GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavfilter/af_pan.c Lines: 178 229 77.7 %
Date: 2020-10-23 17:01:47 Branches: 105 140 75.0 %

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/opt.h"
34
#include "libswresample/swresample.h"
35
#include "audio.h"
36
#include "avfilter.h"
37
#include "formats.h"
38
#include "internal.h"
39
40
#define MAX_CHANNELS 64
41
42
typedef struct PanContext {
43
    const AVClass *class;
44
    char *args;
45
    int64_t out_channel_layout;
46
    double gain[MAX_CHANNELS][MAX_CHANNELS];
47
    int64_t need_renorm;
48
    int need_renumber;
49
    int nb_output_channels;
50
51
    int pure_gains;
52
    /* channel mapping specific */
53
    int channel_map[MAX_CHANNELS];
54
    struct SwrContext *swr;
55
} PanContext;
56
57
206
static void skip_spaces(char **arg)
58
{
59
206
    int len = 0;
60
61
206
    sscanf(*arg, " %n", &len);
62
206
    *arg += len;
63
206
}
64
65
103
static int parse_channel_name(char **arg, int *rchannel, int *rnamed)
66
{
67
    char buf[8];
68
103
    int len, i, channel_id = 0;
69
    int64_t layout, layout0;
70
71
103
    skip_spaces(arg);
72
    /* try to parse a channel name, e.g. "FL" */
73
103
    if (sscanf(*arg, "%7[A-Z]%n", buf, &len)) {
74
18
        layout0 = layout = av_get_channel_layout(buf);
75
        /* channel_id <- first set bit in layout */
76
126
        for (i = 32; i > 0; i >>= 1) {
77
108
            if (layout >= (int64_t)1 << i) {
78
15
                channel_id += i;
79
15
                layout >>= i;
80
            }
81
        }
82
        /* reject layouts that are not a single channel */
83

18
        if (channel_id >= MAX_CHANNELS || layout0 != (int64_t)1 << channel_id)
84
            return AVERROR(EINVAL);
85
18
        *rchannel = channel_id;
86
18
        *rnamed = 1;
87
18
        *arg += len;
88
18
        return 0;
89
    }
90
    /* try to parse a channel number, e.g. "c2" */
91
85
    if (sscanf(*arg, "c%d%n", &channel_id, &len) &&
92

85
        channel_id >= 0 && channel_id < MAX_CHANNELS) {
93
85
        *rchannel = channel_id;
94
85
        *rnamed = 0;
95
85
        *arg += len;
96
85
        return 0;
97
    }
98
    return AVERROR(EINVAL);
99
}
100
101
16
static av_cold int init(AVFilterContext *ctx)
102
{
103
16
    PanContext *const pan = ctx->priv;
104
16
    char *arg, *arg0, *tokenizer, *args = av_strdup(pan->args);
105
16
    int out_ch_id, in_ch_id, len, named, ret, sign = 1;
106
16
    int nb_in_channels[2] = { 0, 0 }; // number of unnamed and named input channels
107
16
    int used_out_ch[MAX_CHANNELS] = {0};
108
    double gain;
109
110
16
    if (!pan->args) {
111
        av_log(ctx, AV_LOG_ERROR,
112
               "pan filter needs a channel layout and a set "
113
               "of channel definitions as parameter\n");
114
        return AVERROR(EINVAL);
115
    }
116
16
    if (!args)
117
        return AVERROR(ENOMEM);
118
16
    arg = av_strtok(args, "|", &tokenizer);
119
16
    if (!arg) {
120
        av_log(ctx, AV_LOG_ERROR, "Channel layout not specified\n");
121
        ret = AVERROR(EINVAL);
122
        goto fail;
123
    }
124
16
    ret = ff_parse_channel_layout(&pan->out_channel_layout,
125
                                  &pan->nb_output_channels, arg, ctx);
126
16
    if (ret < 0)
127
        goto fail;
128
129
    /* parse channel specifications */
130
55
    while ((arg = arg0 = av_strtok(NULL, "|", &tokenizer))) {
131
39
        int used_in_ch[MAX_CHANNELS] = {0};
132
        /* channel name */
133
39
        if (parse_channel_name(&arg, &out_ch_id, &named)) {
134
            av_log(ctx, AV_LOG_ERROR,
135
                   "Expected out channel name, got \"%.8s\"\n", arg);
136
            ret = AVERROR(EINVAL);
137
            goto fail;
138
        }
139
39
        if (named) {
140
7
            if (!((pan->out_channel_layout >> out_ch_id) & 1)) {
141
                av_log(ctx, AV_LOG_ERROR,
142
                       "Channel \"%.8s\" does not exist in the chosen layout\n", arg0);
143
                ret = AVERROR(EINVAL);
144
                goto fail;
145
            }
146
            /* get the channel number in the output channel layout:
147
             * out_channel_layout & ((1 << out_ch_id) - 1) are all the
148
             * channels that come before out_ch_id,
149
             * so their count is the index of out_ch_id */
150
7
            out_ch_id = av_get_channel_layout_nb_channels(pan->out_channel_layout & (((int64_t)1 << out_ch_id) - 1));
151
        }
152

