summaryrefslogtreecommitdiffstats
path: root/libavfilter/af_compand.c
blob: 0bb719fae5a38cefda20d5e027bda90a40319408 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
/*
 * Copyright (c) 1999 Chris Bagwell
 * Copyright (c) 1999 Nick Bailey
 * Copyright (c) 2007 Rob Sykes <robs@users.sourceforge.net>
 * Copyright (c) 2013 Paul B Mahol
 * Copyright (c) 2014 Andrew Kelley
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * audio compand filter
 */

#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/ffmath.h"
#include "libavutil/opt.h"
#include "libavutil/samplefmt.h"
#include "audio.h"
#include "avfilter.h"
#include "internal.h"

typedef struct ChanParam {
    double attack;
    double decay;
    double volume;
} ChanParam;

typedef struct CompandSegment {
    double x, y;
    double a, b;
} CompandSegment;

typedef struct CompandContext {
    const AVClass *class;
    int nb_segments;
    char *attacks, *decays, *points;
    CompandSegment *segments;
    ChanParam *channels;
    double in_min_lin;
    double out_min_lin;
    double curve_dB;
    double gain_dB;
    double initial_volume;
    double delay;
    AVFrame *delay_frame;
    int delay_samples;
    int delay_count;
    int delay_index;
    int64_t pts;

    int (*compand)(AVFilterContext *ctx, AVFrame *frame);
} CompandContext;

#define OFFSET(x) offsetof(CompandContext, x)
#define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

static const AVOption compand_options[] = {
    { "attacks", "set time over which increase of volume is determined", OFFSET(attacks), AV_OPT_TYPE_STRING, { .str = "0.3" }, 0, 0, A },
    { "decays", "set time over which decrease of volume is determined", OFFSET(decays), AV_OPT_TYPE_STRING, { .str = "0.8" }, 0, 0, A },
    { "points", "set points of transfer function", OFFSET(points), AV_OPT_TYPE_STRING, { .str = "-70/-70|-60/-20" }, 0, 0, A },
    { "soft-knee", "set soft-knee", OFFSET(curve_dB), AV_OPT_TYPE_DOUBLE, { .dbl = 0.01 }, 0.01, 900, A },
    { "gain", "set output gain", OFFSET(gain_dB), AV_OPT_TYPE_DOUBLE, { .dbl = 0 }, -900, 900, A },
    { "volume", "set initial volume", OFFSET(initial_volume), AV_OPT_TYPE_DOUBLE, { .dbl = 0 }, -900, 0, A },
    { "delay", "set delay for samples before sending them to volume adjuster", OFFSET(delay), AV_OPT_TYPE_DOUBLE, { .dbl = 0 }, 0, 20, A },
    { NULL }
};

AVFILTER_DEFINE_CLASS(compand);

static av_cold int init(AVFilterContext *ctx)
{
    CompandContext *s = ctx->priv;
    s->pts            = AV_NOPTS_VALUE;
    return 0;
}

static av_cold void uninit(AVFilterContext *ctx)
{
    CompandContext *s = ctx->priv;

    av_freep(&s->channels);
    av_freep(&s->segments);
    av_frame_free(&s->delay_frame);
}

static int query_formats(AVFilterContext *ctx)
{
    AVFilterChannelLayouts *layouts;
    AVFilterFormats *formats;
    static const enum AVSampleFormat sample_fmts[] = {
        AV_SAMPLE_FMT_DBLP,
        AV_SAMPLE_FMT_NONE
    };
    int ret;

    layouts = ff_all_channel_counts();
    if (!layouts)
        return AVERROR(ENOMEM);
    ret = ff_set_common_channel_layouts(ctx, layouts);
    if (ret < 0)
        return ret;

    formats = ff_make_format_list(sample_fmts);
    if (!formats)
        return AVERROR(ENOMEM);
    ret = ff_set_common_formats(ctx, formats);
    if (ret < 0)
        return ret;

    formats = ff_all_samplerates();
    if (!formats)
        return AVERROR(ENOMEM);
    return ff_set_common_samplerates(ctx, formats);
}

static void count_items(char *item_str, int *nb_items)
{
    char *p;

