GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/ffwavesynth.c Lines: 0 253 0.0 %
Date: 2019-11-18 18:00:01 Branches: 0 122 0.0 %

Line Branch Exec Source
1
/*
2
 * Wavesynth pseudo-codec
3
 * Copyright (c) 2011 Nicolas George
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
11
 *
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 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21
22
#include "libavutil/intreadwrite.h"
23
#include "libavutil/log.h"
24
#include "avcodec.h"
25
#include "internal.h"
26
27
28
#define SIN_BITS 14
29
#define WS_MAX_CHANNELS 32
30
#define INF_TS 0x7FFFFFFFFFFFFFFF
31
32
#define PINK_UNIT 128
33
34
/*
35
   Format of the extradata and packets
36
37
   THIS INFORMATION IS NOT PART OF THE PUBLIC API OR ABI.
38
   IT CAN CHANGE WITHOUT NOTIFICATION.
39
40
   All numbers are in little endian.
41
42
   The codec extradata define a set of intervals with uniform content.
43
   Overlapping intervals are added together.
44
45
   extradata:
46
       uint32      number of intervals
47
       ...         intervals
48
49
   interval:
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       int64       start timestamp; time_base must be 1/sample_rate;
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                   start timestamps must be in ascending order
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       int64       end timestamp
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       uint32      type
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       uint32      channels mask
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       ...         additional information, depends on type
56
57
   sine interval (type fourcc "SINE"):
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       int32       start frequency, in 1/(1<<16) Hz
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       int32       end frequency
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       int32       start amplitude, 1<<16 is the full amplitude
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       int32       end amplitude
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       uint32      start phase, 0 is sin(0), 0x20000000 is sin(pi/2), etc.;
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                   n | (1<<31) means to match the phase of previous channel #n
64
65
   pink noise interval (type fourcc "NOIS"):
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       int32       start amplitude
67
       int32       end amplitude
68
69
   The input packets encode the time and duration of the requested segment.
70
71
   packet:
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       int64       start timestamp
73
       int32       duration
74
75
*/
76
77
enum ws_interval_type {
78
    WS_SINE  = MKTAG('S','I','N','E'),
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    WS_NOISE = MKTAG('N','O','I','S'),
80
};
81
82
struct ws_interval {
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    int64_t ts_start, ts_end;
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    uint64_t phi0, dphi0, ddphi;
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    uint64_t amp0, damp;
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    uint64_t phi, dphi, amp;
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    uint32_t channels;
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    enum ws_interval_type type;
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    int next;
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};
91
92
struct wavesynth_context {
93
    int64_t cur_ts;
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    int64_t next_ts;
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    int32_t *sin;
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    struct ws_interval *inter;
97
    uint32_t dither_state;
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    uint32_t pink_state;
99
    int32_t pink_pool[PINK_UNIT];
100
    unsigned pink_need, pink_pos;
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    int nb_inter;
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    int cur_inter;
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    int next_inter;
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};
105
106
#define LCG_A 1284865837
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#define LCG_C 4150755663
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#define LCG_AI 849225893 /* A*AI = 1 [mod 1<<32] */
109
110
static uint32_t lcg_next(uint32_t *s)
111
{
112
    *s = *s * LCG_A + LCG_C;
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    return *s;
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}
115
116
static void lcg_seek(uint32_t *s, uint32_t dt)
117
{
118
    uint32_t a, c, t = *s;
119
120
    a = LCG_A;
121
    c = LCG_C;
122
    while (dt) {
123
        if (dt & 1)
124
            t = a * t + c;
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        c *= a + 1; /* coefficients for a double step */
126
        a *= a;
127
        dt >>= 1;
128
    }
129
    *s = t;
130
}
131
132
/* Emulate pink noise by summing white noise at the sampling frequency,
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 * white noise at half the sampling frequency (each value taken twice),
134
 * etc., with a total of 8 octaves.
