annotate libtwamr/dec_lag3.h @ 458:e26b974f7ba3

doc/AMR-study-utils: update for the current situation
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 10 May 2024 18:45:36 +0000
parents fb001496ca8c
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fb001496ca8c libtwamr: integrate dec_lag3.c
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1 /*
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2 ********************************************************************************
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3 *
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4 * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001
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5 * R99 Version 3.3.0
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6 * REL-4 Version 4.1.0
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7 *
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8 ********************************************************************************
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9 *
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10 * File : dec_lag3.h
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11 * Purpose : Decoding of fractional pitch lag with 1/3 resolution.
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12 * Extract the integer and fraction parts of the pitch lag from
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13 * the received adaptive codebook index.
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14 *
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15 ********************************************************************************
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16 */
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17 #ifndef dec_lag3_h
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18 #define dec_lag3_h "$Id $"
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19
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20 /*
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21 ********************************************************************************
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22 * INCLUDE FILES
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23 ********************************************************************************
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24 */
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25 #include "typedef.h"
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26
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27 /*
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28 ********************************************************************************
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29 * LOCAL VARIABLES AND TABLES
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30 ********************************************************************************
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31 */
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32
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33 /*
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34 ********************************************************************************
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35 * DEFINITION OF DATA TYPES
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36 ********************************************************************************
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37 */
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38
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39 /*
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40 ********************************************************************************
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41 * DECLARATION OF PROTOTYPES
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42 ********************************************************************************
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43 */
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44 /*************************************************************************
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45 * FUNCTION: Dec_lag3
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46 *
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47 * PURPOSE: Decoding of fractional pitch lag with 1/3 resolution.
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48 * Extract the integer and fraction parts of the pitch lag from
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49 * the received adaptive codebook index.
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50 *
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51 * See "Enc_lag3.c" for more details about the encoding procedure.
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52 *
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53 * The fractional lag in 1st and 3rd subframes is encoded with 8 bits
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54 * while that in 2nd and 4th subframes is relatively encoded with 4, 5
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55 * and 6 bits depending on the mode.
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56 *
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57 *************************************************************************/
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58 void Dec_lag3(Word16 index, /* i : received pitch index */
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59 Word16 T0_min, /* i : minimum of search range */
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60 Word16 T0_max, /* i : maximum of search range */
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61 Word16 i_subfr, /* i : subframe flag */
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62 Word16 T0_prev, /* i : integer pitch delay of last subframe
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63 used in 2nd and 4th subframes */
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64 Word16 * T0, /* o : integer part of pitch lag */
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65 Word16 * T0_frac, /* o : fractional part of pitch lag */
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66 Word16 flag4 /* i : flag for encoding with 4 bits */
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67 );
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68
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69 #endif