    *nb_items = 1;
    for (p = item_str; *p; p++) {
        if (*p == ' ' || *p == '|')
            (*nb_items)++;
    }
}

static void update_volume(ChanParam *cp, double in)
{
    double delta = in - cp->volume;

    if (delta > 0.0)
        cp->volume += delta * cp->attack;
    else
        cp->volume += delta * cp->decay;
}

static double get_volume(CompandContext *s, double in_lin)
{
    CompandSegment *cs;
    double in_log, out_log;
    int i;

    if (in_lin < s->in_min_lin)
        return s->out_min_lin;

    in_log = log(in_lin);

    for (i = 1; i < s->nb_segments; i++)
        if (in_log <= s->segments[i].x)
            break;
    cs = &s->segments[i - 1];
    in_log -= cs->x;
    out_log = cs->y + in_log * (cs->a * in_log + cs->b);

    return exp(out_log);
}

static int compand_nodelay(AVFilterContext *ctx, AVFrame *frame)
{
    CompandContext *s    = ctx->priv;
    AVFilterLink *inlink = ctx->inputs[0];
    const int channels   = inlink->channels;
    const int nb_samples = frame->nb_samples;
    AVFrame *out_frame;
    int chan, i;
    int err;

    if (av_frame_is_writable(frame)) {
        out_frame = frame;
    } else {
        out_frame = ff_get_audio_buffer(inlink, nb_samples);
        if (!out_frame) {
            av_frame_free(&frame);
            return AVERROR(ENOMEM);
        }
        err = av_frame_copy_props(out_frame, frame);
        if (err < 0) {
            av_frame_free(&out_frame);
            av_frame_free(&frame);
            return err;
        }
    }

    for (chan = 0; chan < channels; chan++) {
        const double *src = (double *)frame->extended_data[chan];
        double *dst = (double *)out_frame->extended_data[chan];
        ChanParam *cp = &s->channels[chan];

        for (i = 0; i < nb_samples; i++) {
            update_volume(cp, fabs(src[i]));

            dst[i] = src[i] * get_volume(s, cp->volume);
        }
    }

    if (frame != out_frame)
        av_frame_free(&frame);

    return ff_filter_frame(ctx->outputs[0], out_frame);
}

#define MOD(a, b) (((a) >= (b)) ? (a) - (b) : (a))

static int compand_delay(AVFilterContext *ctx, AVFrame *frame)
{
    CompandContext *s    = ctx->priv;
    AVFilterLink *inlink = ctx->inputs[0];
    const int channels = inlink->channels;
    const int nb_samples = frame->nb_samples;
    int chan, i, av_uninit(dindex), oindex, av_uninit(count);
    AVFrame *out_frame   = NULL;
    int err;

    if (s->pts == AV_NOPTS_VALUE) {
        s->pts = (frame->pts == AV_NOPTS_VALUE) ? 0 : frame->pts;
    }

    av_assert1(channels > 0); /* would corrupt delay_count and delay_index */

    for (chan = 0; chan < channels; chan++) {
        AVFrame *delay_frame = s->delay_frame;
        const double *src    = (double *)frame->extended_data[chan];
        double *dbuf         = (double *)delay_frame->extended_data[chan];
        ChanParam *cp        = &s->channels[chan];
        double *dst;

        count  = s->delay_count;
        dindex = s->delay_index;
        for (i = 0, oindex = 0; i < nb_samples; i++) {
            const double in = src[i];
            update_volume(cp, fabs(in));

            if (count >= s->delay_samples) {
                if (!out_frame) {
                    out_frame = ff_get_audio_buffer(inlink, nb_samples - i);
                    if (!out_frame) {
                        av_frame_free(&frame);
                        return AVERROR(ENOMEM);
                    }
                    err = av_frame_copy_props(out_frame, frame);
                    if (err < 0) {
                        av_frame_free(&out_frame);
                        av_frame_free(&frame);
                        return err;
                    }
                    out_frame->pts = s->pts;
                    s->pts += av_rescale_q(nb_samples - i,
                        (AVRational){ 1, inlink->sample_rate },
                        inlink->time_base);
                }

                dst = (double *)out_frame->extended_data[chan];
                dst[oindex++] = dbuf[dindex] * get_volume(s, cp->volume);
            } else {
                count++;
            }

            dbuf[dindex] = in;
            dindex = MOD(dindex + 1, s->delay_samples);
        }
    }

    s->delay_count = count;
    s->delay_index = dindex;

    av_frame_free(&frame);

    if (out_frame) {
        err = ff_filter_frame(ctx->outputs[0], out_frame);
        return err;
    }

    return 0;
}

static int compand_drain(AVFilterLink *outlink)
{
    AVFilterContext *ctx = outlink->src;
    CompandContext *s    = ctx->priv;
    const int channels   = outlink->channels;
    AVFrame *frame       = NULL;
    int chan, i, dindex;

