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      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  Filename: /audio/gsm_amr/c/src/include/bgnscd.h
     35 
     36      Date: 12/29/2002
     37 
     38 ------------------------------------------------------------------------------
     39  REVISION HISTORY
     40 
     41  Description: Moved _cplusplus #ifdef after Include section.
     42 
     43  Description:
     44 
     45 ------------------------------------------------------------------------------
     46  INCLUDE DESCRIPTION
     47 
     48       File             : bgnscd.h
     49       Purpose          : Background noise source charateristic detector (SCD)
     50 
     51 ------------------------------------------------------------------------------
     52 */
     53 
     54 #ifndef _BGNSCD_H_
     55 #define _BGNSCD_H_
     56 
     57 /*----------------------------------------------------------------------------
     58 ; INCLUDES
     59 ----------------------------------------------------------------------------*/
     60 #include "typedef.h"
     61 #include "cnst.h"
     62 
     63 /*--------------------------------------------------------------------------*/
     64 #ifdef __cplusplus
     65 extern "C"
     66 {
     67 #endif
     68 
     69     /*----------------------------------------------------------------------------
     70     ; MACROS
     71     ; [Define module specific macros here]
     72     ----------------------------------------------------------------------------*/
     73 
     74     /*----------------------------------------------------------------------------
     75     ; DEFINES
     76     ; [Include all pre-processor statements here.]
     77     ----------------------------------------------------------------------------*/
     78 #define L_ENERGYHIST 60
     79 #define INV_L_FRAME 102
     80 
     81 
     82     /* 2*(160*x)^2 / 65536  where x is FLP values 150,5 and 50 */
     83 #define FRAMEENERGYLIMIT  17578         /* 150 */
     84 #define LOWERNOISELIMIT      20         /*   5 */
     85 #define UPPERNOISELIMIT    1953         /*  50 */
     86 
     87 
     88     /*----------------------------------------------------------------------------
     89     ; EXTERNAL VARIABLES REFERENCES
     90     ; [Declare variables used in this module but defined elsewhere]
     91     ----------------------------------------------------------------------------*/
     92 
     93     /*----------------------------------------------------------------------------
     94     ; SIMPLE TYPEDEF'S
     95     ----------------------------------------------------------------------------*/
     96 
     97     /*----------------------------------------------------------------------------
     98     ; ENUMERATED TYPEDEF'S
     99     ----------------------------------------------------------------------------*/
    100 
    101     /*----------------------------------------------------------------------------
    102     ; STRUCTURES TYPEDEF'S
    103     ----------------------------------------------------------------------------*/
    104     typedef struct
    105     {
    106         /* history vector of past synthesis speech energy */
    107         Word16 frameEnergyHist[L_ENERGYHIST];
    108 
    109         /* state flags */
    110         Word16 bgHangover; /* counter; number of frames after last speech frame */
    111 
    112     } Bgn_scdState;
    113 
    114     /*----------------------------------------------------------------------------
    115     ; GLOBAL FUNCTION DEFINITIONS
    116     ; [List function prototypes here]
    117     ----------------------------------------------------------------------------*/
    118     /*
    119      *  Function    : Bgn_scd_init
    120      *  Purpose     : Allocates initializes state memory
    121      *  Description : Stores pointer to filter status struct in *st. This
    122      *                pointer has to be passed to Bgn_scd in each call.
    123      *  Returns     : 0 on success
    124      */
    125     Word16 Bgn_scd_init(Bgn_scdState **st);
    126 
    127     /*
    128      *  Function    : Bgn_scd_reset
    129      *  Purpose     : Resets state memory
    130      *  Returns     : 0 on success
    131      */
    132     Word16 Bgn_scd_reset(Bgn_scdState *st);
    133 
    134     /*
    135      *  Function    : Bgn_scd_exit
    136      *  Purpose     : The memory used for state memory is freed
    137      *  Description : Stores NULL in *s
    138      *  Returns     : void
    139      */
    140     void Bgn_scd_exit(Bgn_scdState **st);
    141 
    142     /*
    143      *  Function    : Bgn_scd
    144      *  Purpose     : Charaterice synthesis speech and detect background noise
    145      *  Returns     : background noise decision; 0 = bgn, 1 = no bgn
    146      */
    147     Word16 Bgn_scd(Bgn_scdState *st,       /* i : State variables for bgn SCD         */
    148                    Word16 ltpGainHist[],  /* i : LTP gain history                    */
    149                    Word16 speech[],       /* o : synthesis speech frame              */
    150                    Word16 *voicedHangover,/* o : # of frames after last voiced frame */
    151                    Flag   *pOverflow
    152                   );
    153 
    154 
    155 #ifdef __cplusplus
    156 }
    157 #endif
    158 
    159 #endif  /* _BGNSCD_H_ */
    160