FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavfilter/af_aexciter.c
Date: 2022-12-06 04:36:11
Exec Total Coverage
Lines: 0 116 0.0%
Functions: 0 9 0.0%
Branches: 0 28 0.0%

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1 /*
2 * Copyright (c) Markus Schmidt and Christian Holschuh
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include "libavutil/opt.h"
22 #include "avfilter.h"
23 #include "internal.h"
24 #include "audio.h"
25
26 typedef struct ChannelParams {
27 double blend_old, drive_old;
28 double rdrive, rbdr, kpa, kpb, kna, knb, ap,
29 an, imr, kc, srct, sq, pwrq;
30 double prev_med, prev_out;
31
32 double hp[5], lp[5];
33 double hw[4][2], lw[2][2];
34 } ChannelParams;
35
36 typedef struct AExciterContext {
37 const AVClass *class;
38
39 double level_in;
40 double level_out;
41 double amount;
42 double drive;
43 double blend;
44 double freq;
45 double ceil;
46 int listen;
47
48 ChannelParams *cp;
49 } AExciterContext;
50
51 #define OFFSET(x) offsetof(AExciterContext, x)
52 #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
53
54 static const AVOption aexciter_options[] = {
55 { "level_in", "set level in", OFFSET(level_in), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 64, A },
56 { "level_out", "set level out", OFFSET(level_out), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 64, A },
57 { "amount", "set amount", OFFSET(amount), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 64, A },
58 { "drive", "set harmonics", OFFSET(drive), AV_OPT_TYPE_DOUBLE, {.dbl=8.5}, 0.1, 10, A },
59 { "blend", "set blend harmonics", OFFSET(blend), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -10, 10, A },
60 { "freq", "set scope", OFFSET(freq), AV_OPT_TYPE_DOUBLE, {.dbl=7500}, 2000, 12000, A },
61 { "ceil", "set ceiling", OFFSET(ceil), AV_OPT_TYPE_DOUBLE, {.dbl=9999}, 9999, 20000, A },
62 { "listen", "enable listen mode", OFFSET(listen), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, A },
63 { NULL }
64 };
65
66 AVFILTER_DEFINE_CLASS(aexciter);
67
68 static inline double M(double x)
69 {
70 return (fabs(x) > 0.00000001) ? x : 0.0;
71 }
72
73 static inline double D(double x)
74 {
75 x = fabs(x);
76
77 return (x > 0.00000001) ? sqrt(x) : 0.0;
78 }
79
80 static void set_params(ChannelParams *p,
81 double blend, double drive,
82 double srate, double freq,
83 double ceil)
84 {
85 double a0, a1, a2, b0, b1, b2, w0, alpha;
86
87 p->rdrive = 12.0 / drive;
88 p->rbdr = p->rdrive / (10.5 - blend) * 780.0 / 33.0;
89 p->kpa = D(2.0 * (p->rdrive*p->rdrive) - 1.0) + 1.0;
90 p->kpb = (2.0 - p->kpa) / 2.0;
91 p->ap = ((p->rdrive*p->rdrive) - p->kpa + 1.0) / 2.0;
92 p->kc = p->kpa / D(2.0 * D(2.0 * (p->rdrive*p->rdrive) - 1.0) - 2.0 * p->rdrive*p->rdrive);
93
94 p->srct = (0.1 * srate) / (0.1 * srate + 1.0);
95 p->sq = p->kc*p->kc + 1.0;
96 p->knb = -1.0 * p->rbdr / D(p->sq);
97 p->kna = 2.0 * p->kc * p->rbdr / D(p->sq);
98 p->an = p->rbdr*p->rbdr / p->sq;
99 p->imr = 2.0 * p->knb + D(2.0 * p->kna + 4.0 * p->an - 1.0);
100 p->pwrq = 2.0 / (p->imr + 1.0);
101
102 w0 = 2 * M_PI * freq / srate;
103 alpha = sin(w0) / (2. * 0.707);
104 a0 = 1 + alpha;
105 a1 = -2 * cos(w0);
106 a2 = 1 - alpha;
107 b0 = (1 + cos(w0)) / 2;
108 b1 = -(1 + cos(w0));
109 b2 = (1 + cos(w0)) / 2;
110
111 p->hp[0] =-a1 / a0;
112 p->hp[1] =-a2 / a0;
113 p->hp[2] = b0 / a0;
114 p->hp[3] = b1 / a0;
115 p->hp[4] = b2 / a0;
116
117 w0 = 2 * M_PI * ceil / srate;
118 alpha = sin(w0) / (2. * 0.707);
119 a0 = 1 + alpha;
120 a1 = -2 * cos(w0);
121 a2 = 1 - alpha;
122 b0 = (1 - cos(w0)) / 2;
123 b1 = 1 - cos(w0);
124 b2 = (1 - cos(w0)) / 2;
125
126 p->lp[0] =-a1 / a0;
127 p->lp[1] =-a2 / a0;
128 p->lp[2] = b0 / a0;
129 p->lp[3] = b1 / a0;
130 p->lp[4] = b2 / a0;
131 }
132
133 static double bprocess(double in, const double *const c,
134 double *w1, double *w2)
135 {
136 double out = c[2] * in + *w1;
137
138 *w1 = c[3] * in + *w2 + c[0] * out;
139 *w2 = c[4] * in + c[1] * out;
