q_gain2.c revision 956c553ab0ce72f8074ad0fda2ffd66a0305700c
1/* 2 ** Copyright 2003-2010, VisualOn, Inc. 3 ** 4 ** Licensed under the Apache License, Version 2.0 (the "License"); 5 ** you may not use this file except in compliance with the License. 6 ** You may obtain a copy of the License at 7 ** 8 ** http://www.apache.org/licenses/LICENSE-2.0 9 ** 10 ** Unless required by applicable law or agreed to in writing, software 11 ** distributed under the License is distributed on an "AS IS" BASIS, 12 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 ** See the License for the specific language governing permissions and 14 ** limitations under the License. 15 */ 16 17/************************************************************************** 18* File: q_gain2.c * 19* * 20* Description: * 21* Quantization of pitch and codebook gains. * 22* MA prediction is performed on the innovation energy (in dB with mean * 23* removed). * 24* An initial predicted gain, g_0, is first determined and the correction * 25* factor alpha = gain / g_0 is quantized. * 26* The pitch gain and the correction factor are vector quantized and the * 27* mean-squared weighted error criterion is used in the quantizer search. * 28****************************************************************************/ 29 30#include "typedef.h" 31#include "basic_op.h" 32#include "oper_32b.h" 33#include "math_op.h" 34#include "log2.h" 35#include "acelp.h" 36#include "q_gain2.tab" 37 38#define MEAN_ENER 30 39#define RANGE 64 40#define PRED_ORDER 4 41 42 43/* MA prediction coeff ={0.5, 0.4, 0.3, 0.2} in Q13 */ 44static Word16 pred[PRED_ORDER] = {4096, 3277, 2458, 1638}; 45 46 47void Init_Q_gain2( 48 Word16 * mem /* output :static memory (2 words) */ 49 ) 50{ 51 Word32 i; 52 53 /* 4nd order quantizer energy predictor (init to -14.0 in Q10) */ 54 for (i = 0; i < PRED_ORDER; i++) 55 { 56 mem[i] = -14336; /* past_qua_en[i] */ 57 } 58 59 return; 60} 61 62Word16 Q_gain2( /* Return index of quantization. */ 63 Word16 xn[], /* (i) Q_xn: Target vector. */ 64 Word16 y1[], /* (i) Q_xn: Adaptive codebook. */ 65 Word16 Q_xn, /* (i) : xn and y1 format */ 66 Word16 y2[], /* (i) Q9 : Filtered innovative vector. */ 67 Word16 code[], /* (i) Q9 : Innovative vector. */ 68 Word16 g_coeff[], /* (i) : Correlations <xn y1> <y1 y1> */ 69 /* Compute in G_pitch(). */ 70 Word16 L_subfr, /* (i) : Subframe lenght. */ 71 Word16 nbits, /* (i) : number of bits (6 or 7) */ 72 Word16 * gain_pit, /* (i/o)Q14: Pitch gain. */ 73 Word32 * gain_cod, /* (o) Q16 : Code gain. */ 74 Word16 gp_clip, /* (i) : Gp Clipping flag */ 75 Word16 * mem /* (i/o) : static memory (2 words) */ 76 ) 77{ 78 Word16 index, *p, min_ind, size; 79 Word16 exp, frac, gcode0, exp_gcode0, e_max, exp_code, qua_ener; 80 Word16 g_pitch, g2_pitch, g_code, g_pit_cod, g2_code, g2_code_lo; 81 Word16 coeff[5], coeff_lo[5], exp_coeff[5]; 82 Word16 exp_max[5]; 