FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavfilter/af_afreqshift.c
Date: 2026-04-20 16:43:18
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Lines: 0 120 0.0%
Functions: 0 14 0.0%
Branches: 0 62 0.0%
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1 /*
2 * Copyright (c) Paul B Mahol
3 * Copyright (c) Laurent de Soras, 2005
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "libavutil/channel_layout.h"
23 #include "libavutil/ffmath.h"
24 #include "libavutil/opt.h"
25 #include "avfilter.h"
26 #include "audio.h"
27 #include "filters.h"
28
29 #define MAX_NB_COEFFS 16
30
31 typedef struct AFreqShift {
32 const AVClass *class;
33
34 double shift;
35 double level;
36 int nb_coeffs;
37 int old_nb_coeffs;
38
39 double cd[MAX_NB_COEFFS * 2];
40 float cf[MAX_NB_COEFFS * 2];
41
42 int64_t in_samples;
43
44 AVFrame *i1, *o1;
45 AVFrame *i2, *o2;
46
47 void (*filter_channel)(AVFilterContext *ctx,
48 int channel,
49 AVFrame *in, AVFrame *out);
50 } AFreqShift;
51
52 static const enum AVSampleFormat sample_fmts[] = {
53 AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_DBLP, AV_SAMPLE_FMT_NONE
54 };
55
56 #define PFILTER(name, type, sin, cos, cc) \
57 static void pfilter_channel_## name(AVFilterContext *ctx, \
58 int ch, \
59 AVFrame *in, AVFrame *out) \
60 { \
61 AFreqShift *s = ctx->priv; \
62 const int nb_samples = in->nb_samples; \
63 const type *src = (const type *)in->extended_data[ch]; \
64 type *dst = (type *)out->extended_data[ch]; \
65 type *i1 = (type *)s->i1->extended_data[ch]; \
66 type *o1 = (type *)s->o1->extended_data[ch]; \
67 type *i2 = (type *)s->i2->extended_data[ch]; \
68 type *o2 = (type *)s->o2->extended_data[ch]; \
69 const int nb_coeffs = s->nb_coeffs; \
70 const type *c = s->cc; \
71 const type level = s->level; \
72 type shift = s->shift * M_PI; \
73 type cos_theta = cos(shift); \
74 type sin_theta = sin(shift); \
75 \
76 for (int n = 0; n < nb_samples; n++) { \
77 type xn1 = src[n], xn2 = src[n]; \
78 type I, Q; \
79 \
80 for (int j = 0; j < nb_coeffs; j++) { \
81 I = c[j] * (xn1 + o2[j]) - i2[j]; \
82 i2[j] = i1[j]; \
83 i1[j] = xn1; \
84 o2[j] = o1[j]; \
85 o1[j] = I; \
86 xn1 = I; \
87 } \
88 \
89 for (int j = nb_coeffs; j < nb_coeffs*2; j++) { \
90 Q = c[j] * (xn2 + o2[j]) - i2[j]; \
91 i2[j] = i1[j]; \
92 i1[j] = xn2; \
93 o2[j] = o1[j]; \
94 o1[j] = Q; \
95 xn2 = Q; \
96 } \
97 Q = o2[nb_coeffs * 2 - 1]; \
98 \
99 dst[n] = (I * cos_theta - Q * sin_theta) * level; \
100 } \
101 }
102
103 ✗ PFILTER(flt, float, sin, cos, cf)
104 ✗ PFILTER(dbl, double, sin, cos, cd)
105
106 #define FFILTER(name, type, sin, cos, fmod, cc) \
107 static void ffilter_channel_## name(AVFilterContext *ctx, \
108 int ch, \
109 AVFrame *in, AVFrame *out) \
110 { \
111 AFreqShift *s = ctx->priv; \
112 const int nb_samples = in->nb_samples; \
113 const type *src = (const type *)in->extended_data[ch]; \
