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author | Sean Bartell <wingedtachikoma@gmail.com> | 2011-06-24 01:25:21 -0400 |
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committer | Nils Wallménius <nils@rockbox.org> | 2012-03-18 12:00:39 +0100 |
commit | b5716df4cb2837bbbc42195cf1aefcf03e21d6a6 (patch) | |
tree | 130cd712e2e00893b6df9959a375a8d9523a1aca /apps/eq.c | |
parent | 24bd9d5393dbe39a5c6194877bc00ede669b1d5d (diff) | |
download | rockbox-b5716df4cb2837bbbc42195cf1aefcf03e21d6a6.tar.gz rockbox-b5716df4cb2837bbbc42195cf1aefcf03e21d6a6.zip |
Build librbcodec with DSP and metadata.
All associated files are moved to /lib/rbcodec.
Change-Id: I572ddd2b8a996aae1e98c081d06b1ed356dce222
Diffstat (limited to 'apps/eq.c')
-rw-r--r-- | apps/eq.c | 268 |
1 files changed, 0 insertions, 268 deletions
diff --git a/apps/eq.c b/apps/eq.c deleted file mode 100644 index 122a46a4c5..0000000000 --- a/apps/eq.c +++ /dev/null | |||
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1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2006-2007 Thom Johansen | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version 2 | ||
15 | * of the License, or (at your option) any later version. | ||
16 | * | ||
17 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
18 | * KIND, either express or implied. | ||
19 | * | ||
20 | ****************************************************************************/ | ||
21 | |||
22 | #include <inttypes.h> | ||
23 | #include "config.h" | ||
24 | #include "fixedpoint.h" | ||
25 | #include "fracmul.h" | ||
26 | #include "eq.h" | ||
27 | #include "replaygain.h" | ||
28 | |||
29 | /** | ||
30 | * Calculate first order shelving filter. Filter is not directly usable by the | ||
31 | * eq_filter() function. | ||
32 | * @param cutoff shelf midpoint frequency. See eq_pk_coefs for format. | ||
33 | * @param A decibel value multiplied by ten, describing gain/attenuation of | ||
34 | * shelf. Max value is 24 dB. | ||
35 | * @param low true for low-shelf filter, false for high-shelf filter. | ||
36 | * @param c pointer to coefficient storage. Coefficients are s4.27 format. | ||
37 | */ | ||
38 | void filter_shelf_coefs(unsigned long cutoff, long A, bool low, int32_t *c) | ||
39 | { | ||
40 | long sin, cos; | ||
41 | int32_t b0, b1, a0, a1; /* s3.28 */ | ||
42 | const long g = get_replaygain_int(A*5) << 4; /* 10^(db/40), s3.28 */ | ||
43 | |||
44 | sin = fp_sincos(cutoff/2, &cos); | ||
45 | if (low) { | ||
46 | const int32_t sin_div_g = fp_div(sin, g, 25); | ||
47 | const int32_t sin_g = FRACMUL(sin, g); | ||
48 | cos >>= 3; | ||
49 | b0 = sin_g + cos; /* 0.25 .. 4.10 */ | ||
50 | b1 = sin_g - cos; /* -1 .. 3.98 */ | ||
51 | a0 = sin_div_g + cos; /* 0.25 .. 4.10 */ | ||
52 | a1 = sin_div_g - cos; /* -1 .. 3.98 */ | ||
53 | } else { | ||
54 | const int32_t cos_div_g = fp_div(cos, g, 25); | ||
55 | const int32_t cos_g = FRACMUL(cos, g); | ||
56 | sin >>= 3; | ||
57 | b0 = sin + cos_g; /* 0.25 .. 4.10 */ | ||
58 | b1 = sin - cos_g; /* -3.98 .. 1 */ | ||
59 | a0 = sin + cos_div_g; /* 0.25 .. 4.10 */ | ||
60 | a1 = sin - cos_div_g; /* -3.98 .. 1 */ | ||
61 | } | ||
62 | |||
63 | const int32_t rcp_a0 = fp_div(1, a0, 57); /* 0.24 .. 3.98, s2.29 */ | ||
