g726: wrap the decoder functions with a CONFIG_ADPCM_G726_DECODER check
[libav.git] / libavcodec / g726.c
CommitLineData
e5966052 1/*
115329f1 2 * G.726 ADPCM audio codec
406792e7 3 * Copyright (c) 2004 Roman Shaposhnik
e5966052
RS
4 *
5 * This is a very straightforward rendition of the G.726
115329f1 6 * Section 4 "Computational Details".
e5966052 7 *
2912e87a 8 * This file is part of Libav.
b78e7197 9 *
2912e87a 10 * Libav is free software; you can redistribute it and/or
e5966052
RS
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
b78e7197 13 * version 2.1 of the License, or (at your option) any later version.
e5966052 14 *
2912e87a 15 * Libav is distributed in the hope that it will be useful,
e5966052
RS
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
2912e87a 21 * License along with Libav; if not, write to the Free Software
5509bffa 22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
e5966052
RS
23 */
24#include <limits.h>
50c466d6 25#include "libavutil/avassert.h"
e5966052 26#include "avcodec.h"
9106a698 27#include "get_bits.h"
b2755007 28#include "put_bits.h"
e5966052 29
ef9c5d84
MN
30/**
31 * G.726 11bit float.
115329f1 32 * G.726 Standard uses rather odd 11bit floating point arithmentic for
e5966052
RS
33 * numerous occasions. It's a mistery to me why they did it this way
34 * instead of simply using 32bit integer arithmetic.
35 */
36typedef struct Float11 {
deec52cc
MN
37 uint8_t sign; /**< 1bit sign */
38 uint8_t exp; /**< 4bit exponent */
39 uint8_t mant; /**< 6bit mantissa */
e5966052
RS
40} Float11;
41
5171fd9d 42static inline Float11* i2f(int i, Float11* f)
e5966052 43{
e344c1ea
SH
44 f->sign = (i < 0);
45 if (f->sign)
46 i = -i;
47 f->exp = av_log2_16bit(i) + !!i;
48 f->mant = i? (i<<6) >> f->exp : 1<<5;
49 return f;
e5966052
RS
50}
51
52static inline int16_t mult(Float11* f1, Float11* f2)
53{
bb270c08 54 int res, exp;
e5966052 55
bb270c08 56 exp = f1->exp + f2->exp;
7d7a9e7f
MN
57 res = (((f1->mant * f2->mant) + 0x30) >> 4);
58 res = exp > 19 ? res << (exp - 19) : res >> (19 - exp);
bb270c08 59 return (f1->sign ^ f2->sign) ? -res : res;
e5966052
RS
60}
61
e5966052
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62static inline int sgn(int value)
63{
e344c1ea 64 return (value < 0) ? -1 : 1;
e5966052
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65}
66
67typedef struct G726Tables {
9307db13 68 const int* quant; /**< quantization table */
a0e5830a 69 const int16_t* iquant; /**< inverse quantization table */
e3cafac6
MN
70 const int16_t* W; /**< special table #1 ;-) */
71 const uint8_t* F; /**< special table #2 */
e5966052
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72} G726Tables;
73
74typedef struct G726Context {
05c9f351 75 G726Tables tbls; /**< static tables needed for computation */
e344c1ea
SH
76
77 Float11 sr[2]; /**< prev. reconstructed samples */
78 Float11 dq[6]; /**< prev. difference */
79 int a[2]; /**< second order predictor coeffs */
80 int b[6]; /**< sixth order predictor coeffs */
81 int pk[2]; /**< signs of prev. 2 sez + dq */
82
83 int ap; /**< scale factor control */
84 int yu; /**< fast scale factor */
85 int yl; /**< slow scale factor */
86 int dms; /**< short average magnitude of F[i] */
87 int dml; /**< long average magnitude of F[i] */
88 int td; /**< tone detect */
89
90 int se; /**< estimated signal for the next iteration */
91 int sez; /**< estimated second order prediction */
92 int y; /**< quantizer scaling factor for the next iteration */
