This fixes error handling for BeOS, removing the need for some ifdefs.
[libav.git] / libavcodec / g726.c
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 #include "avcodec.h"
26 #include "common.h"
27 #include "bitstream.h"
28
29 /**
30 * G.726 11bit float.
31 * G.726 Standard uses rather odd 11bit floating point arithmentic for
32 * numerous occasions. It's a mistery to me why they did it this way
33 * instead of simply using 32bit integer arithmetic.
34 */
35 typedef struct Float11 {
36 int sign; /**< 1bit sign */
37 int exp; /**< 4bit exponent */
38 int mant; /**< 6bit mantissa */
39 } Float11;
40
41 static inline Float11* i2f(int16_t i, Float11* f)
42 {
43 f->sign = (i < 0);
44 if (f->sign)
45 i = -i;
46 f->exp = av_log2_16bit(i) + !!i;
47 f->mant = i? (i<<6) >> f->exp : 1<<5;
48 return f;
49 }
50
51 static inline int16_t mult(Float11* f1, Float11* f2)
52 {
53 int res, exp;
54
55 exp = f1->exp + f2->exp;
56 res = (((f1->mant * f2->mant) + 0x30) >> 4) << 7;
57 res = exp > 26 ? res << (exp - 26) : res >> (26 - exp);
58 return (f1->sign ^ f2->sign) ? -res : res;
59 }
60
61 static inline int sgn(int value)
62 {
63 return (value < 0) ? -1 : 1;
64 }
65
66 typedef struct G726Tables {
67 int bits; /**< bits per sample */
68 int* quant; /**< quantization table */
69 int* iquant; /**< inverse quantization table */
70 int* W; /**< special table #1 ;-) */
71 int* F; /**< special table #2 */
72 } G726Tables;
73
74 typedef struct G726Context {
75 G726Tables* tbls; /**< static tables needed for computation */
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 */
93 } G726Context;
94
95 static int quant_tbl16[] = /**< 16kbit/s 2bits per sample */
96 { 260, INT_MAX };
97 static int iquant_tbl16[] =
98 { 116, 365, 365, 116 };
99 static int W_tbl16[] =
100 { -22, 439, 439, -22 };
101 static int F_tbl16[] =
102 { 0, 7, 7, 0 };
103
104 static int quant_tbl24[] = /**< 24kbit/s 3bits per sample */
105 { 7, 217, 330, INT_MAX };
106 static int iquant_tbl24[] =
107 { INT_MIN, 135, 273, 373, 373, 273, 135, INT_MIN };
108 static int W_tbl24[] =
109 { -4, 30, 137, 582, 582, 137, 30, -4 };
110 static int F_tbl24[] =
111 { 0, 1, 2, 7, 7, 2, 1, 0 };
112
113 static int quant_tbl32[] = /**< 32kbit/s 4bits per sample */
114 { -125, 79, 177, 245, 299, 348, 399, INT_MAX };
115 static int iquant_tbl32[] =
116 { INT_MIN, 4, 135, 213, 273, 323, 373, 425,
117 425, 373, 323, 273, 213, 135, 4, INT_MIN };
118 static int W_tbl32[] =
119 { -12, 18, 41, 64, 112, 198, 355, 1122,
120 1122, 355, 198, 112, 64, 41, 18, -12};
121 static int F_tbl32[] =
122 { 0, 0, 0, 1, 1, 1, 3, 7, 7, 3, 1, 1, 1, 0, 0, 0 };
123
124 static int quant_tbl40[] = /**< 40kbit/s 5bits per sample */
125 { -122, -16, 67, 138, 197, 249, 297, 338,
126 377, 412, 444, 474, 501, 527, 552, INT_MAX };
127 static int iquant_tbl40[] =
128 { INT_MIN, -66, 28, 104, 169, 224, 274, 318,
129 358, 395, 429, 459, 488, 514, 539, 566,
130 566, 539, 514, 488, 459, 429, 395, 358,
131 318, 274, 224, 169, 104, 28, -66, INT_MIN };
132 static int W_tbl40[] =
133 { 14, 14, 24, 39, 40, 41, 58, 100,
134 141, 179, 219, 280, 358, 440, 529, 696,
135 696, 529, 440, 358, 280, 219, 179, 141,
136 100, 58, 41, 40, 39, 24, 14, 14 };
137 static int F_tbl40[] =
138 { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 6,
139 6, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
140
141 static G726Tables G726Tables_pool[] =
142 {{ 2, quant_tbl16, iquant_tbl16, W_tbl16, F_tbl16 },
143 { 3, quant_tbl24, iquant_tbl24, W_tbl24, F_tbl24 },
144 { 4, quant_tbl32, iquant_tbl32, W_tbl32, F_tbl32 },
145 { 5, quant_tbl40, iquant_tbl40, W_tbl40, F_tbl40 }};
146
147
148 /**
149 * Para 4.2.2 page 18: Adaptive quantizer.