135
 * This is known as the Voss-McCartney algorithm. */
136
137
static void pink_fill(struct wavesynth_context *ws)
138
{
139
    int32_t vt[7] = { 0 }, v = 0;
140
    int i, j;
141
142
    ws->pink_pos = 0;
143
    if (!ws->pink_need)
144
        return;
145
    for (i = 0; i < PINK_UNIT; i++) {
146
        for (j = 0; j < 7; j++) {
147
            if ((i >> j) & 1)
148
                break;
149
            v -= vt[j];
150
            vt[j] = (int32_t)lcg_next(&ws->pink_state) >> 3;
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            v += vt[j];
152
        }
153
        ws->pink_pool[i] = v + ((int32_t)lcg_next(&ws->pink_state) >> 3);
154
    }
155
    lcg_next(&ws->pink_state); /* so we use exactly 256 steps */
156
}
157
158
/**
159
 * @return  (1<<64) * a / b, without overflow, if a < b
160
 */
161
static uint64_t frac64(uint64_t a, uint64_t b)
162
{
163
    uint64_t r = 0;
164
    int i;
165
166
    if (b < (uint64_t)1 << 32) { /* b small, use two 32-bits steps */
167
        a <<= 32;
168
        return ((a / b) << 32) | ((a % b) << 32) / b;
169
    }
170
    if (b < (uint64_t)1 << 48) { /* b medium, use four 16-bits steps */
171
        for (i = 0; i < 4; i++) {
172
            a <<= 16;
173
            r = (r << 16) | (a / b);
174
            a %= b;
175
        }
176
        return r;
177
    }
178
    for (i = 63; i >= 0; i--) {
179
        if (a >= (uint64_t)1 << 63 || a << 1 >= b) {
180
            r |= (uint64_t)1 << i;
181
            a = (a << 1) - b;
182
        } else {
183
            a <<= 1;
184
        }
185
    }
186
    return r;
187
}
188
189
static uint64_t phi_at(struct ws_interval *in, int64_t ts)
190
{
191
    uint64_t dt = ts - in->ts_start;
192
    uint64_t dt2 = dt & 1 ? /* dt * (dt - 1) / 2 without overflow */
193
                   dt * ((dt - 1) >> 1) : (dt >> 1) * (dt - 1);
194
    return in->phi0 + dt * in->dphi0 + dt2 * in->ddphi;
195
}
196
197
static void wavesynth_seek(struct wavesynth_context *ws, int64_t ts)
198
{
199
    int *last, i;
200
    struct ws_interval *in;
201
202
    last = &ws->cur_inter;
203
    for (i = 0; i < ws->nb_inter; i++) {
204
        in = &ws->inter[i];
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        if (ts < in->ts_start)
206
            break;
207
        if (ts >= in->ts_end)
208
            continue;
209
        *last = i;
210
        last = &in->next;
211
        in->phi  = phi_at(in, ts);
212
        in->dphi = in->dphi0 + (ts - in->ts_start) * in->ddphi;
213
        in->amp  = in->amp0  + (ts - in->ts_start) * in->damp;
214
    }
215
    ws->next_inter = i;
216
    ws->next_ts = i < ws->nb_inter ? ws->inter[i].ts_start : INF_TS;
217
    *last = -1;
218
    lcg_seek(&ws->dither_state, (uint32_t)ts - (uint32_t)ws->cur_ts);
219
    if (ws->pink_need) {
220
        int64_t pink_ts_cur  = (ws->cur_ts + PINK_UNIT - 1) & ~(PINK_UNIT - 1);
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        int64_t pink_ts_next = ts & ~(PINK_UNIT - 1);
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        int pos = ts & (PINK_UNIT - 1);
223
        lcg_seek(&ws->pink_state, (uint32_t)(pink_ts_next - pink_ts_cur) * 2);
224
        if (pos) {
225
            pink_fill(ws);
226
            ws->pink_pos = pos;
227
        } else {
228
            ws->pink_pos = PINK_UNIT;
229
        }
230
    }
231
    ws->cur_ts = ts;
232
}
233
234
static int wavesynth_parse_extradata(AVCodecContext *avc)
235
{
236
    struct wavesynth_context *ws = avc->priv_data;
237
    struct ws_interval *in;
238
    uint8_t *edata, *edata_end;
239
    int32_t f1, f2, a1, a2;
240
    uint32_t phi;
241
    int64_t dphi1, dphi2, dt, cur_ts = -0x8000000000000000;
242
    int i;
243
244
    if (avc->extradata_size < 4)
245
        return AVERROR(EINVAL);
246
    edata = avc->extradata;
247
    edata_end = edata + avc->extradata_size;
248
    ws->nb_inter = AV_RL32(edata);
249
    edata += 4;
250
    if (ws->nb_inter < 0 || (edata_end - edata) / 24 < ws->nb_inter)
251
