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1 /*
2  * Copyright (c) 2018 Paul B Mahol
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 <float.h>
22 
23 #include "libavutil/avstring.h"
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/opt.h"
26 #include "libavutil/xga_font_data.h"
27 #include "audio.h"
28 #include "avfilter.h"
29 #include "internal.h"
30 
31 typedef struct ThreadData {
32     AVFrame *in, *out;
33 } ThreadData;
34 
35 typedef struct Pair {
36     int a, b;
37 } Pair;
38 
39 typedef struct BiquadContext {
40     double a[3];
41     double b[3];
42     double w1, w2;
43 } BiquadContext;
44 
45 typedef struct IIRChannel {
46     int nb_ab[2];
47     double *ab[2];
48     double g;
49     double *cache[2];
50     double fir;
51     BiquadContext *biquads;
52     int clippings;
53 } IIRChannel;
54 
55 typedef struct AudioIIRContext {
56     const AVClass *class;
57     char *a_str, *b_str, *g_str;
58     double dry_gain, wet_gain;
59     double mix;
60     int normalize;
61     int format;
62     int process;
63     int precision;
64     int response;
65     int w, h;
66     int ir_channel;
67     AVRational rate;
68 
69     AVFrame *video;
70 
71     IIRChannel *iir;
72     int channels;
73     enum AVSampleFormat sample_format;
74 
75     int (*iir_channel)(AVFilterContext *ctx, void *arg, int ch, int nb_jobs);
76 } AudioIIRContext;
77 
query_formats(AVFilterContext * ctx)78 static int query_formats(AVFilterContext *ctx)
79 {
80     AudioIIRContext *s = ctx->priv;
81     AVFilterFormats *formats;
82     enum AVSampleFormat sample_fmts[] = {
83         AV_SAMPLE_FMT_DBLP,
84         AV_SAMPLE_FMT_NONE
85     };
86     static const enum AVPixelFormat pix_fmts[] = {
87         AV_PIX_FMT_RGB0,
88         AV_PIX_FMT_NONE
89     };
90     int ret;
91 
92     if (s->response) {
93         AVFilterLink *videolink = ctx->outputs[1];
94 
95         formats = ff_make_format_list(pix_fmts);
96         if ((ret = ff_formats_ref(formats, &videolink->incfg.formats)) < 0)
97             return ret;
98     }
99 
100     ret = ff_set_common_all_channel_counts(ctx);
101     if (ret < 0)
102         return ret;
103 
104     sample_fmts[0] = s->sample_format;
105     ret = ff_set_common_formats_from_list(ctx, sample_fmts);
106     if (ret < 0)
107         return ret;
108 
109     return ff_set_common_all_samplerates(ctx);
110 }
111 
112 #define IIR_CH(name, type, min, max, need_clipping)                     \
113 static int iir_ch_## name(AVFilterContext *ctx, void *arg, int ch, int nb_jobs)  \
114 {                                                                       \
115     AudioIIRContext *s = ctx->priv;                                     \
116     const double ig = s->dry_gain;                                      \
117     const double og = s->wet_gain;                                      \
118     const double mix = s->mix;                                          \
119     ThreadData *td = arg;                                               \
120     AVFrame *in = td->in, *out = td->out;                               \
121     const type *src = (const type *)in->extended_data[ch];              \
122     double *oc = (double *)s->iir[ch].cache[0];                         \
123     double *ic = (double *)s->iir[ch].cache[1];                         \
124     const int nb_a = s->iir[ch].nb_ab[0];                               \
125     const int nb_b = s->iir[ch].nb_ab[1];                               \
126     const double *a = s->iir[ch].ab[0];                                 \
127     const double *b = s->iir[ch].ab[1];                                 \
128     const double g = s->iir[ch].g;                                      \
129     int *clippings = &s->iir[ch].clippings;                             \
130     type *dst = (type *)out->extended_data[ch];                         \
131     int n;                                                              \
132                                                                         \
133     for (n = 0; n < in->nb_samples; n++) {                              \
134         double sample = 0.;                                             \
135         int x;                                                          \
136                                                                         \
137         memmove(&ic[1], &ic[0], (nb_b - 1) * sizeof(*ic));              \
138         memmove(&oc[1], &oc[0], (nb_a - 1) * sizeof(*oc));              \
139         ic[0] = src[n] * ig;                                            \
140         for (x = 0; x < nb_b; x++)                                      \
141             sample += b[x] * ic[x];                                     \
142                                                                         \
143         for (x = 1; x < nb_a; x++)                                      \
144             sample -= a[x] * oc[x];                                     \
145                                                                         \
146         oc[0] = sample;                                                 \
147         sample *= og * g;                                               \
148         sample = sample * mix + ic[0] * (1. - mix);                     \
149         if (need_clipping && sample < min) {                            \
150             (*clippings)++;                                             \
151             dst[n] = min;                                               \
152         } else if (need_clipping && sample > max) {                     \
153             (*clippings)++;                                             \
154             dst[n] = max;                                               \
155         } else {                                                        \
156             dst[n] = sample;                                            \
157         }                                                               \
158     }                                                                   \
159                                                                         \
160     return 0;                                                           \
161 }
162 
163 IIR_CH(s16p, int16_t, INT16_MIN, INT16_MAX, 1)
164 IIR_CH(s32p, int32_t, INT32_MIN, INT32_MAX, 1)
165 IIR_CH(fltp, float,         -1.,        1., 0)
166 IIR_CH(dblp, double,        -1.,        1., 0)
167 
168 #define SERIAL_IIR_CH(name, type, min, max, need_clipping)              \
169 static int iir_ch_serial_## name(AVFilterContext *ctx, void *arg,       \
170                                  int ch, int nb_jobs)                   \
171 {                                                                       \
172     AudioIIRContext *s = ctx->priv;                                     \
173     const double ig = s->dry_gain;                                      \
174     const double og = s->wet_gain;                                      \
175     const double mix = s->mix;                                          \
176     const double imix = 1. - mix;                                       \
177     ThreadData *td = arg;                                               \
178     AVFrame *in = td->in, *out = td->out;                               \
179     const type *src = (const type *)in->extended_data[ch];              \
180     type *dst = (type *)out->extended_data[ch];                         \
181     IIRChannel *iir = &s->iir[ch];                                      \
182     const double g = iir->g;                                            \
183     int *clippings = &iir->clippings;                                   \
184     int nb_biquads = (FFMAX(iir->nb_ab[0], iir->nb_ab[1]) + 1) / 2;     \
185     int n, i;                                                           \
186                                                                         \
187     for (i = nb_biquads - 1; i >= 0; i--) {                             \
188         const double a1 = -iir->biquads[i].a[1];                        \
189         const double a2 = -iir->biquads[i].a[2];                        \
190         const double b0 = iir->biquads[i].b[0];                         \
191         const double b1 = iir->biquads[i].b[1];                         \
192         const double b2 = iir->biquads[i].b[2];                         \