150 */
151 static inline uint8_t quant(G726Context* c, int d)
152 {
153 int sign, exp, i, dln;
154
155 sign = i = 0;
156 if (d < 0) {
157 sign = 1;
158 d = -d;
159 }
160 exp = av_log2_16bit(d);
161 dln = ((exp<<7) + (((d<<7)>>exp)&0x7f)) - (c->y>>2);
162
163 while (c->tbls->quant[i] < INT_MAX && c->tbls->quant[i] < dln)
164 ++i;
165
166 if (sign)
167 i = ~i;
168 if (c->tbls->bits != 2 && i == 0) /* I'm not sure this is a good idea */
169 i = 0xff;
170
171 return i;
172 }
173
174 /**
175 * Para 4.2.3 page 22: Inverse adaptive quantizer.
176 */
177 static inline int16_t inverse_quant(G726Context* c, int i)
178 {
179 int dql, dex, dqt;
180
181 dql = c->tbls->iquant[i] + (c->y >> 2);
182 dex = (dql>>7) & 0xf; /* 4bit exponent */
183 dqt = (1<<7) + (dql & 0x7f); /* log2 -> linear */
184 return (dql < 0) ? 0 : ((dqt<<7) >> (14-dex));
185 }
186
187 static inline int16_t g726_iterate(G726Context* c, int16_t I)
188 {
189 int dq, re_signal, pk0, fa1, i, tr, ylint, ylfrac, thr2, al, dq0;
190 Float11 f;
191
192 dq = inverse_quant(c, I);
193 if (I >> (c->tbls->bits - 1)) /* get the sign */
194 dq = -dq;
195 re_signal = c->se + dq;
196
197 /* Transition detect */
198 ylint = (c->yl >> 15);
199 ylfrac = (c->yl >> 10) & 0x1f;
200 thr2 = (ylint > 9) ? 0x1f << 10 : (0x20 + ylfrac) << ylint;
201 if (c->td == 1 && abs(dq) > ((thr2+(thr2>>1))>>1))
202 tr = 1;
203 else
204 tr = 0;
205
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;
211 c->a[1] = 0;
212 for (i=0; i<6; i++)
213 c->b[i] = 0;
214 } else {
215 /* This is a bit crazy, but it really is +255 not +256 */
216 fa1 = clip((-c->a[0]*c->pk[0]*pk0)>>5, -256, 255);
217
218 c->a[1] += 128*pk0*c->pk[1] + fa1 - (c->a[1]>>7);
219 c->a[1] = clip(c->a[1], -12288, 12288);
220 c->a[0] += 64*3*pk0*c->pk[0] - (c->a[0] >> 8);
221 c->a[0] = clip(c->a[0], -(15360 - c->a[1]), 15360 - c->a[1]);
222
223 for (i=0; i<6; i++)
224 c->b[i] += 128*dq0*sgn(-c->dq[i].sign) - (c->b[i]>>8);
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--)
233 c->dq[i] = c->dq[i-1];
234 i2f(dq, &c->dq[0]);
235 c->dq[0].sign = I >> (c->tbls->bits - 1); /* Isn't it crazy ?!?! */
236
237 /* Update tone detect [I'm not sure 'tr == 0' is really needed] */
238 c->td = (tr == 0 && c->a[1] < -11776);
239
240 /* Update Ap */
241 c->dms += ((c->tbls->F[I]<<9) - c->dms) >> 5;
242 c->dml += ((c->tbls->F[I]<<11) - c->dml) >> 7;
243 if (tr)
244 c->ap = 256;
245 else if (c->y > 1535 && !c->td && (abs((c->dms << 2) - c->dml) < (c->dml >> 3)))
246 c->ap += (-c->ap) >> 4;
247 else
248 c->ap += (0x200 - c->ap) >> 4;
249
250 /* Update Yu and Yl */
251 c->yu = clip(c->y + (((c->tbls->W[I] << 5) - c->y) >> 5), 544, 5120);
252 c->yl += c->yu + ((-c->yl)>>6);
253
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;
257
258 /* Next iteration for SE and SEZ */
259 c->se = 0;
260 for (i=0; i<6; i++)
261 c->se += mult(i2f(c->b[i] >> 2, &f), &c->dq[i]);
262 c->sez = c->se >> 1;
263 for (i=0; i<2; i++)
264 c->se += mult(i2f(c->a[i] >> 2, &f), &c->sr[i]);
265 c->se >>= 1;
266
267 return clip(re_signal << 2, -0xffff, 0xffff);
268 }
269
270 static int g726_reset(G726Context* c, int bit_rate)
271 {
272 int i;
273
274 c->tbls = &G726Tables_pool[bit_rate/8000 - 2];
275 for (i=0; i<2; i++) {
276 i2f(0, &c->sr[i]);
277 c->a[i] = 0;
278 c->pk[i] = 1;
279 }
280 for (i=0; i<6; i++) {
281 i2f(0, &c->dq[i]);
282 c->b[i] = 0;
283 }
284 c->ap = 0;
285 c->dms = 0;
286 c->dml = 0;
