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Diffstat (limited to 'media/openmax_dl/dl/sp/src/omxSP_FFTInit_C_SC32.c')
| -rw-r--r-- | media/openmax_dl/dl/sp/src/omxSP_FFTInit_C_SC32.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/media/openmax_dl/dl/sp/src/omxSP_FFTInit_C_SC32.c b/media/openmax_dl/dl/sp/src/omxSP_FFTInit_C_SC32.c new file mode 100644 index 0000000000..9ea103f3d6 --- /dev/null +++ b/media/openmax_dl/dl/sp/src/omxSP_FFTInit_C_SC32.c @@ -0,0 +1,196 @@ +/* + * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + * + * This file was originally licensed as follows. It has been + * relicensed with permission from the copyright holders. + */ + +/** + * + * File Name: omxSP_FFTInit_C_SC32.c + * OpenMAX DL: v1.0.2 + * Last Modified Revision: 7769 + * Last Modified Date: Thu, 27 Sep 2007 + * + * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved. + * + * + * Description: + * Initializes the specification structures required + */ + +#include "dl/api/armOMX.h" +#include "dl/api/omxtypes.h" +#include "dl/sp/api/armSP.h" +#include "dl/sp/api/omxSP.h" + + +/** + * Function: omxSP_FFTInit_C_SC32 + * + * Description: + * Initializes the specification structures required for the + * complex FFT and IFFT functions. + * + * Remarks: + * Desired block length is specified as an input. The function is used to + * initialize the specification structures for functions <FFTFwd_CToC_SC32_Sfs> + * and <FFTInv_CToC_SC32_Sfs>. Memory for the specification structure *pFFTSpec + * must be allocated prior to calling this function. The space required for + * *pFFTSpec, in bytes, can be determined using <FFTGetBufSize_C_SC32>. + * + * Parameters: + * [in] order base-2 logarithm of the desired block length; + * valid in the range [0,12]. + * [out] pFFTSpec pointer to initialized specification structure. + * + * Return Value: + * Standard omxError result. See enumeration for possible result codes. + * + */ + +OMXResult omxSP_FFTInit_C_SC32( + OMXFFTSpec_C_SC32* pFFTSpec, + OMX_INT order + ) +{ + OMX_INT i,j; + OMX_SC32 *pTwiddle, *pBuf; + OMX_U16 *pBitRev; + OMX_U32 pTmp; + OMX_INT Nby2,N,M,diff, step; + ARMsFFTSpec_SC32 *pFFTStruct = 0; + OMX_S32 x,y,xNeg; + + pFFTStruct = (ARMsFFTSpec_SC32 *) pFFTSpec; + + /* if order zero no init is needed */ + if (order == 0) + { + pFFTStruct->N = 1; + return OMX_Sts_NoErr; + } + + /* Do the initializations */ + Nby2 = 1 << (order - 1); + N = Nby2 << 1; + M = N>>3; + + + pBitRev = NULL ; /* optimized implementations don't use bitreversal */ + + pTwiddle = (OMX_SC32 *) + (sizeof(ARMsFFTSpec_SC32) + (OMX_S8*) pFFTSpec); + + /* Align to 32 byte boundary */ + pTmp = ((OMX_U32)pTwiddle)&31; /* (OMX_U32)pTwiddle % 32 */ + if(pTmp != 0) + pTwiddle = (OMX_SC32*) ((OMX_S8*)pTwiddle + (32-pTmp)); + + pBuf = (OMX_SC32*) + (sizeof(OMX_SC32) * (3*N/4) + (OMX_S8*) pTwiddle); + + /* Align to 32 byte boundary */ + pTmp = ((OMX_U32)pBuf)&31; /* (OMX_U32)pBuf % 32 */ + if(pTmp != 0) + pBuf = (OMX_SC32*) ((OMX_S8*)pBuf + (32-pTmp)); + + + + + /* + * Filling Twiddle factors : + * The original twiddle table "armSP_FFT_S32TwiddleTable" is of size (MaxSize/8 + 1) + * Rest of the values i.e., upto MaxSize are calculated using the symmetries of sin and cos + * The max size of the twiddle table needed is 3N/4 for a radix-4 stage + * + * W = (-2 * PI) / N + * N = 1 << order + * W = -PI >> (order - 1) + */ + + + diff = 12 - order; + step = 1<<diff; /* step into the twiddle table for the current order */ + + x = armSP_FFT_S32TwiddleTable[0]; + y = armSP_FFT_S32TwiddleTable[1]; + xNeg = 0x7FFFFFFF; + + if(order >=3) + { + /* i = 0 case */ + pTwiddle[0].Re = x; + pTwiddle[0].Im = y; + pTwiddle[2*M].Re = -y; + pTwiddle[2*M].Im = xNeg; + pTwiddle[4*M].Re = xNeg; + pTwiddle[4*M].Im = y; + + + for (i=1; i<=M; i++) + { + j = i*step; + + x = armSP_FFT_S32TwiddleTable[2*j]; + y = armSP_FFT_S32TwiddleTable[2*j+1]; + + pTwiddle[i].Re = x; + pTwiddle[i].Im = y; + pTwiddle[2*M-i].Re = -y; + pTwiddle[2*M-i].Im = -x; + pTwiddle[2*M+i].Re = y; + pTwiddle[2*M+i].Im = -x; + pTwiddle[4*M-i].Re = -x; + pTwiddle[4*M-i].Im = y; + pTwiddle[4*M+i].Re = -x; + pTwiddle[4*M+i].Im = -y; + pTwiddle[6*M-i].Re = y; + pTwiddle[6*M-i].Im = x; + } + + + } + else + { + if (order == 2) + { + pTwiddle[0].Re = x; + pTwiddle[0].Im = y; + pTwiddle[1].Re = -y; + pTwiddle[1].Im = xNeg; + pTwiddle[2].Re = xNeg; + pTwiddle[2].Im = y; + + } + if (order == 1) + { + pTwiddle[0].Re = x; + pTwiddle[0].Im = y; + + } + + + } + + + + /* Update the structure */ + pFFTStruct->N = N; + pFFTStruct->pTwiddle = pTwiddle; + pFFTStruct->pBitRev = pBitRev; + pFFTStruct->pBuf = pBuf; + + return OMX_Sts_NoErr; +} + +/***************************************************************************** + * END OF FILE + *****************************************************************************/ + |