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path: root/libavfilter/af_afftfilt.c (plain)
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1/*
2 * Copyright (c) 2016 Paul B Mahol
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU Lesser General Public License as published
8 * by the Free Software Foundation; either version 2.1 of the License,
9 * 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/audio_fifo.h"
22#include "libavutil/avstring.h"
23#include "libavfilter/internal.h"
24#include "libavutil/common.h"
25#include "libavutil/opt.h"
26#include "libavcodec/avfft.h"
27#include "libavutil/eval.h"
28#include "audio.h"
29#include "window_func.h"
30
31typedef struct AFFTFiltContext {
32 const AVClass *class;
33 char *real_str;
34 char *img_str;
35 int fft_bits;
36
37 FFTContext *fft, *ifft;
38 FFTComplex **fft_data;
39 int nb_exprs;
40 int window_size;
41 AVExpr **real;
42 AVExpr **imag;
43 AVAudioFifo *fifo;
44 int64_t pts;
45 int hop_size;
46 float overlap;
47 AVFrame *buffer;
48 int start, end;
49 int win_func;
50 float win_scale;
51 float *window_func_lut;
52} AFFTFiltContext;
53
54static const char *const var_names[] = { "sr", "b", "nb", "ch", "chs", "pts", NULL };
55enum { VAR_SAMPLE_RATE, VAR_BIN, VAR_NBBINS, VAR_CHANNEL, VAR_CHANNELS, VAR_PTS, VAR_VARS_NB };
56
57#define OFFSET(x) offsetof(AFFTFiltContext, x)
58#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
59
60static const AVOption afftfilt_options[] = {
61 { "real", "set channels real expressions", OFFSET(real_str), AV_OPT_TYPE_STRING, {.str = "1" }, 0, 0, A },
62 { "imag", "set channels imaginary expressions", OFFSET(img_str), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, A },
63 { "win_size", "set window size", OFFSET(fft_bits), AV_OPT_TYPE_INT, {.i64=12}, 4, 17, A, "fft" },
64 { "w16", 0, 0, AV_OPT_TYPE_CONST, {.i64=4}, 0, 0, A, "fft" },
65 { "w32", 0, 0, AV_OPT_TYPE_CONST, {.i64=5}, 0, 0, A, "fft" },
66 { "w64", 0, 0, AV_OPT_TYPE_CONST, {.i64=6}, 0, 0, A, "fft" },
67 { "w128", 0, 0, AV_OPT_TYPE_CONST, {.i64=7}, 0, 0, A, "fft" },
68 { "w256", 0, 0, AV_OPT_TYPE_CONST, {.i64=8}, 0, 0, A, "fft" },
69 { "w512", 0, 0, AV_OPT_TYPE_CONST, {.i64=9}, 0, 0, A, "fft" },
70 { "w1024", 0, 0, AV_OPT_TYPE_CONST, {.i64=10}, 0, 0, A, "fft" },
71 { "w2048", 0, 0, AV_OPT_TYPE_CONST, {.i64=11}, 0, 0, A, "fft" },
72 { "w4096", 0, 0, AV_OPT_TYPE_CONST, {.i64=12}, 0, 0, A, "fft" },
73 { "w8192", 0, 0, AV_OPT_TYPE_CONST, {.i64=13}, 0, 0, A, "fft" },
74 { "w16384", 0, 0, AV_OPT_TYPE_CONST, {.i64=14}, 0, 0, A, "fft" },
75 { "w32768", 0, 0, AV_OPT_TYPE_CONST, {.i64=15}, 0, 0, A, "fft" },
76 { "w65536", 0, 0, AV_OPT_TYPE_CONST, {.i64=16}, 0, 0, A, "fft" },
77 { "w131072",0, 0, AV_OPT_TYPE_CONST, {.i64=17}, 0, 0, A, "fft" },
78 { "win_func", "set window function", OFFSET(win_func), AV_OPT_TYPE_INT, {.i64 = WFUNC_HANNING}, 0, NB_WFUNC-1, A, "win_func" },
79 { "rect", "Rectangular", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_RECT}, 0, 0, A, "win_func" },
80 { "bartlett", "Bartlett", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BARTLETT}, 0, 0, A, "win_func" },
81 { "hann", "Hann", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING}, 0, 0, A, "win_func" },
82 { "hanning", "Hanning", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING}, 0, 0, A, "win_func" },
83 { "hamming", "Hamming", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HAMMING}, 0, 0, A, "win_func" },
84 { "sine", "Sine", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_SINE}, 0, 0, A, "win_func" },
85 { "overlap", "set window overlap", OFFSET(overlap), AV_OPT_TYPE_FLOAT, {.dbl=0.75}, 0, 1, A },
86 { NULL },
87};
88
89AVFILTER_DEFINE_CLASS(afftfilt);
90
91static int config_input(AVFilterLink *inlink)
92{
93 AVFilterContext *ctx = inlink->dst;
94 AFFTFiltContext *s = ctx->priv;
95 char *saveptr = NULL;
96 int ret = 0, ch, i;