287 c->yu = 544;
288 c->yl = 34816;
289 c->td = 0;
290
291 c->se = 0;
292 c->sez = 0;
293 c->y = 544;
294
295 return 0;
296 }
297
298 static int16_t g726_decode(G726Context* c, int16_t i)
299 {
300 return g726_iterate(c, i);
301 }
302
303 #ifdef CONFIG_ENCODERS
304 static int16_t g726_encode(G726Context* c, int16_t sig)
305 {
306 uint8_t i;
307
308 i = quant(c, sig/4 - c->se) & ((1<<c->tbls->bits) - 1);
309 g726_iterate(c, i);
310 return i;
311 }
312 #endif
313
314 /* Interfacing to the libavcodec */
315
316 typedef struct AVG726Context {
317 G726Context c;
318 int bits_left;
319 int bit_buffer;
320 int code_size;
321 } AVG726Context;
322
323 static int g726_init(AVCodecContext * avctx)
324 {
325 AVG726Context* c = (AVG726Context*)avctx->priv_data;
326
327 if (avctx->channels != 1 ||
328 (avctx->bit_rate != 16000 && avctx->bit_rate != 24000 &&
329 avctx->bit_rate != 32000 && avctx->bit_rate != 40000)) {
330 av_log(avctx, AV_LOG_ERROR, "G726: unsupported audio format\n");
331 return -1;
332 }
333 if (avctx->sample_rate != 8000 && avctx->strict_std_compliance>FF_COMPLIANCE_INOFFICIAL) {
334 av_log(avctx, AV_LOG_ERROR, "G726: unsupported audio format\n");
335 return -1;
336 }
337 g726_reset(&c->c, avctx->bit_rate);
338 c->code_size = c->c.tbls->bits;
339 c->bit_buffer = 0;
340 c->bits_left = 0;
341
342 avctx->coded_frame = avcodec_alloc_frame();
343 if (!avctx->coded_frame)
344 return AVERROR(ENOMEM);
345 avctx->coded_frame->key_frame = 1;
346
347 return 0;
348 }
349
350 static int g726_close(AVCodecContext *avctx)
351 {
352 av_freep(&avctx->coded_frame);
353 return 0;
354 }
355
356 #ifdef CONFIG_ENCODERS
357 static int g726_encode_frame(AVCodecContext *avctx,
358 uint8_t *dst, int buf_size, void *data)
359 {
360 AVG726Context *c = avctx->priv_data;
361 short *samples = data;
362 PutBitContext pb;
363
364 init_put_bits(&pb, dst, 1024*1024);
365
366 for (; buf_size; buf_size--)
367 put_bits(&pb, c->code_size, g726_encode(&c->c, *samples++));
368
369 flush_put_bits(&pb);
370
371 return put_bits_count(&pb)>>3;
372 }
373 #endif
374
375 static int g726_decode_frame(AVCodecContext *avctx,
376 void *data, int *data_size,
377 uint8_t *buf, int buf_size)
378 {
379 AVG726Context *c = avctx->priv_data;
380 short *samples = data;
381 uint8_t code;
382 uint8_t mask;
383 GetBitContext gb;
384
385 if (!buf_size)
386 goto out;
387
388 mask = (1<<c->code_size) - 1;
389 init_get_bits(&gb, buf, buf_size * 8);
390 if (c->bits_left) {
391 int s = c->code_size - c->bits_left;;
392 code = (c->bit_buffer << s) | get_bits(&gb, s);
393 *samples++ = g726_decode(&c->c, code & mask);
394 }
395
396 while (get_bits_count(&gb) + c->code_size <= buf_size*8)
397 *samples++ = g726_decode(&c->c, get_bits(&gb, c->code_size) & mask);
398
399 c->bits_left = buf_size*8 - get_bits_count(&gb);
400 c->bit_buffer = get_bits(&gb, c->bits_left);
401
402 out:
403 *data_size = (uint8_t*)samples - (uint8_t*)data;
404 return buf_size;
405 }
406
407 #ifdef CONFIG_ENCODERS
408 AVCodec adpcm_g726_encoder = {
409 "g726",
410 CODEC_TYPE_AUDIO,
411 CODEC_ID_ADPCM_G726,
412 sizeof(AVG726Context),
413 g726_init,
414 g726_encode_frame,
415 g726_close,
416 NULL,
417 };
418 #endif //CONFIG_ENCODERS
419
420 AVCodec adpcm_g726_decoder = {
421 "g726",
422 CODEC_TYPE_AUDIO,
423 CODEC_ID_ADPCM_G726,
424 sizeof(AVG726Context),
425 g726_init,
426 NULL,
427 g726_close,
428 g726_decode_frame,
429 };