114 type *dst = (type *)out->extended_data[ch]; \
115 type *i1 = (type *)s->i1->extended_data[ch]; \
116 type *o1 = (type *)s->o1->extended_data[ch]; \
117 type *i2 = (type *)s->i2->extended_data[ch]; \
118 type *o2 = (type *)s->o2->extended_data[ch]; \
119 const int nb_coeffs = s->nb_coeffs; \
120 const type *c = s->cc; \
121 const type level = s->level; \
122 type ts = 1. / in->sample_rate; \
123 type shift = s->shift; \
124 int64_t N = s->in_samples; \
125 \
126 for (int n = 0; n < nb_samples; n++) { \
127 type xn1 = src[n], xn2 = src[n]; \
128 type I, Q, theta; \
129 \
130 for (int j = 0; j < nb_coeffs; j++) { \
131 I = c[j] * (xn1 + o2[j]) - i2[j]; \
132 i2[j] = i1[j]; \
133 i1[j] = xn1; \
134 o2[j] = o1[j]; \
135 o1[j] = I; \
136 xn1 = I; \
137 } \
138 \
139 for (int j = nb_coeffs; j < nb_coeffs*2; j++) { \
140 Q = c[j] * (xn2 + o2[j]) - i2[j]; \
141 i2[j] = i1[j]; \
142 i1[j] = xn2; \
143 o2[j] = o1[j]; \
144 o1[j] = Q; \
145 xn2 = Q; \
146 } \
147 Q = o2[nb_coeffs * 2 - 1]; \
148 \
149 theta = 2. * M_PI * fmod(shift * (N + n) * ts, 1.); \
150 dst[n] = (I * cos(theta) - Q * sin(theta)) * level; \
151 } \
152 }
153
154 ✗ FFILTER(flt, float, sinf, cosf, fmodf, cf)
155 ✗ FFILTER(dbl, double, sin, cos, fmod, cd)
156
157 ✗ static void compute_transition_param(double *K, double *Q, double transition)
158 {
159 double kksqrt, e, e2, e4, k, q;
160
161 ✗ k = tan((1. - transition * 2.) * M_PI / 4.);
162 ✗ k *= k;
163 ✗ kksqrt = pow(1 - k * k, 0.25);
164 ✗ e = 0.5 * (1. - kksqrt) / (1. + kksqrt);
165 ✗ e2 = e * e;
166 ✗ e4 = e2 * e2;
167 ✗ q = e * (1. + e4 * (2. + e4 * (15. + 150. * e4)));
168
169 ✗ *Q = q;
170 ✗ *K = k;
171 ✗ }
172
173 ✗ static double ipowp(double x, int64_t n)
174 {
175 ✗ double z = 1.;
176
177 ✗ while (n != 0) {
178 ✗ if (n & 1)
179 ✗ z *= x;
180 ✗ n >>= 1;
181 ✗ x *= x;
182 }
183
184 ✗ return z;
185 }
186
187 ✗ static double compute_acc_num(double q, int order, int c)
188 {
189 ✗ int64_t i = 0;
190 ✗ int j = 1;
191 ✗ double acc = 0.;
192 double q_ii1;
193
194 do {
195 ✗ q_ii1 = ipowp(q, i * (i + 1));
196 ✗ q_ii1 *= sin((i * 2 + 1) * c * M_PI / order) * j;
197 ✗ acc += q_ii1;
198
199 ✗ j = -j;
200 ✗ i++;
201 ✗ } while (fabs(q_ii1) > 1e-100);
202
203 ✗ return acc;
204 }
205
206 ✗ static double compute_acc_den(double q, int order, int c)
207 {
208 ✗ int64_t i = 1;
209 ✗ int j = -1;
210 ✗ double acc = 0.;
211 double q_i2;
212
213 do {
214 ✗ q_i2 = ipowp(q, i * i);
215 ✗ q_i2 *= cos(i * 2 * c * M_PI / order) * j;
216 ✗ acc += q_i2;
217
218 ✗ j = -j;
219 ✗ i++;
220 ✗ } while (fabs(q_i2) > 1e-100);
221
222 ✗ return acc;
223 }
224
225 ✗ static double compute_coef(int index, double k, double q, int order)
226 {
227 ✗ const int c = index + 1;
228 ✗ const double num = compute_acc_num(q, order, c) * pow(q, 0.25);
229 ✗ const double den = compute_acc_den(q, order, c) + 0.5;
230 ✗ const double ww = num / den;
