec7 | 70 | const REVERBInfo *rvb = spu.rvb;\r |
71 | int IIR_ALPHA = rvb->IIR_ALPHA;\r | |
72 | int IIR_COEF = rvb->IIR_COEF;\r | |
73 | int space = 0x40000 - rvb->StartAddr;\r | |
74 | int l, r, ns;\r | |
1775933a | 75 | \r |
650adfd2 | 76 | for (ns = 0; ns < ns_to * 2; )\r |
ef79bbde | 77 | {\r |
1775933a | 78 | int ACC0, ACC1, FB_A0, FB_A1, FB_B0, FB_B1;\r |
79 | int mix_dest_a0, mix_dest_a1, mix_dest_b0, mix_dest_b1;\r | |
80 | \r | |
05c7cec7 | 81 | int input_L = RVB[ns] * rvb->IN_COEF_L;\r |
82 | int input_R = RVB[ns+1] * rvb->IN_COEF_R;\r | |
1775933a | 83 | \r |
05c7cec7 | 84 | int IIR_INPUT_A0 = ((g_buffer(IIR_SRC_A0) * IIR_COEF) + input_L) >> 15;\r |
85 | int IIR_INPUT_A1 = ((g_buffer(IIR_SRC_A1) * IIR_COEF) + input_R) >> 15;\r | |
86 | int IIR_INPUT_B0 = ((g_buffer(IIR_SRC_B0) * IIR_COEF) + input_L) >> 15;\r | |
87 | int IIR_INPUT_B1 = ((g_buffer(IIR_SRC_B1) * IIR_COEF) + input_R) >> 15;\r | |
1775933a | 88 | \r |
89 | int iir_dest_a0 = g_buffer(IIR_DEST_A0);\r | |
90 | int iir_dest_a1 = g_buffer(IIR_DEST_A1);\r | |
91 | int iir_dest_b0 = g_buffer(IIR_DEST_B0);\r | |
92 | int iir_dest_b1 = g_buffer(IIR_DEST_B1);\r | |
93 | \r | |
94 | int IIR_A0 = iir_dest_a0 + ((IIR_INPUT_A0 - iir_dest_a0) * IIR_ALPHA >> 15);\r | |
95 | int IIR_A1 = iir_dest_a1 + ((IIR_INPUT_A1 - iir_dest_a1) * IIR_ALPHA >> 15);\r | |
96 | int IIR_B0 = iir_dest_b0 + ((IIR_INPUT_B0 - iir_dest_b0) * IIR_ALPHA >> 15);\r | |
97 | int IIR_B1 = iir_dest_b1 + ((IIR_INPUT_B1 - iir_dest_b1) * IIR_ALPHA >> 15);\r | |
98 | \r | |
05c7cec7 | 99 | preload(SSumLR + ns + 64*2/4 - 4);\r |
100 | \r | |
1775933a | 101 | s_buffer1(IIR_DEST_A0, IIR_A0);\r |
102 | s_buffer1(IIR_DEST_A1, IIR_A1);\r | |
103 | s_buffer1(IIR_DEST_B0, IIR_B0);\r | |
104 | s_buffer1(IIR_DEST_B1, IIR_B1);\r | |
105 | \r | |
05c7cec7 | 106 | preload(RVB + ns + 64*2/4 - 4);\r |
107 | \r | |
108 | ACC0 = (g_buffer(ACC_SRC_A0) * rvb->ACC_COEF_A +\r | |
109 | g_buffer(ACC_SRC_B0) * rvb->ACC_COEF_B +\r | |
110 | g_buffer(ACC_SRC_C0) * rvb->ACC_COEF_C +\r | |
111 | g_buffer(ACC_SRC_D0) * rvb->ACC_COEF_D) >> 15;\r | |
112 | ACC1 = (g_buffer(ACC_SRC_A1) * rvb->ACC_COEF_A +\r | |
113 | g_buffer(ACC_SRC_B1) * rvb->ACC_COEF_B +\r | |
114 | g_buffer(ACC_SRC_C1) * rvb->ACC_COEF_C +\r | |
115 | g_buffer(ACC_SRC_D1) * rvb->ACC_COEF_D) >> 15;\r | |
1775933a | 116 | \r |
117 | FB_A0 = g_buffer(FB_SRC_A0);\r | |
118 | FB_A1 = g_buffer(FB_SRC_A1);\r | |
119 | FB_B0 = g_buffer(FB_SRC_B0);\r | |
120 | FB_B1 = g_buffer(FB_SRC_B1);\r | |
121 | \r | |
05c7cec7 | 122 | mix_dest_a0 = ACC0 - ((FB_A0 * rvb->FB_ALPHA) >> 15);\r |
