GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/g726.c Lines: 156 175 89.1 %
Date: 2019-11-18 18:00:01 Branches: 81 96 84.4 %

Line Branch Exec Source
1
/*
2
 * G.726 ADPCM audio codec
3
 * Copyright (c) 2004 Roman Shaposhnik
4
 *
5
 * This is a very straightforward rendition of the G.726
6
 * Section 4 "Computational Details".
7
 *
8
 * This file is part of FFmpeg.
9
 *
10
 * FFmpeg is free software; you can redistribute it and/or
11
 * modify it under the terms of the GNU Lesser General Public
12
 * License as published by the Free Software Foundation; either
13
 * version 2.1 of the License, or (at your option) any later version.
14
 *
15
 * FFmpeg is distributed in the hope that it will be useful,
16
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18
 * Lesser General Public License for more details.
19
 *
20
 * You should have received a copy of the GNU Lesser General Public
21
 * License along with FFmpeg; if not, write to the Free Software
22
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23
 */
24
#include <limits.h>
25
26
#include "libavutil/channel_layout.h"
27
#include "libavutil/opt.h"
28
#include "avcodec.h"
29
#include "internal.h"
30
#include "get_bits.h"
31
#include "put_bits.h"
32
33
/**
34
 * G.726 11-bit float.
35
 * G.726 Standard uses rather odd 11-bit floating point arithmetic for
36
 * numerous occasions. It's a mystery to me why they did it this way
37
 * instead of simply using 32-bit integer arithmetic.
38
 */
39
typedef struct Float11 {
40
    uint8_t sign;   /**< 1 bit sign */
41
    uint8_t exp;    /**< 4 bits exponent */
42
    uint8_t mant;   /**< 6 bits mantissa */
43
} Float11;
44
45
3840000
static inline Float11* i2f(int i, Float11* f)
46
{
47
3840000
    f->sign = (i < 0);
48
3840000
    if (f->sign)
49
1903568
        i = -i;
50
3840000
    f->exp = av_log2_16bit(i) + !!i;
51
3840000
    f->mant = i? (i<<6) >> f->exp : 1<<5;
52
3840000
    return f;
53
}
54
55
3072000
static inline int16_t mult(Float11* f1, Float11* f2)
56
{
57
        int res, exp;
58
59
3072000
        exp = f1->exp + f2->exp;
60
3072000
        res = (((f1->mant * f2->mant) + 0x30) >> 4);
61
3072000
        res = exp > 19 ? res << (exp - 19) : res >> (19 - exp);
62
3072000
        return (f1->sign ^ f2->sign) ? -res : res;
63
}
64
65
3022660
static inline int sgn(int value)
66
{
67
3022660
    return (value < 0) ? -1 : 1;
68
}
69
70
typedef struct G726Tables {
71
    const int* quant;         /**< quantization table */
72
    const int16_t* iquant;    /**< inverse quantization table */
73
    const int16_t* W;         /**< special table #1 ;-) */
74
    const uint8_t* F;         /**< special table #2 */
75
} G726Tables;
76
77
typedef struct G726Context {
78
    AVClass *class;
79
    G726Tables tbls;    /**< static tables needed for computation */
80
81
    Float11 sr[2];      /**< prev. reconstructed samples */
82
    Float11 dq[6];      /**< prev. difference */
83
    int a[2];           /**< second order predictor coeffs */
84
    int b[6];           /**< sixth order predictor coeffs */
85
    int pk[2];          /**< signs of prev. 2 sez + dq */
86
87
    int ap;             /**< scale factor control */
88
    int yu;             /**< fast scale factor */
89
    int yl;             /**< slow scale factor */
90
    int dms;            /**< short average magnitude of F[i] */
91
    int dml;            /**< long average magnitude of F[i] */
92
    int td;             /**< tone detect */
93
94
    int se;             /**< estimated signal for the next iteration */
95
    int sez;            /**< estimated second order prediction */
96
