FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavfilter/af_pan.c
Date: 2024-04-24 18:52:15
Exec Total Coverage
Lines: 161 213 75.6%
Functions: 8 8 100.0%
Branches: 93 126 73.8%
Line Branch Exec Source
1 /*
2 * Copyright (c) 2002 Anders Johansson <ajh@atri.curtin.edu.au>
3 * Copyright (c) 2011 Clément Bœsch <u pkh me>
4 * Copyright (c) 2011 Nicolas George <nicolas.george@normalesup.org>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 /**
24 * @file
25 * Audio panning filter (channels mixing)
26 * Original code written by Anders Johansson for MPlayer,
27 * reimplemented for FFmpeg.
28 */
29
30 #include <stdio.h>
31 #include "libavutil/avstring.h"
32 #include "libavutil/channel_layout.h"
33 #include "libavutil/mem.h"
34 #include "libavutil/opt.h"
35 #include "libswresample/swresample.h"
36 #include "audio.h"
37 #include "avfilter.h"
38 #include "formats.h"
39 #include "internal.h"
40
41 #define MAX_CHANNELS 64
42
43 typedef struct PanContext {
44 const AVClass *class;
45 char *args;
46 AVChannelLayout out_channel_layout;
47 double gain[MAX_CHANNELS][MAX_CHANNELS];
48 int64_t need_renorm;
49 int need_renumber;
50 int nb_output_channels;
51
52 int pure_gains;
53 /* channel mapping specific */
54 int channel_map[MAX_CHANNELS];
55 struct SwrContext *swr;
56 } PanContext;
57
58 588 static void skip_spaces(char **arg)
59 {
60 588 int len = 0;
61
62 588 sscanf(*arg, " %n", &len);
63 588 *arg += len;
64 588 }
65
66 294 static int parse_channel_name(char **arg, int *rchannel, int *rnamed)
67 {
68 char buf[8];
69 294 int len, channel_id = 0;
70
71 294 skip_spaces(arg);
72 /* try to parse a channel name, e.g. "FL" */
73
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 294 if (sscanf(*arg, "%7[A-Z]%n", buf, &len)) {
74 36 channel_id = av_channel_from_string(buf);
75
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 36 if (channel_id < 0)
76 ✗ return channel_id;
77
78 36 *rchannel = channel_id;
79 36 *rnamed = 1;
80 36 *arg += len;
81 36 return 0;
82 }
83 /* try to parse a channel number, e.g. "c2" */
84
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 258 if (sscanf(*arg, "c%d%n", &channel_id, &len) &&
85
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 258 channel_id >= 0 && channel_id < MAX_CHANNELS) {
86 258 *rchannel = channel_id;
87 258 *rnamed = 0;
88 258 *arg += len;
89 258 return 0;
90 }
91 ✗ return AVERROR(EINVAL);
92 }
93
94 48 static av_cold int init(AVFilterContext *ctx)
95 {
96 48 PanContext *const pan = ctx->priv;
97 48 char *arg, *arg0, *tokenizer, *args = av_strdup(pan->args);
98 48 int out_ch_id, in_ch_id, len, named, ret, sign = 1;
99 48 int nb_in_channels[2] = { 0, 0 }; // number of unnamed and named input channels
100 48 int used_out_ch[MAX_CHANNELS] = {0};
101 double gain;
102
103
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 48 if (!pan->args) {
104 ✗ av_log(ctx, AV_LOG_ERROR,
105 "pan filter needs a channel layout and a set "
106 "of channel definitions as parameter\n");
107 ✗ return AVERROR(EINVAL);
108 }
109
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 48 if (!args)
110 ✗ return AVERROR(ENOMEM);
111 48 arg = av_strtok(args, "|", &tokenizer);
112
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 48 if (!arg) {
113 ✗ av_log(ctx, AV_LOG_ERROR, "Channel layout not specified\n");
114 ✗ ret = AVERROR(EINVAL);
115 ✗ goto fail;
116 }
117 48 ret = ff_parse_channel_layout(&pan->out_channel_layout,
118 &pan->nb_output_channels, arg, ctx);
119
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 48 if (ret < 0)
120 ✗ goto fail;
121
122 /* parse channel specifications */
123
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 170 while ((arg = arg0 = av_strtok(NULL, "|", &tokenizer))) {
124 122 int used_in_ch[MAX_CHANNELS] = {0};
125 /* channel name */
126
