1 | //filter_goertzel.c: |
---|
2 | |
---|
3 | /* |
---|
4 | * Copyright (C) Philipp 'ph3-der-loewe' Schafft - 2008-2013 |
---|
5 | * |
---|
6 | * This file is part of libroardsp a part of RoarAudio, |
---|
7 | * a cross-platform sound system for both, home and professional use. |
---|
8 | * See README for details. |
---|
9 | * |
---|
10 | * This file is free software; you can redistribute it and/or modify |
---|
11 | * it under the terms of the GNU General Public License version 3 |
---|
12 | * as published by the Free Software Foundation. |
---|
13 | * |
---|
14 | * libroardsp is distributed in the hope that it will be useful, |
---|
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
---|
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
---|
17 | * GNU General Public License for more details. |
---|
18 | * |
---|
19 | * You should have received a copy of the GNU General Public License |
---|
20 | * along with this software; see the file COPYING. If not, write to |
---|
21 | * the Free Software Foundation, 51 Franklin Street, Fifth Floor, |
---|
22 | * Boston, MA 02110-1301, USA. |
---|
23 | * |
---|
24 | */ |
---|
25 | |
---|
26 | #include "libroardsp.h" |
---|
27 | |
---|
28 | #ifdef ROAR_HAVE_LIBM |
---|
29 | |
---|
30 | #define DEFAULT_FREQ 1000.0 |
---|
31 | |
---|
32 | struct roardsp_goertzel { |
---|
33 | float freq; |
---|
34 | int32_t coeff; |
---|
35 | int32_t old[ROAR_MAX_CHANNELS][2]; |
---|
36 | }; |
---|
37 | |
---|
38 | int roardsp_goertzel_init (struct roardsp_filter * filter, struct roar_stream * stream, int id) { |
---|
39 | struct roardsp_goertzel * self = roar_mm_malloc(sizeof(struct roardsp_goertzel)); |
---|
40 | |
---|
41 | (void)stream, (void)id; |
---|
42 | |
---|
43 | if ( self == NULL ) |
---|
44 | return -1; |
---|
45 | |
---|
46 | memset(self, 0, sizeof(struct roardsp_goertzel)); |
---|
47 | |
---|
48 | filter->inst = (void*) self; |
---|
49 | |
---|
50 | roardsp_goertzel_reset(filter, ROARDSP_RESET_FULL); |
---|
51 | |
---|
52 | return 0; |
---|
53 | } |
---|
54 | |
---|
55 | int roardsp_goertzel_uninit(struct roardsp_filter * filter) { |
---|
56 | |
---|
57 | roar_mm_free(filter->inst); |
---|
58 | return 0; |
---|
59 | } |
---|
60 | |
---|
61 | #define _calcX(bits,twobits,limit) \ |
---|
62 | int roardsp_goertzel_calc##bits (struct roardsp_filter * filter, void * data, size_t samples) { \ |
---|
63 | struct roardsp_goertzel * self = (struct roardsp_goertzel *) filter->inst; \ |
---|
64 | int##bits##_t * samp = (int##bits##_t *) data; \ |
---|
65 | /*register int##twobits##_t s, g, h;*/ \ |
---|
66 | register float s, g, h; \ |
---|
67 | /*register int64_t s, g, h;*/ \ |
---|
68 | int channel; \ |
---|
69 | size_t i; \ |
---|
70 | \ |
---|
71 | roardsp_goertzel_reset(filter, ROARDSP_RESET_STATE); \ |
---|
72 | \ |
---|
73 | for (i = 0, channel = 0; i < samples; i++, channel = channel == (filter->channels - 1) ? 0 : channel + 1) { \ |
---|
74 | g = self->old[channel][0]; \ |