123 | mix_dest_a1 = ACC1 - ((FB_A1 * rvb->FB_ALPHA) >> 15);\r | |
1775933a | 124 | \r |
05c7cec7 | 125 | mix_dest_b0 = FB_A0 + (((ACC0 - FB_A0) * rvb->FB_ALPHA - FB_B0 * rvb->FB_X) >> 15);\r |
126 | mix_dest_b1 = FB_A1 + (((ACC1 - FB_A1) * rvb->FB_ALPHA - FB_B1 * rvb->FB_X) >> 15);\r | |
1775933a | 127 | \r |
128 | s_buffer(MIX_DEST_A0, mix_dest_a0);\r | |
129 | s_buffer(MIX_DEST_A1, mix_dest_a1);\r | |
130 | s_buffer(MIX_DEST_B0, mix_dest_b0);\r | |
131 | s_buffer(MIX_DEST_B1, mix_dest_b1);\r | |
132 | \r | |
b72f17a1 | 133 | l = (mix_dest_a0 + mix_dest_b0) / 2;\r |
134 | r = (mix_dest_a1 + mix_dest_b1) / 2;\r | |
1775933a | 135 | \r |
05c7cec7 | 136 | l = (l * rvb->VolLeft) >> 15; // 15?\r |
137 | r = (r * rvb->VolRight) >> 15;\r | |
b72f17a1 | 138 | \r |
b72f17a1 | 139 | SSumLR[ns++] += l;\r |
140 | SSumLR[ns++] += r;\r | |
05c7cec7 | 141 | SSumLR[ns++] += l;\r |
142 | SSumLR[ns++] += r;\r | |
b72f17a1 | 143 | \r |
144 | curr_addr++;\r | |
05c7cec7 | 145 | if (curr_addr >= 0x40000) curr_addr = rvb->StartAddr;\r |
b72f17a1 | 146 | }\r |
b72f17a1 | 147 | }\r |
148 | \r | |
05c7cec7 | 149 | static void MixREVERB_off(int *SSumLR, int ns_to, int curr_addr)\r |
b72f17a1 | 150 | {\r |
05c7cec7 | 151 | const REVERBInfo *rvb = spu.rvb;\r |
152 | int space = 0x40000 - rvb->StartAddr;\r | |
153 | int l, r, ns;\r | |
b72f17a1 | 154 | \r |
650adfd2 | 155 | for (ns = 0; ns < ns_to * 2; )\r |
b72f17a1 | 156 | {\r |
05c7cec7 | 157 | preload(SSumLR + ns + 64*2/4 - 4);\r |
158 | \r | |
b72f17a1 | 159 | l = (g_buffer(MIX_DEST_A0) + g_buffer(MIX_DEST_B0)) / 2;\r |
160 | r = (g_buffer(MIX_DEST_A1) + g_buffer(MIX_DEST_B1)) / 2;\r | |
161 | \r | |
05c7cec7 | 162 | l = (l * rvb->VolLeft) >> 15;\r |
163 | r = (r * rvb->VolRight) >> 15;\r | |
1775933a | 164 | \r |
1775933a | 165 | SSumLR[ns++] += l;\r |
166 | SSumLR[ns++] += r;\r | |
05c7cec7 | 167 | SSumLR[ns++] += l;\r |
168 | SSumLR[ns++] += r;\r | |
1775933a | 169 | \r |
170 | curr_addr++;\r | |
05c7cec7 | 171 | if (curr_addr >= 0x40000) curr_addr = rvb->StartAddr;\r |
ef79bbde P |
172 | }\r |
173 | }\r | |
174 | \r | |
05c7cec7 | 175 | static void REVERBPrep(void)\r |
1775933a | 176 | {\r |
05c7cec7 | 177 | REVERBInfo *rvb = spu.rvb;\r |
7b2c4897 | 178 | int space, t;\r |
179 | \r | |
180 | t = spu.regArea[(H_SPUReverbAddr - 0xc00) >> 1];\r | |
181 | if (t == 0xFFFF || t <= 0x200)\r | |
182 | spu.rvb->StartAddr = spu.rvb->CurrAddr = 0;\r | |
183 | else if (spu.rvb->StartAddr != (t << 2))\r | |
184 | spu.rvb->StartAddr = spu.rvb->CurrAddr = t << 2;\r | |
185 | \r | |
186 | space = 0x40000 - rvb->StartAddr;\r | |
187 | \r | |
188 | #define prep_offs(v, r) \\r | |