    int y;              /**< quantizer scaling factor for the next iteration */
97
    int code_size;
98
    int little_endian;  /**< little-endian bitstream as used in aiff and Sun AU */
99
} G726Context;
100
101
static const int quant_tbl16[] =                  /**< 16kbit/s 2 bits per sample */
102
           { 260, INT_MAX };
103
static const int16_t iquant_tbl16[] =
104
           { 116, 365, 365, 116 };
105
static const int16_t W_tbl16[] =
106
           { -22, 439, 439, -22 };
107
static const uint8_t F_tbl16[] =
108
           { 0, 7, 7, 0 };
109
110
static const int quant_tbl24[] =                  /**< 24kbit/s 3 bits per sample */
111
           {  7, 217, 330, INT_MAX };
112
static const int16_t iquant_tbl24[] =
113
           { INT16_MIN, 135, 273, 373, 373, 273, 135, INT16_MIN };
114
static const int16_t W_tbl24[] =
115
           { -4,  30, 137, 582, 582, 137,  30, -4 };
116
static const uint8_t F_tbl24[] =
117
           { 0, 1, 2, 7, 7, 2, 1, 0 };
118
119
static const int quant_tbl32[] =                  /**< 32kbit/s 4 bits per sample */
120
           { -125,  79, 177, 245, 299, 348, 399, INT_MAX };
121
static const int16_t iquant_tbl32[] =
122
         { INT16_MIN,   4, 135, 213, 273, 323, 373, 425,
123
                 425, 373, 323, 273, 213, 135,   4, INT16_MIN };
124
static const int16_t W_tbl32[] =
125
           { -12,  18,  41,  64, 112, 198, 355, 1122,
126
            1122, 355, 198, 112,  64,  41,  18, -12};
127
static const uint8_t F_tbl32[] =
128
           { 0, 0, 0, 1, 1, 1, 3, 7, 7, 3, 1, 1, 1, 0, 0, 0 };
129
130
static const int quant_tbl40[] =                  /**< 40kbit/s 5 bits per sample */
131
           { -122, -16,  67, 138, 197, 249, 297, 338,
132
              377, 412, 444, 474, 501, 527, 552, INT_MAX };
133
static const int16_t iquant_tbl40[] =
134
         { INT16_MIN, -66,  28, 104, 169, 224, 274, 318,
135
                 358, 395, 429, 459, 488, 514, 539, 566,
136
                 566, 539, 514, 488, 459, 429, 395, 358,
137
                 318, 274, 224, 169, 104,  28, -66, INT16_MIN };
138
static const int16_t W_tbl40[] =
139
           {   14,  14,  24,  39,  40,  41,   58,  100,
140
              141, 179, 219, 280, 358, 440,  529,  696,
141
              696, 529, 440, 358, 280, 219,  179,  141,
142
              100,  58,  41,  40,  39,  24,   14,   14 };
143
static const uint8_t F_tbl40[] =
144
           { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 6,
145
             6, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
146
147
static const G726Tables G726Tables_pool[] =
148
           {{ quant_tbl16, iquant_tbl16, W_tbl16, F_tbl16 },
149
            { quant_tbl24, iquant_tbl24, W_tbl24, F_tbl24 },
150
            { quant_tbl32, iquant_tbl32, W_tbl32, F_tbl32 },
151
            { quant_tbl40, iquant_tbl40, W_tbl40, F_tbl40 }};
152
153
154
/**
155
 * Paragraph 4.2.2 page 18: Adaptive quantizer.
156
 */
157
192000
static inline uint8_t quant(G726Context* c, int d)
158
{
159
    int sign, exp, i, dln;
160
161
192000
    sign = i = 0;
162
192000
    if (d < 0) {
163
91006
        sign = 1;
164
91006
        d = -d;
165
    }
166
192000
    exp = av_log2_16bit(d);
167
192000
    dln = ((exp<<7) + (((d<<7)>>exp)&0x7f)) - (c->y>>2);
168
169

628554
    while (c->tbls.quant[i] < INT_MAX && c->tbls.quant[i] < dln)
170
436554
        ++i;
171
172
192000
    if (sign)
173
91006
        i = ~i;
174

192000
    if (c->code_size != 2 && i == 0) /* I'm not sure this is a good idea */
175
12505
        i = 0xff;
176
177
192000
    return i;
178
}
179
180
/**
181
 * Paragraph 4.2.3 page 22: Inverse adaptive quantizer.
