1 /*
2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 /******************************************************************
12
13 iLBC Speech Coder ANSI-C Source Code
14
15 WebRtcIlbcfix_CbMemEnergy.c
16
17 ******************************************************************/
18
19 #include "defines.h"
20 #include "constants.h"
21 #include "cb_mem_energy_calc.h"
22
23 /*----------------------------------------------------------------*
24 * Function WebRtcIlbcfix_CbMemEnergy computes the energy of all
25 * the vectors in the codebook memory that will be used in the
26 * following search for the best match.
27 *----------------------------------------------------------------*/
28
WebRtcIlbcfix_CbMemEnergy(size_t range,int16_t * CB,int16_t * filteredCB,size_t lMem,size_t lTarget,int16_t * energyW16,int16_t * energyShifts,int scale,size_t base_size)29 void WebRtcIlbcfix_CbMemEnergy(
30 size_t range,
31 int16_t *CB, /* (i) The CB memory (1:st section) */
32 int16_t *filteredCB, /* (i) The filtered CB memory (2:nd section) */
33 size_t lMem, /* (i) Length of the CB memory */
34 size_t lTarget, /* (i) Length of the target vector */
35 int16_t *energyW16, /* (o) Energy in the CB vectors */
36 int16_t *energyShifts, /* (o) Shift value of the energy */
37 int scale, /* (i) The scaling of all energy values */
38 size_t base_size /* (i) Index to where energy values should be stored */
39 ) {
40 int16_t *ppi, *ppo, *pp;
41 int32_t energy, tmp32;
42
43 /* Compute the energy and store it in a vector. Also the
44 * corresponding shift values are stored. The energy values
45 * are reused in all three stages. */
46
47 /* Calculate the energy in the first block of 'lTarget' sampels. */
48 ppi = CB+lMem-lTarget-1;
49 ppo = CB+lMem-1;
50
51 pp=CB+lMem-lTarget;
52 energy = WebRtcSpl_DotProductWithScale( pp, pp, lTarget, scale);
53
54 /* Normalize the energy and store the number of shifts */
55 energyShifts[0] = (int16_t)WebRtcSpl_NormW32(energy);
56 tmp32 = energy << energyShifts[0];
57 energyW16[0] = (int16_t)(tmp32 >> 16);
58
59 /* Compute the energy of the rest of the cb memory
60 * by step wise adding and subtracting the next
61 * sample and the last sample respectively. */
62 WebRtcIlbcfix_CbMemEnergyCalc(energy, range, ppi, ppo, energyW16, energyShifts, scale, 0);
63
64 /* Next, precompute the energy values for the filtered cb section */
65 energy=0;
66 pp=filteredCB+lMem-lTarget;
67
68 energy = WebRtcSpl_DotProductWithScale( pp, pp, lTarget, scale);
69
70 /* Normalize the energy and store the number of shifts */
71 energyShifts[base_size] = (int16_t)WebRtcSpl_NormW32(energy);
72 tmp32 = energy << energyShifts[base_size];
73 energyW16[base_size] = (int16_t)(tmp32 >> 16);
74
75 ppi = filteredCB + lMem - 1 - lTarget;
76 ppo = filteredCB + lMem - 1;
77
78 WebRtcIlbcfix_CbMemEnergyCalc(energy, range, ppi, ppo, energyW16, energyShifts, scale, base_size);
79 }
80