c79c1a01 93 int code_size;
e5966052
RS
94} G726Context;
95
9307db13 96static const int quant_tbl16[] = /**< 16kbit/s 2bits per sample */
115329f1 97 { 260, INT_MAX };
a0e5830a 98static const int16_t iquant_tbl16[] =
e5966052 99 { 116, 365, 365, 116 };
e3cafac6 100static const int16_t W_tbl16[] =
e5966052 101 { -22, 439, 439, -22 };
e3cafac6 102static const uint8_t F_tbl16[] =
e5966052 103 { 0, 7, 7, 0 };
115329f1 104
9307db13 105static const int quant_tbl24[] = /**< 24kbit/s 3bits per sample */
e5966052 106 { 7, 217, 330, INT_MAX };
a0e5830a
MN
107static const int16_t iquant_tbl24[] =
108 { INT16_MIN, 135, 273, 373, 373, 273, 135, INT16_MIN };
e3cafac6 109static const int16_t W_tbl24[] =
115329f1 110 { -4, 30, 137, 582, 582, 137, 30, -4 };
e3cafac6 111static const uint8_t F_tbl24[] =
e5966052 112 { 0, 1, 2, 7, 7, 2, 1, 0 };
115329f1 113
9307db13 114static const int quant_tbl32[] = /**< 32kbit/s 4bits per sample */
e5966052 115 { -125, 79, 177, 245, 299, 348, 399, INT_MAX };
a0e5830a
MN
116static const int16_t iquant_tbl32[] =
117 { INT16_MIN, 4, 135, 213, 273, 323, 373, 425,
118 425, 373, 323, 273, 213, 135, 4, INT16_MIN };
e3cafac6 119static const int16_t W_tbl32[] =
e5966052 120 { -12, 18, 41, 64, 112, 198, 355, 1122,
bb270c08 121 1122, 355, 198, 112, 64, 41, 18, -12};
e3cafac6 122static const uint8_t F_tbl32[] =
e5966052 123 { 0, 0, 0, 1, 1, 1, 3, 7, 7, 3, 1, 1, 1, 0, 0, 0 };
115329f1 124
9307db13 125static const int quant_tbl40[] = /**< 40kbit/s 5bits per sample */
e5966052 126 { -122, -16, 67, 138, 197, 249, 297, 338,
bb270c08 127 377, 412, 444, 474, 501, 527, 552, INT_MAX };
a0e5830a
MN
128static const int16_t iquant_tbl40[] =
129 { INT16_MIN, -66, 28, 104, 169, 224, 274, 318,
bb270c08
DB
130 358, 395, 429, 459, 488, 514, 539, 566,
131 566, 539, 514, 488, 459, 429, 395, 358,
a0e5830a 132 318, 274, 224, 169, 104, 28, -66, INT16_MIN };
e3cafac6 133static const int16_t W_tbl40[] =
e5966052 134 { 14, 14, 24, 39, 40, 41, 58, 100,
bb270c08
DB
135 141, 179, 219, 280, 358, 440, 529, 696,
136 696, 529, 440, 358, 280, 219, 179, 141,
137 100, 58, 41, 40, 39, 24, 14, 14 };
e3cafac6 138static const uint8_t F_tbl40[] =
e5966052 139 { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 6,
bb270c08 140 6, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
e5966052 141
9307db13 142static const G726Tables G726Tables_pool[] =
0e0d6cfd
MN
143 {{ quant_tbl16, iquant_tbl16, W_tbl16, F_tbl16 },
144 { quant_tbl24, iquant_tbl24, W_tbl24, F_tbl24 },
145 { quant_tbl32, iquant_tbl32, W_tbl32, F_tbl32 },
146 { quant_tbl40, iquant_tbl40, W_tbl40, F_tbl40 }};
115329f1 147
e5966052 148
ef9c5d84 149/**
115329f1 150 * Para 4.2.2 page 18: Adaptive quantizer.
e5966052
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151 */
152static inline uint8_t quant(G726Context* c, int d)
153{
e344c1ea 154 int sign, exp, i, dln;
115329f1 155
e344c1ea
SH
156 sign = i = 0;
157 if (d < 0) {
158 sign = 1;
159 d = -d;
160 }
161 exp = av_log2_16bit(d);
162 dln = ((exp<<7) + (((d<<7)>>exp)&0x7f)) - (c->y>>2);
115329f1 163
05c9f351 164 while (c->tbls.quant[i] < INT_MAX && c->tbls.quant[i] < dln)
e5966052 165 ++i;
115329f1 166
e344c1ea
SH
167 if (sign)
168 i = ~i;
0e0d6cfd 169 if (c->code_size != 2 && i == 0) /* I'm not sure this is a good idea */
e344c1ea 170 i = 0xff;
e5966052 171
e344c1ea 172 return i;
e5966052
RS
173}
174
ef9c5d84 175/**
e5966052
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176 * Para 4.2.3 page 22: Inverse adaptive quantizer.