64 | *c++ = FRACMUL_SHL(b0, rcp_a0, 1); /* 0.063 .. 15.85 */ | ||
65 | *c++ = FRACMUL_SHL(b1, rcp_a0, 1); /* -15.85 .. 15.85 */ | ||
66 | *c++ = -FRACMUL_SHL(a1, rcp_a0, 1); /* -1 .. 1 */ | ||
67 | } | ||
68 | |||
69 | #ifdef HAVE_SW_TONE_CONTROLS | ||
70 | /** | ||
71 | * Calculate second order section filter consisting of one low-shelf and one | ||
72 | * high-shelf section. | ||
73 | * @param cutoff_low low-shelf midpoint frequency. See eq_pk_coefs for format. | ||
74 | * @param cutoff_high high-shelf midpoint frequency. | ||
75 | * @param A_low decibel value multiplied by ten, describing gain/attenuation of | ||
76 | * low-shelf part. Max value is 24 dB. | ||
77 | * @param A_high decibel value multiplied by ten, describing gain/attenuation of | ||
78 | * high-shelf part. Max value is 24 dB. | ||
79 | * @param A decibel value multiplied by ten, describing additional overall gain. | ||
80 | * @param c pointer to coefficient storage. Coefficients are s4.27 format. | ||
81 | */ | ||
82 | void filter_bishelf_coefs(unsigned long cutoff_low, unsigned long cutoff_high, | ||
83 | long A_low, long A_high, long A, int32_t *c) | ||
84 | { | ||
85 | const long g = get_replaygain_int(A*10) << 7; /* 10^(db/20), s0.31 */ | ||
86 | int32_t c_ls[3], c_hs[3]; | ||
87 | |||
88 | filter_shelf_coefs(cutoff_low, A_low, true, c_ls); | ||
89 | filter_shelf_coefs(cutoff_high, A_high, false, c_hs); | ||
90 | c_ls[0] = FRACMUL(g, c_ls[0]); | ||
91 | c_ls[1] = FRACMUL(g, c_ls[1]); | ||
92 | |||
93 | /* now we cascade the two first order filters to one second order filter | ||
94 | * which can be used by eq_filter(). these resulting coefficients have a | ||
95 | * really wide numerical range, so we use a fixed point format which will | ||
96 | * work for the selected cutoff frequencies (in dsp.c) only. | ||
97 | */ | ||
98 | const int32_t b0 = c_ls[0], b1 = c_ls[1], b2 = c_hs[0], b3 = c_hs[1]; | ||
99 | const int32_t a0 = c_ls[2], a1 = c_hs[2]; | ||
100 | *c++ = FRACMUL_SHL(b0, b2, 4); | ||
101 | *c++ = FRACMUL_SHL(b0, b3, 4) + FRACMUL_SHL(b1, b2, 4); | ||
102 | *c++ = FRACMUL_SHL(b1, b3, 4); | ||
103 | *c++ = a0 + a1; | ||
104 | *c++ = -FRACMUL_SHL(a0, a1, 4); | ||
105 | } | ||
106 | #endif | ||
107 | |||
108 | /* Coef calculation taken from Audio-EQ-Cookbook.txt by Robert Bristow-Johnson. | ||
109 | * Slightly faster calculation can be done by deriving forms which use tan() | ||
110 | * instead of cos() and sin(), but the latter are far easier to use when doing | ||
111 | * fixed point math, and performance is not a big point in the calculation part. | ||
112 | * All the 'a' filter coefficients are negated so we can use only additions | ||
113 | * in the filtering equation. | ||
114 | */ | ||
115 | |||
116 | /** | ||
117 | * Calculate second order section peaking filter coefficients. | ||
118 | * @param cutoff a value from 0 to 0x80000000, where 0 represents 0 Hz and | ||
119 | * 0x80000000 represents the Nyquist frequency (samplerate/2). | ||
120 | * @param Q Q factor value multiplied by ten. Lower bound is artificially set | ||
121 | * at 0.5. | ||
122 | * @param db decibel value multiplied by ten, describing gain/attenuation at | ||
123 | * peak freq. Max value is 24 dB. | ||
