1 #!/usr/bin/awk -f
2 #
3 # SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 #
5 # Copyright (c) 2008-2009 Ariff Abdullah <ariff@FreeBSD.org>
6 # All rights reserved.
7 #
8 # Redistribution and use in source and binary forms, with or without
9 # modification, are permitted provided that the following conditions
10 # are met:
11 # 1. Redistributions of source code must retain the above copyright
12 # notice, this list of conditions and the following disclaimer.
13 # 2. Redistributions in binary form must reproduce the above copyright
14 # notice, this list of conditions and the following disclaimer in the
15 # documentation and/or other materials provided with the distribution.
16 #
17 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 # SUCH DAMAGE.
28 #
29 # $FreeBSD$
30 #
31
32 #
33 # Biquad coefficients generator for Parametric Software Equalizer. Not as ugly
34 # as 'feeder_rate_mkfilter.awk'
35 #
36 # Based on:
37 #
38 # "Cookbook formulae for audio EQ biquad filter coefficients"
39 # by Robert Bristow-Johnson <rbj@audioimagination.com>
40 #
41 # - http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
42 #
43
44
45
46 #
47 # Some basic Math functions.
48 #
49 function abs(x)
50 {
51 return (((x < 0) ? -x : x) + 0);
52 }
53
54 function fabs(x)
55 {
56 return (((x < 0.0) ? -x : x) + 0.0);
57 }
58
59 function floor(x, r)
60 {
61 r = int(x);
62 if (r > x)
63 r--;
64 return (r + 0);
65 }
66
67 function pow(x, y)
68 {
69 return (exp(1.0 * y * log(1.0 * x)));
70 }
71
72 #
73 # What the hell...
74 #
75 function shl(x, y)
76 {
77 while (y > 0) {
78 x *= 2;
79 y--;
80 }
81 return (x);
82 }
83
84 function feedeq_w0(fc, rate)
85 {
86 return ((2.0 * M_PI * fc) / (1.0 * rate));
87 }
88
89 function feedeq_A(gain, A)
90 {
91 if (FEEDEQ_TYPE == FEEDEQ_TYPE_PEQ || FEEDEQ_TYPE == FEEDEQ_TYPE_SHELF)
92 A = pow(10, gain / 40.0);
93 else
94 A = sqrt(pow(10, gain / 20.0));
95
96 return (A);
97 }
98
99 function feedeq_alpha(w0, A, QS)
100 {
101 if (FEEDEQ_TYPE == FEEDEQ_TYPE_PEQ)
102 alpha = sin(w0) / (2.0 * QS);
103 else if (FEEDEQ_TYPE == FEEDEQ_TYPE_SHELF)
104 alpha = sin(w0) * 0.5 * sqrt(A + ((1.0 / A) * \
105 ((1.0 / QS) - 1.0)) + 2.0);
106 else
107 alpha = 0.0;
108
109 return (alpha);
110 }
111
112 function feedeq_fx_floor(v, r)
113 {
114 if (fabs(v) < fabs(smallest))
115 smallest = v;
116 if (fabs(v) > fabs(largest))
117 largest = v;
118
119 r = floor((v * FEEDEQ_COEFF_ONE) + 0.5);
120
121 if (r < INT32_MIN || r > INT32_MAX)
122 printf("\n#error overflow v=%f, " \
123 "please reduce FEEDEQ_COEFF_SHIFT\n", v);
124
125 return (r);
126 }
127
128 function feedeq_gen_biquad_coeffs(coeffs, rate, gain, \
129 w0, A, alpha, a0, a1, a2, b0, b1, b2)