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 122 if (parse_channel_name(&arg, &out_ch_id, &named)) {
127 ✗ av_log(ctx, AV_LOG_ERROR,
128 "Expected out channel name, got \"%.8s\"\n", arg);
129 ✗ ret = AVERROR(EINVAL);
130 ✗ goto fail;
131 }
132
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 122 if (named) {
133
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 14 if ((out_ch_id = av_channel_layout_index_from_channel(&pan->out_channel_layout, out_ch_id)) < 0) {
134 ✗ av_log(ctx, AV_LOG_ERROR,
135 "Channel \"%.8s\" does not exist in the chosen layout\n", arg0);
136 ✗ ret = AVERROR(EINVAL);
137 ✗ goto fail;
138 }
139 }
140
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 122 if (out_ch_id < 0 || out_ch_id >= pan->nb_output_channels) {
141 ✗ av_log(ctx, AV_LOG_ERROR,
142 "Invalid out channel name \"%.8s\"\n", arg0);
143 ✗ ret = AVERROR(EINVAL);
144 ✗ goto fail;
145 }
146
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 122 if (used_out_ch[out_ch_id]) {
147 ✗ av_log(ctx, AV_LOG_ERROR,
148 "Can not reference out channel %d twice\n", out_ch_id);
149 ✗ ret = AVERROR(EINVAL);
150 ✗ goto fail;
151 }
152 122 used_out_ch[out_ch_id] = 1;
153 122 skip_spaces(&arg);
154
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 122 if (*arg == '=') {
155 114 arg++;
156
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 8 } else if (*arg == '<') {
157 8 pan->need_renorm |= (int64_t)1 << out_ch_id;
158 8 arg++;
159 } else {
160 ✗ av_log(ctx, AV_LOG_ERROR,
161 "Syntax error after channel name in \"%.8s\"\n", arg0);
162 ✗ ret = AVERROR(EINVAL);
163 ✗ goto fail;
164 }
165 /* gains */
166 122 sign = 1;
167 while (1) {
168 172 gain = 1;
169
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 172 if (sscanf(arg, "%lf%n *%n", &gain, &len, &len))
170 36 arg += len;
171
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 172 if (parse_channel_name(&arg, &in_ch_id, &named)){
172 ✗ av_log(ctx, AV_LOG_ERROR,
173 "Expected in channel name, got \"%.8s\"\n", arg);
174 ✗ ret = AVERROR(EINVAL);
175 ✗ goto fail;
176 }
177 172 nb_in_channels[named]++;
178
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 172 if (nb_in_channels[!named]) {
179 ✗ av_log(ctx, AV_LOG_ERROR,
180 "Can not mix named and numbered channels\n");
181 ✗ ret = AVERROR(EINVAL);
182 ✗ goto fail;
183 }
184
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 172 if (used_in_ch[in_ch_id]) {
185 ✗ av_log(ctx, AV_LOG_ERROR,
186 "Can not reference in channel %d twice\n", in_ch_id);
187 ✗ ret = AVERROR(EINVAL);
188 ✗ goto fail;
189 }
190 172 used_in_ch[in_ch_id] = 1;
191 172 pan->gain[out_ch_id][in_ch_id] = sign * gain;
192 172 skip_spaces(&arg);
193
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 172 if (!*arg)
194 122 break;
195
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 50 if (*arg == '-') {
196 18 sign = -1;
197
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 32 } else if (*arg != '+') {
198 ✗ av_log(ctx, AV_LOG_ERROR, "Syntax error near \"%.8s\"\n", arg);
199 ✗ ret = AVERROR(EINVAL);
200 ✗ goto fail;
201 } else {
202 32 sign = 1;
203 }
204 50 arg++;
205 }
206 }
207 48 pan->need_renumber = !!nb_in_channels[1];
208
209 48 ret = 0;
210 48 fail:
211 48 av_free(args);
212 48 return ret;
213 }
214
215 24 static int are_gains_pure(const PanContext *pan)
216 {
217 int i, j;
218
219
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 1048 for (i = 0; i < MAX_CHANNELS; i++) {
220 1032 int nb_gain = 0;
221
222
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 66576 for (j = 0; j < MAX_CHANNELS; j++) {
223 65552 double gain = pan->gain[i][j];
224
225 /* channel mapping is effective only if 0% or 100% of a channel is
226 * selected... */
227
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 65552 if (gain != 0. && gain != 1.)