124 | * @param c pointer to coefficient storage. Coefficients are s3.28 format. | ||
125 | */ | ||
126 | void eq_pk_coefs(unsigned long cutoff, unsigned long Q, long db, int32_t *c) | ||
127 | { | ||
128 | long cs; | ||
129 | const long one = 1 << 28; /* s3.28 */ | ||
130 | const long A = get_replaygain_int(db*5) << 5; /* 10^(db/40), s2.29 */ | ||
131 | const long alpha = fp_sincos(cutoff, &cs)/(2*Q)*10 >> 1; /* s1.30 */ | ||
132 | int32_t a0, a1, a2; /* these are all s3.28 format */ | ||
133 | int32_t b0, b1, b2; | ||
134 | const long alphadivA = fp_div(alpha, A, 27); | ||
135 | const long alphaA = FRACMUL(alpha, A); | ||
136 | |||
137 | /* possible numerical ranges are in comments by each coef */ | ||
138 | b0 = one + alphaA; /* [1 .. 5] */ | ||
139 | b1 = a1 = -2*(cs >> 3); /* [-2 .. 2] */ | ||
140 | b2 = one - alphaA; /* [-3 .. 1] */ | ||
141 | a0 = one + alphadivA; /* [1 .. 5] */ | ||
142 | a2 = one - alphadivA; /* [-3 .. 1] */ | ||
143 | |||
144 | /* range of this is roughly [0.2 .. 1], but we'll never hit 1 completely */ | ||
145 | const long rcp_a0 = fp_div(1, a0, 59); /* s0.31 */ | ||
146 | *c++ = FRACMUL(b0, rcp_a0); /* [0.25 .. 4] */ | ||
147 | *c++ = FRACMUL(b1, rcp_a0); /* [-2 .. 2] */ | ||
148 | *c++ = FRACMUL(b2, rcp_a0); /* [-2.4 .. 1] */ | ||
149 | *c++ = FRACMUL(-a1, rcp_a0); /* [-2 .. 2] */ | ||
150 | *c++ = FRACMUL(-a2, rcp_a0); /* [-0.6 .. 1] */ | ||
151 | } | ||
152 | |||
153 | /** | ||
154 | * Calculate coefficients for lowshelf filter. Parameters are as for | ||
155 | * eq_pk_coefs, but the coefficient format is s5.26 fixed point. | ||
156 | */ | ||
157 | void eq_ls_coefs(unsigned long cutoff, unsigned long Q, long db, int32_t *c) | ||
158 | { | ||
159 | long cs; | ||
160 | const long one = 1 << 25; /* s6.25 */ | ||
161 | const long sqrtA = get_replaygain_int(db*5/2) << 2; /* 10^(db/80), s5.26 */ | ||
162 | const long A = FRACMUL_SHL(sqrtA, sqrtA, 8); /* s2.29 */ | ||
163 | const long alpha = fp_sincos(cutoff, &cs)/(2*Q)*10 >> 1; /* s1.30 */ | ||
164 | const long ap1 = (A >> 4) + one; | ||
165 | const long am1 = (A >> 4) - one; | ||
166 | const long ap1_cs = FRACMUL(ap1, cs); | ||
167 | const long am1_cs = FRACMUL(am1, cs); | ||
168 | const long twosqrtalpha = 2*FRACMUL(sqrtA, alpha); | ||
169 | int32_t a0, a1, a2; /* these are all s6.25 format */ | ||
170 | int32_t b0, b1, b2; | ||
171 | |||
172 | /* [0.1 .. 40] */ | ||
173 | b0 = FRACMUL_SHL(A, ap1 - am1_cs + twosqrtalpha, 2); | ||
174 | /* [-16 .. 63.4] */ | ||
175 | b1 = FRACMUL_SHL(A, am1 - ap1_cs, 3); | ||
176 | /* [0 .. 31.7] */ | ||
177 | b2 = FRACMUL_SHL(A, ap1 - am1_cs - twosqrtalpha, 2); | ||
178 | /* [0.5 .. 10] */ | ||
179 | a0 = ap1 + am1_cs + twosqrtalpha; | ||
180 | /* [-16 .. 4] */ | ||
181 | a1 = -2*(am1 + ap1_cs); | ||
182 | /* [0 .. 8] */ | ||
183 | a2 = ap1 + am1_cs - twosqrtalpha; | ||
184 | |||
185 | /* [0.1 .. 1.99] */ | ||
186 | const long rcp_a0 = fp_div(1, a0, 55); /* s1.30 */ | ||
187 | *c++ = FRACMUL_SHL(b0, rcp_a0, 2); /* [0.06 .. 15.9] */ | ||
188 | *c++ = FRACMUL_SHL(b1, rcp_a0, 2); /* [-2 .. 31.7] */ | ||
189 | *c++ = FRACMUL_SHL(b2, rcp_a0, 2); /* [0 .. 15.9] */ | ||
190 | *c++ = FRACMUL_SHL(-a1, rcp_a0, 2); /* [-2 .. 2] */ | ||
191 | *c++ = FRACMUL_SHL(-a2, rcp_a0, 2); /* [0 .. 1] */ | ||
