q_gain_c.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/q_gain.h

     Date: 02/05/2002

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

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

 Description: Moved _cplusplus #ifdef after Include section.

 Description:

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

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

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

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

/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "typedef.h"
#include "mode.h"
#include "gc_pred.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
    ----------------------------------------------------------------------------*/

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

    /*--------------------------------------------------------------------------*
     * Function q_gain_code()                                                   *
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                  *
     * Scalar quantization of the innovative codebook gain.                     *
     *                                                                          *
     * gc_pred() is used for MA prediction of the innovation energy             *
     *--------------------------------------------------------------------------*/
    Word16 q_gain_code(         /* o  : quantization index,            Q0  */
        enum Mode mode,         /* i  : AMR mode                           */
        Word16 exp_gcode0,      /* i  : predicted CB gain (exponent),  Q0  */
        Word16 frac_gcode0,     /* i  : predicted CB gain (fraction),  Q15 */
        Word16 *gain,           /* i/o: quantized fixed codebook gain, Q1  */
        Word16 *qua_ener_MR122, /* o  : quantized energy error,        Q10 */
        /*      (for MR122 MA predictor update)    */
        Word16 *qua_ener,       /* o  : quantized energy error,        Q10 */
        /*      (for other MA predictor update)    */
        Flag   *pOverflow
    );

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

#endif /* q_gain_c_h */