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: p_med_ol.c                                                *
19*                                                                      *
20*      Description: Compute the open loop pitch lag                    *
21*	            output: open loop pitch lag                        *
22************************************************************************/
23
24#include "typedef.h"
25#include "basic_op.h"
26#include "acelp.h"
27#include "oper_32b.h"
28#include "math_op.h"
29#include "p_med_ol.tab"
30
31Word16 Pitch_med_ol(
32		   Word16      wsp[],        /*   i: signal used to compute the open loop pitch*/
33                                     /*      wsp[-pit_max] to wsp[-1] should be known */
34		   Coder_State *st,          /* i/o: codec global structure */
35		   Word16      L_frame       /*   i: length of frame to compute pitch */
36		)
37{
38	Word16 Tm;
39	Word16 hi, lo;
40	Word16 *ww, *we, *hp_wsp;
41	Word16 exp_R0, exp_R1, exp_R2;
42	Word32 i, j, max, R0, R1, R2;
43	Word16 *p1, *p2;
44	Word16 L_min = 17;                   /* minimum pitch lag: PIT_MIN / OPL_DECIM */
45	Word16 L_max = 115;                  /* maximum pitch lag: PIT_MAX / OPL_DECIM */
46	Word16 L_0 = st->old_T0_med;         /* old open-loop pitch */
47	Word16 *gain = &(st->ol_gain);       /* normalize correlation of hp_wsp for the lag */
48	Word16 *hp_wsp_mem = st->hp_wsp_mem; /* memory of the hypass filter for hp_wsp[] (lg = 9)*/
49	Word16 *old_hp_wsp = st->old_hp_wsp; /* hypass wsp[] */
50	Word16 wght_flg = st->ol_wght_flg;   /* is weighting function used */
51
52	ww = &corrweight[198];
53	we = &corrweight[98 + L_max - L_0];
54
55	max = MIN_32;
56	Tm = 0;
57	for (i = L_max; i > L_min; i--)
58	{
59		/* Compute the correlation */
60		R0 = 0;
61		p1 = wsp;
62		p2 = &wsp[-i];
63		for (j = 0; j < L_frame; j+=4)
64		{
65			R0 += vo_L_mult((*p1++), (*p2++));
66			R0 += vo_L_mult((*p1++), (*p2++));
67			R0 += vo_L_mult((*p1++), (*p2++));
68			R0 += vo_L_mult((*p1++), (*p2++));
69		}
70		/* Weighting of the correlation function.   */
71		hi = R0>>16;
72		lo = (R0 & 0xffff)>>1;
73
74		R0 = Mpy_32_16(hi, lo, *ww);
75		ww--;
76
77		if ((L_0 > 0) && (wght_flg > 0))
78		{
79			/* Weight the neighbourhood of the old lag. */
80			hi = R0>>16;
81			lo = (R0 & 0xffff)>>1;
82			R0 = Mpy_32_16(hi, lo, *we);
83			we--;
84		}
85		if(R0 >= max)
86		{
87			max = R0;
88			Tm = i;
89		}
90	}
91
92	/* Hypass the wsp[] vector */
93	hp_wsp = old_hp_wsp + L_max;
94	Hp_wsp(wsp, hp_wsp, L_frame, hp_wsp_mem);
95
96	/* Compute normalize correlation at delay Tm */
97	R0 = 0;
98	R1 = 0;
99	R2 = 0;
100	p1 = hp_wsp;
101	p2 = hp_wsp - Tm;
102	for (j = 0; j < L_frame; j+=4)
103	{
104		R2 += vo_mult32(*p1, *p1);
105		R1 += vo_mult32(*p2, *p2);
106		R0 += vo_mult32(*p1++, *p2++);
107		R2 += vo_mult32(*p1, *p1);
108		R1 += vo_mult32(*p2, *p2);
109		R0 += vo_mult32(*p1++, *p2++);
110		R2 += vo_mult32(*p1, *p1);
111		R1 += vo_mult32(*p2, *p2);
112		R0 += vo_mult32(*p1++, *p2++);
113		R2 += vo_mult32(*p1, *p1);