    /* 2048 is to limit output frame size during drain */
    frame = ff_get_audio_buffer(outlink, FFMIN(2048, s->delay_count));
    if (!frame)
        return AVERROR(ENOMEM);
    frame->pts = s->pts;
    s->pts += av_rescale_q(frame->nb_samples,
            (AVRational){ 1, outlink->sample_rate }, outlink->time_base);

    av_assert0(channels > 0);
    for (chan = 0; chan < channels; chan++) {
        AVFrame *delay_frame = s->delay_frame;
        double *dbuf = (double *)delay_frame->extended_data[chan];
        double *dst = (double *)frame->extended_data[chan];
        ChanParam *cp = &s->channels[chan];

        dindex = s->delay_index;
        for (i = 0; i < frame->nb_samples; i++) {
            dst[i] = dbuf[dindex] * get_volume(s, cp->volume);
            dindex = MOD(dindex + 1, s->delay_samples);
        }
    }
    s->delay_count -= frame->nb_samples;
    s->delay_index = dindex;

    return ff_filter_frame(outlink, frame);
}

static int config_output(AVFilterLink *outlink)
{
    AVFilterContext *ctx  = outlink->src;
    CompandContext *s     = ctx->priv;
    const int sample_rate = outlink->sample_rate;
    double radius         = s->curve_dB * M_LN10 / 20.0;
    char *p, *saveptr     = NULL;
    const int channels    = outlink->channels;
    int nb_attacks, nb_decays, nb_points;
    int new_nb_items, num;
    int i;
    int err;


    count_items(s->attacks, &nb_attacks);
    count_items(s->decays, &nb_decays);
    count_items(s->points, &nb_points);

    if (channels <= 0) {
        av_log(ctx, AV_LOG_ERROR, "Invalid number of channels: %d\n", channels);
        return AVERROR(EINVAL);
    }

    if (nb_attacks > channels || nb_decays > channels) {
        av_log(ctx, AV_LOG_ERROR,
                "Number of attacks/decays bigger than number of channels.\n");
        return AVERROR(EINVAL);
    }

    uninit(ctx);

    s->channels = av_mallocz_array(channels, sizeof(*s->channels));
    s->nb_segments = (nb_points + 4) * 2;
    s->segments = av_mallocz_array(s->nb_segments, sizeof(*s->segments));

    if (!s->channels || !s->segments) {
        uninit(ctx);
        return AVERROR(ENOMEM);
    }

    p = s->attacks;
    for (i = 0, new_nb_items = 0; i < nb_attacks; i++) {
        char *tstr = av_strtok(p, " |", &saveptr);
        p = NULL;
        new_nb_items += sscanf(tstr, "%lf", &s->channels[i].attack) == 1;
        if (s->channels[i].attack < 0) {
            uninit(ctx);
            return AVERROR(EINVAL);
        }
    }
    nb_attacks = new_nb_items;

    p = s->decays;
    for (i = 0, new_nb_items = 0; i < nb_decays; i++) {
        char *tstr = av_strtok(p, " |", &saveptr);
        p = NULL;
        new_nb_items += sscanf(tstr, "%lf", &s->channels[i].decay) == 1;
        if (s->channels[i].decay < 0) {
            uninit(ctx);
            return AVERROR(EINVAL);
        }
    }
    nb_decays = new_nb_items;

    if (nb_attacks != nb_decays) {
        av_log(ctx, AV_LOG_ERROR,
                "Number of attacks %d differs from number of decays %d.\n",
                nb_attacks, nb_decays);
        uninit(ctx);
        return AVERROR(EINVAL);
    }

    for (i = nb_decays; i < channels; i++) {
        s->channels[i].attack = s->channels[nb_decays - 1].attack;
        s->channels[i].decay = s->channels[nb_decays - 1].decay;
    }

#define S(x) s->segments[2 * ((x) + 1)]
    p = s->points;
    for (i = 0, new_nb_items = 0; i < nb_points; i++) {
        char *tstr = av_strtok(p, " |", &saveptr);
        p = NULL;
        if (sscanf(tstr, "%lf/%lf", &S(i).x, &S(i).y) != 2) {
            av_log(ctx, AV_LOG_ERROR,
                    "Invalid and/or missing input/output value.\n");
            uninit(ctx);
            return AVERROR(EINVAL);
        }
        if (i && S(i - 1).x > S(i).x) {
            av_log(ctx, AV_LOG_ERROR,
                    "Transfer function input values must be increasing.\n");
            uninit(ctx);
            return AVERROR(EINVAL);
        }
        S(i).y -= S(i).x;
        av_log(ctx, AV_LOG_DEBUG, "%d: x=%f y=%f\n", i, S(i).x, S(i).y);
        new_nb_items++;
    }
    num = new_nb_items;

    /* Add 0,0 if necessary */
    if (num == 0 || S(num - 1).x)
        num++;

#undef S
#define S(x) s->segments[2 * (x)]
    /* Add a tail off segment at the start */
    S(0).x = S(1).x - 2 * s->curve_dB;
    S(0).y = S(1).y;
    num++;