231 ✗ const double wwsq = ww * ww;
232
233 ✗ const double x = sqrt((1 - wwsq * k) * (1 - wwsq / k)) / (1 + wwsq);
234 ✗ const double coef = (1 - x) / (1 + x);
235
236 ✗ return coef;
237 }
238
239 ✗ static void compute_coefs(double *coef_arrd, float *coef_arrf, int nbr_coefs, double transition)
240 {
241 ✗ const int order = nbr_coefs * 2 + 1;
242 double k, q;
243
244 ✗ compute_transition_param(&k, &q, transition);
245
246 ✗ for (int n = 0; n < nbr_coefs; n++) {
247 ✗ const int idx = (n / 2) + (n & 1) * nbr_coefs / 2;
248
249 ✗ coef_arrd[idx] = compute_coef(n, k, q, order);
250 ✗ coef_arrf[idx] = coef_arrd[idx];
251 }
252 ✗ }
253
254 ✗ static int config_input(AVFilterLink *inlink)
255 {
256 ✗ AVFilterContext *ctx = inlink->dst;
257 ✗ AFreqShift *s = ctx->priv;
258
259 ✗ if (s->old_nb_coeffs != s->nb_coeffs)
260 ✗ compute_coefs(s->cd, s->cf, s->nb_coeffs * 2, 2. * 20. / inlink->sample_rate);
261 ✗ s->old_nb_coeffs = s->nb_coeffs;
262
263 ✗ s->i1 = ff_get_audio_buffer(inlink, MAX_NB_COEFFS * 2);
264 ✗ s->o1 = ff_get_audio_buffer(inlink, MAX_NB_COEFFS * 2);
265 ✗ s->i2 = ff_get_audio_buffer(inlink, MAX_NB_COEFFS * 2);
266 ✗ s->o2 = ff_get_audio_buffer(inlink, MAX_NB_COEFFS * 2);
267 ✗ if (!s->i1 || !s->o1 || !s->i2 || !s->o2)
268 ✗ return AVERROR(ENOMEM);
269
270 ✗ if (inlink->format == AV_SAMPLE_FMT_DBLP) {
271 ✗ if (!strcmp(ctx->filter->name, "afreqshift"))
272 ✗ s->filter_channel = ffilter_channel_dbl;
273 else
274 ✗ s->filter_channel = pfilter_channel_dbl;
275 } else {
276 ✗ if (!strcmp(ctx->filter->name, "afreqshift"))
277 ✗ s->filter_channel = ffilter_channel_flt;
278 else
279 ✗ s->filter_channel = pfilter_channel_flt;
280 }
281
282 ✗ return 0;
283 }
284
285 typedef struct ThreadData {
286 AVFrame *in, *out;
287 } ThreadData;
288
289 ✗ static int filter_channels(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
290 {
291 ✗ AFreqShift *s = ctx->priv;
292 ✗ ThreadData *td = arg;
293 ✗ AVFrame *out = td->out;
294 ✗ AVFrame *in = td->in;
295 ✗ const int start = (in->ch_layout.nb_channels * jobnr) / nb_jobs;
296 ✗ const int end = (in->ch_layout.nb_channels * (jobnr+1)) / nb_jobs;
297
298 ✗ for (int ch = start; ch < end; ch++)
299 ✗ s->filter_channel(ctx, ch, in, out);
300
301 ✗ return 0;
302 }
303
304 ✗ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
305 {
306 ✗ AVFilterContext *ctx = inlink->dst;
307 ✗ AVFilterLink *outlink = ctx->outputs[0];
308 ✗ AFreqShift *s = ctx->priv;
309 AVFrame *out;
310 ThreadData td;
311
312 ✗ if (s->old_nb_coeffs != s->nb_coeffs)
313 ✗ compute_coefs(s->cd, s->cf, s->nb_coeffs * 2, 2. * 20. / inlink->sample_rate);
314 ✗ s->old_nb_coeffs = s->nb_coeffs;
315
316 ✗ if (av_frame_is_writable(in)) {
317 ✗ out = in;
318 } else {
319 ✗ out = ff_get_audio_buffer(outlink, in->nb_samples);
320 ✗ if (!out) {
321 ✗ av_frame_free(&in);
322 ✗ return AVERROR(ENOMEM);
323 }
