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Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/q_gain2.c')
-rw-r--r-- | media/libstagefright/codecs/amrwbenc/src/q_gain2.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/q_gain2.c b/media/libstagefright/codecs/amrwbenc/src/q_gain2.c new file mode 100644 index 0000000..e8ca043 --- /dev/null +++ b/media/libstagefright/codecs/amrwbenc/src/q_gain2.c @@ -0,0 +1,346 @@ +/* + ** Copyright 2003-2010, VisualOn, Inc. + ** + ** Licensed under the Apache License, Version 2.0 (the "License"); + ** you may not use this file except in compliance with the License. + ** You may obtain a copy of the License at + ** + ** http://www.apache.org/licenses/LICENSE-2.0 + ** + ** Unless required by applicable law or agreed to in writing, software + ** distributed under the License is distributed on an "AS IS" BASIS, + ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + ** See the License for the specific language governing permissions and + ** limitations under the License. + */ + +/************************************************************************** +* File: q_gain2.c * +* * +* Description: * +* Quantization of pitch and codebook gains. * +* MA prediction is performed on the innovation energy (in dB with mean * +* removed). * +* An initial predicted gain, g_0, is first determined and the correction * +* factor alpha = gain / g_0 is quantized. * +* The pitch gain and the correction factor are vector quantized and the * +* mean-squared weighted error criterion is used in the quantizer search. * +****************************************************************************/ + +#include "typedef.h" +#include "basic_op.h" +#include "oper_32b.h" +#include "math_op.h" +#include "log2.h" +#include "acelp.h" +#include "q_gain2.tab" + +#define MEAN_ENER 30 +#define RANGE 64 +#define PRED_ORDER 4 + + +/* MA prediction coeff ={0.5, 0.4, 0.3, 0.2} in Q13 */ +static Word16 pred[PRED_ORDER] = {4096, 3277, 2458, 1638}; + + +void Init_Q_gain2( + Word16 * mem /* output :static memory (2 words) */ + ) +{ + Word32 i; + + /* 4nd order quantizer energy predictor (init to -14.0 in Q10) */ + for (i = 0; i < PRED_ORDER; i++) + { + mem[i] = -14336; /* past_qua_en[i] */ + } + + return; +} + +Word16 Q_gain2( /* Return index of quantization. */ + Word16 xn[], /* (i) Q_xn: Target vector. */ + Word16 y1[], /* (i) Q_xn: Adaptive codebook. */ + Word16 Q_xn, /* (i) : xn and y1 format */ + Word16 y2[], /* (i) Q9 : Filtered innovative vector. */ + Word16 code[], /* (i) Q9 : Innovative vector. */ + Word16 g_coeff[], /* (i) : Correlations <xn y1> <y1 y1> */ + /* Compute in G_pitch(). */ + Word16 L_subfr, /* (i) : Subframe lenght. */ + Word16 nbits, /* (i) : number of bits (6 or 7) */ + Word16 * gain_pit, /* (i/o)Q14: Pitch gain. */ + Word32 * gain_cod, /* (o) Q16 : Code gain. */ + Word16 gp_clip, /* (i) : Gp Clipping flag */ + Word16 * mem /* (i/o) : static memory (2 words) */ + ) +{ + Word16 index, *p, min_ind, size; + Word16 exp, frac, gcode0, exp_gcode0, e_max, exp_code, qua_ener; + Word16 g_pitch, g2_pitch, g_code, g_pit_cod, g2_code, g2_code_lo; + Word16 coeff[5], coeff_lo[5], exp_coeff[5]; + Word16 exp_max[5]; + Word32 i, j, L_tmp, dist_min; + Word16 *past_qua_en, *t_qua_gain; + + past_qua_en = mem; + + /*-----------------------------------------------------------------* + * - Find the initial quantization pitch index * + * - Set gains search range * + *-----------------------------------------------------------------*/ + if (nbits == 6) + { + t_qua_gain = t_qua_gain6b; + min_ind = 0; + size = RANGE; + + if(gp_clip == 1) + { + size = size - 16; /* limit gain pitch to 1.0 */ + } + } else + { + t_qua_gain = t_qua_gain7b; + + p = t_qua_gain7b + RANGE; /* pt at 1/4th of table */ + + j = nb_qua_gain7b - RANGE; + + if (gp_clip == 1) + { + j = j - 27; /* limit gain pitch to 1.0 */ + } + min_ind = 0; + g_pitch = *gain_pit; + + for (i = 0; i < j; i++, p += 2) + { + if (g_pitch > *p) + { + min_ind = min_ind + 1; + } + } + size = RANGE; + } + + /*------------------------------------------------------------------* + * Compute coefficient need for the quantization. * + * * + * coeff[0] = y1 y1 * + * coeff[1] = -2 xn y1 * + * coeff[2] = y2 y2 * + * coeff[3] = -2 xn y2 * + * coeff[4] = 2 y1 y2 * + * * + * Product <y1 y1> and <xn y1> have been compute in G_pitch() and * + * are in vector g_coeff[]. * + *------------------------------------------------------------------*/ + + coeff[0] = g_coeff[0]; + exp_coeff[0] = g_coeff[1]; + coeff[1] = negate(g_coeff[2]); /* coeff[1] = -2 xn y1 */ + exp_coeff[1] = g_coeff[3] + 1; + + /* Compute scalar product <y2[],y2[]> */ +#ifdef ASM_OPT /* asm optimization branch */ + coeff[2] = extract_h(Dot_product12_asm(y2, y2, L_subfr, &exp)); +#else + coeff[2] = extract_h(Dot_product12(y2, y2, L_subfr, &exp)); +#endif + exp_coeff[2] = (exp - 18) + (Q_xn << 1); /* -18 (y2 Q9) */ + + /* Compute scalar product -2*<xn[],y2[]> */ +#ifdef ASM_OPT /* asm optimization branch */ + coeff[3] = extract_h(L_negate(Dot_product12_asm(xn, y2, L_subfr, &exp))); +#else + coeff[3] = extract_h(L_negate(Dot_product12(xn, y2, L_subfr, &exp))); +#endif + + exp_coeff[3] = (exp - 8) + Q_xn; /* -9 (y2 Q9), +1 (2 xn y2) */ + + /* Compute scalar product 2*<y1[],y2[]> */ +#ifdef ASM_OPT /* asm optimization branch */ + coeff[4] = extract_h(Dot_product12_asm(y1, y2, L_subfr, &exp)); +#else + coeff[4] = extract_h(Dot_product12(y1, y2, L_subfr, &exp)); +#endif + exp_coeff[4] = (exp - 8) + Q_xn; /* -9 (y2 Q9), +1 (2 y1 y2) */ + + /*-----------------------------------------------------------------* + * Find energy of code and compute: * + * * + * L_tmp = MEAN_ENER - 10log10(energy of code/ L_subfr) * + * = MEAN_ENER - 3.0103*log2(energy of code/ L_subfr) * + *-----------------------------------------------------------------*/ +#ifdef ASM_OPT /* asm optimization branch */ + L_tmp = Dot_product12_asm(code, code, L_subfr, &exp_code); +#else + L_tmp = Dot_product12(code, code, L_subfr, &exp_code); +#endif + /* exp_code: -18 (code in Q9), -6 (/L_subfr), -31 (L_tmp Q31->Q0) */ + exp_code = (exp_code - (18 + 6 + 31)); + + Log2(L_tmp, &exp, &frac); + exp += exp_code; + L_tmp = Mpy_32_16(exp, frac, -24660); /* x -3.0103(Q13) -> Q14 */ + + L_tmp += (MEAN_ENER * 8192)<<1; /* + MEAN_ENER in Q14 */ + + /*-----------------------------------------------------------------* + * Compute gcode0. * + * = Sum(i=0,1) pred[i]*past_qua_en[i] + mean_ener - ener_code * + *-----------------------------------------------------------------*/ + L_tmp = (L_tmp << 10); /* From Q14 to Q24 */ + L_tmp += (pred[0] * past_qua_en[0])<<1; /* Q13*Q10 -> Q24 */ + L_tmp += (pred[1] * past_qua_en[1])<<1; /* Q13*Q10 -> Q24 */ + L_tmp += (pred[2] * past_qua_en[2])<<1; /* Q13*Q10 -> Q24 */ + L_tmp += (pred[3] * past_qua_en[3])<<1; /* Q13*Q10 -> Q24 */ + + gcode0 = extract_h(L_tmp); /* From Q24 to Q8 */ + + /*-----------------------------------------------------------------* + * gcode0 = pow(10.0, gcode0/20) * + * = pow(2, 3.321928*gcode0/20) * + * = pow(2, 0.166096*gcode0) * + *-----------------------------------------------------------------*/ + + L_tmp = vo_L_mult(gcode0, 5443); /* *0.166096 in Q15 -> Q24 */ + L_tmp = L_tmp >> 8; /* From Q24 to Q16 */ + VO_L_Extract(L_tmp, &exp_gcode0, &frac); /* Extract exponent of gcode0 */ + + gcode0 = (Word16)(Pow2(14, frac)); /* Put 14 as exponent so that */ + /* output of Pow2() will be: */ + /* 16384 < Pow2() <= 32767 */ + exp_gcode0 -= 14; + + /*-------------------------------------------------------------------------* + * Find