193         double w1 = iir->biquads[i].w1;                                 \
194         double w2 = iir->biquads[i].w2;                                 \
195                                                                         \
196         for (n = 0; n < in->nb_samples; n++) {                          \
197             double i0 = ig * (i ? dst[n] : src[n]);                     \
198             double o0 = i0 * b0 + w1;                                   \
199                                                                         \
200             w1 = b1 * i0 + w2 + a1 * o0;                                \
201             w2 = b2 * i0 + a2 * o0;                                     \
202             o0 *= og * g;                                               \
203                                                                         \
204             o0 = o0 * mix + imix * i0;                                  \
205             if (need_clipping && o0 < min) {                            \
206                 (*clippings)++;                                         \
207                 dst[n] = min;                                           \
208             } else if (need_clipping && o0 > max) {                     \
209                 (*clippings)++;                                         \
210                 dst[n] = max;                                           \
211             } else {                                                    \
212                 dst[n] = o0;                                            \
213             }                                                           \
214         }                                                               \
215         iir->biquads[i].w1 = w1;                                        \
216         iir->biquads[i].w2 = w2;                                        \
217     }                                                                   \
218                                                                         \
219     return 0;                                                           \
220 }
221 
222 SERIAL_IIR_CH(s16p, int16_t, INT16_MIN, INT16_MAX, 1)
223 SERIAL_IIR_CH(s32p, int32_t, INT32_MIN, INT32_MAX, 1)
224 SERIAL_IIR_CH(fltp, float,         -1.,        1., 0)
225 SERIAL_IIR_CH(dblp, double,        -1.,        1., 0)
226 
227 #define PARALLEL_IIR_CH(name, type, min, max, need_clipping)            \
228 static int iir_ch_parallel_## name(AVFilterContext *ctx, void *arg,     \
229                                    int ch, int nb_jobs)                 \
230 {                                                                       \
231     AudioIIRContext *s = ctx->priv;                                     \
232     const double ig = s->dry_gain;                                      \
233     const double og = s->wet_gain;                                      \
234     const double mix = s->mix;                                          \
235     const double imix = 1. - mix;                                       \
236     ThreadData *td = arg;                                               \
237     AVFrame *in = td->in, *out = td->out;                               \
238     const type *src = (const type *)in->extended_data[ch];              \
239     type *dst = (type *)out->extended_data[ch];                         \
240     IIRChannel *iir = &s->iir[ch];                                      \
241     const double g = iir->g;                                            \
242     const double fir = iir->fir;                                        \
243     int *clippings = &iir->clippings;                                   \
244     int nb_biquads = (FFMAX(iir->nb_ab[0], iir->nb_ab[1]) + 1) / 2;     \
245     int n, i;                                                           \
246                                                                         \
247     for (i = 0; i < nb_biquads; i++) {                                  \
248         const double a1 = -iir->biquads[i].a[1];                        \
249         const double a2 = -iir->biquads[i].a[2];                        \
250         const double b1 = iir->biquads[i].b[1];                         \
251         const double b2 = iir->biquads[i].b[2];                         \
252         double w1 = iir->biquads[i].w1;                                 \
253         double w2 = iir->biquads[i].w2;                                 \
254                                                                         \
255         for (n = 0; n < in->nb_samples; n++) {                          \
256             double i0 = ig * src[n];                                    \
257             double o0 = w1;                                             \
258                                                                         \
259             w1 = b1 * i0 + w2 + a1 * o0;                                \
260             w2 = b2 * i0 + a2 * o0;                                     \
261             o0 *= og * g;                                               \
262             o0 += dst[n];                                               \
263                                                                         \
264             if (need_clipping && o0 < min) {                            \
265                 (*clippings)++;                                         \
266                 dst[n] = min;                                           \
267             } else if (need_clipping && o0 > max) {                     \
268                 (*clippings)++;                                         \
269                 dst[n] = max;                                           \
270             } else {                                                    \
271                 dst[n] = o0;                                            \
272             }                                                           \
273         }                                                               \
274         iir->biquads[i].w1 = w1;                                        \
275         iir->biquads[i].w2 = w2;                                        \
276     }                                                                   \
277                                                                         \
278     for (n = 0; n < in->nb_samples; n++) {                              \
279         dst[n] += fir * src[n];                                         \
280         dst[n] = dst[n] * mix + imix * src[n];                          \
281     }                                                                   \
282                                                                         \
283     return 0;                                                           \
284 }
285 
286 PARALLEL_IIR_CH(s16p, int16_t, INT16_MIN, INT16_MAX, 1)
287 PARALLEL_IIR_CH(s32p, int32_t, INT32_MIN, INT32_MAX, 1)
288 PARALLEL_IIR_CH(fltp, float,         -1.,        1., 0)
289 PARALLEL_IIR_CH(dblp, double,        -1.,        1., 0)
290 
291 #define LATTICE_IIR_CH(name, type, min, max, need_clipping)             \
292 static int iir_ch_lattice_## name(AVFilterContext *ctx, void *arg,      \
293                                   int ch, int nb_jobs)                  \
294 {                                                                       \
295     AudioIIRContext *s = ctx->priv;                                     \
296     const double ig = s->dry_gain;                                      \
297     const double og = s->wet_gain;                                      \
298     const double mix = s->mix;                                          \
299     ThreadData *td = arg;                                               \
300     AVFrame *in = td->in, *out = td->out;                               \
301     const type *src = (const type *)in->extended_data[ch];              \
302     double n0, n1, p0, *x = (double *)s->iir[ch].cache[0];              \
303     const int nb_stages = s->iir[ch].nb_ab[1];                          \
304     const double *v = s->iir[ch].ab[0];                                 \
305     const double *k = s->iir[ch].ab[1];                                 \
306     const double g = s->iir[ch].g;                                      \
307     int *clippings = &s->iir[ch].clippings;                             \