177 */
178static inline int16_t inverse_quant(G726Context* c, int i)
179{
180 int dql, dex, dqt;
115329f1 181
05c9f351 182 dql = c->tbls.iquant[i] + (c->y >> 2);
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183 dex = (dql>>7) & 0xf; /* 4bit exponent */
184 dqt = (1<<7) + (dql & 0x7f); /* log2 -> linear */
6aa37bcf 185 return (dql < 0) ? 0 : ((dqt<<dex) >> 7);
e5966052
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186}
187
fc234250 188static int16_t g726_decode(G726Context* c, int I)
e5966052
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189{
190 int dq, re_signal, pk0, fa1, i, tr, ylint, ylfrac, thr2, al, dq0;
191 Float11 f;
0e0d6cfd 192 int I_sig= I >> (c->code_size - 1);
115329f1 193
e5966052 194 dq = inverse_quant(c, I);
e5966052
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195
196 /* Transition detect */
197 ylint = (c->yl >> 15);
198 ylfrac = (c->yl >> 10) & 0x1f;
199 thr2 = (ylint > 9) ? 0x1f << 10 : (0x20 + ylfrac) << ylint;
73ff4f83
MN
200 tr= (c->td == 1 && dq > ((3*thr2)>>2));
201
cb26c9d6 202 if (I_sig) /* get the sign */
73ff4f83
MN
203 dq = -dq;
204 re_signal = c->se + dq;
115329f1 205
e5966052
RS
206 /* Update second order predictor coefficient A2 and A1 */
207 pk0 = (c->sez + dq) ? sgn(c->sez + dq) : 0;
208 dq0 = dq ? sgn(dq) : 0;
209 if (tr) {
210 c->a[0] = 0;
bb270c08 211 c->a[1] = 0;
e5966052 212 for (i=0; i<6; i++)
e344c1ea 213 c->b[i] = 0;
e5966052 214 } else {
bb270c08 215 /* This is a bit crazy, but it really is +255 not +256 */
f66e4f5f 216 fa1 = av_clip((-c->a[0]*c->pk[0]*pk0)>>5, -256, 255);
115329f1 217
bb270c08 218 c->a[1] += 128*pk0*c->pk[1] + fa1 - (c->a[1]>>7);
f66e4f5f 219 c->a[1] = av_clip(c->a[1], -12288, 12288);
e5966052 220 c->a[0] += 64*3*pk0*c->pk[0] - (c->a[0] >> 8);
f66e4f5f 221 c->a[0] = av_clip(c->a[0], -(15360 - c->a[1]), 15360 - c->a[1]);
e5966052
RS
222
223 for (i=0; i<6; i++)
e344c1ea 224 c->b[i] += 128*dq0*sgn(-c->dq[i].sign) - (c->b[i]>>8);
e5966052
RS
225 }
226
227 /* Update Dq and Sr and Pk */
228 c->pk[1] = c->pk[0];
229 c->pk[0] = pk0 ? pk0 : 1;
230 c->sr[1] = c->sr[0];
231 i2f(re_signal, &c->sr[0]);
232 for (i=5; i>0; i--)
e344c1ea 233 c->dq[i] = c->dq[i-1];
e5966052 234 i2f(dq, &c->dq[0]);
cb26c9d6 235 c->dq[0].sign = I_sig; /* Isn't it crazy ?!?! */
115329f1 236
428c82cb 237 c->td = c->a[1] < -11776;
115329f1 238
e5966052 239 /* Update Ap */
74d94417
MN
240 c->dms += (c->tbls.F[I]<<4) + ((- c->dms) >> 5);
241 c->dml += (c->tbls.F[I]<<4) + ((- c->dml) >> 7);
115329f1 242 if (tr)
e344c1ea 243 c->ap = 256;
50c52d22 244 else {
e344c1ea 245 c->ap += (-c->ap) >> 4;
50c52d22
MN
246 if (c->y <= 1535 || c->td || abs((c->dms << 2) - c->dml) >= (c->dml >> 3))
247 c->ap += 0x20;
248 }
e5966052
RS
249
250 /* Update Yu and Yl */
05c9f351 251 c->yu = av_clip(c->y + c->tbls.W[I] + ((-c->y)>>5), 544, 5120);
e5966052 252 c->yl += c->yu + ((-c->yl)>>6);
115329f1 253
e5966052
RS
254 /* Next iteration for Y */
255 al = (c->ap >= 256) ? 1<<6 : c->ap >> 2;
256 c->y = (c->yl + (c->yu - (c->yl>>6))*al) >> 6;
115329f1 257
e5966052
RS
258 /* Next iteration for SE and SEZ */
259 c->se = 0;
260 for (i=0; i<6; i++)
e344c1ea 261 c->se += mult(i2f(c->b[i] >> 2, &f), &c->dq[i]);
e5966052
