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