182
 */
183
384000
static inline int16_t inverse_quant(G726Context* c, int i)
184
{
185
    int dql, dex, dqt;
186
187
384000
    dql = c->tbls.iquant[i] + (c->y >> 2);
188
384000
    dex = (dql>>7) & 0xf;        /* 4-bit exponent */
189
384000
    dqt = (1<<7) + (dql & 0x7f); /* log2 -> linear */
190
384000
    return (dql < 0) ? 0 : ((dqt<<dex) >> 7);
191
}
192
193
384000
static int16_t g726_decode(G726Context* c, int I)
194
{
195
    int dq, re_signal, pk0, fa1, i, tr, ylint, ylfrac, thr2, al, dq0;
196
    Float11 f;
197
384000
    int I_sig= I >> (c->code_size - 1);
198
199
384000
    dq = inverse_quant(c, I);
200
201
    /* Transition detect */
202
384000
    ylint = (c->yl >> 15);
203
384000
    ylfrac = (c->yl >> 10) & 0x1f;
204
384000
    thr2 = (ylint > 9) ? 0x1f << 10 : (0x20 + ylfrac) << ylint;
205

384000
    tr= (c->td == 1 && dq > ((3*thr2)>>2));
206
207
384000
    if (I_sig)  /* get the sign */
208
207022
        dq = -dq;
209
384000
    re_signal = (int16_t)(c->se + dq);
210
211
    /* Update second order predictor coefficient A2 and A1 */
212
384000
    pk0 = (c->sez + dq) ? sgn(c->sez + dq) : 0;
213
384000
    dq0 = dq ? sgn(dq) : 0;
214
384000
    if (tr) {
215
6
        c->a[0] = 0;
216
6
        c->a[1] = 0;
217
42
        for (i=0; i<6; i++)
218
36
            c->b[i] = 0;
219
    } else {
220
        /* This is a bit crazy, but it really is +255 not +256 */
221
383994
        fa1 = av_clip_intp2((-c->a[0]*c->pk[0]*pk0)>>5, 8);
222
223
383994
        c->a[1] += 128*pk0*c->pk[1] + fa1 - (c->a[1]>>7);
224
383994
        c->a[1] = av_clip(c->a[1], -12288, 12288);
225
383994
        c->a[0] += 64*3*pk0*c->pk[0] - (c->a[0] >> 8);
226
383994
        c->a[0] = av_clip(c->a[0], -(15360 - c->a[1]), 15360 - c->a[1]);
227
228
2687958
        for (i=0; i<6; i++)
229
2303964
            c->b[i] += 128*dq0*sgn(-c->dq[i].sign) - (c->b[i]>>8);
230
    }
231
232
    /* Update Dq and Sr and Pk */
233
384000
    c->pk[1] = c->pk[0];
234
384000
    c->pk[0] = pk0 ? pk0 : 1;
235
384000
    c->sr[1] = c->sr[0];
236
384000
    i2f(re_signal, &c->sr[0]);
237
2304000
    for (i=5; i>0; i--)
238
1920000
        c->dq[i] = c->dq[i-1];
239
384000
    i2f(dq, &c->dq[0]);
240
384000
    c->dq[0].sign = I_sig; /* Isn't it crazy ?!?! */
241
242
384000
    c->td = c->a[1] < -11776;
243
244
    /* Update Ap */
245
384000
    c->dms += (c->tbls.F[I]<<4) + ((- c->dms) >> 5);
246
384000
    c->dml += (c->tbls.F[I]<<4) + ((- c->dml) >> 7);
247
384000
    if (tr)
248
6
        c->ap = 256;
249
    else {
250
383994
        c->ap += (-c->ap) >> 4;
251

383994
        if (c->y <= 1535 || c->td || abs((c->dms << 2) - c->dml) >= (c->dml >> 3))
252
270694
            c->ap += 0x20;
253
    }
254
255
    /* Update Yu and Yl */
256
384000
    c->yu = av_clip(c->y + c->tbls.W[I] + ((-c->y)>>5), 544, 5120);
257
384000
    c->yl += c->yu + ((-c->yl)>>6);
258
259
    /* Next iteration for Y */
260
384000
    al = (c->ap >= 256) ? 1<<6 : c->ap >> 2;
261
384000
    c->y = (c->yl + (c->yu - (c->yl>>6))*al) >> 6;
262
263
    /* Next iteration for SE and SEZ */
