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annotate src/lag_wind.c @ 0:56410792419a

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src: original EFR source from ETSI
author Mychaela Falconia <falcon@freecalypso.org>
date Wed, 03 Apr 2024 05:31:37 +0000
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56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
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1 /*************************************************************************
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2 *
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3 * FUNCTION: Lag_window()
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4 *
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5 * PURPOSE: Lag windowing of autocorrelations.
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6 *
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7 * DESCRIPTION:
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8 * r[i] = r[i]*lag_wind[i], i=1,...,10
56410792419a src: original EFR source from ETSI
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9 *
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10 * r[i] and lag_wind[i] are in special double precision format.
56410792419a src: original EFR source from ETSI
Mychaela Falconia <falcon@freecalypso.org>
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11 * See "oper_32b.c" for the format.
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12 *
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13 *************************************************************************/
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14
56410792419a src: original EFR source from ETSI
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15 #include "typedef.h"
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16 #include "basic_op.h"
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17 #include "oper_32b.h"
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18 #include "count.h"
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19
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20 #include "lag_wind.tab"
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21
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22 void Lag_window (
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23 Word16 m, /* (i) : LPC order */
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24 Word16 r_h[], /* (i/o) : Autocorrelations (msb) */
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25 Word16 r_l[] /* (i/o) : Autocorrelations (lsb) */
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26 )
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27 {
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28 Word16 i;
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29 Word32 x;
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30
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31 for (i = 1; i <= m; i++)
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32 {
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33 x = Mpy_32 (r_h[i], r_l[i], lag_h[i - 1], lag_l[i - 1]);
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34 L_Extract (x, &r_h[i], &r_l[i]);
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35 }
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36 return;
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37 }