228 7 return 0;
229 /* ...and if the output channel is only composed of one input */
230
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 65545 if (gain && nb_gain++)
231 1 return 0;
232 }
233 }
234 16 return 1;
235 }
236
237 24 static int query_formats(AVFilterContext *ctx)
238 {
239 24 PanContext *pan = ctx->priv;
240 24 AVFilterLink *inlink = ctx->inputs[0];
241 24 AVFilterLink *outlink = ctx->outputs[0];
242 AVFilterChannelLayouts *layouts;
243 int ret;
244
245 24 pan->pure_gains = are_gains_pure(pan);
246 /* libswr supports any sample and packing formats */
247
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 24 if ((ret = ff_set_common_formats(ctx, ff_all_formats(AVMEDIA_TYPE_AUDIO))) < 0)
248 ✗ return ret;
249
250
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 24 if ((ret = ff_set_common_all_samplerates(ctx)) < 0)
251 ✗ return ret;
252
253 // inlink supports any channel layout
254 24 layouts = ff_all_channel_counts();
255
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 24 if ((ret = ff_channel_layouts_ref(layouts, &inlink->outcfg.channel_layouts)) < 0)
256 ✗ return ret;
257
258 // outlink supports only requested output channel layout
259 24 layouts = NULL;
260
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 24 if ((ret = ff_add_channel_layout(&layouts, &pan->out_channel_layout)) < 0)
261 ✗ return ret;
262 24 return ff_channel_layouts_ref(layouts, &outlink->incfg.channel_layouts);
263 }
264
265 24 static int config_props(AVFilterLink *link)
266 {
267 24 AVFilterContext *ctx = link->dst;
268 24 PanContext *pan = ctx->priv;
269 char buf[1024], *cur;
270 int i, j, k, r, ret;
271 double t;
272
273
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 24 if (pan->need_renumber) {
274 // input channels were given by their name: renumber them
275
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 195 for (i = j = 0; i < MAX_CHANNELS; i++) {
276
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 192 if (av_channel_layout_index_from_channel(&link->ch_layout, i) >= 0) {
277
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 25 for (k = 0; k < pan->nb_output_channels; k++)
278 16 pan->gain[k][j] = pan->gain[k][i];
279 9 j++;
280 }
281 }
282 }
283
284 // sanity check; can't be done in query_formats since the inlink
285 // channel layout is unknown at that time
286
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 24 if (link->ch_layout.nb_channels > MAX_CHANNELS ||
287
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 24 pan->nb_output_channels > MAX_CHANNELS) {
288 ✗ av_log(ctx, AV_LOG_ERROR,
289 "af_pan supports a maximum of %d channels. "
290 "Feel free to ask for a higher limit.\n", MAX_CHANNELS);
291 ✗ return AVERROR_PATCHWELCOME;
292 }
293
294 // init libswresample context
295 24 ret = swr_alloc_set_opts2(&pan->swr,
296 24 &pan->out_channel_layout, link->format, link->sample_rate,
297 24 &link->ch_layout, link->format, link->sample_rate,
298 0, ctx);
299
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 24 if (ret < 0)
300 ✗ return AVERROR(ENOMEM);
301
302 // gains are pure, init the channel mapping
303
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 24 if (pan->pure_gains) {
304
305 // get channel map from the pure gains
306
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 50 for (i = 0; i < pan->nb_output_channels; i++) {
307 34 int ch_id = -1;
308
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 42 for (j = 0; j < link->ch_layout.nb_channels; j++) {
309
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 35 if (pan->gain[i][j]) {
310 27 ch_id = j;
311 27 break;
312 }
313 }
314 34 pan->channel_map[i] = ch_id;
315 }
316
317 16 av_opt_set_chlayout(pan->swr, "uchl", &pan->out_channel_layout, 0);
318 16 swr_set_channel_mapping(pan->swr, pan->channel_map);
319 } else {
320 // renormalize
321
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 35 for (i = 0; i < pan->nb_output_channels; i++) {
322
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 27 if (!((pan->need_renorm >> i) & 1))