39
        if (out_ch_id < 0 || out_ch_id >= pan->nb_output_channels) {
153
            av_log(ctx, AV_LOG_ERROR,
154
                   "Invalid out channel name \"%.8s\"\n", arg0);
155
            ret = AVERROR(EINVAL);
156
            goto fail;
157
        }
158
39
        if (used_out_ch[out_ch_id]) {
159
            av_log(ctx, AV_LOG_ERROR,
160
                   "Can not reference out channel %d twice\n", out_ch_id);
161
            ret = AVERROR(EINVAL);
162
            goto fail;
163
        }
164
39
        used_out_ch[out_ch_id] = 1;
165
39
        skip_spaces(&arg);
166
39
        if (*arg == '=') {
167
35
            arg++;
168
4
        } else if (*arg == '<') {
169
4
            pan->need_renorm |= (int64_t)1 << out_ch_id;
170
4
            arg++;
171
        } else {
172
            av_log(ctx, AV_LOG_ERROR,
173
                   "Syntax error after channel name in \"%.8s\"\n", arg0);
174
            ret = AVERROR(EINVAL);
175
            goto fail;
176
        }
177
        /* gains */
178
39
        sign = 1;
179
        while (1) {
180
64
            gain = 1;
181
64
            if (sscanf(arg, "%lf%n *%n", &gain, &len, &len))
182
18
                arg += len;
183
64
            if (parse_channel_name(&arg, &in_ch_id, &named)){
184
                av_log(ctx, AV_LOG_ERROR,
185
                       "Expected in channel name, got \"%.8s\"\n", arg);
186
                 ret = AVERROR(EINVAL);
187
                 goto fail;
188
            }
189
64
            nb_in_channels[named]++;
190
64
            if (nb_in_channels[!named]) {
191
                av_log(ctx, AV_LOG_ERROR,
192
                       "Can not mix named and numbered channels\n");
193
                ret = AVERROR(EINVAL);
194
                goto fail;
195
            }
196
64
            if (used_in_ch[in_ch_id]) {
197
                av_log(ctx, AV_LOG_ERROR,
198
                       "Can not reference in channel %d twice\n", in_ch_id);
199
                ret = AVERROR(EINVAL);
200
                goto fail;
201
            }
202
64
            used_in_ch[in_ch_id] = 1;
203
64
            pan->gain[out_ch_id][in_ch_id] = sign * gain;
204
64
            skip_spaces(&arg);
205
64
            if (!*arg)
206
39
                break;
207
25
            if (*arg == '-') {
208
9
                sign = -1;
209
16
            } else if (*arg != '+') {
210
                av_log(ctx, AV_LOG_ERROR, "Syntax error near \"%.8s\"\n", arg);
211
                ret = AVERROR(EINVAL);
212
                goto fail;
213
            } else {
214
16
                sign = 1;
215
            }
216
25
            arg++;
217
        }
218
    }
219
16
    pan->need_renumber = !!nb_in_channels[1];
220
221
16
    ret = 0;
222
16
fail:
223
16
    av_free(args);
224
16
    return ret;
225
}
226
227
16
static int are_gains_pure(const PanContext *pan)
228
{
229
    int i, j;
230
231
528
    for (i = 0; i < MAX_CHANNELS; i++) {
232
520
        int nb_gain = 0;
233
234
33296
        for (j = 0; j < MAX_CHANNELS; j++) {
235
32784
            double gain = pan->gain[i][j];
236
237
            /* channel mapping is effective only if 0% or 100% of a channel is
238
             * selected... */
239

32784
            if (gain != 0. && gain != 1.)
240
7
                return 0;
241
            /* ...and if the output channel is only composed of one input */
242