        return AVERROR(EINVAL);
252
    ws->inter = av_calloc(ws->nb_inter, sizeof(*ws->inter));
253
    if (!ws->inter)
254
        return AVERROR(ENOMEM);
255
    for (i = 0; i < ws->nb_inter; i++) {
256
        in = &ws->inter[i];
257
        if (edata_end - edata < 24)
258
            return AVERROR(EINVAL);
259
        in->ts_start = AV_RL64(edata +  0);
260
        in->ts_end   = AV_RL64(edata +  8);
261
        in->type     = AV_RL32(edata + 16);
262
        in->channels = AV_RL32(edata + 20);
263
        edata += 24;
264
        if (in->ts_start < cur_ts ||
265
            in->ts_end <= in->ts_start ||
266
            (uint64_t)in->ts_end - in->ts_start > INT64_MAX
267
        )
268
            return AVERROR(EINVAL);
269
        cur_ts = in->ts_start;
270
        dt = in->ts_end - in->ts_start;
271
        switch (in->type) {
272
            case WS_SINE:
273
                if (edata_end - edata < 20 || avc->sample_rate <= 0)
274
                    return AVERROR(EINVAL);
275
                f1  = AV_RL32(edata +  0);
276
                f2  = AV_RL32(edata +  4);
277
                a1  = AV_RL32(edata +  8);
278
                a2  = AV_RL32(edata + 12);
279
                phi = AV_RL32(edata + 16);
280
                edata += 20;
281
                dphi1 = frac64(f1, (int64_t)avc->sample_rate << 16);
282
                dphi2 = frac64(f2, (int64_t)avc->sample_rate << 16);
283
                in->dphi0 = dphi1;
284
                in->ddphi = (dphi2 - dphi1) / dt;
285
                if (phi & 0x80000000) {
286
                    phi &= ~0x80000000;
287
                    if (phi >= i)
288
                        return AVERROR(EINVAL);
289
                    in->phi0 = phi_at(&ws->inter[phi], in->ts_start);
290
                } else {
291
                    in->phi0 = (uint64_t)phi << 33;
292
                }
293
                break;
294
            case WS_NOISE:
295
                if (edata_end - edata < 8)
296
                    return AVERROR(EINVAL);
297
                a1  = AV_RL32(edata +  0);
298
                a2  = AV_RL32(edata +  4);
299
                edata += 8;
300
                break;
301
            default:
302
                return AVERROR(EINVAL);
303
        }
304
        in->amp0 = (uint64_t)a1 << 32;
305
        in->damp = (int64_t)(((uint64_t)a2 << 32) - ((uint64_t)a1 << 32)) / dt;
306
    }
307
    if (edata != edata_end)
308
        return AVERROR(EINVAL);
309
    return 0;
310
}
311
312
static av_cold int wavesynth_init(AVCodecContext *avc)
313
{
314
    struct wavesynth_context *ws = avc->priv_data;
315
    int i, r;
316
317
    if (avc->channels > WS_MAX_CHANNELS) {
318
        av_log(avc, AV_LOG_ERROR,
319
               "This implementation is limited to %d channels.\n",
320
               WS_MAX_CHANNELS);
321
        return AVERROR(EINVAL);
322
    }
323
    r = wavesynth_parse_extradata(avc);
324
    if (r < 0) {
325
        av_log(avc, AV_LOG_ERROR, "Invalid intervals definitions.\n");
326
        goto fail;
327
    }
328
    ws->sin = av_malloc(sizeof(*ws->sin) << SIN_BITS);
329
    if (!ws->sin) {
330
        r = AVERROR(ENOMEM);
331
        goto fail;
332
    }
333
    for (i = 0; i < 1 << SIN_BITS; i++)
334
        ws->sin[i] = floor(32767 * sin(2 * M_PI * i / (1 << SIN_BITS)));
335
    ws->dither_state = MKTAG('D','I','T','H');
336
    for (i = 0; i < ws->nb_inter; i++)
337
        ws->pink_need += ws->inter[i].type == WS_NOISE;
338
    ws->pink_state = MKTAG('P','I','N','K');
339
    ws->pink_pos = PINK_UNIT;
340
    wavesynth_seek(ws, 0);
341
    avc->sample_fmt = AV_SAMPLE_FMT_S16;
342
    return 0;
343
344
fail:
345
    av_freep(&ws->inter);
346
    av_freep(&ws->sin);
347
    return r;
348
}
349
350
static void wavesynth_synth_sample(struct wavesynth_context *ws, int64_t ts,
351
                                   int32_t *channels)
352
{
353
    int32_t amp, val, *cv;
354
    struct ws_interval *in;
355
    int i, *last, pink;
356
    uint32_t c, all_ch = 0;
357
