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00024 #include <limits.h>
00025 #include "avcodec.h"
00026 #include "bitstream.h"
00027
00034 typedef struct Float11 {
00035 int sign;
00036 int exp;
00037 int mant;
00038 } Float11;
00039
00040 static inline Float11* i2f(int16_t i, Float11* f)
00041 {
00042 f->sign = (i < 0);
00043 if (f->sign)
00044 i = -i;
00045 f->exp = av_log2_16bit(i) + !!i;
00046 f->mant = i? (i<<6) >> f->exp : 1<<5;
00047 return f;
00048 }
00049
00050 static inline int16_t mult(Float11* f1, Float11* f2)
00051 {
00052 int res, exp;
00053
00054 exp = f1->exp + f2->exp;
00055 res = (((f1->mant * f2->mant) + 0x30) >> 4) << 7;
00056 res = exp > 26 ? res << (exp - 26) : res >> (26 - exp);
00057 return (f1->sign ^ f2->sign) ? -res : res;
00058 }
00059
00060 static inline int sgn(int value)
00061 {
00062 return (value < 0) ? -1 : 1;
00063 }
00064
00065 typedef struct G726Tables {
00066 int bits;
00067 const int* quant;
00068 const int* iquant;
00069 const int* W;
00070 const int* F;
00071 } G726Tables;
00072
00073 typedef struct G726Context {
00074 const G726Tables* tbls;
00076 Float11 sr[2];
00077 Float11 dq[6];
00078 int a[2];
00079 int b[6];
00080 int pk[2];
00082 int ap;
00083 int yu;
00084 int yl;
00085 int dms;
00086 int dml;
00087 int td;
00089 int se;
00090 int sez;
00091 int y;
00092 } G726Context;
00093
00094 static const int quant_tbl16[] =
00095 { 260, INT_MAX };
00096 static const int iquant_tbl16[] =
00097 { 116, 365, 365, 116 };
00098 static const int W_tbl16[] =
00099 { -22, 439, 439, -22 };
00100 static const int F_tbl16[] =
00101 { 0, 7, 7, 0 };
00102
00103 static const int quant_tbl24[] =
00104 { 7, 217, 330, INT_MAX };
00105 static const int iquant_tbl24[] =
00106 { INT_MIN, 135, 273, 373, 373, 273, 135, INT_MIN };
00107 static const int W_tbl24[] =
00108 { -4, 30, 137, 582, 582, 137, 30, -4 };
00109 static const int F_tbl24[] =
00110 { 0, 1, 2, 7, 7, 2, 1, 0 };
00111
00112 static const int quant_tbl32[] =
00113 { -125, 79, 177, 245, 299, 348, 399, INT_MAX };
00114 static const int iquant_tbl32[] =
00115 { INT_MIN, 4, 135, 213, 273, 323, 373, 425,
00116 425, 373, 323, 273, 213, 135, 4, INT_MIN };
00117 static const int W_tbl32[] =
00118 { -12, 18, 41, 64, 112, 198, 355, 1122,
00119 1122, 355, 198, 112, 64, 41, 18, -12};
00120 static const int F_tbl32[] =
00121 { 0, 0, 0, 1, 1, 1, 3, 7, 7, 3, 1, 1, 1, 0, 0, 0 };
00122
00123 static const int quant_tbl40[] =
00124 { -122, -16, 67, 138, 197, 249, 297, 338,
00125 377, 412, 444, 474, 501, 527, 552, INT_MAX };
00126 static const int iquant_tbl40[] =
00127 { INT_MIN, -66, 28, 104, 169, 224, 274, 318,
00128 358, 395, 429, 459, 488, 514, 539, 566,
00129 566, 539, 514, 488, 459, 429, 395, 358,
00130 318, 274, 224, 169, 104, 28, -66, INT_MIN };
00131 static const int W_tbl40[] =
00132 { 14, 14, 24, 39, 40, 41, 58, 100,
00133 141, 179, 219, 280, 358, 440, 529, 696,
00134 696, 529, 440, 358, 280, 219, 179, 141,
00135 100, 58, 41, 40, 39, 24, 14, 14 };
00136 static const int F_tbl40[] =
00137 { 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 6,
00138 6, 6, 5, 4, 3, 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
00139
00140 static const G726Tables G726Tables_pool[] =
00141 {{ 2, quant_tbl16, iquant_tbl16, W_tbl16, F_tbl16 },
00142 { 3, quant_tbl24, iquant_tbl24, W_tbl24, F_tbl24 },
00143 { 4, quant_tbl32, iquant_tbl32, W_tbl32, F_tbl32 },
00144 { 5, quant_tbl40, iquant_tbl40, W_tbl40, F_tbl40 }};
00145
00146
00150 static inline uint8_t quant(G726Context* c, int d)
