FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavfilter/af_atilt.c
Date: 2024-07-17 14:05:47
Exec Total Coverage
Lines: 0 71 0.0%
Functions: 0 14 0.0%
Branches: 0 33 0.0%

Line Branch Exec Source
1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include "libavutil/channel_layout.h"
20 #include "libavutil/ffmath.h"
21 #include "libavutil/opt.h"
22 #include "avfilter.h"
23 #include "audio.h"
24
25 #define MAX_ORDER 30
26
27 typedef struct Coeffs {
28 double g;
29 double a1;
30 double b0, b1;
31 } Coeffs;
32
33 typedef struct ATiltContext {
34 const AVClass *class;
35
36 double freq;
37 double level;
38 double slope;
39 double width;
40 int order;
41
42 Coeffs coeffs[MAX_ORDER];
43
44 AVFrame *w;
45
46 int (*filter_channels)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
47 } ATiltContext;
48
49 static double prewarp(double w, double T, double wp)
50 {
51 return wp * tan(w * T * 0.5) / tan(wp * T * 0.5);
52 }
53
54 static double mz(int i, double w0, double r, double alpha)
55 {
56 return w0 * pow(r, -alpha + i);
57 }
58
59 static double mp(int i, double w0, double r)
60 {
61 return w0 * pow(r, i);
62 }
63
64 static double mzh(int i, double T, double w0, double r, double alpha)
65 {
66 return prewarp(mz(i, w0, r, alpha), T, w0);
67 }
68
69 static double mph(int i, double T, double w0, double r)
70 {
71 return prewarp(mp(i, w0, r), T, w0);
72 }
73
74 static void set_tf1s(Coeffs *coeffs, double b1, double b0, double a0,
75 double w1, double sr, double alpha)
76 {
77 double c = 1.0 / tan(w1 * 0.5 / sr);
78 double d = a0 + c;
79
80 coeffs->b1 = (b0 - b1 * c) / d;
81 coeffs->b0 = (b0 + b1 * c) / d;
82 coeffs->a1 = (a0 - c) / d;
83 coeffs->g = a0 / b0;
84 }
85
86 static void set_filter(AVFilterContext *ctx,
87 int order, double sr, double f0,
88 double bw, double alpha)
89 {
90 ATiltContext *s = ctx->priv;
91 const double w0 = 2. * M_PI * f0;
92 const double f1 = f0 + bw;
93 const double w1 = 1.;
94 const double r = pow(f1 / f0, 1.0 / (order - 1.0));
95 const double T = 1. / sr;
96
97 for (int i = 0; i < order; i++) {
98 Coeffs *coeffs = &s->coeffs[i];
99
100 set_tf1s(coeffs, 1.0, mzh(i, T, w0, r, alpha), mph(i, T, w0, r),
101 w1, sr, alpha);
102 }
103 }
104
105 static int get_coeffs(AVFilterContext *ctx)
106 {
107 ATiltContext *s = ctx->priv;
108 AVFilterLink *inlink = ctx->inputs[0];
109
110 set_filter(ctx, s->order, inlink->sample_rate, s->freq, s->width, s->slope);
111
112 return 0;
113 }
114
115 typedef struct ThreadData {
116 AVFrame *in, *out;
117 } ThreadData;
118
119 #define FILTER(name, type) \
120 static int filter_channels_## name(AVFilterContext *ctx, void *arg, \
121 int jobnr, int nb_jobs) \
122 { \
123 ATiltContext *s = ctx->priv; \
124 ThreadData *td = arg; \
125 AVFrame *out = td->out; \
126 AVFrame *in = td->in; \
127 const int start = (in->ch_layout.nb_channels * jobnr) / nb_jobs; \
128 const int end = (in->ch_layout.nb_channels * (jobnr+1)) / nb_jobs; \
129 const type level = s->level; \
130 \
131 for (int ch = start; ch < end; ch++) { \
132 const type *src = (const type *)in->extended_data[ch]; \
133 type *dst = (type *)out->extended_data[ch]; \
134 \
135 for (int b = 0; b < s->order; b++) { \
136 Coeffs *coeffs = &s->coeffs[b]; \
137 const type g = coeffs->g; \
138 const type a1 = coeffs->a1; \
139 const type b0 = coeffs->b0; \
140 const type b1 = coeffs->b1; \
141 type *w = ((type *)s->w->extended_data[ch]) + b * 2; \