308     type *dst = (type *)out->extended_data[ch];                         \
309     int n;                                                              \
310                                                                         \
311     for (n = 0; n < in->nb_samples; n++) {                              \
312         const double in = src[n] * ig;                                  \
313         double out = 0.;                                                \
314                                                                         \
315         n1 = in;                                                        \
316         for (int i = nb_stages - 1; i >= 0; i--) {                      \
317             n0 = n1 - k[i] * x[i];                                      \
318             p0 = n0 * k[i] + x[i];                                      \
319             out += p0 * v[i+1];                                         \
320             x[i] = p0;                                                  \
321             n1 = n0;                                                    \
322         }                                                               \
323                                                                         \
324         out += n1 * v[0];                                               \
325         memmove(&x[1], &x[0], nb_stages * sizeof(*x));                  \
326         x[0] = n1;                                                      \
327         out *= og * g;                                                  \
328         out = out * mix + in * (1. - mix);                              \
329         if (need_clipping && out < min) {                               \
330             (*clippings)++;                                             \
331             dst[n] = min;                                               \
332         } else if (need_clipping && out > max) {                        \
333             (*clippings)++;                                             \
334             dst[n] = max;                                               \
335         } else {                                                        \
336             dst[n] = out;                                               \
337         }                                                               \
338     }                                                                   \
339                                                                         \
340     return 0;                                                           \
341 }
342 
343 LATTICE_IIR_CH(s16p, int16_t, INT16_MIN, INT16_MAX, 1)
344 LATTICE_IIR_CH(s32p, int32_t, INT32_MIN, INT32_MAX, 1)
345 LATTICE_IIR_CH(fltp, float,         -1.,        1., 0)
346 LATTICE_IIR_CH(dblp, double,        -1.,        1., 0)
347 
count_coefficients(char * item_str,int * nb_items)348 static void count_coefficients(char *item_str, int *nb_items)
349 {
350     char *p;
351 
352     if (!item_str)
353         return;
354 
355     *nb_items = 1;
356     for (p = item_str; *p && *p != '|'; p++) {
357         if (*p == ' ')
358             (*nb_items)++;
359     }
360 }
361 
read_gains(AVFilterContext * ctx,char * item_str,int nb_items)362 static int read_gains(AVFilterContext *ctx, char *item_str, int nb_items)
363 {
364     AudioIIRContext *s = ctx->priv;
365     char *p, *arg, *old_str, *prev_arg = NULL, *saveptr = NULL;
366     int i;
367 
368     p = old_str = av_strdup(item_str);
369     if (!p)
370         return AVERROR(ENOMEM);
371     for (i = 0; i < nb_items; i++) {
372         if (!(arg = av_strtok(p, "|", &saveptr)))
373             arg = prev_arg;
374 
375         if (!arg) {
376             av_freep(&old_str);
377             return AVERROR(EINVAL);
378         }
379 
380         p = NULL;
381         if (av_sscanf(arg, "%lf", &s->iir[i].g) != 1) {
382             av_log(ctx, AV_LOG_ERROR, "Invalid gains supplied: %s\n", arg);
383             av_freep(&old_str);
384             return AVERROR(EINVAL);
385         }
386 
387         prev_arg = arg;
388     }
389 
390     av_freep(&old_str);
391 
392     return 0;
393 }
394 
read_tf_coefficients(AVFilterContext * ctx,char * item_str,int nb_items,double * dst)395 static int read_tf_coefficients(AVFilterContext *ctx, char *item_str, int nb_items, double *dst)
396 {
397     char *p, *arg, *old_str, *saveptr = NULL;
398     int i;
399 
400     p = old_str = av_strdup(item_str);
401     if (!p)
402         return AVERROR(ENOMEM);
403     for (i = 0; i < nb_items; i++) {
404         if (!(arg = av_strtok(p, " ", &saveptr)))
405             break;
406 
407         p = NULL;
408         if (av_sscanf(arg, "%lf", &dst[i]) != 1) {
409             av_log(ctx, AV_LOG_ERROR, "Invalid coefficients supplied: %s\n", arg);
410             av_freep(&old_str);
411             return AVERROR(EINVAL);
412         }
413     }
414 
415     av_freep(&old_str);
416 
417     return 0;
418 }
419 
read_zp_coefficients(AVFilterContext * ctx,char * item_str,int nb_items,double * dst,const char * format)420 static int read_zp_coefficients(AVFilterContext *ctx, char *item_str, int nb_items, double *dst, const char *format)
421 {
422     char *p, *arg, *old_str, *saveptr = NULL;
423     int i;
424 
425     p = old_str = av_strdup(item_str);
426     if (!p)
427         return AVERROR(ENOMEM);
428     for (i = 0; i < nb_items; i++) {
429         if (!(arg = av_strtok(p, " ", &saveptr)))
430             break;
431 
432         p = NULL;
433         if (av_sscanf(arg, format, &dst[i*2], &dst[i*2+1]) != 2) {
434             av_log(ctx, AV_LOG_ERROR, "Invalid coefficients supplied: %s\n", arg);
435             av_freep(&old_str);
436             return AVERROR(EINVAL);
437         }
438     }
439 
440     av_freep(&old_str);
441 
442     return 0;
443 }
444 
445 static const char *const format[] = { "%lf", "%lf %lfi", "%lf %lfr", "%lf %lfd", "%lf %lfi" };
446 
read_channels(AVFilterContext * ctx,int channels,uint8_t * item_str,int ab)447 static int read_channels(AVFilterContext *ctx, int channels, uint8_t *item_str, int ab)
448 {
449     AudioIIRContext *s = ctx->priv;
450     char *p, *arg, *old_str, *prev_arg = NULL, *saveptr = NULL;
451     int i, ret;
452 
453     p = old_str = av_strdup(item_str);
454     if (!p)
455         return AVERROR(ENOMEM);
456     for (i = 0; i < channels; i++) {
457         IIRChannel *iir = &s->iir[i];
458 
459         if (!(arg = av_strtok(p, "|", &saveptr)))
460             arg = prev_arg;
461 
462         if (!arg) {
463             av_freep(&old_str);
464             return AVERROR(EINVAL);
465         }
466 
467         count_coefficients(arg, &iir->nb_ab[ab]);
468 
469         p = NULL;
470         iir->cache[ab] = av_calloc(iir->nb_ab[ab] + 1, sizeof(double));
471         iir->ab[ab] = av_calloc(iir->nb_ab[ab] * (!!s->format + 1), sizeof(double));
472         if (!iir->ab[ab] || !iir->cache[ab]) {
473             av_freep(&old_str);
474             return AVERROR(ENOMEM);
475         }
476 
477         if (s->format > 0) {
478             ret = read_zp_coefficients(ctx, arg, iir->nb_ab[ab], iir->ab[ab], format[s->format]);
479         } else {
480             ret = read_tf_coefficients(ctx, arg, iir->nb_ab[ab], iir->ab[ab]);
481         }
482         if (ret < 0) {
483             av_freep(&old_str);
484             return ret;
485         }
486         prev_arg = arg;
487     }
488 
489     av_freep(&old_str);
490 
491     return 0;
492 }
493 
cmul(double re,double im,double re2,double im2,double * RE,double * IM)494 static void cmul(double re, double im, double re2, double im2, double *RE, double *IM)
495 {
496     *RE = re * re2 - im * im2;
497     *IM = re * im2 + re2 * im;
498 }
499 
expand(AVFilterContext * ctx,double * pz,int n,double * coefs)500 static int expand(AVFilterContext *ctx, double *pz, int n, double *coefs)
501 {
502     coefs[2 * n] = 1.0;
503 
504     for (int i = 1; i <= n; i++) {
505         for (int j = n - i; j < n; j++) {
506             double re, im;
507 
508             cmul(coefs[2 * (j + 1)], coefs[2 * (j + 1) + 1],
509                  pz[2 * (i - 1)], pz[2 * (i - 1) + 1], &re, &im);
510 
511             coefs[2 * j]     -= re;
512             coefs[2 * j + 1] -= im;
513         }
514     }
515 
516     for (int i = 0; i < n + 1; i++) {
517         if (fabs(coefs[2 * i + 1]) > FLT_EPSILON) {