140
141 return out;
142 }
143
144 static double distortion_process(AExciterContext *s, ChannelParams *p, double in)
145 {
146 double proc = in, med;
147
148 proc = bprocess(proc, p->hp, &p->hw[0][0], &p->hw[0][1]);
149 proc = bprocess(proc, p->hp, &p->hw[1][0], &p->hw[1][1]);
150
151 if (proc >= 0.0) {
152 med = (D(p->ap + proc * (p->kpa - proc)) + p->kpb) * p->pwrq;
153 } else {
154 med = (D(p->an - proc * (p->kna + proc)) + p->knb) * p->pwrq * -1.0;
155 }
156
157 proc = p->srct * (med - p->prev_med + p->prev_out);
158 p->prev_med = M(med);
159 p->prev_out = M(proc);
160
161 proc = bprocess(proc, p->hp, &p->hw[2][0], &p->hw[2][1]);
162 proc = bprocess(proc, p->hp, &p->hw[3][0], &p->hw[3][1]);
163
164 if (s->ceil >= 10000.) {
165 proc = bprocess(proc, p->lp, &p->lw[0][0], &p->lw[0][1]);
166 proc = bprocess(proc, p->lp, &p->lw[1][0], &p->lw[1][1]);
167 }
168
169 return proc;
170 }
171
172 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
173 {
174 AVFilterContext *ctx = inlink->dst;
175 AExciterContext *s = ctx->priv;
176 AVFilterLink *outlink = ctx->outputs[0];
177 AVFrame *out;
178 const double *src = (const double *)in->data[0];
179 const double level_in = s->level_in;
180 const double level_out = s->level_out;
181 const double amount = s->amount;
182 const double listen = 1.0 - s->listen;
183 double *dst;
184
185 if (av_frame_is_writable(in)) {
186 out = in;
187 } else {
188 out = ff_get_audio_buffer(inlink, in->nb_samples);
189 if (!out) {
190 av_frame_free(&in);
191 return AVERROR(ENOMEM);
192 }
193 av_frame_copy_props(out, in);
194 }
195
196 dst = (double *)out->data[0];
197 for (int n = 0; n < in->nb_samples; n++) {
198 for (int c = 0; c < inlink->ch_layout.nb_channels; c++) {
199 double sample = src[c] * level_in;
200
201 sample = distortion_process(s, &s->cp[c], sample);
202 sample = sample * amount + listen * src[c];
203
204 sample *= level_out;
205 if (ctx->is_disabled)
206 dst[c] = src[c];
207 else
208 dst[c] = sample;
209 }
210
211 src += inlink->ch_layout.nb_channels;
212 dst += inlink->ch_layout.nb_channels;
213 }
214
215 if (in != out)
216 av_frame_free(&in);
217
218 return ff_filter_frame(outlink, out);
219 }
220
221 static av_cold void uninit(AVFilterContext *ctx)
222 {
223 AExciterContext *s = ctx->priv;
224
225 av_freep(&s->cp);
226 }
227
228 static int config_input(AVFilterLink *inlink)
229 {
230 AVFilterContext *ctx = inlink->dst;
231 AExciterContext *s = ctx->priv;
232
233 if (!s->cp)
234 s->cp = av_calloc(inlink->ch_layout.nb_channels, sizeof(*s->cp));
235 if (!s->cp)
236 return AVERROR(ENOMEM);
237
238 for (int i = 0; i < inlink->ch_layout.nb_channels; i++)
239 set_params(&s->cp[i], s->blend, s->drive, inlink->sample_rate,
240 s->freq, s->ceil);
241
242 return 0;
243 }
244
245 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
246 char *res, int res_len, int flags)
247 {
248 AVFilterLink *inlink = ctx->inputs[0];
249 int ret;
250
251 ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags);
252 if (ret < 0)
253 return ret;
254
255 return config_input(inlink);
256 }
257
258 static const AVFilterPad avfilter_af_aexciter_inputs[] = {
259 {
260 .name = "default",
261 .type = AVMEDIA_TYPE_AUDIO,
262 .config_props = config_input,
263 .filter_frame = filter_frame,
264 },
265 };
266
267 static const AVFilterPad avfilter_af_aexciter_outputs[] = {
268 {
269 .name = "default",
270 .type = AVMEDIA_TYPE_AUDIO,
271 },
272 };
273
274 const AVFilter ff_af_aexciter = {
275 .name = "aexciter",
276 .description = NULL_IF_CONFIG_SMALL("Enhance high frequency part of audio."),
277 .priv_size = sizeof(AExciterContext),
278 .priv_class = &aexciter_class,
279 .uninit = uninit,
280 FILTER_INPUTS(avfilter_af_aexciter_inputs),
281 FILTER_OUTPUTS(avfilter_af_aexciter_outputs),
282 FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_DBL),
283 .process_command = process_command,
284 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
285 };
286