RS
262 c->sez = c->se >> 1;
263 for (i=0; i<2; i++)
e344c1ea 264 c->se += mult(i2f(c->a[i] >> 2, &f), &c->sr[i]);
e5966052
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265 c->se >>= 1;
266
f66e4f5f 267 return av_clip(re_signal << 2, -0xffff, 0xffff);
e5966052
RS
268}
269
8161c28c 270static av_cold int g726_reset(G726Context* c, int index)
e5966052
RS
271{
272 int i;
273
05c9f351 274 c->tbls = G726Tables_pool[index];
e5966052 275 for (i=0; i<2; i++) {
aeaa7c3d 276 c->sr[i].mant = 1<<5;
e344c1ea 277 c->pk[i] = 1;
e5966052
RS
278 }
279 for (i=0; i<6; i++) {
aeaa7c3d 280 c->dq[i].mant = 1<<5;
e5966052 281 }
e5966052
RS
282 c->yu = 544;
283 c->yl = 34816;
e5966052 284
e5966052
RS
285 c->y = 544;
286
287 return 0;
288}
289
b250f9c6 290#if CONFIG_ADPCM_G726_ENCODER
e5966052
RS
291static int16_t g726_encode(G726Context* c, int16_t sig)
292{
e344c1ea 293 uint8_t i;
115329f1 294
0e0d6cfd 295 i = quant(c, sig/4 - c->se) & ((1<<c->code_size) - 1);
cf409a6f 296 g726_decode(c, i);
e344c1ea 297 return i;
e5966052
RS
298}
299
300/* Interfacing to the libavcodec */
301
d405237b 302static av_cold int g726_encode_init(AVCodecContext *avctx)
e5966052 303{
c79c1a01 304 G726Context* c = avctx->priv_data;
bd10f6e1 305
9e78d8cf
JR
306 if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL &&
307 avctx->sample_rate != 8000) {
308 av_log(avctx, AV_LOG_ERROR, "Sample rates other than 8kHz are not "
309 "allowed when the compliance level is higher than unofficial. "
310 "Resample or reduce the compliance level.\n");
311 return AVERROR(EINVAL);
312 }
50c466d6 313 av_assert0(avctx->sample_rate > 0);
bd10f6e1 314
8b470cc5
MN
315 if(avctx->channels != 1){
316 av_log(avctx, AV_LOG_ERROR, "Only mono is supported\n");
50969c0f 317 return AVERROR(EINVAL);
8b470cc5 318 }
6ac34eed
JR
319
320 if (avctx->bit_rate % avctx->sample_rate) {
321 av_log(avctx, AV_LOG_ERROR, "Bitrate - Samplerate combination is invalid\n");
322 return AVERROR(EINVAL);
323 }
324 c->code_size = (avctx->bit_rate + avctx->sample_rate/2) / avctx->sample_rate;
325 if (c->code_size < 2 || c->code_size > 5) {
326 av_log(avctx, AV_LOG_ERROR, "Invalid number of bits %d\n", c->code_size);
327 return AVERROR(EINVAL);
35d0e16b 328 }
6ac34eed
JR
329 avctx->bits_per_coded_sample = c->code_size;
330
331 g726_reset(c, c->code_size - 2);
e5966052 332
826ca104
RS
333 avctx->coded_frame = avcodec_alloc_frame();
334 if (!avctx->coded_frame)
8fa36ae0 335 return AVERROR(ENOMEM);
826ca104
RS
336 avctx->coded_frame->key_frame = 1;
337
c7d89948
JR
338 /* select a frame size that will end on a byte boundary and have a size of
339 approximately 1024 bytes */
6ac34eed 340 avctx->frame_size = ((int[]){ 4096, 2736, 2048, 1640 })[c->code_size - 2];
c7d89948 341
826ca104
RS
342 return 0;
343}
344
d405237b 345static av_cold int g726_encode_close(AVCodecContext *avctx)
826ca104
RS
346{
347 av_freep(&avctx->coded_frame);
e5966052
RS
348 return 0;
349}
350
351static int g726_encode_frame(AVCodecContext *avctx,
352 uint8_t *dst, int buf_size, void *data)
353{
c79c1a01 354 G726Context *c = avctx->priv_data;
e61a670b 355 const int16_t *samples = data;
e5966052 356 PutBitContext pb;
c7d89948 357 int i;
e5966052
RS
358