518             av_log(ctx, AV_LOG_ERROR, "coefs: %f of z^%d is not real; poles/zeros are not complex conjugates.\n",
519                    coefs[2 * i + 1], i);
520             return AVERROR(EINVAL);
521         }
522     }
523 
524     return 0;
525 }
526 
normalize_coeffs(AVFilterContext * ctx,int ch)527 static void normalize_coeffs(AVFilterContext *ctx, int ch)
528 {
529     AudioIIRContext *s = ctx->priv;
530     IIRChannel *iir = &s->iir[ch];
531     double sum_den = 0.;
532 
533     if (!s->normalize)
534         return;
535 
536     for (int i = 0; i < iir->nb_ab[1]; i++) {
537         sum_den += iir->ab[1][i];
538     }
539 
540     if (sum_den > 1e-6) {
541         double factor, sum_num = 0.;
542 
543         for (int i = 0; i < iir->nb_ab[0]; i++) {
544             sum_num += iir->ab[0][i];
545         }
546 
547         factor = sum_num / sum_den;
548 
549         for (int i = 0; i < iir->nb_ab[1]; i++) {
550             iir->ab[1][i] *= factor;
551         }
552     }
553 }
554 
convert_zp2tf(AVFilterContext * ctx,int channels)555 static int convert_zp2tf(AVFilterContext *ctx, int channels)
556 {
557     AudioIIRContext *s = ctx->priv;
558     int ch, i, j, ret = 0;
559 
560     for (ch = 0; ch < channels; ch++) {
561         IIRChannel *iir = &s->iir[ch];
562         double *topc, *botc;
563 
564         topc = av_calloc((iir->nb_ab[1] + 1) * 2, sizeof(*topc));
565         botc = av_calloc((iir->nb_ab[0] + 1) * 2, sizeof(*botc));
566         if (!topc || !botc) {
567             ret = AVERROR(ENOMEM);
568             goto fail;
569         }
570 
571         ret = expand(ctx, iir->ab[0], iir->nb_ab[0], botc);
572         if (ret < 0) {
573             goto fail;
574         }
575 
576         ret = expand(ctx, iir->ab[1], iir->nb_ab[1], topc);
577         if (ret < 0) {
578             goto fail;
579         }
580 
581         for (j = 0, i = iir->nb_ab[1]; i >= 0; j++, i--) {
582             iir->ab[1][j] = topc[2 * i];
583         }
584         iir->nb_ab[1]++;
585 
586         for (j = 0, i = iir->nb_ab[0]; i >= 0; j++, i--) {
587             iir->ab[0][j] = botc[2 * i];
588         }
589         iir->nb_ab[0]++;
590 
591         normalize_coeffs(ctx, ch);
592 
593 fail:
594         av_free(topc);
595         av_free(botc);
596         if (ret < 0)
597             break;
598     }
599 
600     return ret;
601 }
602 
decompose_zp2biquads(AVFilterContext * ctx,int channels)603 static int decompose_zp2biquads(AVFilterContext *ctx, int channels)
604 {
605     AudioIIRContext *s = ctx->priv;
606     int ch, ret;
607 
608     for (ch = 0; ch < channels; ch++) {
609         IIRChannel *iir = &s->iir[ch];
610         int nb_biquads = (FFMAX(iir->nb_ab[0], iir->nb_ab[1]) + 1) / 2;
611         int current_biquad = 0;
612 
613         iir->biquads = av_calloc(nb_biquads, sizeof(BiquadContext));
614         if (!iir->biquads)
615             return AVERROR(ENOMEM);
616 
617         while (nb_biquads--) {
618             Pair outmost_pole = { -1, -1 };
619             Pair nearest_zero = { -1, -1 };
620             double zeros[4] = { 0 };
621             double poles[4] = { 0 };
622             double b[6] = { 0 };
623             double a[6] = { 0 };
624             double min_distance = DBL_MAX;
625             double max_mag = 0;
626             double factor;
627             int i;
628 
629             for (i = 0; i < iir->nb_ab[0]; i++) {
630                 double mag;
631 
632                 if (isnan(iir->ab[0][2 * i]) || isnan(iir->ab[0][2 * i + 1]))
633                     continue;
634                 mag = hypot(iir->ab[0][2 * i], iir->ab[0][2 * i + 1]);
635 
636                 if (mag > max_mag) {
637                     max_mag = mag;
638                     outmost_pole.a = i;
639                 }
640             }
641 
642             for (i = 0; i < iir->nb_ab[0]; i++) {
643                 if (isnan(iir->ab[0][2 * i]) || isnan(iir->ab[0][2 * i + 1]))
644                     continue;
645 
646                 if (iir->ab[0][2 * i    ] ==  iir->ab[0][2 * outmost_pole.a    ] &&
647                     iir->ab[0][2 * i + 1] == -iir->ab[0][2 * outmost_pole.a + 1]) {
648                     outmost_pole.b = i;
649                     break;
650                 }
651             }
652 
653             av_log(ctx, AV_LOG_VERBOSE, "outmost_pole is %d.%d\n", outmost_pole.a, outmost_pole.b);
654 
655             if (outmost_pole.a < 0 || outmost_pole.b < 0)
656                 return AVERROR(EINVAL);
657 
658             for (i = 0; i < iir->nb_ab[1]; i++) {
659                 double distance;
660 
661                 if (isnan(iir->ab[1][2 * i]) || isnan(iir->ab[1][2 * i + 1]))
662                     continue;
663                 distance = hypot(iir->ab[0][2 * outmost_pole.a    ] - iir->ab[1][2 * i    ],
664                                  iir->ab[0][2 * outmost_pole.a + 1] - iir->ab[1][2 * i + 1]);
665 
666                 if (distance < min_distance) {
667                     min_distance = distance;
668                     nearest_zero.a = i;
669                 }
670             }
671 
672             for (i = 0; i < iir->nb_ab[1]; i++) {
673                 if (isnan(iir->ab[1][2 * i]) || isnan(iir->ab[1][2 * i + 1]))
674                     continue;
675 
676                 if (iir->ab[1][2 * i    ] ==  iir->ab[1][2 * nearest_zero.a    ] &&
677                     iir->ab[1][2 * i + 1] == -iir->ab[1][2 * nearest_zero.a + 1]) {
678                     nearest_zero.b = i;
679                     break;
680                 }
681             }
682 
683             av_log(ctx, AV_LOG_VERBOSE, "nearest_zero is %d.%d\n", nearest_zero.a, nearest_zero.b);
684 
685             if (nearest_zero.a < 0 || nearest_zero.b < 0)
686                 return AVERROR(EINVAL);
687 
688             poles[0] = iir->ab[0][2 * outmost_pole.a    ];
689             poles[1] = iir->ab[0][2 * outmost_pole.a + 1];
690 
691             zeros[0] = iir->ab[1][2 * nearest_zero.a    ];
692             zeros[1] = iir->ab[1][2 * nearest_zero.a + 1];
693 
694             if (nearest_zero.a == nearest_zero.b && outmost_pole.a == outmost_pole.b) {
695                 zeros[2] = 0;
696                 zeros[3] = 0;
697 
698                 poles[2] = 0;
699                 poles[3] = 0;
700             } else {
701                 poles[2] = iir->ab[0][2 * outmost_pole.b    ];
702                 poles[3] = iir->ab[0][2 * outmost_pole.b + 1];
703 
704                 zeros[2] = iir->ab[1][2 * nearest_zero.b    ];
705                 zeros[3] = iir->ab[1][2 * nearest_zero.b + 1];
706             }
707 
708             ret = expand(ctx, zeros, 2, b);
709             if (ret < 0)
710                 return ret;
711 
712             ret = expand(ctx, poles, 2, a);
713             if (ret < 0)
714                 return ret;
715 
716             iir->ab[0][2 * outmost_pole.a] = iir->ab[0][2 * outmost_pole.a + 1] = NAN;
717             iir->ab[0][2 * outmost_pole.b] = iir->ab[0][2 * outmost_pole.b + 1] = NAN;
718             iir->ab[1][2 * nearest_zero.a] = iir->ab[1][2 * nearest_zero.a + 1] = NAN;
719             iir->ab[1][2 * nearest_zero.b] = iir->ab[1][2 * nearest_zero.b + 1] = NAN;
720 
721             iir->biquads[current_biquad].a[0] = 1.;
722             iir->biquads[current_biquad].a[1] = a[2] / a[4];
723             iir->biquads[current_biquad].a[2] = a[0] / a[4];
724             iir->biquads[current_biquad].b[0] = b[4] / a[4];
725             iir->biquads[current_biquad].b[1] = b[2] / a[4];
726             iir->biquads[current_biquad].b[2] = b[0] / a[4];
727 
728             if (s->normalize &&
729                 fabs(iir->biquads[current_biquad].b[0] +
730                      iir->biquads[current_biquad].b[1] +
731                      iir->biquads[current_biquad].b[2]) > 1e-6) {
732                 factor = (iir->biquads[current_biquad].a[0] +
733                           iir->biquads[current_biquad].a[1] +
734                           iir->biquads[current_biquad].a[2]) /
735                          (iir->biquads[current_biquad].b[0] +
736                           iir->biquads[current_biquad].b[1] +
737                           iir->biquads[current_biquad].b[2]);
738 
739                 av_log(ctx, AV_LOG_VERBOSE, "factor=%f\n", factor);
740 
741                 iir->biquads[current_biquad].b[0] *= factor;
