Add openmax dl routines for review. MUST NOT BE LANDED

third_party/openmax_dl/dl/sp/src/omxSP_FFTInit_R_F32.c

+/*
+ *  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 is a modification of omxSP_FFTInit_R_S32.c to support float
+ *  instead of S32.
+ */
+
+#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_R_F32
+ *
+ * Description:
+ * Initialize the real forward-FFT specification information struct.
+ *
+ * Remarks:
+ * This function is used to initialize the specification structures
+ * for functions <ippsFFTFwd_RToCCS_F32_Sfs> and
+ * <ippsFFTInv_CCSToR_F32_Sfs>. Memory for *pFFTSpec must be
+ * allocated prior to calling this function. The number of bytes
+ * required for *pFFTSpec can be determined using
+ * <FFTGetBufSize_R_F32>.
+ *
+ * Parameters:
+ * [in]  order       base-2 logarithm of the desired block length;
+ *                         valid in the range [1,12].  ([1,15] if
+ *                         BIG_FFT_TABLE is defined.)
+ * [out] pFFTFwdSpec pointer to the initialized specification structure.
+ *
+ * Return Value:
+ * Standard omxError result. See enumeration for possible result codes.
+ *
+ */
+OMXResult omxSP_FFTInit_R_F32(OMXFFTSpec_R_F32* pFFTSpec, OMX_INT order) {
+  OMX_INT i;
+  OMX_INT j;
+  OMX_FC32* pTwiddle;
+  OMX_FC32* pTwiddle1;
+  OMX_FC32* pTwiddle2;
+  OMX_FC32* pTwiddle3;
+  OMX_FC32* pTwiddle4;
+  OMX_F32* pBuf;
+  OMX_U16* pBitRev;
+  OMX_U32 pTmp;
+  OMX_INT Nby2;
+  OMX_INT N;
+  OMX_INT M;
+  OMX_INT diff;
+  OMX_INT step;
+  OMX_F32 x;
+  OMX_F32 y;
+  OMX_F32 xNeg;
+  ARMsFFTSpec_R_FC32* pFFTStruct = 0;
+
+  pFFTStruct = (ARMsFFTSpec_R_FC32 *) pFFTSpec;
+
+  /* Validate args */
+  if (!pFFTSpec || (order < 1) || (order > TWIDDLE_TABLE_ORDER))
+    return OMX_Sts_BadArgErr;
+
+  /* Do the initializations */
+  Nby2 = 1 << (order - 1);
+  N = Nby2 << 1;
+
+  /* optimized implementations don't use bitreversal */
+  pBitRev = NULL;
+
+  pTwiddle = (OMX_FC32 *) (sizeof(ARMsFFTSpec_R_SC32) + (OMX_S8*) pFFTSpec);
+
+  /* Align to 32 byte boundary */
+  pTmp = ((OMX_U32)pTwiddle) & 31;
+  if (pTmp)
+    pTwiddle = (OMX_FC32*) ((OMX_S8*)pTwiddle + (32 - pTmp));
+
+  pBuf = (OMX_F32*) (sizeof(OMX_FC32)*(5*N/8) + (OMX_S8*) pTwiddle);
+
+  /* Align to 32 byte boundary */
+  pTmp = ((OMX_U32)pBuf)&31;                 /* (OMX_U32)pBuf % 32 */
+  if (pTmp)
+    pBuf = (OMX_F32*) ((OMX_S8*)pBuf + (32 - pTmp));
+
+  /*
+   * Filling Twiddle factors :
+   *
+   * exp^(-j*2*PI*k/ (N/2) ) ; k=0,1,2,...,3/4(N/2)
+   *
+   * N/2 point complex FFT is used to compute N point real FFT The
+   * original twiddle table "armSP_FFT_F32TwiddleTable" 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 3/4(N/2) for a radix-4 stage
+   *
+   * W = (-2 * PI) / N
+   * N = 1 << order
+   * W = -PI >> (order - 1)
+   */
+
+  M = Nby2 >> 3;
+  diff = TWIDDLE_TABLE_ORDER - (order - 1);
+  /* step into the twiddle table for the current order */
+  step = 1 << diff;
+
+  x = armSP_FFT_F32TwiddleTable[0];
+  y = armSP_FFT_F32TwiddleTable[1];
+  xNeg = 1;
+
+  if ((order - 1) >= 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_F32TwiddleTable[2*j];
+      y = armSP_FFT_F32TwiddleTable[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 - 1) == 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;
+  } else if ((order-1) == 1) {
+    pTwiddle[0].Re = x;
+    pTwiddle[0].Im = y;
+  }
+
+  /*
+   * Now fill the last N/4 values : exp^(-j*2*PI*k/N) ;
+   * k=1,3,5,...,N/2-1 These are used for the final twiddle fix-up for
+   * converting complex to real FFT
+   */
+
+  M = N >> 3;
+  diff = TWIDDLE_TABLE_ORDER - order;
+  step = 1 << diff;
+
+  pTwiddle1 = pTwiddle + 3*N/8;
+  pTwiddle4 = pTwiddle1 + (N/4 - 1);
+  pTwiddle3 = pTwiddle1 + N/8;
+  pTwiddle2 = pTwiddle1 + (N/8 - 1);
+
+  x = armSP_FFT_F32TwiddleTable[0];
+  y = armSP_FFT_F32TwiddleTable[1];
+  xNeg = 1;
+
+  if (order >=3) {
+    for (i = 1; i <= M; i += 2) {
+      j = i*step;
+
+      x = armSP_FFT_F32TwiddleTable[2*j];
+      y = armSP_FFT_F32TwiddleTable[2*j+1];
+
+      pTwiddle1[0].Re = x;
+      pTwiddle1[0].Im = y;
+      pTwiddle1 += 1;
+      pTwiddle2[0].Re = -y;
+      pTwiddle2[0].Im = -x;
+      pTwiddle2 -= 1;
+      pTwiddle3[0].Re = y;
+      pTwiddle3[0].Im = -x;
+      pTwiddle3 += 1;
+      pTwiddle4[0].Re = -x;
+      pTwiddle4[0].Im = y;
+      pTwiddle4 -= 1;
+    }
+  } else {
+    if (order == 2) {
+      pTwiddle1[0].Re = -y;
+      pTwiddle1[0].Im = xNeg;
+    }
+  }
+
+
+  /* Update the structure */
+  pFFTStruct->N = N;
+  pFFTStruct->pTwiddle = pTwiddle;
+  pFFTStruct->pBitRev = pBitRev;
+  pFFTStruct->pBuf = pBuf;
+
+  return OMX_Sts_NoErr;
+}