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/*
** 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);
}
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