| 1 | /* Copyright (C) 2010-2020 The RetroArch team |
| 2 | * |
| 3 | * --------------------------------------------------------------------------------------- |
| 4 | * The following license statement only applies to this file (echo.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 <stdlib.h> |
| 24 | |
| 25 | #include <retro_miscellaneous.h> |
| 26 | #include <libretro_dspfilter.h> |
| 27 | |
| 28 | struct echo_channel |
| 29 | { |
| 30 | float *buffer; |
| 31 | unsigned ptr; |
| 32 | unsigned frames; |
| 33 | float feedback; |
| 34 | }; |
| 35 | |
| 36 | struct echo_data |
| 37 | { |
| 38 | struct echo_channel *channels; |
| 39 | unsigned num_channels; |
| 40 | float amp; |
| 41 | }; |
| 42 | |
| 43 | static void echo_free(void *data) |
| 44 | { |
| 45 | unsigned i; |
| 46 | struct echo_data *echo = (struct echo_data*)data; |
| 47 | |
| 48 | for (i = 0; i < echo->num_channels; i++) |
| 49 | free(echo->channels[i].buffer); |
| 50 | free(echo->channels); |
| 51 | free(echo); |
| 52 | } |
| 53 | |
| 54 | static void echo_process(void *data, struct dspfilter_output *output, |
| 55 | const struct dspfilter_input *input) |
| 56 | { |
| 57 | unsigned i, c; |
| 58 | float *out = NULL; |
| 59 | struct echo_data *echo = (struct echo_data*)data; |
| 60 | |
| 61 | output->samples = input->samples; |
| 62 | output->frames = input->frames; |
| 63 | |
| 64 | out = output->samples; |
| 65 | |
| 66 | for (i = 0; i < input->frames; i++, out += 2) |
| 67 | { |
| 68 | float left, right; |
| 69 | float echo_left = 0.0f; |
| 70 | float echo_right = 0.0f; |
| 71 | |
| 72 | for (c = 0; c < echo->num_channels; c++) |
| 73 | { |
| 74 | echo_left += echo->channels[c].buffer[(echo->channels[c].ptr << 1) + 0]; |
| 75 | echo_right += echo->channels[c].buffer[(echo->channels[c].ptr << 1) + 1]; |
| 76 | } |
| 77 | |
| 78 | echo_left *= echo->amp; |
| 79 | echo_right *= echo->amp; |
| 80 | |
| 81 | left = out[0] + echo_left; |
| 82 | right = out[1] + echo_right; |
| 83 | |
| 84 | for (c = 0; c < echo->num_channels; c++) |
| 85 | { |
| 86 | float feedback_left = out[0] + echo->channels[c].feedback * echo_left; |
| 87 | float feedback_right = out[1] + echo->channels[c].feedback * echo_right; |
| 88 | |
| 89 | echo->channels[c].buffer[(echo->channels[c].ptr << 1) + 0] = feedback_left; |
| 90 | echo->channels[c].buffer[(echo->channels[c].ptr << 1) + 1] = feedback_right; |
| 91 | |
| 92 | echo->channels[c].ptr = (echo->channels[c].ptr + 1) % echo->channels[c].frames; |
| 93 | } |
| 94 | |
| 95 | out[0] = left; |
| 96 | out[1] = right; |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | static void *echo_init(const struct dspfilter_info *info, |
| 101 | const struct dspfilter_config *config, void *userdata) |
| 102 | { |
| 103 | unsigned i, channels; |
| 104 | struct echo_channel *echo_channels = NULL; |
| 105 | float *delay = NULL; |
| 106 | float *feedback = NULL; |
| 107 | unsigned num_delay = 0; |
| 108 | unsigned num_feedback = 0; |
| 109 | |
| 110 | static const float default_delay[] = { 200.0f }; |
| 111 | static const float default_feedback[] = { 0.5f }; |
| 112 | struct echo_data *echo = (struct echo_data*) |
| 113 | calloc(1, sizeof(*echo)); |
| 114 | |
| 115 | if (!echo) |
| 116 | return NULL; |
| 117 | |
| 118 | config->get_float_array(userdata, "delay", &delay, |
| 119 | &num_delay, default_delay, 1); |
| 120 | config->get_float_array(userdata, "feedback", &feedback, |
| 121 | &num_feedback, default_feedback, 1); |
| 122 | config->get_float(userdata, "amp", &echo->amp, 0.2f); |
| 123 | |
| 124 | channels = num_feedback = num_delay = MIN(num_delay, num_feedback); |
| 125 | |
| 126 | if (!(echo_channels = (struct echo_channel*)calloc(channels, |
| 127 | sizeof(*echo_channels)))) |
| 128 | goto error; |
| 129 | |
| 130 | echo->channels = echo_channels; |
| 131 | echo->num_channels = channels; |
| 132 | |
| 133 | for (i = 0; i < channels; i++) |
| 134 | { |
| 135 | unsigned frames = (unsigned)(delay[i] * info->input_rate / 1000.0f + 0.5f); |
| 136 | if (!frames) |
| 137 | goto error; |
| 138 | |
| 139 | if (!(echo->channels[i].buffer = (float*)calloc(frames, 2 * sizeof(float)))) |
| 140 | goto error; |
| 141 | |
| 142 | echo->channels[i].frames = frames; |
| 143 | echo->channels[i].feedback = feedback[i]; |
| 144 | } |
| 145 | |
| 146 | config->free(delay); |
| 147 | config->free(feedback); |
| 148 | return echo; |
| 149 | |
| 150 | error: |
| 151 | config->free(delay); |
| 152 | config->free(feedback); |
| 153 | echo_free(echo); |
| 154 | return NULL; |
| 155 | } |
| 156 | |
| 157 | static const struct dspfilter_implementation echo_plug = { |
| 158 | echo_init, |
| 159 | echo_process, |
| 160 | echo_free, |
| 161 | |
| 162 | DSPFILTER_API_VERSION, |
| 163 | "Multi-Echo", |
| 164 | "echo", |
| 165 | }; |
| 166 | |
| 167 | #ifdef HAVE_FILTERS_BUILTIN |
| 168 | #define dspfilter_get_implementation echo_dspfilter_get_implementation |
| 169 | #endif |
| 170 | |
| 171 | const struct dspfilter_implementation *dspfilter_get_implementation(dspfilter_simd_mask_t mask) |
| 172 | { |
| 173 | return &echo_plug; |
| 174 | } |
| 175 | |
| 176 | #undef dspfilter_get_implementation |