114		R1 += vo_mult32(*p2, *p2);
115		R0 += vo_mult32(*p1++, *p2++);
116	}
117	R0 = R0 <<1;
118	R1 = (R1 <<1) + 1L;
119	R2 = (R2 <<1) + 1L;
120	/* gain = R0/ sqrt(R1*R2) */
121
122	exp_R0 = norm_l(R0);
123	R0 = (R0 << exp_R0);
124
125	exp_R1 = norm_l(R1);
126	R1 = (R1 << exp_R1);
127
128	exp_R2 = norm_l(R2);
129	R2 = (R2 << exp_R2);
130
131
132	R1 = vo_L_mult(vo_round(R1), vo_round(R2));
133
134	i = norm_l(R1);
135	R1 = (R1 << i);
136
137	exp_R1 += exp_R2;
138	exp_R1 += i;
139	exp_R1 = 62 - exp_R1;
140
141	Isqrt_n(&R1, &exp_R1);
142
143	R0 = vo_L_mult(voround(R0), voround(R1));
144	exp_R0 = 31 - exp_R0;
145	exp_R0 += exp_R1;
146
147	*gain = vo_round(L_shl(R0, exp_R0));
148
149	/* Shitf hp_wsp[] for next frame */
150
151	for (i = 0; i < L_max; i++)
152	{
153		old_hp_wsp[i] = old_hp_wsp[i + L_frame];
154	}
155
156	return (Tm);
157}
158
159/************************************************************************
160*  Function: median5                                                    *
161*                                                                       *
162*      Returns the median of the set {X[-2], X[-1],..., X[2]},          *
163*      whose elements are 16-bit integers.                              *
164*                                                                       *
165*  Input:                                                               *
166*      X[-2:2]   16-bit integers.                                       *
167*                                                                       *
168*  Return:                                                              *
169*      The median of {X[-2], X[-1],..., X[2]}.                          *
170************************************************************************/
171
172Word16 median5(Word16 x[])
173{
174	Word16 x1, x2, x3, x4, x5;
175	Word16 tmp;
176
177	x1 = x[-2];
178	x2 = x[-1];
179	x3 = x[0];
180	x4 = x[1];
181	x5 = x[2];
182
183	if (x2 < x1)
184	{
185		tmp = x1;
186		x1 = x2;
187		x2 = tmp;
188	}
189	if (x3 < x1)
190	{
191		tmp = x1;
192		x1 = x3;
193		x3 = tmp;
194	}
195	if (x4 < x1)
196	{
197		tmp = x1;
198		x1 = x4;
199		x4 = tmp;
200	}
201	if (x5 < x1)
202	{
203		x5 = x1;
204	}
205	if (x3 < x2)
206	{
207		tmp = x2;
208		x2 = x3;
209		x3 = tmp;
210	}
211	if (x4 < x2)
212	{
213		tmp = x2;
214		x2 = x4;
215		x4 = tmp;
216	}
217	if (x5 < x2)
218	{
219		x5 = x2;
220	}
221	if (x4 < x3)
222	{
223		x3 = x4;
224	}
225	if (x5 < x3)
226	{
227		x3 = x5;
228	}
229	return (x3);
230}
231
232
233Word16 Med_olag(                           /* output : median of  5 previous open-loop lags       */
234		Word16 prev_ol_lag,                /* input  : previous open-loop lag                     */
235		Word16 old_ol_lag[5]
236	       )
237{
238	Word32 i;
239
240	/* Use median of 5 previous open-loop lags as old lag */
241
242	for (i = 4; i > 0; i--)
243	{
244		old_ol_lag[i] = old_ol_lag[i - 1];
245	}
246
247	old_ol_lag[0] = prev_ol_lag;
248
249	i = median5(&old_ol_lag[2]);
250
251	return i;
252
253}
254
255
256
257