130 {
131 w0 = feedeq_w0(FEEDEQ_TREBLE_SFREQ, 1.0 * rate);
132 A = feedeq_A(1.0 * gain);
133 alpha = feedeq_alpha(w0, A, FEEDEQ_TREBLE_SLOPE);
134
135 if (FEEDEQ_TYPE == FEEDEQ_TYPE_PEQ) {
136 b0 = 1.0 + (alpha * A);
137 b1 = -2.0 * cos(w0);
138 b2 = 1.0 - (alpha * A);
139 a0 = 1.0 + (alpha / A);
140 a1 = -2.0 * cos(w0);
141 a2 = 1.0 - (alpha / A);
142 } else if (FEEDEQ_TYPE == FEEDEQ_TYPE_SHELF) {
143 b0 = A*((A+1.0)+((A-1.0)*cos(w0))+(2.0*sqrt(A)*alpha));
144 b1 = -2.0*A*((A-1.0)+((A+1.0)*cos(w0)) );
145 b2 = A*((A+1.0)+((A-1.0)*cos(w0))-(2.0*sqrt(A)*alpha));
146 a0 = (A+1.0)-((A-1.0)*cos(w0))+(2.0*sqrt(A)*alpha );
147 a1 = 2.0 * ((A-1.0)-((A+1.0)*cos(w0)) );
148 a2 = (A+1.0)-((A-1.0)*cos(w0))-(2.0*sqrt(A)*alpha );
149 } else
150 b0 = b1 = b2 = a0 = a1 = a2 = 0.0;
151
152 b0 /= a0;
153 b1 /= a0;
154 b2 /= a0;
155 a1 /= a0;
156 a2 /= a0;
157
158 coeffs["treble", gain, 0] = feedeq_fx_floor(a0);
159 coeffs["treble", gain, 1] = feedeq_fx_floor(a1);
160 coeffs["treble", gain, 2] = feedeq_fx_floor(a2);
161 coeffs["treble", gain, 3] = feedeq_fx_floor(b0);
162 coeffs["treble", gain, 4] = feedeq_fx_floor(b1);
163 coeffs["treble", gain, 5] = feedeq_fx_floor(b2);
164
165 w0 = feedeq_w0(FEEDEQ_BASS_SFREQ, 1.0 * rate);
166 A = feedeq_A(1.0 * gain);
167 alpha = feedeq_alpha(w0, A, FEEDEQ_BASS_SLOPE);
168
169 if (FEEDEQ_TYPE == FEEDEQ_TYPE_PEQ) {
170 b0 = 1.0 + (alpha * A);
171 b1 = -2.0 * cos(w0);
172 b2 = 1.0 - (alpha * A);
173 a0 = 1.0 + (alpha / A);
174 a1 = -2.0 * cos(w0);
175 a2 = 1.0 - (alpha / A);
176 } else if (FEEDEQ_TYPE == FEEDEQ_TYPE_SHELF) {
177 b0 = A*((A+1.0)-((A-1.0)*cos(w0))+(2.0*sqrt(A)*alpha));
178 b1 = 2.0*A*((A-1.0)-((A+1.0)*cos(w0)) );
179 b2 = A*((A+1.0)-((A-1.0)*cos(w0))-(2.0*sqrt(A)*alpha));
180 a0 = (A+1.0)+((A-1.0)*cos(w0))+(2.0*sqrt(A)*alpha );
181 a1 = -2.0 * ((A-1.0)+((A+1.0)*cos(w0)) );
182 a2 = (A+1.0)+((A-1.0)*cos(w0))-(2.0*sqrt(A)*alpha );
183 } else
184 b0 = b1 = b2 = a0 = a1 = a2 = 0.0;
185
186 b0 /= a0;
187 b1 /= a0;
188 b2 /= a0;
189 a1 /= a0;
190 a2 /= a0;
191
192 coeffs["bass", gain, 0] = feedeq_fx_floor(a0);
193 coeffs["bass", gain, 1] = feedeq_fx_floor(a1);
194 coeffs["bass", gain, 2] = feedeq_fx_floor(a2);
195 coeffs["bass", gain, 3] = feedeq_fx_floor(b0);
196 coeffs["bass", gain, 4] = feedeq_fx_floor(b1);
197 coeffs["bass", gain, 5] = feedeq_fx_floor(b2);
198 }
199
200 function feedeq_gen_freq_coeffs(frq, g, i, v)
201 {
202 coeffs[0] = 0;
203
204 for (g = (FEEDEQ_GAIN_MIN * FEEDEQ_GAIN_DIV); \
205 g <= (FEEDEQ_GAIN_MAX * FEEDEQ_GAIN_DIV); \
206 g += FEEDEQ_GAIN_STEP) {
207 feedeq_gen_biquad_coeffs(coeffs, frq, \
208 g * FEEDEQ_GAIN_RECIPROCAL);
209 }
210
211 printf("\nstatic struct feed_eq_coeff eq_%d[%d] " \