742                 iir->biquads[current_biquad].b[1] *= factor;
743                 iir->biquads[current_biquad].b[2] *= factor;
744             }
745 
746             iir->biquads[current_biquad].b[0] *= (current_biquad ? 1.0 : iir->g);
747             iir->biquads[current_biquad].b[1] *= (current_biquad ? 1.0 : iir->g);
748             iir->biquads[current_biquad].b[2] *= (current_biquad ? 1.0 : iir->g);
749 
750             av_log(ctx, AV_LOG_VERBOSE, "a=%f %f %f:b=%f %f %f\n",
751                    iir->biquads[current_biquad].a[0],
752                    iir->biquads[current_biquad].a[1],
753                    iir->biquads[current_biquad].a[2],
754                    iir->biquads[current_biquad].b[0],
755                    iir->biquads[current_biquad].b[1],
756                    iir->biquads[current_biquad].b[2]);
757 
758             current_biquad++;
759         }
760     }
761 
762     return 0;
763 }
764 
biquad_process(double * x,double * y,int length,double b0,double b1,double b2,double a1,double a2)765 static void biquad_process(double *x, double *y, int length,
766                            double b0, double b1, double b2,
767                            double a1, double a2)
768 {
769     double w1 = 0., w2 = 0.;
770 
771     a1 = -a1;
772     a2 = -a2;
773 
774     for (int n = 0; n < length; n++) {
775         double out, in = x[n];
776 
777         y[n] = out = in * b0 + w1;
778         w1 = b1 * in + w2 + a1 * out;
779         w2 = b2 * in + a2 * out;
780     }
781 }
782 
solve(double * matrix,double * vector,int n,double * y,double * x,double * lu)783 static void solve(double *matrix, double *vector, int n, double *y, double *x, double *lu)
784 {
785     double sum = 0.;
786 
787     for (int i = 0; i < n; i++) {
788         for (int j = i; j < n; j++) {
789             sum = 0.;
790             for (int k = 0; k < i; k++)
791                 sum += lu[i * n + k] * lu[k * n + j];
792             lu[i * n + j] = matrix[j * n + i] - sum;
793         }
794         for (int j = i + 1; j < n; j++) {
795             sum = 0.;
796             for (int k = 0; k < i; k++)
797                 sum += lu[j * n + k] * lu[k * n + i];
798             lu[j * n + i] = (1. / lu[i * n + i]) * (matrix[i * n + j] - sum);
799         }
800     }
801 
802     for (int i = 0; i < n; i++) {
803         sum = 0.;
804         for (int k = 0; k < i; k++)
805             sum += lu[i * n + k] * y[k];
806         y[i] = vector[i] - sum;
807     }
808 
809     for (int i = n - 1; i >= 0; i--) {
810         sum = 0.;
811         for (int k = i + 1; k < n; k++)
812             sum += lu[i * n + k] * x[k];
813         x[i] = (1 / lu[i * n + i]) * (y[i] - sum);
814     }
815 }
816 
convert_serial2parallel(AVFilterContext * ctx,int channels)817 static int convert_serial2parallel(AVFilterContext *ctx, int channels)
818 {
819     AudioIIRContext *s = ctx->priv;
820     int ret = 0;
821 
822     for (int ch = 0; ch < channels; ch++) {
823         IIRChannel *iir = &s->iir[ch];
824         int nb_biquads = (FFMAX(iir->nb_ab[0], iir->nb_ab[1]) + 1) / 2;
825         int length = nb_biquads * 2 + 1;
826         double *impulse = av_calloc(length, sizeof(*impulse));
827         double *y = av_calloc(length, sizeof(*y));
828         double *resp = av_calloc(length, sizeof(*resp));
829         double *M = av_calloc((length - 1) * 2 * nb_biquads, sizeof(*M));
830         double *W = av_calloc((length - 1) * 2 * nb_biquads, sizeof(*W));
831 
832         if (!impulse || !y || !resp || !M) {
833             av_free(impulse);
834             av_free(y);
835             av_free(resp);
836             av_free(M);
837             av_free(W);
838             return AVERROR(ENOMEM);
839         }
840 
841         impulse[0] = 1.;
842 
843         for (int n = 0; n < nb_biquads; n++) {
844             BiquadContext *biquad = &iir->biquads[n];
845 
846             biquad_process(n ? y : impulse, y, length,
847                            biquad->b[0], biquad->b[1], biquad->b[2],
848                            biquad->a[1], biquad->a[2]);
849         }
850 
851         for (int n = 0; n < nb_biquads; n++) {
852             BiquadContext *biquad = &iir->biquads[n];
853 
854             biquad_process(impulse, resp, length - 1,
855                            1., 0., 0., biquad->a[1], biquad->a[2]);
856 
857             memcpy(M + n * 2 * (length - 1), resp, sizeof(*resp) * (length - 1));
858             memcpy(M + n * 2 * (length - 1) + length, resp, sizeof(*resp) * (length - 2));
859             memset(resp, 0, length * sizeof(*resp));
860         }
861 
862         solve(M, &y[1], length - 1, &impulse[1], resp, W);
863 
864         iir->fir = y[0];
865 
866         for (int n = 0; n < nb_biquads; n++) {
867             BiquadContext *biquad = &iir->biquads[n];
868 
869             biquad->b[0] = 0.;
870             biquad->b[1] = resp[n * 2 + 0];
871             biquad->b[2] = resp[n * 2 + 1];
872         }
873 
874         av_free(impulse);
875         av_free(y);
876         av_free(resp);
877         av_free(M);
878         av_free(W);
879 
880         if (ret < 0)
881             return ret;
882     }
883 
884     return 0;
885 }
886 
convert_pr2zp(AVFilterContext * ctx,int channels)887 static void convert_pr2zp(AVFilterContext *ctx, int channels)
888 {
889     AudioIIRContext *s = ctx->priv;
890     int ch;
891 
892     for (ch = 0; ch < channels; ch++) {
893         IIRChannel *iir = &s->iir[ch];
894         int n;
895 
896         for (n = 0; n < iir->nb_ab[0]; n++) {
897             double r = iir->ab[0][2*n];
898             double angle = iir->ab[0][2*n+1];
899 
900             iir->ab[0][2*n]   = r * cos(angle);
901             iir->ab[0][2*n+1] = r * sin(angle);
902         }
903 
904         for (n = 0; n < iir->nb_ab[1]; n++) {
905             double r = iir->ab[1][2*n];
906             double angle = iir->ab[1][2*n+1];
907 
908             iir->ab[1][2*n]   = r * cos(angle);
909             iir->ab[1][2*n+1] = r * sin(angle);
910         }
911     }
912 }
913 
convert_sp2zp(AVFilterContext * ctx,int channels)914 static void convert_sp2zp(AVFilterContext *ctx, int channels)
915 {
916     AudioIIRContext *s = ctx->priv;
917     int ch;
918 
919     for (ch = 0; ch < channels; ch++) {
920         IIRChannel *iir = &s->iir[ch];
921         int n;
922 
923         for (n = 0; n < iir->nb_ab[0]; n++) {
924             double sr = iir->ab[0][2*n];
925             double si = iir->ab[0][2*n+1];
926 
927             iir->ab[0][2*n]   = exp(sr) * cos(si);
928             iir->ab[0][2*n+1] = exp(sr) * sin(si);
929         }
930 
931         for (n = 0; n < iir->nb_ab[1]; n++) {
932             double sr = iir->ab[1][2*n];
933             double si = iir->ab[1][2*n+1];
934 
935             iir->ab[1][2*n]   = exp(sr) * cos(si);
936             iir->ab[1][2*n+1] = exp(sr) * sin(si);
937         }
938     }
939 }
940 
fact(double i)941 static double fact(double i)
942 {
943     if (i <= 0.)
944         return 1.;
945     return i * fact(i - 1.);
946 }
947 
coef_sf2zf(double * a,int N,int n)948 static double coef_sf2zf(double *a, int N, int n)
949 {
950     double z = 0.;
951 
952     for (int i = 0; i <= N; i++) {
953         double acc = 0.;
954 
955         for (int k = FFMAX(n - N + i, 0); k <= FFMIN(i, n); k++) {
956             acc += ((fact(i) * fact(N - i)) /
957                     (fact(k) * fact(i - k) * fact(n - k) * fact(N - i - n + k))) *
958                    ((k & 1) ? -1. : 1.);
959         }
960 
961         z += a[i] * pow(2., i) * acc;
962     }
963 
964     return z;
965 }
966 
convert_sf2tf(AVFilterContext * ctx,int channels)967 static void convert_sf2tf(AVFilterContext *ctx, int channels)
968 {
969     AudioIIRContext *s = ctx->priv;
970     int ch;
971 
972     for (ch = 0; ch < channels; ch++) {
973         IIRChannel *iir = &s->iir[ch];
974         double *temp0 = av_calloc(iir->nb_ab[0], sizeof(*temp0));
975         double *temp1 = av_calloc(iir->nb_ab[1], sizeof(*temp1));
976 
977         if (!temp0 || !temp1)
978             goto next;
979 
980         memcpy(temp0, iir->ab[0], iir->nb_ab[0] * sizeof(*temp0));
981         memcpy(temp1, iir->ab[1], iir->nb_ab[1] * sizeof(*temp1));
982 
983         for (int n = 0; n < iir->nb_ab[0]; n++)
984             iir->ab[0][n] = coef_sf2zf(temp0, iir->nb_ab[0] - 1, n);
985 
986         for (int n = 0; n < iir->nb_ab[1]; n++)
