omxsp_fftgetbufsize_r_s32.c

来自「The OpenMAX DL (Development Layer) APIs 」· C语言 代码 · 共 85 行

/**
 * 
 * File Name:  omxSP_FFTGetBufSize_R_S32.c
 * OpenMAX DL: v1.0.2
 * Revision:   10586
 * Date:       Wednesday, March 5, 2008
 * 
 * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
 * 
 * 
 * Description:
 * Computes the size of the specification structure required.
 */

#include "omxtypes.h"
#include "armOMX.h"
#include "omxSP.h"
#include "armCOMM.h"
#include "armSP.h"

/**
 * Function:  omxSP_FFTGetBufSize_R_S32   (2.2.4.1.8)
 *
 * Description:
 * These functions compute the size of the specification structure 
 * required for the length 2^order real FFT and IFFT functions.  The function 
 * <FFTGetBufSize_R_S32> is used in conjunction with the 32-bit functions 
 * <FFTFwd_RToCCS_S32_Sfs> and <FFTInv_CCSToR_S32_Sfs>. 
 *
 * Input Arguments:
 *   
 *   order - base-2 logarithm of the length; valid in the range [0,12] 
 *
 * Output Arguments:
 *   
 *   pSize - pointer to the number of bytes required for the specification 
 *            structure 
 *
 * Return Value:
 *    
 *    OMX_Sts_NoErr - no error 
 *    OMX_Sts_BadArgErr - bad arguments The function returns 
 *              OMX_Sts_BadArgErr if one or more of the following is true: 
 *    pSize is NULL 
 *    order < 0 or order > 12 
 *
 */

OMXResult omxSP_FFTGetBufSize_R_S32(
     OMX_INT order,     
     OMX_INT *pSize
 )
{
    OMX_INT     NBy2;
    
    /* Input parameter check */ 
    armRetArgErrIf(pSize == NULL, OMX_Sts_BadArgErr)
    armRetArgErrIf(order < 0, OMX_Sts_BadArgErr)
    armRetArgErrIf(order > 12, OMX_Sts_BadArgErr)

    /* Check for order zero */
    if (order == 0)
    {
        *pSize = sizeof(ARMsFFTSpec_FC64);   
        return OMX_Sts_NoErr;
    }
    
    NBy2 = 1 << (order - 1);
    
    /* 2 pointers to store bitreversed array and twiddle factor array */
    *pSize = sizeof(ARMsFFTSpec_FC64)
    /* N bitreversed Numbers */
           + sizeof(OMX_U16) * NBy2
    /* Twiddle factors  */
           + sizeof(OMX_FC64) * NBy2
           + sizeof(OMX_F64) * (2 + (NBy2 << 1));

    return OMX_Sts_NoErr;
}

/*****************************************************************************
 *                              END OF FILE
 *****************************************************************************/