189 | t = spu.regArea[(0x1c0 + r) >> 1] * 4; \\r | |
1775933a | 190 | while (t >= space) \\r |
191 | t -= space; \\r | |
7b2c4897 | 192 | rvb->v = t\r |
193 | #define prep_offs2(d, r1, r2) \\r | |
194 | t = spu.regArea[(0x1c0 + r1) >> 1] * 4; \\r | |
195 | t -= spu.regArea[(0x1c0 + r2) >> 1] * 4; \\r | |
196 | while (t < 0) \\r | |
197 | t += space; \\r | |
1775933a | 198 | while (t >= space) \\r |
199 | t -= space; \\r | |
7b2c4897 | 200 | rvb->d = t\r |
201 | \r | |
202 | prep_offs(IIR_SRC_A0, 32);\r | |
203 | prep_offs(IIR_SRC_A1, 34);\r | |
204 | prep_offs(IIR_SRC_B0, 36);\r | |
205 | prep_offs(IIR_SRC_B1, 38);\r | |
206 | prep_offs(IIR_DEST_A0, 20);\r | |
207 | prep_offs(IIR_DEST_A1, 22);\r | |
208 | prep_offs(IIR_DEST_B0, 36);\r | |
209 | prep_offs(IIR_DEST_B1, 38);\r | |
210 | prep_offs(ACC_SRC_A0, 24);\r | |
211 | prep_offs(ACC_SRC_A1, 26);\r | |
212 | prep_offs(ACC_SRC_B0, 28);\r | |
213 | prep_offs(ACC_SRC_B1, 30);\r | |
214 | prep_offs(ACC_SRC_C0, 40);\r | |
215 | prep_offs(ACC_SRC_C1, 42);\r | |
216 | prep_offs(ACC_SRC_D0, 44);\r | |
217 | prep_offs(ACC_SRC_D1, 46);\r | |
218 | prep_offs(MIX_DEST_A0, 52);\r | |
219 | prep_offs(MIX_DEST_A1, 54);\r | |
220 | prep_offs(MIX_DEST_B0, 56);\r | |
221 | prep_offs(MIX_DEST_B1, 58);\r | |
222 | prep_offs2(FB_SRC_A0, 52, 0);\r | |
223 | prep_offs2(FB_SRC_A1, 54, 0);\r | |
224 | prep_offs2(FB_SRC_B0, 56, 2);\r | |
225 | prep_offs2(FB_SRC_B1, 58, 2);\r | |
1775933a | 226 | \r |
227 | #undef prep_offs\r | |
228 | #undef prep_offs2\r | |
05c7cec7 | 229 | rvb->dirty = 0;\r |
1775933a | 230 | }\r |
ef79bbde | 231 | \r |
05c7cec7 | 232 | INLINE void REVERBDo(int *SSumLR, int *RVB, int ns_to, int curr_addr)\r |
ef79bbde | 233 | {\r |
3154bfab | 234 | if (spu.spuCtrl & 0x80) // -> reverb on? oki\r |
1775933a | 235 | {\r |
05c7cec7 | 236 | MixREVERB(SSumLR, RVB, ns_to, curr_addr);\r |
b72f17a1 | 237 | }\r |
05c7cec7 | 238 | else if (spu.rvb->VolLeft || spu.rvb->VolRight)\r |
1775933a | 239 | {\r |
05c7cec7 | 240 | MixREVERB_off(SSumLR, ns_to, curr_addr);\r |
1775933a | 241 | }\r |
ef79bbde P |
242 | }\r |
243 | \r | |
244 | ////////////////////////////////////////////////////////////////////////\r | |
245 | \r | |
246 | #endif\r | |
247 | \r | |
248 | /*\r | |
249 | -----------------------------------------------------------------------------\r | |
250 | PSX reverb hardware notes\r | |
251 | by Neill Corlett\r | |
252 | -----------------------------------------------------------------------------\r | |
253 | \r | |
254 | Yadda yadda disclaimer yadda probably not perfect yadda well it's okay anyway\r | |
