hackedteam/core-winphone

/* ------------------------------------------------------------------
 * Copyright (C) 1998-2009 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: d_gain_p.cpp
 Functions: d_gain_p

 ------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    mode  -- enumerated type -- AMR mode
    index -- Word16          -- index of quantization
 Outputs:
    None

 Returns:
    Word16 gain -- (Q14)

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 Function    : d_gain_pitch
 Purpose     : Decodes the pitch gain using the received index.
               output is in Q14

------------------------------------------------------------------------------
 REQUIREMENTS



------------------------------------------------------------------------------
 REFERENCES

 d_gain_p.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE



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


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

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

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


    /*----------------------------------------------------------------------------
    ; DEFINES
    ; Include all pre-processor statements here. Include conditional
    ; compile variables also.
    ----------------------------------------------------------------------------*/

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


    /*----------------------------------------------------------------------------
    ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
    ; Variable declaration - defined here and used outside this module
    ----------------------------------------------------------------------------*/

    /*----------------------------------------------------------------------------
    ; EXTERNAL FUNCTION REFERENCES
    ; Declare functions defined elsewhere and referenced in this module
    ----------------------------------------------------------------------------*/

    /*----------------------------------------------------------------------------
    ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
    ; Declare variables used in this module but defined elsewhere
    ----------------------------------------------------------------------------*/

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

/*----------------------------------------------------------------------------
; FUNCTION CODE
----------------------------------------------------------------------------*/

Word16 d_gain_pitch(       /* return value: gain (Q14)                */
    enum Mode mode,        /* i   : AMR mode                          */
    Word16 index,          /* i   : index of quantization             */
    const Word16* qua_gain_pitch_ptr /* i : pointer to read-only tables   */
)
{
    Word16 gain;

    gain = qua_gain_pitch_ptr[index];

    if (mode == MR122)
    {
        /* clear 2 LSBits */
        gain &= 0xFFFC;
    }

    return gain;
}