00151 {
00152 int sign, exp, i, dln;
00153
00154 sign = i = 0;
00155 if (d < 0) {
00156 sign = 1;
00157 d = -d;
00158 }
00159 exp = av_log2_16bit(d);
00160 dln = ((exp<<7) + (((d<<7)>>exp)&0x7f)) - (c->y>>2);
00161
00162 while (c->tbls->quant[i] < INT_MAX && c->tbls->quant[i] < dln)
00163 ++i;
00164
00165 if (sign)
00166 i = ~i;
00167 if (c->tbls->bits != 2 && i == 0)
00168 i = 0xff;
00169
00170 return i;
00171 }
00172
00176 static inline int16_t inverse_quant(G726Context* c, int i)
00177 {
00178 int dql, dex, dqt;
00179
00180 dql = c->tbls->iquant[i] + (c->y >> 2);
00181 dex = (dql>>7) & 0xf;
00182 dqt = (1<<7) + (dql & 0x7f);
00183 return (dql < 0) ? 0 : ((dqt<<7) >> (14-dex));
00184 }
00185
00186 static inline int16_t g726_iterate(G726Context* c, int16_t I)
00187 {
00188 int dq, re_signal, pk0, fa1, i, tr, ylint, ylfrac, thr2, al, dq0;
00189 Float11 f;
00190
00191 dq = inverse_quant(c, I);
00192 if (I >> (c->tbls->bits - 1))
00193 dq = -dq;
00194 re_signal = c->se + dq;
00195
00196
00197 ylint = (c->yl >> 15);
00198 ylfrac = (c->yl >> 10) & 0x1f;
00199 thr2 = (ylint > 9) ? 0x1f << 10 : (0x20 + ylfrac) << ylint;
00200 if (c->td == 1 && abs(dq) > ((thr2+(thr2>>1))>>1))
00201 tr = 1;
00202 else
00203 tr = 0;
00204
00205
00206 pk0 = (c->sez + dq) ? sgn(c->sez + dq) : 0;
00207 dq0 = dq ? sgn(dq) : 0;
00208 if (tr) {
00209 c->a[0] = 0;
00210 c->a[1] = 0;
00211 for (i=0; i<6; i++)
00212 c->b[i] = 0;
00213 } else {
00214
00215 fa1 = av_clip((-c->a[0]*c->pk[0]*pk0)>>5, -256, 255);
00216
00217 c->a[1] += 128*pk0*c->pk[1] + fa1 - (c->a[1]>>7);
00218 c->a[1] = av_clip(c->a[1], -12288, 12288);
00219 c->a[0] += 64*3*pk0*c->pk[0] - (c->a[0] >> 8);
00220 c->a[0] = av_clip(c->a[0], -(15360 - c->a[1]), 15360 - c->a[1]);
00221
00222 for (i=0; i<6; i++)
00223 c->b[i] += 128*dq0*sgn(-c->dq[i].sign) - (c->b[i]>>8);
00224 }
00225
00226
00227 c->pk[1] = c->pk[0];
00228 c->pk[0] = pk0 ? pk0 : 1;
00229 c->sr[1] = c->sr[0];
00230 i2f(re_signal, &c->sr[0]);
00231 for (i=5; i>0; i--)
00232 c->dq[i] = c->dq[i-1];
00233 i2f(dq, &c->dq[0]);
00234 c->dq[0].sign = I >> (c->tbls->bits - 1);
00235
00236
00237 c->td = (tr == 0 && c->a[1] < -11776);
00238
00239
00240 c->dms += ((c->tbls->F[I]<<9) - c->dms) >> 5;
00241 c->dml += ((c->tbls->F[I]<<11) - c->dml) >> 7;
00242 if (tr)
00243 c->ap = 256;
00244 else if (c->y > 1535 && !c->td && (abs((c->dms << 2) - c->dml) < (c->dml >> 3)))
00245 c->ap += (-c->ap) >> 4;
00246 else
00247 c->ap += (0x200 - c->ap) >> 4;
00248
00249
00250 c->yu = av_clip(c->y + (((c->tbls->W[I] << 5) - c->y) >> 5), 544, 5120);
00251 c->yl += c->yu + ((-c->yl)>>6);
00252
00253
00254 al = (c->ap >= 256) ? 1<<6 : c->ap >> 2;
00255 c->y = (c->yl + (c->yu - (c->yl>>6))*al) >> 6;
00256
00257
00258 c->se = 0;
00259 for (i=0; i<6; i++)
00260 c->se += mult(i2f(c->b[i] >> 2, &f), &c->dq[i]);
00261 c->sez = c->se >> 1;
00262 for (i=0; i<2; i++)
00263 c->se += mult(i2f(c->a[i] >> 2, &f), &c->sr[i]);
00264 c->se >>= 1;
00265
00266 return av_clip(re_signal << 2, -0xffff, 0xffff);
00267 }
00268
00269 static int g726_reset(G726Context* c, int bit_rate)
00270 {
00271 int i;
00272
00273 c->tbls = &G726Tables_pool[bit_rate/8000 - 2];
00274 for (i=0; i<2; i++) {
00275 i2f(0, &c->sr[i]);
00276 c->a[i] = 0;
00277 c->pk[i] = 1;
00278 }
00279 for (i=0; i<6; i++) {
00280 i2f(0, &c->dq[i]);
00281 c->b[i] = 0;
00282 }
00283 c->ap = 0;
00284 c->dms = 0;
00285 c->dml = 0;
00286 c->yu = 544;
00287 c->yl = 34816;
00288 c->td = 0;
00289
00290 c->se = 0;
00291 c->sez = 0;
00292 c->y = 544;
00293
