vad1.h

实现3GPP的GSM中AMR语音的CODECS。

/* ------------------------------------------------------------------
 * Copyright (C) 2008 PacketVideo
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 * -------------------------------------------------------------------
 */
/****************************************************************************************
Portions of this file are derived from the following 3GPP standard:

    3GPP TS 26.073
    ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
    Available from http://www.3gpp.org

(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
Permission to distribute, modify and use this file under the standard license
terms listed above has been obtained from the copyright holder.
****************************************************************************************/
/*
------------------------------------------------------------------------------



 Filename: /audio/gsm_amr/c/include/vad_1.h

     Date: 02/04/2002

------------------------------------------------------------------------------
 REVISION HISTORY

 Description: Placed header file in the proper template format.  Added
 parameter pOverflow for the basic math ops.

 Description:  Replaced "int" and/or "char" with OSCL defined types.

 Description: Moved _cplusplus #ifdef after Include section.

 Description:

------------------------------------------------------------------------------
 INCLUDE DESCRIPTION

 This file contains all the constant definitions, prototype and structure
 definitions needed by vad_1.c

------------------------------------------------------------------------------
*/

/*----------------------------------------------------------------------------
; CONTINUE ONLY IF NOT ALREADY DEFINED
----------------------------------------------------------------------------*/
#ifndef vad_1_h
#define vad_1_h "$Id $"

/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "typedef.h"
#include "cnst_vad.h"

/*--------------------------------------------------------------------------*/
#ifdef __cplusplus
extern "C"
{
#endif

    /*----------------------------------------------------------------------------
    ; MACROS
    ; Define module specific macros here
    ----------------------------------------------------------------------------*/

    /*----------------------------------------------------------------------------
    ; DEFINES
    ; Include all pre-processor statements here.
    ----------------------------------------------------------------------------*/

    /*----------------------------------------------------------------------------
    ; EXTERNAL VARIABLES REFERENCES
    ; Declare variables used in this module but defined elsewhere
    ----------------------------------------------------------------------------*/

    /*----------------------------------------------------------------------------
    ; SIMPLE TYPEDEF'S
    ----------------------------------------------------------------------------*/

    /*----------------------------------------------------------------------------
    ; ENUMERATED TYPEDEF'S
    ----------------------------------------------------------------------------*/

    /*----------------------------------------------------------------------------
    ; STRUCTURES TYPEDEF'S
    ----------------------------------------------------------------------------*/
    /* state variable */
    typedef struct
    {

        Word16 bckr_est[COMPLEN];    /* background noise estimate                */
        Word16 ave_level[COMPLEN];   /* averaged input components for stationary */
        /*    estimation                            */
        Word16 old_level[COMPLEN];   /* input levels of the previous frame       */
        Word16 sub_level[COMPLEN];   /* input levels calculated at the end of
                                      a frame (lookahead)                   */
        Word16 a_data5[3][2];        /* memory for the filter bank               */
        Word16 a_data3[5];           /* memory for the filter bank               */

        Word16 burst_count;          /* counts length of a speech burst          */
        Word16 hang_count;           /* hangover counter                         */
        Word16 stat_count;           /* stationary counter                       */

        /* Note that each of the following three variables (vadreg, pitch and tone)
           holds 15 flags. Each flag reserves 1 bit of the variable. The newest
           flag is in the bit 15 (assuming that LSB is bit 1 and MSB is bit 16). */
        Word16 vadreg;               /* flags for intermediate VAD decisions     */
        Word16 pitch;                /* flags for pitch detection                */
        Word16 tone;                 /* flags for tone detection                 */
        Word16 complex_high;         /* flags for complex detection              */
        Word16 complex_low;          /* flags for complex detection              */

        Word16 oldlag_count, oldlag; /* variables for pitch detection            */

        Word16 complex_hang_count;   /* complex hangover counter, used by VAD    */
        Word16 complex_hang_timer;   /* hangover initiator, used by CAD          */

        Word16 best_corr_hp;         /* FIP filtered value Q15                   */

        Word16 speech_vad_decision;  /* final decision                           */
        Word16 complex_warning;      /* complex background warning               */

        Word16 sp_burst_count;       /* counts length of a speech burst incl     */
        Word16 corr_hp_fast;         /* filtered value                           */
    } vadState1;
    /*----------------------------------------------------------------------------
    ; GLOBAL FUNCTION DEFINITIONS
    ; Function Prototype declaration
    ----------------------------------------------------------------------------*/
    Word16 vad1_init(vadState1 **st);
    /* initialize one instance of the pre processing state.
       Stores pointer to filter status struct in *st. This pointer has to
       be passed to vad in each call.
       returns 0 on success
     */

    Word16 vad1_reset(vadState1 *st);
    /* reset of pre processing state (i.e. set state memory to zero)
       returns 0 on success
     */

    void vad1_exit(vadState1 **st);
    /* de-initialize pre processing state (i.e. free status struct)
       stores NULL in *st
     */

    void vad_complex_detection_update(vadState1 *st,       /* i/o : State struct     */
                                      Word16 best_corr_hp /* i   : best Corr Q15    */
                                     );

    void vad_tone_detection(vadState1 *st,  /* i/o : State struct            */
                            Word32 t0,     /* i   : autocorrelation maxima  */
                            Word32 t1,     /* i   : energy                  */
                            Flag   *pOverflow
                           );

    void vad_tone_detection_update(
        vadState1 *st,             /* i/o : State struct              */
        Word16 one_lag_per_frame,  /* i   : 1 if one open-loop lag is
                                              calculated per each frame,
                                              otherwise 0                     */
        Flag *pOverflow
    );

    void vad_pitch_detection(vadState1 *st,   /* i/o : State struct                  */
                             Word16 lags[],  /* i   : speech encoder open loop lags */
                             Flag   *pOverflow
                            );

    Word16 vad1(vadState1 *st,   /* i/o : State struct                      */
                Word16 in_buf[], /* i   : samples of the input frame
                                inbuf[159] is the very last sample,
                                incl lookahead                          */
                Flag *pOverflow
               );

    /*----------------------------------------------------------------------------
    ; END
    ----------------------------------------------------------------------------*/
#ifdef __cplusplus
}
#endif

#endif /* _VAD1_H_ */