32777
            if (gain && nb_gain++)
243
1
                return 0;
244
        }
245
    }
246
8
    return 1;
247
}
248
249
16
static int query_formats(AVFilterContext *ctx)
250
{
251
16
    PanContext *pan = ctx->priv;
252
16
    AVFilterLink *inlink  = ctx->inputs[0];
253
16
    AVFilterLink *outlink = ctx->outputs[0];
254
16
    AVFilterFormats *formats = NULL;
255
    AVFilterChannelLayouts *layouts;
256
    int ret;
257
258
16
    pan->pure_gains = are_gains_pure(pan);
259
    /* libswr supports any sample and packing formats */
260
16
    if ((ret = ff_set_common_formats(ctx, ff_all_formats(AVMEDIA_TYPE_AUDIO))) < 0)
261
        return ret;
262
263
16
    formats = ff_all_samplerates();
264
16
    if ((ret = ff_set_common_samplerates(ctx, formats)) < 0)
265
        return ret;
266
267
    // inlink supports any channel layout
268
16
    layouts = ff_all_channel_counts();
269
16
    if ((ret = ff_channel_layouts_ref(layouts, &inlink->outcfg.channel_layouts)) < 0)
270
        return ret;
271
272
    // outlink supports only requested output channel layout
273
16
    layouts = NULL;
274
16
    if ((ret = ff_add_channel_layout(&layouts,
275
16
                          pan->out_channel_layout ? pan->out_channel_layout :
276
5
                          FF_COUNT2LAYOUT(pan->nb_output_channels))) < 0)
277
        return ret;
278
16
    return ff_channel_layouts_ref(layouts, &outlink->incfg.channel_layouts);
279
}
280
281
16
static int config_props(AVFilterLink *link)
282
{
283
16
    AVFilterContext *ctx = link->dst;
284
16
    PanContext *pan = ctx->priv;
285
    char buf[1024], *cur;
286
    int i, j, k, r;
287
    double t;
288
289
16
    if (pan->need_renumber) {
290
        // input channels were given by their name: renumber them
291
195
        for (i = j = 0; i < MAX_CHANNELS; i++) {
292
192
            if ((link->channel_layout >> i) & 1) {
293
25
                for (k = 0; k < pan->nb_output_channels; k++)
294
16
                    pan->gain[k][j] = pan->gain[k][i];
295
9
                j++;
296
            }
297
        }
298
    }
299
300
    // sanity check; can't be done in query_formats since the inlink
301
    // channel layout is unknown at that time
302
16
    if (link->channels > MAX_CHANNELS ||
303
16
        pan->nb_output_channels > MAX_CHANNELS) {
304
        av_log(ctx, AV_LOG_ERROR,
305
               "af_pan supports a maximum of %d channels. "
306
               "Feel free to ask for a higher limit.\n", MAX_CHANNELS);
307
        return AVERROR_PATCHWELCOME;
308
    }
309
310
    // init libswresample context
311
32
    pan->swr = swr_alloc_set_opts(pan->swr,
312
16
                                  pan->out_channel_layout, link->format, link->sample_rate,
313
16
                                  link->channel_layout,    link->format, link->sample_rate,
314
                                  0, ctx);
315
16
    if (!pan->swr)
316
        return AVERROR(ENOMEM);
317
16
    if (!link->channel_layout) {
318
3
        if (av_opt_set_int(pan->swr, "ich", link->channels, 0) < 0)
319
            return AVERROR(EINVAL);
320
    }
321
16
    if (!pan->out_channel_layout) {
322
5
        if (av_opt_set_int(pan->swr, "och", pan->nb_output_channels, 0) < 0)
323
            return AVERROR(EINVAL);
324
    }
325
326
    // gains are pure, init the channel mapping
327
16
    if (pan->pure_gains) {
328
329
        // get channel map from the pure gains
330
21
        for (i = 0; i < pan->nb_output_channels; i++) {
331
13
            int ch_id = -1;
332
21
            for (j = 0; j < link->channels; j++) {
333
19
                if (pan->gain[i][j]) {
334
11
                    ch_id = j;
335
11
                    break;
336
                }
337
            }
338
13
            pan->channel_map[i] = ch_id;
339
        }
340
341
8
        av_opt_set_int(pan->swr, "icl", pan->out_channel_layout, 0);
342
8
        av_opt_set_int(pan->swr, "uch", pan->nb_output_channels, 0);
343
8
        swr_set_channel_mapping(pan->swr, pan->channel_map);
344
    } else {
345
        // renormalize
346
35
        for (i = 0; i < pan->nb_output_channels; i++) {
347
27
            if (!((pan->need_renorm >> i) & 1))
348
23
                continue;
349
4
            t = 0;
350
16
            for (j = 0; j < link->channels; j++)
351
12
                t += fabs(pan->gain[i][j]);
352