00294 return 0;
00295 }
00296
00297 static int16_t g726_decode(G726Context* c, int16_t i)
00298 {
00299 return g726_iterate(c, i);
00300 }
00301
00302 #ifdef CONFIG_ENCODERS
00303 static int16_t g726_encode(G726Context* c, int16_t sig)
00304 {
00305 uint8_t i;
00306
00307 i = quant(c, sig/4 - c->se) & ((1<<c->tbls->bits) - 1);
00308 g726_iterate(c, i);
00309 return i;
00310 }
00311 #endif
00312
00313
00314
00315 typedef struct AVG726Context {
00316 G726Context c;
00317 int bits_left;
00318 int bit_buffer;
00319 int code_size;
00320 } AVG726Context;
00321
00322 static int g726_init(AVCodecContext * avctx)
00323 {
00324 AVG726Context* c = (AVG726Context*)avctx->priv_data;
00325
00326 if (avctx->channels != 1 ||
00327 (avctx->bit_rate != 16000 && avctx->bit_rate != 24000 &&
00328 avctx->bit_rate != 32000 && avctx->bit_rate != 40000)) {
00329 av_log(avctx, AV_LOG_ERROR, "G726: unsupported audio format\n");
00330 return -1;
00331 }
00332 if (avctx->sample_rate != 8000 && avctx->strict_std_compliance>FF_COMPLIANCE_INOFFICIAL) {
00333 av_log(avctx, AV_LOG_ERROR, "G726: unsupported audio format\n");
00334 return -1;
00335 }
00336 g726_reset(&c->c, avctx->bit_rate);
00337 c->code_size = c->c.tbls->bits;
00338 c->bit_buffer = 0;
00339 c->bits_left = 0;
00340
00341 avctx->coded_frame = avcodec_alloc_frame();
00342 if (!avctx->coded_frame)
00343 return AVERROR(ENOMEM);
00344 avctx->coded_frame->key_frame = 1;
00345
00346 return 0;
00347 }
00348
00349 static int g726_close(AVCodecContext *avctx)
00350 {
00351 av_freep(&avctx->coded_frame);
00352 return 0;
00353 }
00354
00355 #ifdef CONFIG_ENCODERS
00356 static int g726_encode_frame(AVCodecContext *avctx,
00357 uint8_t *dst, int buf_size, void *data)
00358 {
00359 AVG726Context *c = avctx->priv_data;
00360 short *samples = data;
00361 PutBitContext pb;
00362
00363 init_put_bits(&pb, dst, 1024*1024);
00364
00365 for (; buf_size; buf_size--)
00366 put_bits(&pb, c->code_size, g726_encode(&c->c, *samples++));
00367
00368 flush_put_bits(&pb);
00369
00370 return put_bits_count(&pb)>>3;
00371 }
00372 #endif
00373
00374 static int g726_decode_frame(AVCodecContext *avctx,
00375 void *data, int *data_size,
00376 const uint8_t *buf, int buf_size)
00377 {
00378 AVG726Context *c = avctx->priv_data;
00379 short *samples = data;
00380 uint8_t code;
00381 uint8_t mask;
00382 GetBitContext gb;
00383
00384 if (!buf_size)
00385 goto out;
00386
00387 mask = (1<<c->code_size) - 1;
00388 init_get_bits(&gb, buf, buf_size * 8);
00389 if (c->bits_left) {
00390 int s = c->code_size - c->bits_left;;
00391 code = (c->bit_buffer << s) | get_bits(&gb, s);
00392 *samples++ = g726_decode(&c->c, code & mask);
00393 }
00394
00395 while (get_bits_count(&gb) + c->code_size <= buf_size*8)
00396 *samples++ = g726_decode(&c->c, get_bits(&gb, c->code_size) & mask);
00397
00398 c->bits_left = buf_size*8 - get_bits_count(&gb);
00399 c->bit_buffer = get_bits(&gb, c->bits_left);
00400
00401 out:
00402 *data_size = (uint8_t*)samples - (uint8_t*)data;
00403 return buf_size;
00404 }
00405
00406 #ifdef CONFIG_ENCODERS
00407 AVCodec adpcm_g726_encoder = {
00408 "g726",
00409 CODEC_TYPE_AUDIO,
00410 CODEC_ID_ADPCM_G726,
00411 sizeof(AVG726Context),
00412 g726_init,
00413 g726_encode_frame,
00414 g726_close,
00415 NULL,
00416 };
00417 #endif //CONFIG_ENCODERS
00418
00419 AVCodec adpcm_g726_decoder = {
00420 "g726",
00421 CODEC_TYPE_AUDIO,
00422 CODEC_ID_ADPCM_G726,
00423 sizeof(AVG726Context),
00424 g726_init,
00425 NULL,
00426 g726_close,
00427 g726_decode_frame,
00428 };