192 | } | ||
193 | |||
194 | /** | ||
195 | * Calculate coefficients for highshelf filter. Parameters are as for | ||
196 | * eq_pk_coefs, but the coefficient format is s5.26 fixed point. | ||
197 | */ | ||
198 | void eq_hs_coefs(unsigned long cutoff, unsigned long Q, long db, int32_t *c) | ||
199 | { | ||
200 | long cs; | ||
201 | const long one = 1 << 25; /* s6.25 */ | ||
202 | const long sqrtA = get_replaygain_int(db*5/2) << 2; /* 10^(db/80), s5.26 */ | ||
203 | const long A = FRACMUL_SHL(sqrtA, sqrtA, 8); /* s2.29 */ | ||
204 | const long alpha = fp_sincos(cutoff, &cs)/(2*Q)*10 >> 1; /* s1.30 */ | ||
205 | const long ap1 = (A >> 4) + one; | ||
206 | const long am1 = (A >> 4) - one; | ||
207 | const long ap1_cs = FRACMUL(ap1, cs); | ||
208 | const long am1_cs = FRACMUL(am1, cs); | ||
209 | const long twosqrtalpha = 2*FRACMUL(sqrtA, alpha); | ||
210 | int32_t a0, a1, a2; /* these are all s6.25 format */ | ||
211 | int32_t b0, b1, b2; | ||
212 | |||
213 | /* [0.1 .. 40] */ | ||
214 | b0 = FRACMUL_SHL(A, ap1 + am1_cs + twosqrtalpha, 2); | ||
215 | /* [-63.5 .. 16] */ | ||
216 | b1 = -FRACMUL_SHL(A, am1 + ap1_cs, 3); | ||
217 | /* [0 .. 32] */ | ||
218 | b2 = FRACMUL_SHL(A, ap1 + am1_cs - twosqrtalpha, 2); | ||
219 | /* [0.5 .. 10] */ | ||
220 | a0 = ap1 - am1_cs + twosqrtalpha; | ||
221 | /* [-4 .. 16] */ | ||
222 | a1 = 2*(am1 - ap1_cs); | ||
223 | /* [0 .. 8] */ | ||
224 | a2 = ap1 - am1_cs - twosqrtalpha; | ||
225 | |||
226 | /* [0.1 .. 1.99] */ | ||
227 | const long rcp_a0 = fp_div(1, a0, 55); /* s1.30 */ | ||
228 | *c++ = FRACMUL_SHL(b0, rcp_a0, 2); /* [0 .. 16] */ | ||
229 | *c++ = FRACMUL_SHL(b1, rcp_a0, 2); /* [-31.7 .. 2] */ | ||
230 | *c++ = FRACMUL_SHL(b2, rcp_a0, 2); /* [0 .. 16] */ | ||
231 | *c++ = FRACMUL_SHL(-a1, rcp_a0, 2); /* [-2 .. 2] */ | ||
232 | *c++ = FRACMUL_SHL(-a2, rcp_a0, 2); /* [0 .. 1] */ | ||
233 | } | ||
234 | |||
235 | /* We realise the filters as a second order direct form 1 structure. Direct | ||
236 | * form 1 was chosen because of better numerical properties for fixed point | ||
237 | * implementations. | ||
238 | */ | ||
239 | |||
240 | #if (!defined(CPU_COLDFIRE) && !defined(CPU_ARM)) | ||
241 | void eq_filter(int32_t **x, struct eqfilter *f, unsigned num, | ||
242 | unsigned channels, unsigned shift) | ||
243 | { | ||
244 | unsigned c, i; | ||
245 | long long acc; | ||
246 | |||
247 | /* Direct form 1 filtering code. | ||
248 | y[n] = b0*x[i] + b1*x[i - 1] + b2*x[i - 2] + a1*y[i - 1] + a2*y[i - 2], | ||
249 | where y[] is output and x[] is input. | ||
250 | */ | ||
251 | |||
252 | for (c = 0; c < channels; c++) { | ||
253 | for (i = 0; i < num; i++) { | ||
254 | acc = (long long) x[c][i] * f->coefs[0]; | ||
255 | acc += (long long) f->history[c][0] * f->coefs[1]; | ||
256 | acc += (long long) f->history[c][1] * f->coefs[2]; | ||
257 | acc += (long long) f->history[c][2] * f->coefs[3]; | ||
258 | acc += (long long) f->history[c][3] * f->coefs[4]; | ||
259 | f->history[c][1] = f->history[c][0]; | ||
260 | f->history[c][0] = x[c][i]; | ||
261 | f->history[c][3] = f->history[c][2]; | ||
262 | x[c][i] = (acc << shift) >> 32; | ||
263 | f->history[c][2] = x[c][i]; | ||
264 | } | ||
265 | } | ||
266 | } | ||
267 | #endif | ||
268 | |||