4
            if (t > -1E-5 && t < 1E-5) {
353
                // t is almost 0 but not exactly, this is probably a mistake
354
                if (t)
355
                    av_log(ctx, AV_LOG_WARNING,
356
                           "Degenerate coefficients while renormalizing\n");
357
                continue;
358
            }
359
16
            for (j = 0; j < link->channels; j++)
360
12
                pan->gain[i][j] /= t;
361
        }
362
8
        av_opt_set_int(pan->swr, "icl", link->channel_layout, 0);
363
8
        av_opt_set_int(pan->swr, "ocl", pan->out_channel_layout, 0);
364
8
        swr_set_matrix(pan->swr, pan->gain[0], pan->gain[1] - pan->gain[0]);
365
    }
366
367
16
    r = swr_init(pan->swr);
368
16
    if (r < 0)
369
        return r;
370
371
    // summary
372
56
    for (i = 0; i < pan->nb_output_channels; i++) {
373
40
        cur = buf;
374
207
        for (j = 0; j < link->channels; j++) {
375
167
            r = snprintf(cur, buf + sizeof(buf) - cur, "%s%.3g i%d",
376
                         j ? " + " : "", pan->gain[i][j], j);
377
167
            cur += FFMIN(buf + sizeof(buf) - cur, r);
378
        }
379
40
        av_log(ctx, AV_LOG_VERBOSE, "o%d = %s\n", i, buf);
380
    }
381
    // add channel mapping summary if possible
382
16
    if (pan->pure_gains) {
383
8
        av_log(ctx, AV_LOG_INFO, "Pure channel mapping detected:");
384
21
        for (i = 0; i < pan->nb_output_channels; i++)
385
13
            if (pan->channel_map[i] < 0)
386
2
                av_log(ctx, AV_LOG_INFO, " M");
387
            else
388
11
                av_log(ctx, AV_LOG_INFO, " %d", pan->channel_map[i]);
389
8
        av_log(ctx, AV_LOG_INFO, "\n");
390
8
        return 0;
391
    }
392
8
    return 0;
393
}
394
395
2076
static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
396
{
397
    int ret;
398
2076
    int n = insamples->nb_samples;
399
2076
    AVFilterLink *const outlink = inlink->dst->outputs[0];
400
2076
    AVFrame *outsamples = ff_get_audio_buffer(outlink, n);
401
2076
    PanContext *pan = inlink->dst->priv;
402
403
2076
    if (!outsamples) {
404
        av_frame_free(&insamples);
405
        return AVERROR(ENOMEM);
406
    }
407
2076
    swr_convert(pan->swr, outsamples->extended_data, n,
408
2076
                (void *)insamples->extended_data, n);
409
2076
    av_frame_copy_props(outsamples, insamples);
410
2076
    outsamples->channel_layout = outlink->channel_layout;
411
2076
    outsamples->channels = outlink->channels;
412
413
2076
    ret = ff_filter_frame(outlink, outsamples);
414
2076
    av_frame_free(&insamples);
415
2076
    return ret;
416
}
417
418
16
static av_cold void uninit(AVFilterContext *ctx)
419
{
420
16
    PanContext *pan = ctx->priv;
421
16
    swr_free(&pan->swr);
422
16
}
423
424
#define OFFSET(x) offsetof(PanContext, x)
425
426
static const AVOption pan_options[] = {
427
    { "args", NULL, OFFSET(args), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM },
428
    { NULL }
429
};
430
431
AVFILTER_DEFINE_CLASS(pan);
432
433
static const AVFilterPad pan_inputs[] = {
434
    {
435
        .name         = "default",
436
        .type         = AVMEDIA_TYPE_AUDIO,
437
        .config_props = config_props,
438
        .filter_frame = filter_frame,
439
    },
440
    { NULL }
441
};
442
443
static const AVFilterPad pan_outputs[] = {
444
    {
445
        .name = "default",
446
        .type = AVMEDIA_TYPE_AUDIO,
447
    },
448
    { NULL }
449
};
450
451
AVFilter ff_af_pan = {
452
    .name          = "pan",
453
    .description   = NULL_IF_CONFIG_SMALL("Remix channels with coefficients (panning)."),
454
    .priv_size     = sizeof(PanContext),
455
    .priv_class    = &pan_class,
456
    .init          = init,
457
    .uninit        = uninit,
458
    .query_formats = query_formats,
459
    .inputs        = pan_inputs,
460
    .outputs       = pan_outputs,
461
};