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: g_pitch.c *
19 * *
20 * Description:Compute the gain of pitch. Result in Q12 *
21 * if(gain < 0) gain = 0 *
22 * if(gain > 1.2) gain = 1.2 *
23 ************************************************************************/
24
25 #include "typedef.h"
26 #include "basic_op.h"
27 #include "math_op.h"
28
G_pitch(Word16 xn[],Word16 y1[],Word16 g_coeff[],Word16 L_subfr)29 Word16 G_pitch( /* (o) Q14 : Gain of pitch lag saturated to 1.2 */
30 Word16 xn[], /* (i) : Pitch target. */
31 Word16 y1[], /* (i) : filtered adaptive codebook. */
32 Word16 g_coeff[], /* : Correlations need for gain quantization. */
33 Word16 L_subfr /* : Length of subframe. */
34 )
35 {
36 Word32 i;
37 Word16 xy, yy, exp_xy, exp_yy, gain;
38 /* Compute scalar product <y1[],y1[]> */
39 #ifdef ASM_OPT /* asm optimization branch */
40 /* Compute scalar product <xn[],y1[]> */
41 xy = extract_h(Dot_product12_asm(xn, y1, L_subfr, &exp_xy));
42 yy = extract_h(Dot_product12_asm(y1, y1, L_subfr, &exp_yy));
43
44 #else
45 /* Compute scalar product <xn[],y1[]> */
46 xy = extract_h(Dot_product12(xn, y1, L_subfr, &exp_xy));
47 yy = extract_h(Dot_product12(y1, y1, L_subfr, &exp_yy));
48
49 #endif
50
51 g_coeff[0] = yy;
52 g_coeff[1] = exp_yy;
53 g_coeff[2] = xy;
54 g_coeff[3] = exp_xy;
55
56 /* If (xy < 0) gain = 0 */
57 if (xy < 0)
58 return ((Word16) 0);
59
60 /* compute gain = xy/yy */
61
62 xy >>= 1; /* Be sure xy < yy */
63 gain = div_s(xy, yy);
64
65 i = exp_xy;
66 i -= exp_yy;
67
68 gain = shl(gain, i);
69
70 /* if (gain > 1.2) gain = 1.2 in Q14 */
71 if(gain > 19661)
72 {
73 gain = 19661;
74 }
75 return (gain);
76 }
77
78
79
80