359 init_put_bits(&pb, dst, 1024*1024);
360
c7d89948 361 for (i = 0; i < avctx->frame_size; i++)
c79c1a01 362 put_bits(&pb, c->code_size, g726_encode(c, *samples++));
e5966052
RS
363
364 flush_put_bits(&pb);
365
115329f1
DB
366 return put_bits_count(&pb)>>3;
367}
437c11ca
JR
368
369AVCodec ff_adpcm_g726_encoder = {
370 .name = "g726",
371 .type = AVMEDIA_TYPE_AUDIO,
372 .id = CODEC_ID_ADPCM_G726,
373 .priv_data_size = sizeof(G726Context),
374 .init = g726_encode_init,
375 .encode = g726_encode_frame,
376 .close = g726_encode_close,
377 .capabilities = CODEC_CAP_SMALL_LAST_FRAME,
378 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
379 .long_name = NULL_IF_CONFIG_SMALL("G.726 ADPCM"),
380};
62bb489b 381#endif
e5966052 382
7abb73d4 383#if CONFIG_ADPCM_G726_DECODER
d405237b
JR
384static av_cold int g726_decode_init(AVCodecContext *avctx)
385{
386 G726Context* c = avctx->priv_data;
d405237b 387
9e78d8cf
JR
388 if (avctx->strict_std_compliance >= FF_COMPLIANCE_STRICT &&
389 avctx->sample_rate != 8000) {
390 av_log(avctx, AV_LOG_ERROR, "Only 8kHz sample rate is allowed when "
391 "the compliance level is strict. Reduce the compliance level "
392 "if you wish to decode the stream anyway.\n");
393 return AVERROR(EINVAL);
394 }
395
d405237b
JR
396 if(avctx->channels != 1){
397 av_log(avctx, AV_LOG_ERROR, "Only mono is supported\n");
50969c0f 398 return AVERROR(EINVAL);
d405237b 399 }
6ac34eed
JR
400
401 c->code_size = avctx->bits_per_coded_sample;
402 if (c->code_size < 2 || c->code_size > 5) {
403 av_log(avctx, AV_LOG_ERROR, "Invalid number of bits %d\n", c->code_size);
404 return AVERROR(EINVAL);
d405237b 405 }
6ac34eed 406 g726_reset(c, c->code_size - 2);
d405237b
JR
407
408 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
409
410 return 0;
411}
412
e5966052
RS
413static int g726_decode_frame(AVCodecContext *avctx,
414 void *data, int *data_size,
7a00bbad 415 AVPacket *avpkt)
e5966052 416{
7a00bbad
TB
417 const uint8_t *buf = avpkt->data;
418 int buf_size = avpkt->size;
c79c1a01 419 G726Context *c = avctx->priv_data;
e61a670b 420 int16_t *samples = data;
115329f1 421 GetBitContext gb;
c8d36d25
JR
422 int out_samples, out_size;
423
424 out_samples = buf_size * 8 / c->code_size;
425 out_size = out_samples * av_get_bytes_per_sample(avctx->sample_fmt);
426 if (*data_size < out_size) {
427 av_log(avctx, AV_LOG_ERROR, "Output buffer is too small\n");
428 return AVERROR(EINVAL);
429 }
115329f1 430
e5966052 431 init_get_bits(&gb, buf, buf_size * 8);
115329f1 432
c8d36d25 433 while (out_samples--)
c79c1a01 434 *samples++ = g726_decode(c, get_bits(&gb, c->code_size));
115329f1 435
c8d36d25 436 if (get_bits_left(&gb) > 0)
ef4c5c6d 437 av_log(avctx, AV_LOG_ERROR, "Frame invalidly split, missing parser?\n");
115329f1 438
c8d36d25 439 *data_size = out_size;
e5966052
RS
440 return buf_size;
441}
442
d36beb3f 443AVCodec ff_adpcm_g726_decoder = {
ec6402b7
AK
444 .name = "g726",
445 .type = AVMEDIA_TYPE_AUDIO,
446 .id = CODEC_ID_ADPCM_G726,
447 .priv_data_size = sizeof(G726Context),
d405237b 448 .init = g726_decode_init,
ec6402b7 449 .decode = g726_decode_frame,
fe4bf374 450 .long_name = NULL_IF_CONFIG_SMALL("G.726 ADPCM"),
e5966052 451};
7abb73d4 452#endif