987             iir->ab[1][n] = coef_sf2zf(temp1, iir->nb_ab[1] - 1, n);
988 
989 next:
990         av_free(temp0);
991         av_free(temp1);
992     }
993 }
994 
convert_pd2zp(AVFilterContext * ctx,int channels)995 static void convert_pd2zp(AVFilterContext *ctx, int channels)
996 {
997     AudioIIRContext *s = ctx->priv;
998     int ch;
999 
1000     for (ch = 0; ch < channels; ch++) {
1001         IIRChannel *iir = &s->iir[ch];
1002         int n;
1003 
1004         for (n = 0; n < iir->nb_ab[0]; n++) {
1005             double r = iir->ab[0][2*n];
1006             double angle = M_PI*iir->ab[0][2*n+1]/180.;
1007 
1008             iir->ab[0][2*n]   = r * cos(angle);
1009             iir->ab[0][2*n+1] = r * sin(angle);
1010         }
1011 
1012         for (n = 0; n < iir->nb_ab[1]; n++) {
1013             double r = iir->ab[1][2*n];
1014             double angle = M_PI*iir->ab[1][2*n+1]/180.;
1015 
1016             iir->ab[1][2*n]   = r * cos(angle);
1017             iir->ab[1][2*n+1] = r * sin(angle);
1018         }
1019     }
1020 }
1021 
check_stability(AVFilterContext * ctx,int channels)1022 static void check_stability(AVFilterContext *ctx, int channels)
1023 {
1024     AudioIIRContext *s = ctx->priv;
1025     int ch;
1026 
1027     for (ch = 0; ch < channels; ch++) {
1028         IIRChannel *iir = &s->iir[ch];
1029 
1030         for (int n = 0; n < iir->nb_ab[0]; n++) {
1031             double pr = hypot(iir->ab[0][2*n], iir->ab[0][2*n+1]);
1032 
1033             if (pr >= 1.) {
1034                 av_log(ctx, AV_LOG_WARNING, "pole %d at channel %d is unstable\n", n, ch);
1035                 break;
1036             }
1037         }
1038     }
1039 }
1040 
drawtext(AVFrame * pic,int x,int y,const char * txt,uint32_t color)1041 static void drawtext(AVFrame *pic, int x, int y, const char *txt, uint32_t color)
1042 {
1043     const uint8_t *font;
1044     int font_height;
1045     int i;
1046 
1047     font = avpriv_cga_font, font_height = 8;
1048 
1049     for (i = 0; txt[i]; i++) {
1050         int char_y, mask;
1051 
1052         uint8_t *p = pic->data[0] + y * pic->linesize[0] + (x + i * 8) * 4;
1053         for (char_y = 0; char_y < font_height; char_y++) {
1054             for (mask = 0x80; mask; mask >>= 1) {
1055                 if (font[txt[i] * font_height + char_y] & mask)
1056                     AV_WL32(p, color);
1057                 p += 4;
1058             }
1059             p += pic->linesize[0] - 8 * 4;
1060         }
1061     }
1062 }
1063 
draw_line(AVFrame * out,int x0,int y0,int x1,int y1,uint32_t color)1064 static void draw_line(AVFrame *out, int x0, int y0, int x1, int y1, uint32_t color)
1065 {
1066     int dx = FFABS(x1-x0);
1067     int dy = FFABS(y1-y0), sy = y0 < y1 ? 1 : -1;
1068     int err = (dx>dy ? dx : -dy) / 2, e2;
1069 
1070     for (;;) {
1071         AV_WL32(out->data[0] + y0 * out->linesize[0] + x0 * 4, color);
1072 
1073         if (x0 == x1 && y0 == y1)
1074             break;
1075 
1076         e2 = err;
1077 
1078         if (e2 >-dx) {
1079             err -= dy;
1080             x0--;
1081         }
1082 
1083         if (e2 < dy) {
1084             err += dx;
1085             y0 += sy;
1086         }
1087     }
1088 }
1089 
distance(double x0,double x1,double y0,double y1)1090 static double distance(double x0, double x1, double y0, double y1)
1091 {
1092     return hypot(x0 - x1, y0 - y1);
1093 }
1094 
get_response(int channel,int format,double w,const double * b,const double * a,int nb_b,int nb_a,double * magnitude,double * phase)1095 static void get_response(int channel, int format, double w,
1096                          const double *b, const double *a,
1097                          int nb_b, int nb_a, double *magnitude, double *phase)
1098 {
1099     double realz, realp;
1100     double imagz, imagp;
1101     double real, imag;
1102     double div;
1103 
1104     if (format == 0) {
1105         realz = 0., realp = 0.;
1106         imagz = 0., imagp = 0.;
1107         for (int x = 0; x < nb_a; x++) {
1108             realz += cos(-x * w) * a[x];
1109             imagz += sin(-x * w) * a[x];
1110         }
1111 
1112         for (int x = 0; x < nb_b; x++) {
1113             realp += cos(-x * w) * b[x];
1114             imagp += sin(-x * w) * b[x];
1115         }
1116 
1117         div = realp * realp + imagp * imagp;
1118         real = (realz * realp + imagz * imagp) / div;
1119         imag = (imagz * realp - imagp * realz) / div;
1120 
1121         *magnitude = hypot(real, imag);
1122         *phase = atan2(imag, real);
1123     } else {
1124         double p = 1., z = 1.;
1125         double acc = 0.;
1126 
1127         for (int x = 0; x < nb_a; x++) {
1128             z *= distance(cos(w), a[2 * x], sin(w), a[2 * x + 1]);
1129             acc += atan2(sin(w) - a[2 * x + 1], cos(w) - a[2 * x]);
1130         }
1131 
1132         for (int x = 0; x < nb_b; x++) {
1133             p *= distance(cos(w), b[2 * x], sin(w), b[2 * x + 1]);
1134             acc -= atan2(sin(w) - b[2 * x + 1], cos(w) - b[2 * x]);
1135         }
1136 
1137         *magnitude = z / p;
1138         *phase = acc;
1139     }
1140 }
1141 
draw_response(AVFilterContext * ctx,AVFrame * out,int sample_rate)1142 static void draw_response(AVFilterContext *ctx, AVFrame *out, int sample_rate)
1143 {
1144     AudioIIRContext *s = ctx->priv;
1145     double *mag, *phase, *temp, *delay, min = DBL_MAX, max = -DBL_MAX;
1146     double min_delay = DBL_MAX, max_delay = -DBL_MAX, min_phase, max_phase;
1147     int prev_ymag = -1, prev_yphase = -1, prev_ydelay = -1;
1148     char text[32];
1149     int ch, i;
1150 
1151     memset(out->data[0], 0, s->h * out->linesize[0]);
1152 
1153     phase = av_malloc_array(s->w, sizeof(*phase));
1154     temp = av_malloc_array(s->w, sizeof(*temp));
1155     mag = av_malloc_array(s->w, sizeof(*mag));
1156     delay = av_malloc_array(s->w, sizeof(*delay));
1157     if (!mag || !phase || !delay || !temp)
1158         goto end;
1159 
1160     ch = av_clip(s->ir_channel, 0, s->channels - 1);
1161     for (i = 0; i < s->w; i++) {
1162         const double *b = s->iir[ch].ab[0];
1163         const double *a = s->iir[ch].ab[1];
1164         const int nb_b = s->iir[ch].nb_ab[0];
1165         const int nb_a = s->iir[ch].nb_ab[1];
1166         double w = i * M_PI / (s->w - 1);
1167         double m, p;
1168 
1169         get_response(ch, s->format, w, b, a, nb_b, nb_a, &m, &p);
1170 
1171         mag[i] = s->iir[ch].g * m;
1172         phase[i] = p;
1173         min = fmin(min, mag[i]);
1174         max = fmax(max, mag[i]);
1175     }
1176 
1177     temp[0] = 0.;
1178     for (i = 0; i < s->w - 1; i++) {
1179         double d = phase[i] - phase[i + 1];
1180         temp[i + 1] = ceil(fabs(d) / (2. * M_PI)) * 2. * M_PI * ((d > M_PI) - (d < -M_PI));
1181     }
1182 
1183     min_phase = phase[0];
1184     max_phase = phase[0];
1185     for (i = 1; i < s->w; i++) {
1186         temp[i] += temp[i - 1];
1187         phase[i] += temp[i];
1188         min_phase = fmin(min_phase, phase[i]);
1189         max_phase = fmax(max_phase, phase[i]);
1190     }
1191 
1192     for (i = 0; i < s->w - 1; i++) {
1193         double div = s->w / (double)sample_rate;
1194 
1195         delay[i + 1] = -(phase[i] - phase[i + 1]) / div;
1196         min_delay = fmin(min_delay, delay[i + 1]);
1197         max_delay = fmax(max_delay, delay[i + 1]);
1198     }
1199     delay[0] = delay[1];
1200 
1201     for (i = 0; i < s->w; i++) {
1202         int ymag = mag[i] / max * (s->h - 1);
1203         int ydelay = (delay[i] - min_delay) / (max_delay - min_delay) * (s->h - 1);
1204         int yphase = (phase[i] - min_phase) / (max_phase - min_phase) * (s->h - 1);
1205 
1206         ymag = s->h - 1 - av_clip(ymag, 0, s->h - 1);
1207         yphase = s->h - 1 - av_clip(yphase, 0, s->h - 1);
1208         ydelay = s->h - 1 - av_clip(ydelay, 0, s->h - 1);
1209 
1210         if (prev_ymag < 0)
1211             prev_ymag = ymag;
1212         if (prev_yphase < 0)
1213             prev_yphase = yphase;
1214         if (prev_ydelay < 0)
1215             prev_ydelay = ydelay;
1216 
1217         draw_line(out, i,   ymag, FFMAX(i - 1, 0),   prev_ymag, 0xFFFF00FF);
1218         draw_line(out, i, yphase, FFMAX(i - 1, 0), prev_yphase, 0xFF00FF00);
1219         draw_line(out, i, ydelay, FFMAX(i - 1, 0), prev_ydelay, 0xFF00FFFF);
