1 /* ------------------------------------------------------------------
2 * Copyright (C) 1998-2009 PacketVideo
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
13 * express or implied.
14 * See the License for the specific language governing permissions
15 * and limitations under the License.
16 * -------------------------------------------------------------------
17 */
18 /****************************************************************************************
19 Portions of this file are derived from the following 3GPP standard:
20
21 3GPP TS 26.073
22 ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
23 Available from http://www.3gpp.org
24
25 (C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
26 Permission to distribute, modify and use this file under the standard license
27 terms listed above has been obtained from the copyright holder.
28 ****************************************************************************************/
29 /*
30 ------------------------------------------------------------------------------
31
32
33
34 Pathname: ./audio/gsm-amr/c/src/cor_h_x2.c
35
36 Date: 11/07/2001
37
38 ------------------------------------------------------------------------------
39 REVISION HISTORY
40
41 Description: Created a separate file for cor_h_x2 function.
42
43 Description: Fixed typecasting issue with TI C compiler and defined one
44 local variable per line. Updated copyright year.
45
46 Description: Added #define for log2(32) = 5.
47
48 Description: Added call to round() and L_shl() functions in the last FOR
49 loop to make code bit-exact.
50
51 Description: Added pOverflow as a variable that's passed in for the EPOC
52 modifications.
53
54 Description: Changed round function name to pv_round to avoid conflict with
55 round function in C standard library.
56
57 Description: Using intrinsics from fxp_arithmetic.h .
58
59 Description: Replacing fxp_arithmetic.h with basic_op.h.
60
61 Description:
62
63 ------------------------------------------------------------------------------
64 */
65
66 /*----------------------------------------------------------------------------
67 ; INCLUDES
68 ----------------------------------------------------------------------------*/
69 #include "typedef.h"
70 #include "cnst.h"
71 #include "cor_h_x.h"
72 #include "cor_h_x2.h" // BX
73 #include "basic_op.h"
74
75 /*----------------------------------------------------------------------------
76 ; MACROS
77 ; Define module specific macros here
78 ----------------------------------------------------------------------------*/
79
80
81 /*----------------------------------------------------------------------------
82 ; DEFINES
83 ; Include all pre-processor statements here. Include conditional
84 ; compile variables also.
85 ----------------------------------------------------------------------------*/
86 #define LOG2_OF_32 5
87
88 /*----------------------------------------------------------------------------
89 ; LOCAL FUNCTION DEFINITIONS
90 ; Function Prototype declaration
91 ----------------------------------------------------------------------------*/
92
93 /*----------------------------------------------------------------------------
94 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
95 ; Variable declaration - defined here and used outside this module
96 ----------------------------------------------------------------------------*/
97
98
99 /*
100 ------------------------------------------------------------------------------
101 FUNCTION NAME: cor_h_x2
102 ------------------------------------------------------------------------------
103 INPUT AND OUTPUT DEFINITIONS
104
105 Inputs:
106 h = vector containing the impulse response of the weighted synthesis
107 filter; vector contents are of type Word16; vector length is
108 2 * L_SUBFR
109 x = target signal vector; vector contents are of type Word16; vector
110 length is L_SUBFR
111 dn = vector containing the correlation between the target and the
112 impulse response; vector contents are of type Word16; vector
113 length is L_CODE
114 sf = scaling factor of type Word16 ; 2 when mode is MR122, 1 for all
115 other modes
116 nb_track = number of ACB tracks (Word16)
117 step = step size between pulses in one track (Word16)
118 pOverflow = pointer to overflow (Flag)
119
120 Outputs:
121 dn contents are the newly calculated correlation values
122 pOverflow = 1 if the math functions called by cor_h_x2 result in overflow
123 else zero.
124
125 Returns:
126 None
127
128 Global Variables Used:
129 None
130
131 Local Variables Needed:
132 None
133
134 ------------------------------------------------------------------------------
135 FUNCTION DESCRIPTION
136
137 This function computes the correlation between the target signal (x) and the
138 impulse response (h).
139
140 The correlation is given by: d[n] = sum_{i=n}^{L-1} x[i] h[i-n],
141 where: n=0,...,L-1
142
143 d[n] is normalized such that the sum of 5 maxima of d[n] corresponding to
144 each position track does not saturate.