323 23 continue;
324 4 t = 0;
325
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 16 for (j = 0; j < link->ch_layout.nb_channels; j++)
326 12 t += fabs(pan->gain[i][j]);
327
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 4 if (t > -1E-5 && t < 1E-5) {
328 // t is almost 0 but not exactly, this is probably a mistake
329 ✗ if (t)
330 ✗ av_log(ctx, AV_LOG_WARNING,
331 "Degenerate coefficients while renormalizing\n");
332 ✗ continue;
333 }
334
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 16 for (j = 0; j < link->ch_layout.nb_channels; j++)
335 12 pan->gain[i][j] /= t;
336 }
337 8 swr_set_matrix(pan->swr, pan->gain[0], pan->gain[1] - pan->gain[0]);
338 }
339
340 24 r = swr_init(pan->swr);
341
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 24 if (r < 0)
342 ✗ return r;
343
344 // summary
345
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 85 for (i = 0; i < pan->nb_output_channels; i++) {
346 61 cur = buf;
347
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 223 for (j = 0; j < link->ch_layout.nb_channels; j++) {
348
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 162 r = snprintf(cur, buf + sizeof(buf) - cur, "%s%.3g i%d",
349 j ? " + " : "", pan->gain[i][j], j);
350
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 162 cur += FFMIN(buf + sizeof(buf) - cur, r);
351 }
352 61 av_log(ctx, AV_LOG_VERBOSE, "o%d = %s\n", i, buf);
353 }
354 // add channel mapping summary if possible
355
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 24 if (pan->pure_gains) {
356 16 av_log(ctx, AV_LOG_INFO, "Pure channel mapping detected:");
357
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 50 for (i = 0; i < pan->nb_output_channels; i++)
358
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 34 if (pan->channel_map[i] < 0)
359 7 av_log(ctx, AV_LOG_INFO, " M");
360 else
361 27 av_log(ctx, AV_LOG_INFO, " %d", pan->channel_map[i]);
362 16 av_log(ctx, AV_LOG_INFO, "\n");
363 16 return 0;
364 }
365 8 return 0;
366 }
367
368 1110 static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
369 {
370 int ret;
371 1110 int n = insamples->nb_samples;
372 1110 AVFilterLink *const outlink = inlink->dst->outputs[0];
373 1110 AVFrame *outsamples = ff_get_audio_buffer(outlink, n);
374 1110 PanContext *pan = inlink->dst->priv;
375
376
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 1110 if (!outsamples) {
377 ✗ av_frame_free(&insamples);
378 ✗ return AVERROR(ENOMEM);
379 }
380 1110 swr_convert(pan->swr, outsamples->extended_data, n,
381 1110 (void *)insamples->extended_data, n);
382 1110 av_frame_copy_props(outsamples, insamples);
383
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 1110 if ((ret = av_channel_layout_copy(&outsamples->ch_layout, &outlink->ch_layout)) < 0) {
384 ✗ av_frame_free(&outsamples);
385 ✗ av_frame_free(&insamples);
386 ✗ return ret;
387 }
388
389 1110 av_frame_free(&insamples);
390 1110 return ff_filter_frame(outlink, outsamples);
391 }
392
393 48 static av_cold void uninit(AVFilterContext *ctx)
394 {
395 48 PanContext *pan = ctx->priv;
396 48 swr_free(&pan->swr);
397 48 av_channel_layout_uninit(&pan->out_channel_layout);
398 48 }
399
400 #define OFFSET(x) offsetof(PanContext, x)
401
402 static const AVOption pan_options[] = {
403 { "args", NULL, OFFSET(args), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM },
404 { NULL }
405 };
406
407 AVFILTER_DEFINE_CLASS(pan);
408
409 static const AVFilterPad pan_inputs[] = {
410 {
411 .name = "default",
412 .type = AVMEDIA_TYPE_AUDIO,
413 .config_props = config_props,
414 .filter_frame = filter_frame,
415 },
416 };
417
418 const AVFilter ff_af_pan = {
419 .name = "pan",
420 .description = NULL_IF_CONFIG_SMALL("Remix channels with coefficients (panning)."),
421 .priv_size = sizeof(PanContext),
422 .priv_class = &pan_class,
423 .init = init,
424 .uninit = uninit,
425 FILTER_INPUTS(pan_inputs),
426 FILTER_OUTPUTS(ff_audio_default_filterpad),
427 FILTER_QUERY_FUNC(query_formats),
428 };
429