212 "= {\n", frq, FEEDEQ_LEVELS);
213 for (g = (FEEDEQ_GAIN_MIN * FEEDEQ_GAIN_DIV); \
214 g <= (FEEDEQ_GAIN_MAX * FEEDEQ_GAIN_DIV); \
215 g += FEEDEQ_GAIN_STEP) {
216 printf(" {{ ");
217 for (i = 1; i < 6; i++) {
218 v = coeffs["treble", g * FEEDEQ_GAIN_RECIPROCAL, i];
219 printf("%s0x%08x%s", \
220 (v < 0) ? "-" : " ", abs(v), \
221 (i == 5) ? " " : ", ");
222 }
223 printf("},\n { ");
224 for (i = 1; i < 6; i++) {
225 v = coeffs["bass", g * FEEDEQ_GAIN_RECIPROCAL, i];
226 printf("%s0x%08x%s", \
227 (v < 0) ? "-" : " ", abs(v), \
228 (i == 5) ? " " : ", ");
229 }
230 printf("}}%s\n", \
231 (g < (FEEDEQ_GAIN_MAX * FEEDEQ_GAIN_DIV)) ? "," : "");
232 }
233 printf("};\n");
234 }
235
236 function feedeq_calc_preamp(norm, gain, shift, mul, bit, attn)
237 {
238 shift = FEEDEQ_PREAMP_SHIFT;
239
240 if (floor(FEEDEQ_PREAMP_BITDB) == 6 && \
241 (1.0 * floor(gain)) == gain && (floor(gain) % 6) == 0) {
242 mul = 1;
243 shift = floor(floor(gain) / 6);
244 } else {
245 bit = 32.0 - ((1.0 * gain) / (1.0 * FEEDEQ_PREAMP_BITDB));
246 attn = pow(2.0, bit) / pow(2.0, 32.0);
247 mul = floor((attn * FEEDEQ_PREAMP_ONE) + 0.5);
248 }
249
250 while ((mul % 2) == 0 && shift > 0) {
251 mul = floor(mul / 2);
252 shift--;
253 }
254
255 norm["mul"] = mul;
256 norm["shift"] = shift;
257 }
258
259 BEGIN {
260 M_PI = atan2(0.0, -1.0);
261
262 INT32_MAX = 1 + ((shl(1, 30) - 1) * 2);
263 INT32_MIN = -1 - INT32_MAX;
264
265 FEEDEQ_TYPE_PEQ = 0;
266 FEEDEQ_TYPE_SHELF = 1;
267
268 FEEDEQ_TYPE = FEEDEQ_TYPE_PEQ;
269
270 FEEDEQ_COEFF_SHIFT = 24;
271 FEEDEQ_COEFF_ONE = shl(1, FEEDEQ_COEFF_SHIFT);
272
273 FEEDEQ_PREAMP_SHIFT = 31;
274 FEEDEQ_PREAMP_ONE = shl(1, FEEDEQ_PREAMP_SHIFT);
275 FEEDEQ_PREAMP_BITDB = 6; # 20.0 * (log(2.0) / log(10.0));
276
277 FEEDEQ_GAIN_DIV = 10;
278 i = 0;
279 j = 1;
280 while (j < FEEDEQ_GAIN_DIV) {
281 j *= 2;
282 i++;
283 }
284 FEEDEQ_GAIN_SHIFT = i;
285 FEEDEQ_GAIN_FMASK = shl(1, FEEDEQ_GAIN_SHIFT) - 1;
286
287 FEEDEQ_GAIN_RECIPROCAL = 1.0 / FEEDEQ_GAIN_DIV;
288
289 if (ARGC == 2) {
290 i = 1;
291 split(ARGV[1], arg, ":");
292 while (match(arg[i], "^[^0-9]*$")) {
293 if (arg[i] == "PEQ") {
294 FEEDEQ_TYPE = FEEDEQ_TYPE_PEQ;
295 } else if (arg[i] == "SHELF") {
296 FEEDEQ_TYPE = FEEDEQ_TYPE_SHELF;
297 }
298 i++;
299 }
300 split(arg[i++], subarg, ",");
301 FEEDEQ_TREBLE_SFREQ = 1.0 * subarg[1];
302 FEEDEQ_TREBLE_SLOPE = 1.0 * subarg[2];
303 split(arg[i++], subarg, ",");
304 FEEDEQ_BASS_SFREQ = 1.0 * subarg[1];
305 FEEDEQ_BASS_SLOPE = 1.0 * subarg[2];
306 split(arg[i++], subarg, ",");
307 FEEDEQ_GAIN_MIN = floor(1.0 * subarg[1]);
308 FEEDEQ_GAIN_MAX = floor(1.0 * subarg[2]);
309 if (length(subarg) > 2) {
310 j = floor(1.0 * FEEDEQ_GAIN_DIV * subarg[3]);