358
    i = ws->cur_inter;
359
    last = &ws->cur_inter;
360
    if (ws->pink_pos == PINK_UNIT)
361
        pink_fill(ws);
362
    pink = ws->pink_pool[ws->pink_pos++] >> 16;
363
    while (i >= 0) {
364
        in = &ws->inter[i];
365
        i = in->next;
366
        if (ts >= in->ts_end) {
367
            *last = i;
368
            continue;
369
        }
370
        last = &in->next;
371
        amp = in->amp >> 32;
372
        in->amp  += in->damp;
373
        switch (in->type) {
374
            case WS_SINE:
375
                val = amp * ws->sin[in->phi >> (64 - SIN_BITS)];
376
                in->phi  += in->dphi;
377
                in->dphi += in->ddphi;
378
                break;
379
            case WS_NOISE:
380
                val = amp * (unsigned)pink;
381
                break;
382
            default:
383
                val = 0;
384
        }
385
        all_ch |= in->channels;
386
        for (c = in->channels, cv = channels; c; c >>= 1, cv++)
387
            if (c & 1)
388
                *cv += (unsigned)val;
389
    }
390
    val = (int32_t)lcg_next(&ws->dither_state) >> 16;
391
    for (c = all_ch, cv = channels; c; c >>= 1, cv++)
392
        if (c & 1)
393
            *cv += val;
394
}
395
396
static void wavesynth_enter_intervals(struct wavesynth_context *ws, int64_t ts)
397
{
398
    int *last, i;
399
    struct ws_interval *in;
400
401
    last = &ws->cur_inter;
402
    for (i = ws->cur_inter; i >= 0; i = ws->inter[i].next)
403
        last = &ws->inter[i].next;
404
    for (i = ws->next_inter; i < ws->nb_inter; i++) {
405
        in = &ws->inter[i];
406
        if (ts < in->ts_start)
407
            break;
408
        if (ts >= in->ts_end)
409
            continue;
410
        *last = i;
411
        last = &in->next;
412
        in->phi = in->phi0;
413
        in->dphi = in->dphi0;
414
        in->amp = in->amp0;
415
    }
416
    ws->next_inter = i;
417
    ws->next_ts = i < ws->nb_inter ? ws->inter[i].ts_start : INF_TS;
418
    *last = -1;
419
}
420
421
static int wavesynth_decode(AVCodecContext *avc, void *rframe, int *rgot_frame,
422
                            AVPacket *packet)
423
{
424
    struct wavesynth_context *ws = avc->priv_data;
425
    AVFrame *frame = rframe;
426
    int64_t ts;
427
    int duration;
428
    int s, c, r;
429
    int16_t *pcm;
430
    int32_t channels[WS_MAX_CHANNELS];
431
432
    *rgot_frame = 0;
433
    if (packet->size != 12)
434
        return AVERROR_INVALIDDATA;
435
    ts = AV_RL64(packet->data);
436
    if (ts != ws->cur_ts)
437
        wavesynth_seek(ws, ts);
438
    duration = AV_RL32(packet->data + 8);
439
    if (duration <= 0)
440
        return AVERROR(EINVAL);
441
    frame->nb_samples = duration;
442
    r = ff_get_buffer(avc, frame, 0);
443
    if (r < 0)
444
        return r;
445
    pcm = (int16_t *)frame->data[0];
446
    for (s = 0; s < duration; s++, ts++) {
447
        memset(channels, 0, avc->channels * sizeof(*channels));
448
        if (ts >= ws->next_ts)
449
            wavesynth_enter_intervals(ws, ts);
450
        wavesynth_synth_sample(ws, ts, channels);
451
        for (c = 0; c < avc->channels; c++)
452
            *(pcm++) = channels[c] >> 16;
453
    }
454
    ws->cur_ts += duration;
455
    *rgot_frame = 1;
456
    return packet->size;
457
}
458
459
static av_cold int wavesynth_close(AVCodecContext *avc)
460
{
461
    struct wavesynth_context *ws = avc->priv_data;
462
463
    av_freep(&ws->sin);
464
    av_freep(&ws->inter);
465
    return 0;
466
}
467
468
AVCodec ff_ffwavesynth_decoder = {
469
    .name           = "wavesynth",
470
    .long_name      = NULL_IF_CONFIG_SMALL("Wave synthesis pseudo-codec"),
471
    .type           = AVMEDIA_TYPE_AUDIO,
472
    .id             = AV_CODEC_ID_FFWAVESYNTH,
473
    .priv_data_size = sizeof(struct wavesynth_context),
474
    .init           = wavesynth_init,
475
    .close          = wavesynth_close,
476
    .decode         = wavesynth_decode,
477
    .capabilities   = AV_CODEC_CAP_DR1,
478
};