omxacaac_longtermreconstruct_s32_i.c

来自「The OpenMAX DL (Development Layer) APIs 」· C语言 代码 · 共 105 行

/**
 * 
 * File Name:  omxACAAC_LongTermReconstruct_S32_I.c
 * OpenMAX DL: v1.0.2
 * Revision:   10586
 * Date:       Wednesday, March 5, 2008
 * 
 * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
 * 
 * 
 *
 * Description:
 * This file contains module for Long Term Reconstruction for an AAC decoder
 *
 */

#include "omxtypes.h"
#include "armOMX.h"
#include "omxAC.h"

#include "armAC.h"
#include "armCOMM.h"

#include "armACAAC_Tables.h"

/**
 * Function:  omxACAAC_LongTermReconstruct_S32_I   (3.2.3.7.1)
 *
 * Description:
 * Reconstruction portion of the LTP loop; adds the vector of decoded 
 * spectral coefficients and the corresponding spectral-domain LTP output 
 * vector to obtain a vector of reconstructed spectral samples. 
 *
 * Reference: [ISO14496-3], sub-clause 4.6.7 
 *
 * Input Arguments:
 *   
 *   pSrcDstSpec - pointer to decoded spectral coefficients; coefficients are 
 *            represented using Q28.3 
 *   pSrcEstSpec - pointer to the spectral-domain LTP output vector; 
 *            coefficients are represented using Q28.3 
 *   samplingFreqIndex - sampling frequency index 
 *   pLtpFlag - pointer to the vector of scalefactor band LTP indicator flags 
 *
 * Output Arguments:
 *   pSrcDstSpec - pointer to reconstructed spectral coefficient vector; 
 *            coefficients are represented using Q28.3 
 *
 * Return Value:
 *    
 *    OMX_Sts_NoErr - no error 
 *    OMX_Sts_BadArgErr - bad arguments 
 *    -    one or more of the following pointers is NULL: 
 *            - pSrcDstSpec, 
 *            - pSrcEstSpec, or 
 *            - pLtpFlag 
 *    -    samplingFreqIndex is outside the range [0,12] 
 *
 */

OMXResult omxACAAC_LongTermReconstruct_S32_I(
     OMX_S32 *pSrcDstSpec,
     OMX_S32 *pSrcEstSpec,
     OMX_INT *pLtpFlag,
     OMX_INT samplingFreqIndex
 )
{
    OMX_INT numSwb,sfbNum;
    OMX_INT ltpFlag,width,coeffNum;
    const OMX_U16 *pOffsetTable;
     
    /* Argument Check */
    armRetArgErrIf( pSrcEstSpec == NULL, OMX_Sts_BadArgErr);
    armRetArgErrIf( pSrcDstSpec == NULL, OMX_Sts_BadArgErr);
    armRetArgErrIf( pLtpFlag    == NULL, OMX_Sts_BadArgErr);

    armRetArgErrIf( samplingFreqIndex > 12,  OMX_Sts_BadArgErr);
    armRetArgErrIf( samplingFreqIndex < 0 , OMX_Sts_BadArgErr);

    /* Processing */
    numSwb       = armACAAC_numSwbLong[samplingFreqIndex];
    pOffsetTable = armACAAC_swbOffsetLongWindow[samplingFreqIndex];
    
    for(sfbNum = 0 ; sfbNum < numSwb ; sfbNum ++)
    {
        ltpFlag = pLtpFlag[sfbNum];
        width   = pOffsetTable[sfbNum + 1] - pOffsetTable[sfbNum];
        
        if(ltpFlag == 1)
        {
            for(coeffNum = 0; coeffNum < width ; coeffNum++)
            {
                pSrcDstSpec[coeffNum] = armSatAdd_S32(pSrcDstSpec[coeffNum],pSrcEstSpec[coeffNum]);
            }
        }

        pSrcDstSpec += width;
        pSrcEstSpec += width;
    }
       
    return OMX_Sts_NoErr;
}

/*End of File*/