264
384000
    c->se = 0;
265
2688000
    for (i=0; i<6; i++)
266
2304000
        c->se += mult(i2f(c->b[i] >> 2, &f), &c->dq[i]);
267
384000
    c->sez = c->se >> 1;
268
1152000
    for (i=0; i<2; i++)
269
768000
        c->se += mult(i2f(c->a[i] >> 2, &f), &c->sr[i]);
270
384000
    c->se >>= 1;
271
272
384000
    return av_clip(re_signal * 4, -0xffff, 0xffff);
273
}
274
275
12
static av_cold int g726_reset(G726Context *c)
276
{
277
    int i;
278
279
12
    c->tbls = G726Tables_pool[c->code_size - 2];
280
36
    for (i=0; i<2; i++) {
281
24
        c->sr[i].mant = 1<<5;
282
24
        c->pk[i] = 1;
283
    }
284
84
    for (i=0; i<6; i++) {
285
72
        c->dq[i].mant = 1<<5;
286
    }
287
12
    c->yu = 544;
288
12
    c->yl = 34816;
289
290
12
    c->y = 544;
291
292
12
    return 0;
293
}
294
295
#if CONFIG_ADPCM_G726_ENCODER || CONFIG_ADPCM_G726LE_ENCODER
296
192000
static int16_t g726_encode(G726Context* c, int16_t sig)
297
{
298
    uint8_t i;
299
300
192000
    i = av_mod_uintp2(quant(c, sig/4 - c->se), c->code_size);
301
192000
    g726_decode(c, i);
302
192000
    return i;
303
}
304
305
/* Interfacing to the libavcodec */
306
307
4
static av_cold int g726_encode_init(AVCodecContext *avctx)
308
{
309
4
    G726Context* c = avctx->priv_data;
310
311
4
    c->little_endian = !strcmp(avctx->codec->name, "g726le");
312
313
4
    if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL &&
314
4
        avctx->sample_rate != 8000) {
315
        av_log(avctx, AV_LOG_ERROR, "Sample rates other than 8kHz are not "
316
               "allowed when the compliance level is higher than unofficial. "
317
               "Resample or reduce the compliance level.\n");
318
        return AVERROR(EINVAL);
319
    }
320
4
    if (avctx->sample_rate <= 0) {
321
        av_log(avctx, AV_LOG_ERROR, "Invalid sample rate %d\n",
322
               avctx->sample_rate);
323
        return AVERROR(EINVAL);
324
    }
325
326
4
    if(avctx->channels != 1){
327
        av_log(avctx, AV_LOG_ERROR, "Only mono is supported\n");
328
        return AVERROR(EINVAL);
329
    }
330
331
4
    if (avctx->bit_rate)
332
4
        c->code_size = (avctx->bit_rate + avctx->sample_rate/2) / avctx->sample_rate;
333
334
4
    c->code_size = av_clip(c->code_size, 2, 5);
335
4
    avctx->bit_rate = c->code_size * avctx->sample_rate;
336
4
    avctx->bits_per_coded_sample = c->code_size;
337
338
4
    g726_reset(c);
339
340
    /* select a frame size that will end on a byte boundary and have a size of
341
       approximately 1024 bytes */
342
4
    avctx->frame_size = ((int[]){ 4096, 2736, 2048, 1640 })[c->code_size - 2];
343
344
4
    return 0;
345
}
346
347
84
static int g726_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
348
                             const AVFrame *frame, int *got_packet_ptr)
349
{
350
84
    G726Context *c = avctx->priv_data;
351
84
    const int16_t *samples = (const int16_t *)frame->data[0];
352
    PutBitContext pb;
353
    int i, ret, out_size;
354
355
84
    out_size = (frame->nb_samples * c->code_size + 7) / 8;
356
84