142 \
143 for (int n = 0; n < in->nb_samples; n++) { \
144 type sain = b ? dst[n] : src[n] * level; \
145 type saout = sain * b0 + w[0] * b1 - w[1] * a1; \
146 \
147 w[0] = sain; \
148 w[1] = saout; \
149 \
150 dst[n] = saout * g; \
151 } \
152 } \
153 } \
154 \
155 return 0; \
156 }
157
158 FILTER(fltp, float)
159 FILTER(dblp, double)
160
161 static int config_input(AVFilterLink *inlink)
162 {
163 AVFilterContext *ctx = inlink->dst;
164 ATiltContext *s = ctx->priv;
165
166 switch (inlink->format) {
167 case AV_SAMPLE_FMT_FLTP: s->filter_channels = filter_channels_fltp; break;
168 case AV_SAMPLE_FMT_DBLP: s->filter_channels = filter_channels_dblp; break;
169 }
170
171 s->w = ff_get_audio_buffer(inlink, 2 * MAX_ORDER);
172 if (!s->w)
173 return AVERROR(ENOMEM);
174
175 return get_coeffs(ctx);
176 }
177
178 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
179 {
180 AVFilterContext *ctx = inlink->dst;
181 ATiltContext *s = ctx->priv;
182 AVFilterLink *outlink = ctx->outputs[0];
183 ThreadData td;
184 AVFrame *out;
185
186 if (av_frame_is_writable(in)) {
187 out = in;
188 } else {
189 out = ff_get_audio_buffer(outlink, in->nb_samples);
190 if (!out) {
191 av_frame_free(&in);
192 return AVERROR(ENOMEM);
193 }
194 av_frame_copy_props(out, in);
195 }
196
197 td.in = in; td.out = out;
198 ff_filter_execute(ctx, s->filter_channels, &td, NULL, FFMIN(inlink->ch_layout.nb_channels,
199 ff_filter_get_nb_threads(ctx)));
200
201 if (out != in)
202 av_frame_free(&in);
203 return ff_filter_frame(outlink, out);
204 }
205
206 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
207 char *res, int res_len, int flags)
208 {
209 int ret;
210
211 ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags);
212 if (ret < 0)
213 return ret;
214
215 return get_coeffs(ctx);
216 }
217
218 static av_cold void uninit(AVFilterContext *ctx)
219 {
220 ATiltContext *s = ctx->priv;
221
222 av_frame_free(&s->w);
223 }
224
225 #define OFFSET(x) offsetof(ATiltContext, x)
226 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
227
228 static const AVOption atilt_options[] = {
229 { "freq", "set central frequency",OFFSET(freq), AV_OPT_TYPE_DOUBLE, {.dbl=10000}, 20, 192000, FLAGS },
230 { "slope", "set filter slope", OFFSET(slope), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
231 { "width", "set filter width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1000}, 100, 10000, FLAGS },
232 { "order", "set filter order", OFFSET(order), AV_OPT_TYPE_INT, {.i64=5}, 2,MAX_ORDER, FLAGS },
233 { "level", "set input level", OFFSET(level), AV_OPT_TYPE_DOUBLE, {.dbl=1.}, 0., 4., FLAGS },
234 { NULL }
235 };
236
237 AVFILTER_DEFINE_CLASS(atilt);
238
239 static const AVFilterPad inputs[] = {
240 {
241 .name = "default",
242 .type = AVMEDIA_TYPE_AUDIO,
243 .filter_frame = filter_frame,
244 .config_props = config_input,
245 },
246 };
247
248 const AVFilter ff_af_atilt = {
249 .name = "atilt",
250 .description = NULL_IF_CONFIG_SMALL("Apply spectral tilt to audio."),
251 .priv_size = sizeof(ATiltContext),
252 .priv_class = &atilt_class,
253 .uninit = uninit,
254 FILTER_INPUTS(inputs),
255 FILTER_OUTPUTS(ff_audio_default_filterpad),
256 FILTER_SAMPLEFMTS(AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_DBLP),
257 .process_command = process_command,
258 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC |
259 AVFILTER_FLAG_SLICE_THREADS,
260 };
261