255 | yadda yadda.\r | |
256 | \r | |
257 | -----------------------------------------------------------------------------\r | |
258 | \r | |
259 | Basics\r | |
260 | ------\r | |
261 | \r | |
262 | - The reverb buffer is 22khz 16-bit mono PCM.\r | |
263 | - It starts at the reverb address given by 1DA2, extends to\r | |
264 | the end of sound RAM, and wraps back to the 1DA2 address.\r | |
265 | \r | |
266 | Setting the address at 1DA2 resets the current reverb work address.\r | |
267 | \r | |
268 | This work address ALWAYS increments every 1/22050 sec., regardless of\r | |
269 | whether reverb is enabled (bit 7 of 1DAA set).\r | |
270 | \r | |
271 | And the contents of the reverb buffer ALWAYS play, scaled by the\r | |
272 | "reverberation depth left/right" volumes (1D84/1D86).\r | |
273 | (which, by the way, appear to be scaled so 3FFF=approx. 1.0, 4000=-1.0)\r | |
274 | \r | |
275 | -----------------------------------------------------------------------------\r | |
276 | \r | |
277 | Register names\r | |
278 | --------------\r | |
279 | \r | |
280 | These are probably not their real names.\r | |
281 | These are probably not even correct names.\r | |
282 | We will use them anyway, because we can.\r | |
283 | \r | |
284 | 1DC0: FB_SRC_A (offset)\r | |
285 | 1DC2: FB_SRC_B (offset)\r | |
286 | 1DC4: IIR_ALPHA (coef.)\r | |
287 | 1DC6: ACC_COEF_A (coef.)\r | |
288 | 1DC8: ACC_COEF_B (coef.)\r | |
289 | 1DCA: ACC_COEF_C (coef.)\r | |
290 | 1DCC: ACC_COEF_D (coef.)\r | |
291 | 1DCE: IIR_COEF (coef.)\r | |
292 | 1DD0: FB_ALPHA (coef.)\r | |
293 | 1DD2: FB_X (coef.)\r | |
294 | 1DD4: IIR_DEST_A0 (offset)\r | |
295 | 1DD6: IIR_DEST_A1 (offset)\r | |
296 | 1DD8: ACC_SRC_A0 (offset)\r | |
297 | 1DDA: ACC_SRC_A1 (offset)\r | |
298 | 1DDC: ACC_SRC_B0 (offset)\r | |
299 | 1DDE: ACC_SRC_B1 (offset)\r | |
300 | 1DE0: IIR_SRC_A0 (offset)\r | |
301 | 1DE2: IIR_SRC_A1 (offset)\r | |
302 | 1DE4: IIR_DEST_B0 (offset)\r | |
303 | 1DE6: IIR_DEST_B1 (offset)\r | |
304 | 1DE8: ACC_SRC_C0 (offset)\r | |
305 | 1DEA: ACC_SRC_C1 (offset)\r | |
306 | 1DEC: ACC_SRC_D0 (offset)\r | |
307 | 1DEE: ACC_SRC_D1 (offset)\r | |
308 | 1DF0: IIR_SRC_B1 (offset)\r | |
309 | 1DF2: IIR_SRC_B0 (offset)\r | |
310 | 1DF4: MIX_DEST_A0 (offset)\r | |
311 | 1DF6: MIX_DEST_A1 (offset)\r | |
312 | 1DF8: MIX_DEST_B0 (offset)\r | |
313 | 1DFA: MIX_DEST_B1 (offset)\r | |
314 | 1DFC: IN_COEF_L (coef.)\r | |
315 | 1DFE: IN_COEF_R (coef.)\r | |
316 | \r | |
317 | The coefficients are signed fractional values.\r | |
318 | -32768 would be -1.0\r | |
319 | 32768 would be 1.0 (if it were possible... the highest is of course 32767)\r | |