the best quantizer * + * ~~~~~~~~~~~~~~~~~~~~~~~ * + * Before doing the computation we need to aling exponents of coeff[] * + * to be sure to have the maximum precision. * + * * + * In the table the pitch gains are in Q14, the code gains are in Q11 and * + * are multiply by gcode0 which have been multiply by 2^exp_gcode0. * + * Also when we compute g_pitch*g_pitch, g_code*g_code and g_pitch*g_code * + * we divide by 2^15. * + * Considering all the scaling above we have: * + * * + * exp_code = exp_gcode0-11+15 = exp_gcode0+4 * + * * + * g_pitch*g_pitch = -14-14+15 * + * g_pitch = -14 * + * g_code*g_code = (2*exp_code)+15 * + * g_code = exp_code * + * g_pitch*g_code = -14 + exp_code +15 * + * * + * g_pitch*g_pitch * coeff[0] ;exp_max0 = exp_coeff[0] - 13 * + * g_pitch * coeff[1] ;exp_max1 = exp_coeff[1] - 14 * + * g_code*g_code * coeff[2] ;exp_max2 = exp_coeff[2] +15+(2*exp_code) * + * g_code * coeff[3] ;exp_max3 = exp_coeff[3] + exp_code * + * g_pitch*g_code * coeff[4] ;exp_max4 = exp_coeff[4] + 1 + exp_code * + *-------------------------------------------------------------------------*/ + + exp_code = (exp_gcode0 + 4); + exp_max[0] = (exp_coeff[0] - 13); + exp_max[1] = (exp_coeff[1] - 14); + exp_max[2] = (exp_coeff[2] + (15 + (exp_code << 1))); + exp_max[3] = (exp_coeff[3] + exp_code); + exp_max[4] = (exp_coeff[4] + (1 + exp_code)); + + /* Find maximum exponant */ + + e_max = exp_max[0]; + for (i = 1; i < 5; i++) + { + if(exp_max[i] > e_max) + { + e_max = exp_max[i]; + } + } + + /* align coeff[] and save in special 32 bit double precision */ + + for (i = 0; i < 5; i++) + { + j = add1(vo_sub(e_max, exp_max[i]), 2);/* /4 to avoid overflow */ + L_tmp = L_deposit_h(coeff[i]); + L_tmp = L_shr(L_tmp, j); + VO_L_Extract(L_tmp, &coeff[i], &coeff_lo[i]); + coeff_lo[i] = (coeff_lo[i] >> 3); /* lo >> 3 */ + } + + /* Codebook search */ + dist_min = MAX_32; + p = &t_qua_gain[min_ind << 1]; + + index = 0; + for (i = 0; i < size; i++) + { + g_pitch = *p++; + g_code = *p++; + + g_code = ((g_code * gcode0) + 0x4000)>>15; + g2_pitch = ((g_pitch * g_pitch) + 0x4000)>>15; + g_pit_cod = ((g_code * g_pitch) + 0x4000)>>15; + L_tmp = (g_code * g_code)<<1; + VO_L_Extract(L_tmp, &g2_code, &g2_code_lo); + + L_tmp = (coeff[2] * g2_code_lo)<<1; + L_tmp = (L_tmp >> 3); + L_tmp += (coeff_lo[0] * g2_pitch)<<1; + L_tmp += (coeff_lo[1] * g_pitch)<<1; + L_tmp += (coeff_lo[2] * g2_code)<<1; + L_tmp += (coeff_lo[3] * g_code)<<1; + L_tmp += (coeff_lo[4] * g_pit_cod)<<1; + L_tmp = (L_tmp >> 12); + L_tmp += (coeff[0] * g2_pitch)<<1; + L_tmp += (coeff[1] * g_pitch)<<1; + L_tmp += (coeff[2] * g2_code)<<1; + L_tmp += (coeff[3] * g_code)<<1; + L_tmp += (coeff[4] * g_pit_cod)<<1; + + if(L_tmp < dist_min) + { + dist_min = L_tmp; + index = i; + } + } + + /* Read the quantized gains */ + index = index + min_ind; + p = &t_qua_gain[(index + index)]; + *gain_pit = *p++; /* selected pitch gain in Q14 */ + g_code = *p++; /* selected code gain in Q11 */ + + L_tmp = vo_L_mult(g_code, gcode0); /* Q11*Q0 -> Q12 */ + L_tmp = L_shl(L_tmp, (exp_gcode0 + 4)); /* Q12 -> Q16 */ + + *gain_cod = L_tmp; /* gain of code in Q16 */ + + /*---------------------------------------------------* + * qua_ener = 20*log10(g_code) * + * = 6.0206*log2(g_code) * + * = 6.0206*(log2(g_codeQ11) - 11) * + *---------------------------------------------------*/ + + L_tmp = L_deposit_l(g_code); + Log2(L_tmp, &exp, &frac); + exp -= 11; + L_tmp = Mpy_32_16(exp, frac, 24660); /* x 6.0206 in Q12 */ + + qua_ener = (Word16)(L_tmp >> 3); /* result in Q10 */ + + /* update table of past quantized energies */ + + past_qua_en[3] = past_qua_en[2]; + past_qua_en[2] = past_qua_en[1]; + past_qua_en[1] = past_qua_en[0]; + past_qua_en[0] = qua_ener; + + return (index); +} + + + + |