97 float overlap;
98 char *args;
99 const char *last_expr = "1";
100
101 s->fft = av_fft_init(s->fft_bits, 0);
102 s->ifft = av_fft_init(s->fft_bits, 1);
103 if (!s->fft || !s->ifft)
104 return AVERROR(ENOMEM);
105
106 s->window_size = 1 << s->fft_bits;
107
108 s->fft_data = av_calloc(inlink->channels, sizeof(*s->fft_data));
109 if (!s->fft_data)
110 return AVERROR(ENOMEM);
111
112 for (ch = 0; ch < inlink->channels; ch++) {
113 s->fft_data[ch] = av_calloc(s->window_size, sizeof(**s->fft_data));
114 if (!s->fft_data[ch])
115 return AVERROR(ENOMEM);
116 }
117
118 s->real = av_calloc(inlink->channels, sizeof(*s->real));
119 if (!s->real)
120 return AVERROR(ENOMEM);
121
122 s->imag = av_calloc(inlink->channels, sizeof(*s->imag));
123 if (!s->imag)
124 return AVERROR(ENOMEM);
125
126 args = av_strdup(s->real_str);
127 if (!args)
128 return AVERROR(ENOMEM);
129
130 for (ch = 0; ch < inlink->channels; ch++) {
131 char *arg = av_strtok(ch == 0 ? args : NULL, "|", &saveptr);
132
133 ret = av_expr_parse(&s->real[ch], arg ? arg : last_expr, var_names,
134 NULL, NULL, NULL, NULL, 0, ctx);
135 if (ret < 0)
136 break;
137 if (arg)
138 last_expr = arg;
139 s->nb_exprs++;
140 }
141
142 av_free(args);
143
144 args = av_strdup(s->img_str ? s->img_str : s->real_str);
145 if (!args)
146 return AVERROR(ENOMEM);
147
148 for (ch = 0; ch < inlink->channels; ch++) {
149 char *arg = av_strtok(ch == 0 ? args : NULL, "|", &saveptr);
150
151 ret = av_expr_parse(&s->imag[ch], arg ? arg : last_expr, var_names,
152 NULL, NULL, NULL, NULL, 0, ctx);
153 if (ret < 0)
154 break;
155 if (arg)
156 last_expr = arg;
157 }
158
159 av_free(args);
160
161 s->fifo = av_audio_fifo_alloc(inlink->format, inlink->channels, s->window_size);
162 if (!s->fifo)
163 return AVERROR(ENOMEM);
164
165 s->window_func_lut = av_realloc_f(s->window_func_lut, s->window_size,
166 sizeof(*s->window_func_lut));
167 if (!s->window_func_lut)
168 return AVERROR(ENOMEM);
169 ff_generate_window_func(s->window_func_lut, s->window_size, s->win_func, &overlap);
170 if (s->overlap == 1)
171 s->overlap = overlap;
172
173 for (s->win_scale = 0, i = 0; i < s->window_size; i++) {
174 s->win_scale += s->window_func_lut[i] * s->window_func_lut[i];
175 }
176
177 s->hop_size = s->window_size * (1 - s->overlap);
178 if (s->hop_size <= 0)
179 return AVERROR(EINVAL);
180
181 s->buffer = ff_get_audio_buffer(inlink, s->window_size * 2);
182 if (!s->buffer)
183 return AVERROR(ENOMEM);
184
185 return ret;
186}
187
188static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
189{
190 AVFilterContext *ctx = inlink->dst;
191 AVFilterLink *outlink = ctx->outputs[0];
192 AFFTFiltContext *s = ctx->priv;
193 const int window_size = s->window_size;
194 const float f = 1. / s->win_scale;
195 double values[VAR_VARS_NB];
196 AVFrame *out, *in = NULL;
197 int ch, n, ret, i, j, k;
198 int start = s->start, end = s->end;
199
200 av_audio_fifo_write(s->fifo, (void **)frame->extended_data, frame->nb_samples);
201 av_frame_free(&frame);
202
203 while (av_audio_fifo_size(s->fifo) >= window_size) {
204 if (!in) {
205 in = ff_get_audio_buffer(outlink, window_size);
206 if (!in)
207 return AVERROR(ENOMEM);
208 }
209
210 ret = av_audio_fifo_peek(s->fifo, (void **)in->extended_data, window_size);
211 if (ret < 0)
212 break;
213
214 for (ch = 0; ch < inlink->channels; ch++) {
215 const float *src = (float *)in->extended_data[ch];
216 FFTComplex *fft_data = s->fft_data[ch];
217
218 for (n = 0; n < in->nb_samples; n++) {
219 fft_data[n].re = src[n] * s->window_func_lut[n];
220 fft_data[n].im = 0;
221 }
222
223 for (; n < window_size; n++) {
224 fft_data[n].re = 0;
225 fft_data[n].im = 0;
226 }
227 }
228
229 values[VAR_PTS] = s->pts;
230 values[VAR_SAMPLE_RATE] = inlink->sample_rate;
231 values[VAR_NBBINS] = window_size / 2;
232 values[VAR_CHANNELS] = inlink->channels;
233
234 for (ch = 0; ch < inlink->channels; ch++) {