311 if (j < 2)
312 j = 1;
313 else if (j < 5)
314 j = 2;
315 else if (j < 10)
316 j = 5;
317 else
318 j = 10;
319 if (j > FEEDEQ_GAIN_DIV || (FEEDEQ_GAIN_DIV % j) != 0)
320 j = FEEDEQ_GAIN_DIV;
321 FEEDEQ_GAIN_STEP = j;
322 } else
323 FEEDEQ_GAIN_STEP = FEEDEQ_GAIN_DIV;
324 split(arg[i], subarg, ",");
325 for (i = 1; i <= length(subarg); i++)
326 allfreq[i - 1] = floor(1.0 * subarg[i]);
327 } else {
328 FEEDEQ_TREBLE_SFREQ = 16000.0;
329 FEEDEQ_TREBLE_SLOPE = 0.25;
330 FEEDEQ_BASS_SFREQ = 62.0;
331 FEEDEQ_BASS_SLOPE = 0.25;
332
333 FEEDEQ_GAIN_MIN = -9;
334 FEEDEQ_GAIN_MAX = 9;
335
336 FEEDEQ_GAIN_STEP = FEEDEQ_GAIN_DIV;
337
338
339 allfreq[0] = 44100;
340 allfreq[1] = 48000;
341 allfreq[2] = 88200;
342 allfreq[3] = 96000;
343 allfreq[4] = 176400;
344 allfreq[5] = 192000;
345 }
346
347 FEEDEQ_LEVELS = ((FEEDEQ_GAIN_MAX - FEEDEQ_GAIN_MIN) * \
348 floor(FEEDEQ_GAIN_DIV / FEEDEQ_GAIN_STEP)) + 1;
349
350 FEEDEQ_ERR_CLIP = 0;
351
352 smallest = 10.000000;
353 largest = 0.000010;
354
355 printf("#ifndef _FEEDER_EQ_GEN_H_\n");
356 printf("#define _FEEDER_EQ_GEN_H_\n\n");
357 printf("/*\n");
358 printf(" * Generated using feeder_eq_mkfilter.awk, heaven, wind and awesome.\n");
359 printf(" *\n");
360 printf(" * DO NOT EDIT!\n");
361 printf(" */\n\n");
362 printf("/*\n");
363 printf(" * EQ: %s\n", (FEEDEQ_TYPE == FEEDEQ_TYPE_SHELF) ? \
364 "Shelving" : "Peaking EQ");
365 printf(" */\n");
366 printf("#define FEEDER_EQ_PRESETS\t\"");
367 printf("%s:%d,%.4f,%d,%.4f:%d,%d,%.1f:", \
368 (FEEDEQ_TYPE == FEEDEQ_TYPE_SHELF) ? "SHELF" : "PEQ", \
369 FEEDEQ_TREBLE_SFREQ, FEEDEQ_TREBLE_SLOPE, \
370 FEEDEQ_BASS_SFREQ, FEEDEQ_BASS_SLOPE, \
371 FEEDEQ_GAIN_MIN, FEEDEQ_GAIN_MAX, \
372 FEEDEQ_GAIN_STEP * FEEDEQ_GAIN_RECIPROCAL);
373 for (i = 0; i < length(allfreq); i++) {
374 if (i != 0)
375 printf(",");
376 printf("%d", allfreq[i]);
377 }
378 printf("\"\n\n");
379 printf("struct feed_eq_coeff_tone {\n");
380 printf("\tint32_t a1, a2;\n");
381 printf("\tint32_t b0, b1, b2;\n");
382 printf("};\n\n");
383 printf("struct feed_eq_coeff {\n");
384 #printf("\tstruct {\n");
385 #printf("\t\tint32_t a1, a2;\n");
386 #printf("\t\tint32_t b0, b1, b2;\n");
387 #printf("\t} treble, bass;\n");
388 printf("\tstruct feed_eq_coeff_tone treble;\n");
389 printf("\tstruct feed_eq_coeff_tone bass;\n");
390 #printf("\tstruct {\n");
391 #printf("\t\tint32_t a1, a2;\n");
392 #printf("\t\tint32_t b0, b1, b2;\n");
393 #printf("\t} bass;\n");
394 printf("};\n");
395 for (i = 0; i < length(allfreq); i++)
396 feedeq_gen_freq_coeffs(allfreq[i]);
397 printf("\n");
398 printf("static const struct {\n");
399 printf("\tuint32_t rate;\n");
400 printf("\tstruct feed_eq_coeff *coeff;\n");