1220 
1221         prev_ymag   = ymag;
1222         prev_yphase = yphase;
1223         prev_ydelay = ydelay;
1224     }
1225 
1226     if (s->w > 400 && s->h > 100) {
1227         drawtext(out, 2, 2, "Max Magnitude:", 0xDDDDDDDD);
1228         snprintf(text, sizeof(text), "%.2f", max);
1229         drawtext(out, 15 * 8 + 2, 2, text, 0xDDDDDDDD);
1230 
1231         drawtext(out, 2, 12, "Min Magnitude:", 0xDDDDDDDD);
1232         snprintf(text, sizeof(text), "%.2f", min);
1233         drawtext(out, 15 * 8 + 2, 12, text, 0xDDDDDDDD);
1234 
1235         drawtext(out, 2, 22, "Max Phase:", 0xDDDDDDDD);
1236         snprintf(text, sizeof(text), "%.2f", max_phase);
1237         drawtext(out, 15 * 8 + 2, 22, text, 0xDDDDDDDD);
1238 
1239         drawtext(out, 2, 32, "Min Phase:", 0xDDDDDDDD);
1240         snprintf(text, sizeof(text), "%.2f", min_phase);
1241         drawtext(out, 15 * 8 + 2, 32, text, 0xDDDDDDDD);
1242 
1243         drawtext(out, 2, 42, "Max Delay:", 0xDDDDDDDD);
1244         snprintf(text, sizeof(text), "%.2f", max_delay);
1245         drawtext(out, 11 * 8 + 2, 42, text, 0xDDDDDDDD);
1246 
1247         drawtext(out, 2, 52, "Min Delay:", 0xDDDDDDDD);
1248         snprintf(text, sizeof(text), "%.2f", min_delay);
1249         drawtext(out, 11 * 8 + 2, 52, text, 0xDDDDDDDD);
1250     }
1251 
1252 end:
1253     av_free(delay);
1254     av_free(temp);
1255     av_free(phase);
1256     av_free(mag);
1257 }
1258 
config_output(AVFilterLink * outlink)1259 static int config_output(AVFilterLink *outlink)
1260 {
1261     AVFilterContext *ctx = outlink->src;
1262     AudioIIRContext *s = ctx->priv;
1263     AVFilterLink *inlink = ctx->inputs[0];
1264     int ch, ret, i;
1265 
1266     s->channels = inlink->ch_layout.nb_channels;
1267     s->iir = av_calloc(s->channels, sizeof(*s->iir));
1268     if (!s->iir)
1269         return AVERROR(ENOMEM);
1270 
1271     ret = read_gains(ctx, s->g_str, inlink->ch_layout.nb_channels);
1272     if (ret < 0)
1273         return ret;
1274 
1275     ret = read_channels(ctx, inlink->ch_layout.nb_channels, s->a_str, 0);
1276     if (ret < 0)
1277         return ret;
1278 
1279     ret = read_channels(ctx, inlink->ch_layout.nb_channels, s->b_str, 1);
1280     if (ret < 0)
1281         return ret;
1282 
1283     if (s->format == -1) {
1284         convert_sf2tf(ctx, inlink->ch_layout.nb_channels);
1285         s->format = 0;
1286     } else if (s->format == 2) {
1287         convert_pr2zp(ctx, inlink->ch_layout.nb_channels);
1288     } else if (s->format == 3) {
1289         convert_pd2zp(ctx, inlink->ch_layout.nb_channels);
1290     } else if (s->format == 4) {
1291         convert_sp2zp(ctx, inlink->ch_layout.nb_channels);
1292     }
1293     if (s->format > 0) {
1294         check_stability(ctx, inlink->ch_layout.nb_channels);
1295     }
1296 
1297     av_frame_free(&s->video);
1298     if (s->response) {
1299         s->video = ff_get_video_buffer(ctx->outputs[1], s->w, s->h);
1300         if (!s->video)
1301             return AVERROR(ENOMEM);
1302 
1303         draw_response(ctx, s->video, inlink->sample_rate);
1304     }
1305 
1306     if (s->format == 0)
1307         av_log(ctx, AV_LOG_WARNING, "transfer function coefficients format is not recommended for too high number of zeros/poles.\n");
1308 
1309     if (s->format > 0 && s->process == 0) {
1310         av_log(ctx, AV_LOG_WARNING, "Direct processsing is not recommended for zp coefficients format.\n");
1311 
1312         ret = convert_zp2tf(ctx, inlink->ch_layout.nb_channels);
1313         if (ret < 0)
1314             return ret;
1315     } else if (s->format == -2 && s->process > 0) {
1316         av_log(ctx, AV_LOG_ERROR, "Only direct processing is implemented for lattice-ladder function.\n");
1317         return AVERROR_PATCHWELCOME;
1318     } else if (s->format <= 0 && s->process == 1) {
1319         av_log(ctx, AV_LOG_ERROR, "Serial processing is not implemented for transfer function.\n");
1320         return AVERROR_PATCHWELCOME;
1321     } else if (s->format <= 0 && s->process == 2) {
1322         av_log(ctx, AV_LOG_ERROR, "Parallel processing is not implemented for transfer function.\n");
1323         return AVERROR_PATCHWELCOME;
1324     } else if (s->format > 0 && s->process == 1) {
1325         ret = decompose_zp2biquads(ctx, inlink->ch_layout.nb_channels);
1326         if (ret < 0)
1327             return ret;
1328     } else if (s->format > 0 && s->process == 2) {
1329         if (s->precision > 1)
1330             av_log(ctx, AV_LOG_WARNING, "Parallel processing is not recommended for fixed-point precisions.\n");
1331         ret = decompose_zp2biquads(ctx, inlink->ch_layout.nb_channels);
1332         if (ret < 0)
1333             return ret;
1334         ret = convert_serial2parallel(ctx, inlink->ch_layout.nb_channels);
1335         if (ret < 0)
1336             return ret;
1337     }
1338 
1339     for (ch = 0; s->format == -2 && ch < inlink->ch_layout.nb_channels; ch++) {
1340         IIRChannel *iir = &s->iir[ch];
1341 
1342         if (iir->nb_ab[0] != iir->nb_ab[1] + 1) {
1343             av_log(ctx, AV_LOG_ERROR, "Number of ladder coefficients must be one more than number of reflection coefficients.\n");
1344             return AVERROR(EINVAL);
1345         }
1346     }
1347 
1348     for (ch = 0; s->format == 0 && ch < inlink->ch_layout.nb_channels; ch++) {
1349         IIRChannel *iir = &s->iir[ch];
1350 
1351         for (i = 1; i < iir->nb_ab[0]; i++) {
1352             iir->ab[0][i] /= iir->ab[0][0];
1353         }
1354 
1355         iir->ab[0][0] = 1.0;
1356         for (i = 0; i < iir->nb_ab[1]; i++) {
1357             iir->ab[1][i] *= iir->g;
1358         }
1359 
1360         normalize_coeffs(ctx, ch);
1361     }
1362 
1363     switch (inlink->format) {
1364     case AV_SAMPLE_FMT_DBLP: s->iir_channel = s->process == 2 ? iir_ch_parallel_dblp : s->process == 1 ? iir_ch_serial_dblp : iir_ch_dblp; break;
1365     case AV_SAMPLE_FMT_FLTP: s->iir_channel = s->process == 2 ? iir_ch_parallel_fltp : s->process == 1 ? iir_ch_serial_fltp : iir_ch_fltp; break;
1366     case AV_SAMPLE_FMT_S32P: s->iir_channel = s->process == 2 ? iir_ch_parallel_s32p : s->process == 1 ? iir_ch_serial_s32p : iir_ch_s32p; break;
1367     case AV_SAMPLE_FMT_S16P: s->iir_channel = s->process == 2 ? iir_ch_parallel_s16p : s->process == 1 ? iir_ch_serial_s16p : iir_ch_s16p; break;
1368     }
1369 
1370     if (s->format == -2) {
1371         switch (inlink->format) {
1372         case AV_SAMPLE_FMT_DBLP: s->iir_channel = iir_ch_lattice_dblp; break;
1373         case AV_SAMPLE_FMT_FLTP: s->iir_channel = iir_ch_lattice_fltp; break;
1374         case AV_SAMPLE_FMT_S32P: s->iir_channel = iir_ch_lattice_s32p; break;
1375         case AV_SAMPLE_FMT_S16P: s->iir_channel = iir_ch_lattice_s16p; break;
1376         }
1377     }
1378 
1379     return 0;
1380 }
1381 
filter_frame(AVFilterLink * inlink,AVFrame * in)1382 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
1383 {
1384     AVFilterContext *ctx = inlink->dst;
1385     AudioIIRContext *s = ctx->priv;
1386     AVFilterLink *outlink = ctx->outputs[0];
1387     ThreadData td;
1388     AVFrame *out;
1389     int ch, ret;
1390 
1391     if (av_frame_is_writable(in) && s->process != 2) {
1392         out = in;
1393     } else {
1394         out = ff_get_audio_buffer(outlink, in->nb_samples);
1395         if (!out) {
1396             av_frame_free(&in);
1397             return AVERROR(ENOMEM);
1398         }
1399         av_frame_copy_props(out, in);
1400     }
1401 
1402     td.in  = in;
1403     td.out = out;
1404     ff_filter_execute(ctx, s->iir_channel, &td, NULL, outlink->ch_layout.nb_channels);
1405 
1406     for (ch = 0; ch < outlink->ch_layout.nb_channels; ch++) {
1407         if (s->iir[ch].clippings > 0)
1408             av_log(ctx, AV_LOG_WARNING, "Channel %d clipping %d times. Please reduce gain.\n",
1409                    ch, s->iir[ch].clippings);
1410         s->iir[ch].clippings = 0;
1411     }
1412 
1413     if (in != out)
1414         av_frame_free(&in);
1415 
1416     if (s->response) {
1417         AVFilterLink *outlink = ctx->outputs[1];
1418         int64_t old_pts = s->video->pts;
1419         int64_t new_pts = av_rescale_q(out->pts, ctx->inputs[0]->time_base, outlink->time_base);
1420 
1421         if (new_pts > old_pts) {
1422             AVFrame *clone;