235 FFTComplex *fft_data = s->fft_data[ch];
236 float *buf = (float *)s->buffer->extended_data[ch];
237 int x;
238
239 values[VAR_CHANNEL] = ch;
240
241 av_fft_permute(s->fft, fft_data);
242 av_fft_calc(s->fft, fft_data);
243
244 for (n = 0; n < window_size / 2; n++) {
245 float fr, fi;
246
247 values[VAR_BIN] = n;
248
249 fr = av_expr_eval(s->real[ch], values, s);
250 fi = av_expr_eval(s->imag[ch], values, s);
251
252 fft_data[n].re *= fr;
253 fft_data[n].im *= fi;
254 }
255
256 for (n = window_size / 2 + 1, x = window_size / 2 - 1; n < window_size; n++, x--) {
257 fft_data[n].re = fft_data[x].re;
258 fft_data[n].im = -fft_data[x].im;
259 }
260
261 av_fft_permute(s->ifft, fft_data);
262 av_fft_calc(s->ifft, fft_data);
263
264 start = s->start;
265 end = s->end;
266 k = end;
267 for (i = 0, j = start; j < k && i < window_size; i++, j++) {
268 buf[j] += s->fft_data[ch][i].re * f;
269 }
270
271 for (; i < window_size; i++, j++) {
272 buf[j] = s->fft_data[ch][i].re * f;
273 }
274
275 start += s->hop_size;
276 end = j;
277 }
278
279 s->start = start;
280 s->end = end;
281
282 if (start >= window_size) {
283 float *dst, *buf;
284
285 start -= window_size;
286 end -= window_size;
287
288 s->start = start;
289 s->end = end;
290
291 out = ff_get_audio_buffer(outlink, window_size);
292 if (!out) {
293 ret = AVERROR(ENOMEM);
294 break;
295 }
296
297 out->pts = s->pts;
298 s->pts += window_size;
299
300 for (ch = 0; ch < inlink->channels; ch++) {
301 dst = (float *)out->extended_data[ch];
302 buf = (float *)s->buffer->extended_data[ch];
303
304 for (n = 0; n < window_size; n++) {
305 dst[n] = buf[n] * (1 - s->overlap);
306 }
307 memmove(buf, buf + window_size, window_size * 4);
308 }
309
310 ret = ff_filter_frame(outlink, out);
311 if (ret < 0)
312 break;
313 }
314
315 av_audio_fifo_drain(s->fifo, s->hop_size);
316 }
317
318 av_frame_free(&in);
319 return ret;
320}
321
322static int query_formats(AVFilterContext *ctx)
323{
324 AVFilterFormats *formats;
325 AVFilterChannelLayouts *layouts;
326 static const enum AVSampleFormat sample_fmts[] = {
327 AV_SAMPLE_FMT_FLTP,
328 AV_SAMPLE_FMT_NONE
329 };
330 int ret;
331
332 layouts = ff_all_channel_counts();
333 if (!layouts)
334 return AVERROR(ENOMEM);
335 ret = ff_set_common_channel_layouts(ctx, layouts);
336 if (ret < 0)
337 return ret;
338
339 formats = ff_make_format_list(sample_fmts);
340 if (!formats)
341 return AVERROR(ENOMEM);
342 ret = ff_set_common_formats(ctx, formats);
343 if (ret < 0)
344 return ret;
345
346 formats = ff_all_samplerates();
347 if (!formats)
348 return AVERROR(ENOMEM);
349 return ff_set_common_samplerates(ctx, formats);
350}
351
352static av_cold void uninit(AVFilterContext *ctx)
353{
354 AFFTFiltContext *s = ctx->priv;
355 int i;
356
357 av_fft_end(s->fft);
358 av_fft_end(s->ifft);
359
360 for (i = 0; i < s->nb_exprs; i++) {
361 if (s->fft_data)
362 av_freep(&s->fft_data[i]);
363 }
364 av_freep(&s->fft_data);
365
366 for (i = 0; i < s->nb_exprs; i++) {
367 av_expr_free(s->real[i]);
368 av_expr_free(s->imag[i]);
369 }
370
371 av_freep(&s->real);
372 av_freep(&s->imag);
373 av_frame_free(&s->buffer);
374}
375
376static const AVFilterPad inputs[] = {
377 {
378 .name = "default",
379 .type = AVMEDIA_TYPE_AUDIO,
380 .config_props = config_input,
381 .filter_frame = filter_frame,
382 },
383 { NULL }
384};
385
386static const AVFilterPad outputs[] = {
387 {
388 .name = "default",
389 .type = AVMEDIA_TYPE_AUDIO,
390 },
391 { NULL }
392};
393
394AVFilter ff_af_afftfilt = {
395 .name = "afftfilt",
396 .description = NULL_IF_CONFIG_SMALL("Apply arbitrary expressions to samples in frequency domain."),
397 .priv_size = sizeof(AFFTFiltContext),
398 .priv_class = &afftfilt_class,
399 .inputs = inputs,
400 .outputs = outputs,
401 .query_formats = query_formats,
402 .uninit = uninit,
403};
404
generated by cgit at 2024-05-17 08:25:55 (GMT)