    if ((ret = ff_alloc_packet2(avctx, avpkt, out_size, 0)) < 0)
357
        return ret;
358
84
    init_put_bits(&pb, avpkt->data, avpkt->size);
359
360
192084
    for (i = 0; i < frame->nb_samples; i++)
361
192000
        if (c->little_endian) {
362
            put_bits_le(&pb, c->code_size, g726_encode(c, *samples++));
363
        } else {
364
192000
            put_bits(&pb, c->code_size, g726_encode(c, *samples++));
365
        }
366
367
84
    if (c->little_endian) {
368
        flush_put_bits_le(&pb);
369
    } else {
370
84
        flush_put_bits(&pb);
371
    }
372
373
84
    avpkt->size = out_size;
374
84
    *got_packet_ptr = 1;
375
84
    return 0;
376
}
377
378
#define OFFSET(x) offsetof(G726Context, x)
379
#define AE AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
380
static const AVOption options[] = {
381
    { "code_size", "Bits per code", OFFSET(code_size), AV_OPT_TYPE_INT, { .i64 = 4 }, 2, 5, AE },
382
    { NULL },
383
};
384
385
static const AVCodecDefault defaults[] = {
386
    { "b", "0" },
387
    { NULL },
388
};
389
#endif
390
391
#if CONFIG_ADPCM_G726_ENCODER
392
static const AVClass g726_class = {
393
    .class_name = "g726",
394
    .item_name  = av_default_item_name,
395
    .option     = options,
396
    .version    = LIBAVUTIL_VERSION_INT,
397
};
398
399
AVCodec ff_adpcm_g726_encoder = {
400
    .name           = "g726",
401
    .long_name      = NULL_IF_CONFIG_SMALL("G.726 ADPCM"),
402
    .type           = AVMEDIA_TYPE_AUDIO,
403
    .id             = AV_CODEC_ID_ADPCM_G726,
404
    .priv_data_size = sizeof(G726Context),
405
    .init           = g726_encode_init,
406
    .encode2        = g726_encode_frame,
407
    .capabilities   = AV_CODEC_CAP_SMALL_LAST_FRAME,
408
    .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
409
                                                     AV_SAMPLE_FMT_NONE },
410
    .priv_class     = &g726_class,
411
    .defaults       = defaults,
412
};
413
#endif
414
415
#if CONFIG_ADPCM_G726LE_ENCODER
416
static const AVClass g726le_class = {
417
    .class_name = "g726le",
418
    .item_name  = av_default_item_name,
419
    .option     = options,
420
    .version    = LIBAVUTIL_VERSION_INT,
421
};
422
423
AVCodec ff_adpcm_g726le_encoder = {
424
    .name           = "g726le",
425
    .long_name      = NULL_IF_CONFIG_SMALL("G.726 little endian ADPCM (\"right-justified\")"),
426
    .type           = AVMEDIA_TYPE_AUDIO,
427
    .id             = AV_CODEC_ID_ADPCM_G726LE,
428
    .priv_data_size = sizeof(G726Context),
429
    .init           = g726_encode_init,
430
    .encode2        = g726_encode_frame,
431
    .capabilities   = AV_CODEC_CAP_SMALL_LAST_FRAME,
432
    .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
433
                                                     AV_SAMPLE_FMT_NONE },
434
    .priv_class     = &g726le_class,
435
    .defaults       = defaults,
436
};
437
#endif
438
439
#if CONFIG_ADPCM_G726_DECODER || CONFIG_ADPCM_G726LE_DECODER
440
8
static av_cold int g726_decode_init(AVCodecContext *avctx)
441
{
442
8
    G726Context* c = avctx->priv_data;