83 Word32 i, j, L_tmp, dist_min; 84 Word16 *past_qua_en, *t_qua_gain; 85 86 past_qua_en = mem; 87 88 /*-----------------------------------------------------------------* 89 * - Find the initial quantization pitch index * 90 * - Set gains search range * 91 *-----------------------------------------------------------------*/ 92 if (nbits == 6) 93 { 94 t_qua_gain = t_qua_gain6b; 95 min_ind = 0; 96 size = RANGE; 97 98 if(gp_clip == 1) 99 { 100 size = size - 16; /* limit gain pitch to 1.0 */ 101 } 102 } else 103 { 104 t_qua_gain = t_qua_gain7b; 105 106 p = t_qua_gain7b + RANGE; /* pt at 1/4th of table */ 107 108 j = nb_qua_gain7b - RANGE; 109 110 if (gp_clip == 1) 111 { 112 j = j - 27; /* limit gain pitch to 1.0 */ 113 } 114 min_ind = 0; 115 g_pitch = *gain_pit; 116 117 for (i = 0; i < j; i++, p += 2) 118 { 119 if (g_pitch > *p) 120 { 121 min_ind = min_ind + 1; 122 } 123 } 124 size = RANGE; 125 } 126 127 /*------------------------------------------------------------------* 128 * Compute coefficient need for the quantization. * 129 * * 130 * coeff[0] = y1 y1 * 131 * coeff[1] = -2 xn y1 * 132 * coeff[2] = y2 y2 * 133 * coeff[3] = -2 xn y2 * 134 * coeff[4] = 2 y1 y2 * 135 * * 136 * Product <y1 y1> and <xn y1> have been compute in G_pitch() and * 137 * are in vector g_coeff[]. * 138 *------------------------------------------------------------------*/ 139 140 coeff[0] = g_coeff[0]; 141 exp_coeff[0] = g_coeff[1]; 142 coeff[1] = negate(g_coeff[2]); /* coeff[1] = -2 xn y1 */ 143 exp_coeff[1] = g_coeff[3] + 1; 144 145 /* Compute scalar product <y2[],y2[]> */ 146#ifdef ASM_OPT /* asm optimization branch */ 147 coeff[2] = extract_h(Dot_product12_asm(y2, y2, L_subfr, &exp)); 148#else 149 coeff[2] = extract_h(Dot_product12(y2, y2, L_subfr, &exp)); 150#endif 151 exp_coeff[2] = (exp - 18) + (Q_xn << 1); /* -18 (y2 Q9) */ 152 153 /* Compute scalar product -2*<xn[],y2[]> */ 154#ifdef ASM_OPT /* asm optimization branch */ 155 coeff[3] = extract_h(L_negate(Dot_product12_asm(xn, y2, L_subfr, &exp))); 156#else 157 coeff[3] = extract_h(L_negate(Dot_product12(xn, y2, L_subfr, &exp))); 158#endif 159 160 exp_coeff[3] = (exp - 8) + Q_xn; /* -9 (y2 Q9), +1 (2 xn y2) */ 161 162 /* Compute scalar product 2*<y1[],y2[]> */ 163#ifdef ASM_OPT /* asm optimization branch */ 164 coeff[4] = extract_h(Dot_product12_asm(y1, y2, L_subfr, &exp)); 165#else 166 coeff[4] = extract_h(Dot_product12(y1, y2, L_subfr, &exp)); 167#endif 168 exp_coeff[4] = (exp - 8) + Q_xn; /* -9 (y2 Q9), +1 (2 y1 y2) */ 169 170 /*-----------------------------------------------------------------* 171 * Find energy of code and compute: * 172 * * 173 * L_tmp = MEAN_ENER - 10log10(energy of code/ L_subfr) * 174 * = MEAN_ENER - 3.0103*log2(energy of code/ L_subfr) * 175 *-----------------------------------------------------------------*/ 176#ifdef ASM_OPT /* asm optimization branch */ 177 L_tmp = Dot_product12_asm(code, code, L_subfr, &exp_code); 178#else 179 L_tmp = Dot_product12(code, code, L_subfr, &exp_code); 180#endif 181 /* exp_code: -18 (code in Q9), -6 (/L_subfr), -31 (L_tmp Q31->Q0) */ 182 exp_code = (exp_code - (18 + 6 + 31)); 183 184 Log2(L_tmp, &exp, &frac); 185 exp += exp_code; 186 L_tmp = Mpy_32_16(exp, frac, -24660); /* x -3.0103(Q13) -> Q14 */ 187 188 L_tmp += (MEAN_ENER * 8192)<<1; /* + MEAN_ENER in Q14 */ 189 190 /*-----------------------------------------------------------------* 191 * Compute gcode0. * 192 * = Sum(i=0,1) pred[i]*past_qua_en[i] + mean_ener - ener_code * 193 *-----------------------------------------------------------------*/ 194 L_tmp = (L_tmp << 10); /* From Q14 to Q24 */ 195 L_tmp += (pred[0] * past_qua_en[0])<<1; /* Q13*Q10 -> Q24 */ 196 L_tmp += (pred[1] * past_qua_en[1])<<1; /* Q13*Q10 -> Q24 */ 197 L_tmp += (pred[2] * past_qua_en[2])<<1; /* Q13*Q10 -> Q24 */ 198 L_tmp += (pred[3] * past_qua_en[3])<<1; /* Q13*Q10 -> Q24 */ 199 200 gcode0 = extract_h(L_tmp); /* From Q24 to Q8 */ 201 202 /*-----------------------------------------------------------------* 203 * gcode0 = pow(10.0, gcode0/20) * 204 * = pow(2, 3.321928*gcode0/20) * 205 * = pow(2, 0.166096*gcode0) * 206 *-----------------------------------------------------------------*/ 207 208 L_tmp = vo_L_mult(gcode0, 5443); /* *0.166096 in Q15 -> Q24 */ 209 L_tmp = L_tmp >> 8; /* From Q24 to Q16 */ 210 VO_L_Extract(L_tmp, &exp_gcode0, &frac); /* Extract exponent of gcode0 */ 211 212 gcode0 = (Word16)(Pow2(14, frac)); /* Put 14 as exponent so that */ 213 /* output of Pow2() will be: */ 214 /* 16384 < Pow2() <= 32767 */ 215 exp_gcode0 -= 14; 216 217 /*-------------------------------------------------------------------------* 218 * Find the best quantizer * 219 * ~~~~~~~~~~~~~~~~~~~~~~~ * 220 * Before doing the computation we need to aling exponents of coeff[] * 221 * to be sure to have the maximum precision. * 222 * * 223 * In the table the pitch gains are in Q14, the code gains are in Q11 and * 224 * are multiply by gcode0 which have been multiply by 2^exp_gcode0. * 225 * Also when we compute g_pitch*g_pitch, g_code*g_code and g_pitch*g_code * 226 * we divide by 2^15. * 227 * Considering all the scaling above we have: * 228 * * 229 * exp_code = exp_gcode0-11+15 = exp_gcode0+4 * 230 * * 231 * g_pitch*g_pitch = -14-14+15 * 232 * g_pitch = -14 * 233 * g_code*g_code = (2*exp_code)+15 * 234 * g_code = exp_code * 235 * g_pitch*g_code = -14 + exp_code +15 * 236 * * 237 * g_pitch*g_pitch * coeff[0] ;exp_max0 = exp_coeff[0] - 13 * 238 * g_pitch * coeff[1] ;exp_max1 = exp_coeff[1] - 14 * 239 * g_code*g_code * coeff[2] ;exp_max2 = exp_coeff[2] +15+(2*exp_code) * 240 * g_code * coeff[3] ;exp_max3 = exp_coeff[3] + exp_code * 241 * g_pitch*g_code * coeff[4] ;exp_max4 = exp_coeff[4] + 1 + exp_code * 242 *-------------------------------------------------------------------------*/ 