401 printf("} feed_eq_tab[] = {\n");
402 for (i = 0; i < length(allfreq); i++) {
403 printf("\t{ %6d, eq_%-6d },\n", allfreq[i], allfreq[i]);
404 }
405 printf("};\n");
406
407 printf("\n#define FEEDEQ_RATE_MIN\t\t%d\n", allfreq[0]);
408 printf("#define FEEDEQ_RATE_MAX\t\t%d\n", allfreq[length(allfreq) - 1]);
409 printf("\n#define FEEDEQ_TAB_SIZE\t\t\t\t\t\t\t\\\n");
410 printf("\t((int32_t)(sizeof(feed_eq_tab) / sizeof(feed_eq_tab[0])))\n");
411
412 printf("\nstatic const struct {\n");
413 printf("\tint32_t mul, shift;\n");
414 printf("} feed_eq_preamp[] = {\n");
415 for (i = (FEEDEQ_GAIN_MAX * 2 * FEEDEQ_GAIN_DIV); i >= 0; \
416 i -= FEEDEQ_GAIN_STEP) {
417 feedeq_calc_preamp(norm, i * FEEDEQ_GAIN_RECIPROCAL);
418 dbgain = ((FEEDEQ_GAIN_MAX * FEEDEQ_GAIN_DIV) - i) * \
419 FEEDEQ_GAIN_RECIPROCAL;
420 printf("\t{ 0x%08x, 0x%08x },\t/* %+5.1f dB */\n", \
421 norm["mul"], norm["shift"], dbgain);
422 }
423 printf("};\n");
424
425 printf("\n#define FEEDEQ_GAIN_MIN\t\t%d", FEEDEQ_GAIN_MIN);
426 printf("\n#define FEEDEQ_GAIN_MAX\t\t%d\n", FEEDEQ_GAIN_MAX);
427
428 printf("\n#define FEEDEQ_GAIN_SHIFT\t%d\n", FEEDEQ_GAIN_SHIFT);
429 printf("#define FEEDEQ_GAIN_DIV\t\t%d\n", FEEDEQ_GAIN_DIV);
430 printf("#define FEEDEQ_GAIN_FMASK\t0x%08x\n", FEEDEQ_GAIN_FMASK);
431 printf("#define FEEDEQ_GAIN_STEP\t%d\n", FEEDEQ_GAIN_STEP);
432
433 #printf("\n#define FEEDEQ_PREAMP_MIN\t-%d\n", \
434 # shl(FEEDEQ_GAIN_MAX, FEEDEQ_GAIN_SHIFT));
435 #printf("#define FEEDEQ_PREAMP_MAX\t%d\n", \
436 # shl(FEEDEQ_GAIN_MAX, FEEDEQ_GAIN_SHIFT));
437
438 printf("\n#define FEEDEQ_COEFF_SHIFT\t%d\n", FEEDEQ_COEFF_SHIFT);
439
440 #feedeq_calc_preamp(norm, FEEDEQ_GAIN_MAX);
441
442 #printf("#define FEEDEQ_COEFF_NORM(v)\t(");
443 #if (norm["mul"] == 1)
444 # printf("(v) >> %d", norm["shift"]);
445 #else
446 # printf("(0x%xLL * (v)) >> %d", norm["mul"], norm["shift"]);
447 #printf(")\n");
448
449 #printf("\n#define FEEDEQ_LEVELS\t\t%d\n", FEEDEQ_LEVELS);
450 if (FEEDEQ_ERR_CLIP != 0)
451 printf("\n#define FEEDEQ_ERR_CLIP\t\t%d\n", FEEDEQ_ERR_CLIP);
452 printf("\n/*\n");
453 printf(" * volume level mapping (0 - 100):\n");
454 printf(" *\n");
455
456 for (i = 0; i <= 100; i++) {
457 ind = floor((i * FEEDEQ_LEVELS) / 100);
458 if (ind >= FEEDEQ_LEVELS)
459 ind = FEEDEQ_LEVELS - 1;
460 printf(" *\t%3d -> %3d (%+5.1f dB)\n", \
461 i, ind, FEEDEQ_GAIN_MIN + \
462 (ind * (FEEDEQ_GAIN_RECIPROCAL * FEEDEQ_GAIN_STEP)));
463 }
464
465 printf(" */\n");
466 printf("\n/*\n * smallest: %.32f\n * largest: %.32f\n */\n", \
467 smallest, largest);
468 printf("\n#endif\t/* !_FEEDER_EQ_GEN_H_ */\n");
469 }
Cache object: 37fd24054179c5cecf03c4e595fcf6da
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