dtx_dec.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/dtx_dec.h

     Date: 02/06/2002

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

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

 Description: Moved _cplusplus #ifdef after Include section.

 Description:

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

    File             : dtx_dec.h
    Purpose          : Decode comfort noice when in DTX

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

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

/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "typedef.h"
#include "d_plsf.h"
#include "gc_pred.h"
#include "c_g_aver.h"
#include "frame.h"
#include "dtx_common_def.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
    ----------------------------------------------------------------------------*/
    enum DTXStateType {SPEECH = 0, DTX, DTX_MUTE};

    /*----------------------------------------------------------------------------
    ; STRUCTURES TYPEDEF'S
    ----------------------------------------------------------------------------*/
    typedef struct
    {
        Word16 since_last_sid;
        Word16 true_sid_period_inv;
        Word16 log_en;
        Word16 old_log_en;
        Word32 L_pn_seed_rx;
        Word16 lsp[M];
        Word16 lsp_old[M];

        Word16 lsf_hist[M*DTX_HIST_SIZE];
        Word16 lsf_hist_ptr;
        Word16 lsf_hist_mean[M*DTX_HIST_SIZE];
        Word16 log_pg_mean;
        Word16 log_en_hist[DTX_HIST_SIZE];
        Word16 log_en_hist_ptr;

        Word16 log_en_adjust;

        Word16 dtxHangoverCount;
        Word16 decAnaElapsedCount;

        Word16 sid_frame;
        Word16 valid_data;
        Word16 dtxHangoverAdded;

        enum DTXStateType dtxGlobalState;     /* contains previous state */
        /* updated in main decoder */

        Word16 data_updated;      /* marker to know if CNI data is ever renewed */

    } dtx_decState;

    /*----------------------------------------------------------------------------
    ; GLOBAL FUNCTION DEFINITIONS
    ; Function Prototype declaration
    ----------------------------------------------------------------------------*/

    /*
     *  Function    : dtx_dec_reset
     *  Purpose     : Resets state memory
     *  Returns     : 0 on success
     */
    Word16 dtx_dec_reset(dtx_decState *st);

    /*
     *  Function    : dtx_dec
     *  Purpose     :
     *  Description :
     */
    void dtx_dec(
        dtx_decState *st,                /* i/o : State struct                    */
        Word16 mem_syn[],                /* i/o : AMR decoder state               */
        D_plsfState* lsfState,           /* i/o : decoder lsf states              */
        gc_predState* predState,         /* i/o : prediction states               */
        Cb_gain_averageState* averState, /* i/o : CB gain average states          */
        enum DTXStateType new_state,     /* i   : new DTX state                   */
        enum Mode mode,                  /* i   : AMR mode                        */
        Word16 parm[],                   /* i   : Vector of synthesis parameters  */
        Word16 synth[],                  /* o   : synthesised speech              */
        Word16 A_t[],                    /* o   : decoded LP filter in 4 subframes*/
        Flag   *pOverflow
    );

    void dtx_dec_activity_update(dtx_decState *st,
                                 Word16 lsf[],
                                 Word16 frame[],
                                 Flag   *pOverflow);

    /*
     *  Function    : rx_dtx_handler
     *  Purpose     : reads the frame type and checks history
     *  Description : to decide what kind of DTX/CNI action to perform
     */
    enum DTXStateType rx_dtx_handler(dtx_decState *st,           /* i/o : State struct */
                                     enum RXFrameType frame_type,/* i   : Frame type   */
                                     Flag *pOverflow);

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

#endif /* DEC_AMR_H_ */