---|
75 | g *= self->coeff; \ |
---|
76 | g /= 32767; \ |
---|
77 | s = samp[i]; \ |
---|
78 | ROAR_DBG("roardsp_goertzel_calc*(*): channel=%i, g=%f, s=%f, old[0]=%li, old[1]=%li", channel, g, s, (long int)self->old[channel][0], (long int)self->old[channel][1]); \ |
---|
79 | s += g; \ |
---|
80 | s -= self->old[channel][1]; \ |
---|
81 | self->old[channel][1] = self->old[channel][0]; \ |
---|
82 | self->old[channel][0] = s; \ |
---|
83 | /* samp[i] = s; */ \ |
---|
84 | g = s; \ |
---|
85 | g *= self->old[channel][1]; \ |
---|
86 | g *= self->coeff; \ |
---|
87 | g /= 32767; \ |
---|
88 | h = self->old[channel][1]; \ |
---|
89 | h *= self->old[channel][1]; \ |
---|
90 | s *= s; \ |
---|
91 | s += h; \ |
---|
92 | s -= g; \ |
---|
93 | s *= 0.0001; \ |
---|
94 | s /= (float)((i+1)*(i+1)); \ |
---|
95 | if ( s > (limit) ) \ |
---|
96 | s = (limit); \ |
---|
97 | samp[i] = s; \ |
---|
98 | } \ |
---|
99 | \ |
---|
100 | return 0; \ |
---|
101 | } |
---|
102 | |
---|
103 | _calcX(8,16,127.) |
---|
104 | _calcX(16,32,32767.) |
---|
105 | _calcX(32,64,2147483647.) |
---|
106 | |
---|
107 | int roardsp_goertzel_ctl (struct roardsp_filter * filter, int cmd, void * data) { |
---|
108 | struct roardsp_goertzel * self = (struct roardsp_goertzel *) filter->inst; |
---|
109 | float old; |
---|
110 | |
---|
111 | switch (cmd) { |
---|
112 | case ROARDSP_FCTL_FREQ: |
---|
113 | old = self->freq; |
---|
114 | self->freq = *(float*)data; |
---|
115 | *(float*)data = old; |
---|
116 | old = 2.*cos(2.*M_PI*self->freq/(float)filter->rate); |
---|
117 | self->coeff = old*32767.; |
---|
118 | ROAR_DBG("roardsp_goertzel_ctl(filter=%p, cmd=%i, data=%p): self->coeff=%li (%f)", filter, cmd, data, (long int)self->coeff, old); |
---|
119 | break; |
---|
120 | default: |
---|
121 | roar_err_set(ROAR_ERROR_BADRQC); |
---|
122 | return -1; |
---|
123 | break; |
---|
124 | } |
---|
125 | |
---|
126 | return 0; |
---|
127 | } |
---|
128 | |
---|
129 | int roardsp_goertzel_reset (struct roardsp_filter * filter, int what) { |
---|
130 | struct roardsp_goertzel * self; |
---|
131 | float freq; |
---|
132 | |
---|
133 | if ( filter == NULL ) |
---|
134 | return -1; |
---|
135 | |
---|
136 | if ( filter->inst == NULL ) |
---|
137 | return -1; |
---|
138 | |
---|
139 | self = filter->inst; |
---|
140 | |
---|
141 | switch (what) { |
---|
142 | case ROARDSP_RESET_NONE: |
---|
143 | return 0; |
---|
144 | break; |
---|
145 | case ROARDSP_RESET_FULL: |
---|
146 | freq = self->freq = DEFAULT_FREQ; |
---|
147 | roardsp_goertzel_ctl(filter, ROARDSP_FCTL_FREQ, &freq); |
---|
148 | case ROARDSP_RESET_STATE: |
---|
149 | memset(self->old, 0, sizeof(self->old)); |
---|
150 | return 0; |
---|
151 | break; |
---|
152 | default: |
---|
153 | roar_err_set(ROAR_ERROR_BADRQC); |
---|
154 | return -1; |
---|
155 | break; |
---|
156 | } |
---|
157 | |
---|
158 | return -1; |
---|
159 | } |
---|
160 | |
---|
161 | #endif |
---|
162 | |
---|
163 | //ll |
---|