324 ✗ av_frame_copy_props(out, in);
325 }
326
327 ✗ td.in = in; td.out = out;
328 ✗ ff_filter_execute(ctx, filter_channels, &td, NULL,
329 ✗ FFMIN(inlink->ch_layout.nb_channels, ff_filter_get_nb_threads(ctx)));
330
331 ✗ s->in_samples += in->nb_samples;
332
333 ✗ if (out != in)
334 ✗ av_frame_free(&in);
335 ✗ return ff_filter_frame(outlink, out);
336 }
337
338 ✗ static av_cold void uninit(AVFilterContext *ctx)
339 {
340 ✗ AFreqShift *s = ctx->priv;
341
342 ✗ av_frame_free(&s->i1);
343 ✗ av_frame_free(&s->o1);
344 ✗ av_frame_free(&s->i2);
345 ✗ av_frame_free(&s->o2);
346 ✗ }
347
348 #define OFFSET(x) offsetof(AFreqShift, x)
349 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
350
351 static const AVOption afreqshift_options[] = {
352 { "shift", "set frequency shift", OFFSET(shift), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -INT_MAX, INT_MAX, FLAGS },
353 { "level", "set output level", OFFSET(level), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.0, 1.0, FLAGS },
354 { "order", "set filter order", OFFSET(nb_coeffs),AV_OPT_TYPE_INT, {.i64=8}, 1, MAX_NB_COEFFS, FLAGS },
355 { NULL }
356 };
357
358 AVFILTER_DEFINE_CLASS(afreqshift);
359
360 static const AVFilterPad inputs[] = {
361 {
362 .name = "default",
363 .type = AVMEDIA_TYPE_AUDIO,
364 .filter_frame = filter_frame,
365 .config_props = config_input,
366 },
367 };
368
369 const FFFilter ff_af_afreqshift = {
370 .p.name = "afreqshift",
371 .p.description = NULL_IF_CONFIG_SMALL("Apply frequency shifting to input audio."),
372 .p.priv_class = &afreqshift_class,
373 .p.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC |
374 AVFILTER_FLAG_SLICE_THREADS,
375 .priv_size = sizeof(AFreqShift),
376 .uninit = uninit,
377 FILTER_INPUTS(inputs),
378 FILTER_OUTPUTS(ff_audio_default_filterpad),
379 FILTER_SAMPLEFMTS_ARRAY(sample_fmts),
380 .process_command = ff_filter_process_command,
381 };
382
383 static const AVOption aphaseshift_options[] = {
384 { "shift", "set phase shift", OFFSET(shift), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1.0, 1.0, FLAGS },
385 { "level", "set output level",OFFSET(level), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0.0, 1.0, FLAGS },
386 { "order", "set filter order",OFFSET(nb_coeffs), AV_OPT_TYPE_INT,{.i64=8}, 1, MAX_NB_COEFFS, FLAGS },
387 { NULL }
388 };
389
390 AVFILTER_DEFINE_CLASS(aphaseshift);
391
392 const FFFilter ff_af_aphaseshift = {
393 .p.name = "aphaseshift",
394 .p.description = NULL_IF_CONFIG_SMALL("Apply phase shifting to input audio."),
395 .p.priv_class = &aphaseshift_class,
396 .p.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC |
397 AVFILTER_FLAG_SLICE_THREADS,
398 .priv_size = sizeof(AFreqShift),
399 .uninit = uninit,
400 FILTER_INPUTS(inputs),
401 FILTER_OUTPUTS(ff_audio_default_filterpad),
402 FILTER_SAMPLEFMTS_ARRAY(sample_fmts),
403 .process_command = ff_filter_process_command,
404 };
405