320 | \r | |
321 | The offsets are (byte/8) offsets into the reverb buffer.\r | |
322 | i.e. you multiply them by 8, you get byte offsets.\r | |
323 | You can also think of them as (samples/4) offsets.\r | |
324 | They appear to be signed. They can be negative.\r | |
325 | None of the documented presets make them negative, though.\r | |
326 | \r | |
327 | Yes, 1DF0 and 1DF2 appear to be backwards. Not a typo.\r | |
328 | \r | |
329 | -----------------------------------------------------------------------------\r | |
330 | \r | |
331 | What it does\r | |
332 | ------------\r | |
333 | \r | |
334 | We take all reverb sources:\r | |
335 | - regular channels that have the reverb bit on\r | |
336 | - cd and external sources, if their reverb bits are on\r | |
337 | and mix them into one stereo 44100hz signal.\r | |
338 | \r | |
339 | Lowpass/downsample that to 22050hz. The PSX uses a proper bandlimiting\r | |
340 | algorithm here, but I haven't figured out the hysterically exact specifics.\r | |
341 | I use an 8-tap filter with these coefficients, which are nice but probably\r | |
342 | not the real ones:\r | |
343 | \r | |
344 | 0.037828187894\r | |
345 | 0.157538631280\r | |
346 | 0.321159685278\r | |
347 | 0.449322115345\r | |
348 | 0.449322115345\r | |
349 | 0.321159685278\r | |
350 | 0.157538631280\r | |
351 | 0.037828187894\r | |
352 | \r | |
353 | So we have two input samples (INPUT_SAMPLE_L, INPUT_SAMPLE_R) every 22050hz.\r | |
354 | \r | |
355 | * IN MY EMULATION, I divide these by 2 to make it clip less.\r | |
356 | (and of course the L/R output coefficients are adjusted to compensate)\r | |
357 | The real thing appears to not do this.\r | |
358 | \r | |
359 | At every 22050hz tick:\r | |
360 | - If the reverb bit is enabled (bit 7 of 1DAA), execute the reverb\r | |
361 | steady-state algorithm described below\r | |
362 | - AFTERWARDS, retrieve the "wet out" L and R samples from the reverb buffer\r | |
363 | (This part may not be exactly right and I guessed at the coefs. TODO: check later.)\r | |
364 | L is: 0.333 * (buffer[MIX_DEST_A0] + buffer[MIX_DEST_B0])\r | |
365 | R is: 0.333 * (buffer[MIX_DEST_A1] + buffer[MIX_DEST_B1])\r | |
366 | - Advance the current buffer position by 1 sample\r | |
367 | \r | |
368 | The wet out L and R are then upsampled to 44100hz and played at the\r | |
369 | "reverberation depth left/right" (1D84/1D86) volume, independent of the main\r | |
370 | volume.\r | |
371 | \r | |
372 | -----------------------------------------------------------------------------\r | |
373 | \r | |
374 | Reverb steady-state\r | |