443
444
8
    if(avctx->channels > 1){
445
        avpriv_request_sample(avctx, "Decoding more than one channel");
446
        return AVERROR_PATCHWELCOME;
447
    }
448
8
    avctx->channels       = 1;
449
8
    avctx->channel_layout = AV_CH_LAYOUT_MONO;
450
451
8
    c->little_endian = !strcmp(avctx->codec->name, "g726le");
452
453
8
    c->code_size = avctx->bits_per_coded_sample;
454

8
    if (c->code_size < 2 || c->code_size > 5) {
455
        av_log(avctx, AV_LOG_ERROR, "Invalid number of bits %d\n", c->code_size);
456
        return AVERROR(EINVAL);
457
    }
458
8
    g726_reset(c);
459
460
8
    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
461
462
8
    return 0;
463
}
464
465
22
static int g726_decode_frame(AVCodecContext *avctx, void *data,
466
                             int *got_frame_ptr, AVPacket *avpkt)
467
{
468
22
    AVFrame *frame     = data;
469
22
    const uint8_t *buf = avpkt->data;
470
22
    int buf_size = avpkt->size;
471
22
    G726Context *c = avctx->priv_data;
472
    int16_t *samples;
473
    GetBitContext gb;
474
    int out_samples, ret;
475
476
22
    out_samples = buf_size * 8 / c->code_size;
477
478
    /* get output buffer */
479
22
    frame->nb_samples = out_samples;
480
22
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
481
        return ret;
482
22
    samples = (int16_t *)frame->data[0];
483
484
22
    init_get_bits(&gb, buf, buf_size * 8);
485
486
192022
    while (out_samples--)
487
384000
        *samples++ = g726_decode(c, c->little_endian ?
488
                                    get_bits_le(&gb, c->code_size) :
489
192000
                                    get_bits(&gb, c->code_size));
490
491
22
    if (get_bits_left(&gb) > 0)
492
        av_log(avctx, AV_LOG_ERROR, "Frame invalidly split, missing parser?\n");
493
494
22
    *got_frame_ptr = 1;
495
496
22
    return buf_size;
497
}
498
499
static void g726_decode_flush(AVCodecContext *avctx)
500
{
501
    G726Context *c = avctx->priv_data;
502
    g726_reset(c);
503
}
504
#endif
505
506
#if CONFIG_ADPCM_G726_DECODER
507
AVCodec ff_adpcm_g726_decoder = {
508
    .name           = "g726",
509
    .long_name      = NULL_IF_CONFIG_SMALL("G.726 ADPCM"),
510
    .type           = AVMEDIA_TYPE_AUDIO,
511
    .id             = AV_CODEC_ID_ADPCM_G726,
512
    .priv_data_size = sizeof(G726Context),
513
    .init           = g726_decode_init,
514
    .decode         = g726_decode_frame,
515
    .flush          = g726_decode_flush,
516
    .capabilities   = AV_CODEC_CAP_DR1,
517
};
518
#endif
519
520
#if CONFIG_ADPCM_G726LE_DECODER
521
AVCodec ff_adpcm_g726le_decoder = {
522
    .name           = "g726le",
523
    .type           = AVMEDIA_TYPE_AUDIO,
524
    .id             = AV_CODEC_ID_ADPCM_G726LE,
525
    .priv_data_size = sizeof(G726Context),
526
    .init           = g726_decode_init,
527
    .decode         = g726_decode_frame,
528
    .flush          = g726_decode_flush,
529
    .capabilities   = AV_CODEC_CAP_DR1,
530
    .long_name      = NULL_IF_CONFIG_SMALL("G.726 ADPCM little-endian"),
531
};
532
#endif