243 244 exp_code = (exp_gcode0 + 4); 245 exp_max[0] = (exp_coeff[0] - 13); 246 exp_max[1] = (exp_coeff[1] - 14); 247 exp_max[2] = (exp_coeff[2] + (15 + (exp_code << 1))); 248 exp_max[3] = (exp_coeff[3] + exp_code); 249 exp_max[4] = (exp_coeff[4] + (1 + exp_code)); 250 251 /* Find maximum exponant */ 252 253 e_max = exp_max[0]; 254 for (i = 1; i < 5; i++) 255 { 256 if(exp_max[i] > e_max) 257 { 258 e_max = exp_max[i]; 259 } 260 } 261 262 /* align coeff[] and save in special 32 bit double precision */ 263 264 for (i = 0; i < 5; i++) 265 { 266 j = add1(vo_sub(e_max, exp_max[i]), 2);/* /4 to avoid overflow */ 267 L_tmp = L_deposit_h(coeff[i]); 268 L_tmp = L_shr(L_tmp, j); 269 VO_L_Extract(L_tmp, &coeff[i], &coeff_lo[i]); 270 coeff_lo[i] = (coeff_lo[i] >> 3); /* lo >> 3 */ 271 } 272 273 /* Codebook search */ 274 dist_min = MAX_32; 275 p = &t_qua_gain[min_ind << 1]; 276 277 index = 0; 278 for (i = 0; i < size; i++) 279 { 280 g_pitch = *p++; 281 g_code = *p++; 282 283 g_code = ((g_code * gcode0) + 0x4000)>>15; 284 g2_pitch = ((g_pitch * g_pitch) + 0x4000)>>15; 285 g_pit_cod = ((g_code * g_pitch) + 0x4000)>>15; 286 L_tmp = (g_code * g_code)<<1; 287 VO_L_Extract(L_tmp, &g2_code, &g2_code_lo); 288 289 L_tmp = (coeff[2] * g2_code_lo)<<1; 290 L_tmp = (L_tmp >> 3); 291 L_tmp += (coeff_lo[0] * g2_pitch)<<1; 292 L_tmp += (coeff_lo[1] * g_pitch)<<1; 293 L_tmp += (coeff_lo[2] * g2_code)<<1; 294 L_tmp += (coeff_lo[3] * g_code)<<1; 295 L_tmp += (coeff_lo[4] * g_pit_cod)<<1; 296 L_tmp = (L_tmp >> 12); 297 L_tmp += (coeff[0] * g2_pitch)<<1; 298 L_tmp += (coeff[1] * g_pitch)<<1; 299 L_tmp += (coeff[2] * g2_code)<<1; 300 L_tmp += (coeff[3] * g_code)<<1; 301 L_tmp += (coeff[4] * g_pit_cod)<<1; 302 303 if(L_tmp < dist_min) 304 { 305 dist_min = L_tmp; 306 index = i; 307 } 308 } 309 310 /* Read the quantized gains */ 311 index = index + min_ind; 312 p = &t_qua_gain[(index + index)]; 313 *gain_pit = *p++; /* selected pitch gain in Q14 */ 314 g_code = *p++; /* selected code gain in Q11 */ 315 316 L_tmp = vo_L_mult(g_code, gcode0); /* Q11*Q0 -> Q12 */ 317 L_tmp = L_shl(L_tmp, (exp_gcode0 + 4)); /* Q12 -> Q16 */ 318 319 *gain_cod = L_tmp; /* gain of code in Q16 */ 320 321 /*---------------------------------------------------* 322 * qua_ener = 20*log10(g_code) * 323 * = 6.0206*log2(g_code) * 324 * = 6.0206*(log2(g_codeQ11) - 11) * 325 *---------------------------------------------------*/ 326 327 L_tmp = L_deposit_l(g_code); 328 Log2(L_tmp, &exp, &frac); 329 exp -= 11; 330 L_tmp = Mpy_32_16(exp, frac, 24660); /* x 6.0206 in Q12 */ 331 332 qua_ener = (Word16)(L_tmp >> 3); /* result in Q10 */ 333 334 /* update table of past quantized energies */ 335 336 past_qua_en[3] = past_qua_en[2]; 337 past_qua_en[2] = past_qua_en[1]; 338 past_qua_en[1] = past_qua_en[0]; 339 past_qua_en[0] = qua_ener; 340 341 return (index); 342} 343 344 345 346 347