375 | -------------------\r | |
376 | \r | |
377 | The reverb steady-state algorithm is fairly clever, and of course by\r | |
378 | "clever" I mean "batshit insane".\r | |
379 | \r | |
380 | buffer[x] is relative to the current buffer position, not the beginning of\r | |
381 | the buffer. Note that all buffer offsets must wrap around so they're\r | |
382 | contained within the reverb work area.\r | |
383 | \r | |
384 | Clipping is performed at the end... maybe also sooner, but definitely at\r | |
385 | the end.\r | |
386 | \r | |
387 | IIR_INPUT_A0 = buffer[IIR_SRC_A0] * IIR_COEF + INPUT_SAMPLE_L * IN_COEF_L;\r | |
388 | IIR_INPUT_A1 = buffer[IIR_SRC_A1] * IIR_COEF + INPUT_SAMPLE_R * IN_COEF_R;\r | |
389 | IIR_INPUT_B0 = buffer[IIR_SRC_B0] * IIR_COEF + INPUT_SAMPLE_L * IN_COEF_L;\r | |
390 | IIR_INPUT_B1 = buffer[IIR_SRC_B1] * IIR_COEF + INPUT_SAMPLE_R * IN_COEF_R;\r | |
391 | \r | |
392 | IIR_A0 = IIR_INPUT_A0 * IIR_ALPHA + buffer[IIR_DEST_A0] * (1.0 - IIR_ALPHA);\r | |
393 | IIR_A1 = IIR_INPUT_A1 * IIR_ALPHA + buffer[IIR_DEST_A1] * (1.0 - IIR_ALPHA);\r | |
394 | IIR_B0 = IIR_INPUT_B0 * IIR_ALPHA + buffer[IIR_DEST_B0] * (1.0 - IIR_ALPHA);\r | |
395 | IIR_B1 = IIR_INPUT_B1 * IIR_ALPHA + buffer[IIR_DEST_B1] * (1.0 - IIR_ALPHA);\r | |
396 | \r | |
397 | buffer[IIR_DEST_A0 + 1sample] = IIR_A0;\r | |
398 | buffer[IIR_DEST_A1 + 1sample] = IIR_A1;\r | |
399 | buffer[IIR_DEST_B0 + 1sample] = IIR_B0;\r | |
400 | buffer[IIR_DEST_B1 + 1sample] = IIR_B1;\r | |
401 | \r | |
402 | ACC0 = buffer[ACC_SRC_A0] * ACC_COEF_A +\r | |
403 | buffer[ACC_SRC_B0] * ACC_COEF_B +\r | |
404 | buffer[ACC_SRC_C0] * ACC_COEF_C +\r | |
405 | buffer[ACC_SRC_D0] * ACC_COEF_D;\r | |
406 | ACC1 = buffer[ACC_SRC_A1] * ACC_COEF_A +\r | |
407 | buffer[ACC_SRC_B1] * ACC_COEF_B +\r | |
408 | buffer[ACC_SRC_C1] * ACC_COEF_C +\r | |
409 | buffer[ACC_SRC_D1] * ACC_COEF_D;\r | |
410 | \r | |
411 | FB_A0 = buffer[MIX_DEST_A0 - FB_SRC_A];\r | |
412 | FB_A1 = buffer[MIX_DEST_A1 - FB_SRC_A];\r | |
413 | FB_B0 = buffer[MIX_DEST_B0 - FB_SRC_B];\r | |
414 | FB_B1 = buffer[MIX_DEST_B1 - FB_SRC_B];\r | |
415 | \r | |
416 | buffer[MIX_DEST_A0] = ACC0 - FB_A0 * FB_ALPHA;\r | |
417 | buffer[MIX_DEST_A1] = ACC1 - FB_A1 * FB_ALPHA;\r | |
418 | buffer[MIX_DEST_B0] = (FB_ALPHA * ACC0) - FB_A0 * (FB_ALPHA^0x8000) - FB_B0 * FB_X;\r | |
419 | buffer[MIX_DEST_B1] = (FB_ALPHA * ACC1) - FB_A1 * (FB_ALPHA^0x8000) - FB_B1 * FB_X;\r | |
420 | \r | |
421 | -----------------------------------------------------------------------------\r | |
422 | */\r | |
423 | \r | |
1775933a | 424 | // vim:shiftwidth=1:expandtab\r |