1423 
1424             s->video->pts = new_pts;
1425             clone = av_frame_clone(s->video);
1426             if (!clone)
1427                 return AVERROR(ENOMEM);
1428             ret = ff_filter_frame(outlink, clone);
1429             if (ret < 0)
1430                 return ret;
1431         }
1432     }
1433 
1434     return ff_filter_frame(outlink, out);
1435 }
1436 
config_video(AVFilterLink * outlink)1437 static int config_video(AVFilterLink *outlink)
1438 {
1439     AVFilterContext *ctx = outlink->src;
1440     AudioIIRContext *s = ctx->priv;
1441 
1442     outlink->sample_aspect_ratio = (AVRational){1,1};
1443     outlink->w = s->w;
1444     outlink->h = s->h;
1445     outlink->frame_rate = s->rate;
1446     outlink->time_base = av_inv_q(outlink->frame_rate);
1447 
1448     return 0;
1449 }
1450 
init(AVFilterContext * ctx)1451 static av_cold int init(AVFilterContext *ctx)
1452 {
1453     AudioIIRContext *s = ctx->priv;
1454     AVFilterPad pad, vpad;
1455     int ret;
1456 
1457     if (!s->a_str || !s->b_str || !s->g_str) {
1458         av_log(ctx, AV_LOG_ERROR, "Valid coefficients are mandatory.\n");
1459         return AVERROR(EINVAL);
1460     }
1461 
1462     switch (s->precision) {
1463     case 0: s->sample_format = AV_SAMPLE_FMT_DBLP; break;
1464     case 1: s->sample_format = AV_SAMPLE_FMT_FLTP; break;
1465     case 2: s->sample_format = AV_SAMPLE_FMT_S32P; break;
1466     case 3: s->sample_format = AV_SAMPLE_FMT_S16P; break;
1467     default: return AVERROR_BUG;
1468     }
1469 
1470     pad = (AVFilterPad){
1471         .name         = "default",
1472         .type         = AVMEDIA_TYPE_AUDIO,
1473         .config_props = config_output,
1474     };
1475 
1476     ret = ff_append_outpad(ctx, &pad);
1477     if (ret < 0)
1478         return ret;
1479 
1480     if (s->response) {
1481         vpad = (AVFilterPad){
1482             .name         = "filter_response",
1483             .type         = AVMEDIA_TYPE_VIDEO,
1484             .config_props = config_video,
1485         };
1486 
1487         ret = ff_append_outpad(ctx, &vpad);
1488         if (ret < 0)
1489             return ret;
1490     }
1491 
1492     return 0;
1493 }
1494 
uninit(AVFilterContext * ctx)1495 static av_cold void uninit(AVFilterContext *ctx)
1496 {
1497     AudioIIRContext *s = ctx->priv;
1498     int ch;
1499 
1500     if (s->iir) {
1501         for (ch = 0; ch < s->channels; ch++) {
1502             IIRChannel *iir = &s->iir[ch];
1503             av_freep(&iir->ab[0]);
1504             av_freep(&iir->ab[1]);
1505             av_freep(&iir->cache[0]);
1506             av_freep(&iir->cache[1]);
1507             av_freep(&iir->biquads);
1508         }
1509     }
1510     av_freep(&s->iir);
1511 
1512     av_frame_free(&s->video);
1513 }
1514 
1515 static const AVFilterPad inputs[] = {
1516     {
1517         .name         = "default",
1518         .type         = AVMEDIA_TYPE_AUDIO,
1519         .filter_frame = filter_frame,
1520     },
1521 };
1522 
1523 #define OFFSET(x) offsetof(AudioIIRContext, x)
1524 #define AF AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
1525 #define VF AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
1526 
1527 static const AVOption aiir_options[] = {
1528     { "zeros", "set B/numerator/zeros/reflection coefficients", OFFSET(b_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
1529     { "z", "set B/numerator/zeros/reflection coefficients",     OFFSET(b_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
1530     { "poles", "set A/denominator/poles/ladder coefficients",   OFFSET(a_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
1531     { "p", "set A/denominator/poles/ladder coefficients",       OFFSET(a_str), AV_OPT_TYPE_STRING, {.str="1+0i 1-0i"}, 0, 0, AF },
1532     { "gains", "set channels gains",               OFFSET(g_str),    AV_OPT_TYPE_STRING, {.str="1|1"}, 0, 0, AF },
1533     { "k", "set channels gains",                   OFFSET(g_str),    AV_OPT_TYPE_STRING, {.str="1|1"}, 0, 0, AF },
1534     { "dry", "set dry gain",                       OFFSET(dry_gain), AV_OPT_TYPE_DOUBLE, {.dbl=1},     0, 1, AF },
1535     { "wet", "set wet gain",                       OFFSET(wet_gain), AV_OPT_TYPE_DOUBLE, {.dbl=1},     0, 1, AF },
1536     { "format", "set coefficients format",         OFFSET(format),   AV_OPT_TYPE_INT,    {.i64=1},    -2, 4, AF, "format" },
1537     { "f", "set coefficients format",              OFFSET(format),   AV_OPT_TYPE_INT,    {.i64=1},    -2, 4, AF, "format" },
1538     { "ll", "lattice-ladder function",             0,                AV_OPT_TYPE_CONST,  {.i64=-2},    0, 0, AF, "format" },
1539     { "sf", "analog transfer function",            0,                AV_OPT_TYPE_CONST,  {.i64=-1},    0, 0, AF, "format" },
1540     { "tf", "digital transfer function",           0,                AV_OPT_TYPE_CONST,  {.i64=0},     0, 0, AF, "format" },
1541     { "zp", "Z-plane zeros/poles",                 0,                AV_OPT_TYPE_CONST,  {.i64=1},     0, 0, AF, "format" },
1542     { "pr", "Z-plane zeros/poles (polar radians)", 0,                AV_OPT_TYPE_CONST,  {.i64=2},     0, 0, AF, "format" },
1543     { "pd", "Z-plane zeros/poles (polar degrees)", 0,                AV_OPT_TYPE_CONST,  {.i64=3},     0, 0, AF, "format" },
1544     { "sp", "S-plane zeros/poles",                 0,                AV_OPT_TYPE_CONST,  {.i64=4},     0, 0, AF, "format" },
1545     { "process", "set kind of processing",         OFFSET(process),  AV_OPT_TYPE_INT,    {.i64=1},     0, 2, AF, "process" },
1546     { "r", "set kind of processing",               OFFSET(process),  AV_OPT_TYPE_INT,    {.i64=1},     0, 2, AF, "process" },
1547     { "d", "direct",                               0,                AV_OPT_TYPE_CONST,  {.i64=0},     0, 0, AF, "process" },
1548     { "s", "serial",                               0,                AV_OPT_TYPE_CONST,  {.i64=1},     0, 0, AF, "process" },
1549     { "p", "parallel",                             0,                AV_OPT_TYPE_CONST,  {.i64=2},     0, 0, AF, "process" },
1550     { "precision", "set filtering precision",      OFFSET(precision),AV_OPT_TYPE_INT,    {.i64=0},     0, 3, AF, "precision" },
1551     { "e", "set precision",                        OFFSET(precision),AV_OPT_TYPE_INT,    {.i64=0},     0, 3, AF, "precision" },
1552     { "dbl", "double-precision floating-point",    0,                AV_OPT_TYPE_CONST,  {.i64=0},     0, 0, AF, "precision" },
1553     { "flt", "single-precision floating-point",    0,                AV_OPT_TYPE_CONST,  {.i64=1},     0, 0, AF, "precision" },
1554     { "i32", "32-bit integers",                    0,                AV_OPT_TYPE_CONST,  {.i64=2},     0, 0, AF, "precision" },
1555     { "i16", "16-bit integers",                    0,                AV_OPT_TYPE_CONST,  {.i64=3},     0, 0, AF, "precision" },
1556     { "normalize", "normalize coefficients",       OFFSET(normalize),AV_OPT_TYPE_BOOL,   {.i64=1},     0, 1, AF },
1557     { "n", "normalize coefficients",               OFFSET(normalize),AV_OPT_TYPE_BOOL,   {.i64=1},     0, 1, AF },
1558     { "mix", "set mix",                            OFFSET(mix),      AV_OPT_TYPE_DOUBLE, {.dbl=1},     0, 1, AF },
1559     { "response", "show IR frequency response",    OFFSET(response), AV_OPT_TYPE_BOOL,   {.i64=0},     0, 1, VF },
1560     { "channel", "set IR channel to display frequency response", OFFSET(ir_channel), AV_OPT_TYPE_INT, {.i64=0}, 0, 1024, VF },
1561     { "size",   "set video size",                  OFFSET(w),        AV_OPT_TYPE_IMAGE_SIZE, {.str = "hd720"}, 0, 0, VF },
1562     { "rate",   "set video rate",                  OFFSET(rate),     AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT32_MAX, VF },
1563     { NULL },
1564 };
1565 
1566 AVFILTER_DEFINE_CLASS(aiir);
1567 
1568 const AVFilter ff_af_aiir = {
1569     .name          = "aiir",
1570     .description   = NULL_IF_CONFIG_SMALL("Apply Infinite Impulse Response filter with supplied coefficients."),
1571     .priv_size     = sizeof(AudioIIRContext),
1572     .priv_class    = &aiir_class,
1573     .init          = init,
1574     .uninit        = uninit,
1575     FILTER_INPUTS(inputs),
1576     FILTER_QUERY_FUNC(query_formats),
1577     .flags         = AVFILTER_FLAG_DYNAMIC_OUTPUTS |
1578                      AVFILTER_FLAG_SLICE_THREADS,
1579 };
1580