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3719602c PC |
1 | /* Copyright (C) 2010-2020 The RetroArch team |
2 | * | |
3 | * --------------------------------------------------------------------------------------- | |
4 | * The following license statement only applies to this file (chorus.c). | |
5 | * --------------------------------------------------------------------------------------- | |
6 | * | |
7 | * Permission is hereby granted, free of charge, | |
8 | * to any person obtaining a copy of this software and associated documentation files (the "Software"), | |
9 | * to deal in the Software without restriction, including without limitation the rights to | |
10 | * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
11 | * and to permit persons to whom the Software is furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, | |
16 | * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. | |
18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, | |
19 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
20 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
21 | */ | |
22 | ||
23 | #include <math.h> | |
24 | #include <stdlib.h> | |
25 | #include <string.h> | |
26 | ||
27 | #include <retro_miscellaneous.h> | |
28 | #include <libretro_dspfilter.h> | |
29 | ||
30 | #define CHORUS_MAX_DELAY 4096 | |
31 | #define CHORUS_DELAY_MASK (CHORUS_MAX_DELAY - 1) | |
32 | ||
33 | struct chorus_data | |
34 | { | |
35 | float old[2][CHORUS_MAX_DELAY]; | |
36 | float delay; | |
37 | float depth; | |
38 | float input_rate; | |
39 | float mix_dry; | |
40 | float mix_wet; | |
41 | unsigned old_ptr; | |
42 | unsigned lfo_ptr; | |
43 | unsigned lfo_period; | |
44 | }; | |
45 | ||
46 | static void chorus_free(void *data) | |
47 | { | |
48 | if (data) | |
49 | free(data); | |
50 | } | |
51 | ||
52 | static void chorus_process(void *data, struct dspfilter_output *output, | |
53 | const struct dspfilter_input *input) | |
54 | { | |
55 | unsigned i; | |
56 | float *out = NULL; | |
57 | struct chorus_data *ch = (struct chorus_data*)data; | |
58 | ||
59 | output->samples = input->samples; | |
60 | output->frames = input->frames; | |
61 | out = output->samples; | |
62 | ||
63 | for (i = 0; i < input->frames; i++, out += 2) | |
64 | { | |
65 | unsigned delay_int; | |
66 | float delay_frac, l_a, l_b, r_a, r_b; | |
67 | float chorus_l, chorus_r; | |
68 | float in[2] = { out[0], out[1] }; | |
69 | float delay = ch->delay + ch->depth * sin((2.0 * M_PI * ch->lfo_ptr++) / ch->lfo_period); | |
70 | ||
71 | delay *= ch->input_rate; | |
72 | if (ch->lfo_ptr >= ch->lfo_period) | |
73 | ch->lfo_ptr = 0; | |
74 | ||
75 | delay_int = (unsigned)delay; | |
76 | ||
77 | if (delay_int >= CHORUS_MAX_DELAY - 1) | |
78 | delay_int = CHORUS_MAX_DELAY - 2; | |
79 | ||
80 | delay_frac = delay - delay_int; | |
81 | ||
82 | ch->old[0][ch->old_ptr] = in[0]; | |
83 | ch->old[1][ch->old_ptr] = in[1]; | |
84 | ||
85 | l_a = ch->old[0][(ch->old_ptr - delay_int - 0) & CHORUS_DELAY_MASK]; | |
86 | l_b = ch->old[0][(ch->old_ptr - delay_int - 1) & CHORUS_DELAY_MASK]; | |
87 | r_a = ch->old[1][(ch->old_ptr - delay_int - 0) & CHORUS_DELAY_MASK]; | |
88 | r_b = ch->old[1][(ch->old_ptr - delay_int - 1) & CHORUS_DELAY_MASK]; | |
89 | ||
90 | /* Lerp introduces aliasing of the chorus component, | |
91 | * but doing full polyphase here is probably overkill. */ | |
92 | chorus_l = l_a * (1.0f - delay_frac) + l_b * delay_frac; | |
93 | chorus_r = r_a * (1.0f - delay_frac) + r_b * delay_frac; | |
94 | ||
95 | out[0] = ch->mix_dry * in[0] + ch->mix_wet * chorus_l; | |
96 | out[1] = ch->mix_dry * in[1] + ch->mix_wet * chorus_r; | |
97 | ||
98 | ch->old_ptr = (ch->old_ptr + 1) & CHORUS_DELAY_MASK; | |
99 | } | |
100 | } | |
101 | ||
102 | static void *chorus_init(const struct dspfilter_info *info, | |
103 | const struct dspfilter_config *config, void *userdata) | |
104 | { | |
105 | float delay, depth, lfo_freq, drywet; | |
106 | struct chorus_data *ch = (struct chorus_data*)calloc(1, sizeof(*ch)); | |
107 | if (!ch) | |
108 | return NULL; | |
109 | ||
110 | config->get_float(userdata, "delay_ms", &delay, 25.0f); | |
111 | config->get_float(userdata, "depth_ms", &depth, 1.0f); | |
112 | config->get_float(userdata, "lfo_freq", &lfo_freq, 0.5f); | |
113 | config->get_float(userdata, "drywet", &drywet, 0.8f); | |
114 | ||
115 | delay /= 1000.0f; | |
116 | depth /= 1000.0f; | |
117 | ||
118 | if (depth > delay) | |
119 | depth = delay; | |
120 | ||
121 | if (drywet < 0.0f) | |
122 | drywet = 0.0f; | |
123 | else if (drywet > 1.0f) | |
124 | drywet = 1.0f; | |
125 | ||
126 | ch->mix_dry = 1.0f - 0.5f * drywet; | |
127 | ch->mix_wet = 0.5f * drywet; | |
128 | ||
129 | ch->delay = delay; | |
130 | ch->depth = depth; | |
131 | ch->lfo_period = (1.0f / lfo_freq) * info->input_rate; | |
132 | ch->input_rate = info->input_rate; | |
133 | if (!ch->lfo_period) | |
134 | ch->lfo_period = 1; | |
135 | return ch; | |
136 | } | |
137 | ||
138 | static const struct dspfilter_implementation chorus_plug = { | |
139 | chorus_init, | |
140 | chorus_process, | |
141 | chorus_free, | |
142 | ||
143 | DSPFILTER_API_VERSION, | |
144 | "Chorus", | |
145 | "chorus", | |
146 | }; | |
147 | ||
148 | #ifdef HAVE_FILTERS_BUILTIN | |
149 | #define dspfilter_get_implementation chorus_dspfilter_get_implementation | |
150 | #endif | |
151 | ||
152 | const struct dspfilter_implementation * | |
153 | dspfilter_get_implementation(dspfilter_simd_mask_t mask) { return &chorus_plug; } | |
154 | ||
155 | #undef dspfilter_get_implementation |