145
146 ------------------------------------------------------------------------------
147 REQUIREMENTS
148
149 None
150
151 ------------------------------------------------------------------------------
152 REFERENCES
153
154 cor_h.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001
155
156 ------------------------------------------------------------------------------
157 PSEUDO-CODE
158
159 The original etsi reference code uses a global flag Overflow. However, in the
160 actual implementation a pointer to a the overflow flag is passed in.
161
162 void cor_h_x2 (
163 Word16 h[], // (i): impulse response of weighted synthesis filter
164 Word16 x[], // (i): target
165 Word16 dn[], // (o): correlation between target and h[]
166 Word16 sf, // (i): scaling factor: 2 for 12.2, 1 for others
167 Word16 nb_track,// (i): the number of ACB tracks
168 Word16 step // (i): step size from one pulse position to the next
169 in one track
170 )
171 {
172 Word16 i, j, k;
173 Word32 s, y32[L_CODE], max, tot;
174
175 // first keep the result on 32 bits and find absolute maximum
176
177 tot = 5;
178
179 for (k = 0; k < nb_track; k++)
180 {
181 max = 0;
182 for (i = k; i < L_CODE; i += step)
183 {
184 s = 0;
185 for (j = i; j < L_CODE; j++)
186 s = L_mac (s, x[j], h[j - i]);
187
188 y32[i] = s;
189
190 s = L_abs (s);
191 if (L_sub (s, max) > (Word32) 0L)
192 max = s;
193 }
194 tot = L_add (tot, L_shr (max, 1));
195 }
196
197 j = sub (norm_l (tot), sf);
198
199 for (i = 0; i < L_CODE; i++)
200 {
201 dn[i] = pv_round (L_shl (y32[i], j));
202 }
203 }
204
205 ------------------------------------------------------------------------------
206 RESOURCES USED [optional]
207
208 When the code is written for a specific target processor the
209 the resources used should be documented below.
210
211 HEAP MEMORY USED: x bytes
212
213 STACK MEMORY USED: x bytes
214
215 CLOCK CYCLES: (cycle count equation for this function) + (variable
216 used to represent cycle count for each subroutine
217 called)
218 where: (cycle count variable) = cycle count for [subroutine
219 name]
220
221 ------------------------------------------------------------------------------
222 CAUTION [optional]
223 [State any special notes, constraints or cautions for users of this function]
224
225 ------------------------------------------------------------------------------
226 */
227
cor_h_x2(Word16 h[],Word16 x[],Word16 dn[],Word16 sf,Word16 nb_track,Word16 step,Flag * pOverflow)228 void cor_h_x2(
229 Word16 h[], /* (i): impulse response of weighted synthesis filter */
230 Word16 x[], /* (i): target */
231 Word16 dn[], /* (o): correlation between target and h[] */
232 Word16 sf, /* (i): scaling factor: 2 for 12.2, 1 for others */
233 Word16 nb_track,/* (i): the number of ACB tracks */
234 Word16 step, /* (i): step size from one pulse position to the next
235 in one track */
236 Flag *pOverflow
237 )
238 {
239 Word16 i;
240 Word16 j;
241 Word16 k;
242 Word32 s;
243 Word32 y32[L_CODE];
244 Word32 max;
245 Word32 tot;
246
247
248 /* first keep the result on 32 bits and find absolute maximum */
249 tot = LOG2_OF_32;
250 for (k = 0; k < nb_track; k++)
251 {
252 max = 0;
253 for (i = k; i < L_CODE; i += step)
254 {
255 s = 0;
256
257 for (j = i; j < L_CODE; j++)
258 {
259 s = amrnb_fxp_mac_16_by_16bb((Word32)x[j], (Word32)h[j-i], s);
260 }
261
262 s = s << 1;
263 y32[i] = s;
264 s = L_abs(s);
265
266 if (s > max)
267 {
268 max = s;
269 }
270 }
271 tot = (tot + (max >> 1));
272 }
273
274 j = sub(norm_l(tot), sf, pOverflow);
275
276 for (i = 0; i < L_CODE; i++)
277 {
278 dn[i] = pv_round(L_shl(y32[i], j, pOverflow), pOverflow);
279 }
280
281 return;
282 }
283