    /* Join adjacent colinear segments */
    for (i = 2; i < num; i++) {
        double g1 = (S(i - 1).y - S(i - 2).y) * (S(i - 0).x - S(i - 1).x);
        double g2 = (S(i - 0).y - S(i - 1).y) * (S(i - 1).x - S(i - 2).x);
        int j;

        if (fabs(g1 - g2))
            continue;
        num--;
        for (j = --i; j < num; j++)
            S(j) = S(j + 1);
    }

    for (i = 0; i < s->nb_segments; i += 2) {
        s->segments[i].y += s->gain_dB;
        s->segments[i].x *= M_LN10 / 20;
        s->segments[i].y *= M_LN10 / 20;
    }

#define L(x) s->segments[i - (x)]
    for (i = 4; i < s->nb_segments; i += 2) {
        double x, y, cx, cy, in1, in2, out1, out2, theta, len, r;

        L(4).a = 0;
        L(4).b = (L(2).y - L(4).y) / (L(2).x - L(4).x);

        L(2).a = 0;
        L(2).b = (L(0).y - L(2).y) / (L(0).x - L(2).x);

        theta = atan2(L(2).y - L(4).y, L(2).x - L(4).x);
        len = hypot(L(2).x - L(4).x, L(2).y - L(4).y);
        r = FFMIN(radius, len);
        L(3).x = L(2).x - r * cos(theta);
        L(3).y = L(2).y - r * sin(theta);

        theta = atan2(L(0).y - L(2).y, L(0).x - L(2).x);
        len = hypot(L(0).x - L(2).x, L(0).y - L(2).y);
        r = FFMIN(radius, len / 2);
        x = L(2).x + r * cos(theta);
        y = L(2).y + r * sin(theta);

        cx = (L(3).x + L(2).x + x) / 3;
        cy = (L(3).y + L(2).y + y) / 3;

        L(2).x = x;
        L(2).y = y;

        in1  = cx - L(3).x;
        out1 = cy - L(3).y;
        in2  = L(2).x - L(3).x;
        out2 = L(2).y - L(3).y;
        L(3).a = (out2 / in2 - out1 / in1) / (in2 - in1);
        L(3).b = out1 / in1 - L(3).a * in1;
    }
    L(3).x = 0;
    L(3).y = L(2).y;

    s->in_min_lin  = exp(s->segments[1].x);
    s->out_min_lin = exp(s->segments[1].y);

    for (i = 0; i < channels; i++) {
        ChanParam *cp = &s->channels[i];

        if (cp->attack > 1.0 / sample_rate)
            cp->attack = 1.0 - exp(-1.0 / (sample_rate * cp->attack));
        else
            cp->attack = 1.0;
        if (cp->decay > 1.0 / sample_rate)
            cp->decay = 1.0 - exp(-1.0 / (sample_rate * cp->decay));
        else
            cp->decay = 1.0;
        cp->volume = ff_exp10(s->initial_volume / 20);
    }

    s->delay_samples = s->delay * sample_rate;
    if (s->delay_samples <= 0) {
        s->compand = compand_nodelay;
        return 0;
    }

    s->delay_frame = av_frame_alloc();
    if (!s->delay_frame) {
        uninit(ctx);
        return AVERROR(ENOMEM);
    }

    s->delay_frame->format         = outlink->format;
    s->delay_frame->nb_samples     = s->delay_samples;
    s->delay_frame->channel_layout = outlink->channel_layout;

    err = av_frame_get_buffer(s->delay_frame, 32);
    if (err)
        return err;

    s->compand = compand_delay;
    return 0;
}

static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
    AVFilterContext *ctx = inlink->dst;
    CompandContext *s    = ctx->priv;

    return s->compand(ctx, frame);
}

static int request_frame(AVFilterLink *outlink)
{
    AVFilterContext *ctx = outlink->src;
    CompandContext *s    = ctx->priv;
    int ret = 0;

    ret = ff_request_frame(ctx->inputs[0]);

    if (ret == AVERROR_EOF && !ctx->is_disabled && s->delay_count)
        ret = compand_drain(outlink);

    return ret;
}

static const AVFilterPad compand_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_AUDIO,
        .filter_frame = filter_frame,
    },
    { NULL }
};

static const AVFilterPad compand_outputs[] = {
    {
        .name          = "default",
        .request_frame = request_frame,
        .config_props  = config_output,
        .type          = AVMEDIA_TYPE_AUDIO,
    },
    { NULL }
};


AVFilter ff_af_compand = {
    .name           = "compand",
    .description    = NULL_IF_CONFIG_SMALL(
            "Compress or expand audio dynamic range."),
    .query_formats  = query_formats,
    .priv_size      = sizeof(CompandContext),
    .priv_class     = &compand_class,
    .init           = init,
    .uninit         = uninit,
    .inputs         = compand_inputs,
    .outputs        = compand_outputs,
};
OpenPOWER on IntegriCloud