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+/*****************************************************************************
+
+ (C) copyright Fraunhofer IIS (2001)
+ All Rights Reserved
+
+ Please be advised that this software and/or program delivery is
+ Confidential Information of Fraunhofer and subject to and covered by the
+
+ Fraunhofer IIS Software Evaluation Agreement
+ between Google Inc. and Fraunhofer
+ effective and in full force since March 1, 2012.
+
+ You may use this software and/or program only under the terms and
+ conditions described in the above mentioned Fraunhofer IIS Software
+ Evaluation Agreement. Any other and/or further use requires a separate agreement.
+
+
+ $Id$
+ Description: FDKaacLdEnc_MdctTransform480:
+ The module FDKaacLdEnc_MdctTransform will perform the MDCT.
+ The MDCT supports the sine window and
+
+ the zero padded window. The algorithm of the MDCT
+ can be divided in Windowing, PreModulation, Fft and
+ PostModulation.
+
+ This software and/or program is protected by copyright law and international
+ treaties. Any reproduction or distribution of this software and/or program,
+ or any portion of it, may result in severe civil and criminal penalties, and
+ will be prosecuted to the maximum extent possible under law.
+
+******************************************************************************/
+
+#include "transform.h"
+
+#include "dct.h"
+#include "psy_const.h"
+#include "aacEnc_rom.h"
+#include "FDK_tools_rom.h"
+
+INT FDKaacEnc_Transform_Real (const INT_PCM * pTimeData,
+ FIXP_DBL *RESTRICT mdctData,
+ const INT blockType,
+ const INT windowShape,
+ INT *prevWindowShape,
+ const INT frameLength,
+ INT *mdctData_e,
+ INT filterType
+ ,FIXP_DBL * RESTRICT overlapAddBuffer
+ )
+{
+ const INT_PCM * RESTRICT timeData;
+
+ INT i;
+ /* tl: transform length
+ fl: left window slope length
+ nl: left window slope offset
+ fr: right window slope length
+ nr: right window slope offset
+ See FDK_tools/doc/intern/mdct.tex for more detail. */
+ int tl, fl, nl, fr, nr;
+
+ const FIXP_WTP * RESTRICT pLeftWindowPart;
+ const FIXP_WTP * RESTRICT pRightWindowPart;
+
+ /*
+ * MDCT scale:
+ * + 1: fMultDiv2() in windowing.
+ * + 1: Because of factor 1/2 in Princen-Bradley compliant windowed TDAC.
+ */
+ *mdctData_e = 1+1;
+
+ tl = frameLength;
+ timeData = pTimeData;
+
+ switch( blockType ) {
+ case LONG_WINDOW:
+ {
+ int offset = (windowShape == LOL_WINDOW) ? ((frameLength * 3)>>2) : 0;
+ fl = frameLength - offset;
+ fr = frameLength - offset;
+ }
+ break;
+ case STOP_WINDOW:
+ fl = frameLength >> 3;
+ fr = frameLength;
+ break;
+ case START_WINDOW: /* or StopStartSequence */
+ fl = frameLength;
+ fr = frameLength >> 3;
+ break;
+ case SHORT_WINDOW:
+ fl = fr = frameLength >> 3;
+ tl >>= 3;
+ timeData = pTimeData + 3*fl + (fl/2);
+ break;
+ default:
+ FDK_ASSERT(0);
+ return -1;
+ break;
+ }
+
+ /* Taken from FDK_tools/src/mdct.cpp Derive NR and NL */
+ nr = (tl - fr)>>1;
+ nl = (tl - fl)>>1;
+
+ pLeftWindowPart = FDKgetWindowSlope(fl, *prevWindowShape);
+ pRightWindowPart = FDKgetWindowSlope(fr, windowShape);
+
+ /* windowing */
+ if (filterType != FB_ELD)
+ {
+ /* Left window slope offset */
+ for (i=0; i<nl ; i++)
+ {
+#if SAMPLE_BITS == DFRACT_BITS /* SPC_BITS and DFRACT_BITS should be equal. */
+ mdctData[(tl/2)+i] = - (FIXP_DBL) timeData[tl-i-1] >> ( 1 );
+#else
+ mdctData[(tl/2)+i] = - (FIXP_DBL) timeData[tl-i-1] << (DFRACT_BITS - SAMPLE_BITS - 1);
+#endif
+ }
+ /* Left window slope */
+ for (i=0; i<fl/2; i++)
+ {
+ FIXP_DBL tmp0;
+ tmp0 = fMultDiv2((FIXP_PCM)timeData[i+nl], pLeftWindowPart[i].v.im);
+ mdctData[(tl/2)+i+nl] = fMultSubDiv2(tmp0, (FIXP_PCM)timeData[tl-nl-i-1], pLeftWindowPart[i].v.re);
+ }
+
+ /* Right window slope offset */
+ for(i=0; i<nr; i++)
+ {
+#if SAMPLE_BITS == DFRACT_BITS /* This should be SPC_BITS instead of DFRACT_BITS. */
+ mdctData[(tl/2)-1-i] = - (FIXP_DBL) timeData[tl+i] >> (1);
+#else
+ mdctData[(tl/2)-1-i] = - (FIXP_DBL) timeData[tl+i] << (DFRACT_BITS - SAMPLE_BITS - 1);
+#endif
+ }
+ /* Right window slope */
+ for (i=0; i<fr/2; i++)
+ {
+ FIXP_DBL tmp1;
+ tmp1 = fMultDiv2((FIXP_PCM)timeData[tl+nr+i], pRightWindowPart[i].v.re);
+ mdctData[(tl/2)-nr-i-1] = -fMultAddDiv2(tmp1, (FIXP_PCM)timeData[(tl*2)-nr-i-1], pRightWindowPart[i].v.im);
+ }
+ }
+
+ if (filterType == FB_ELD)
+ {
+ const FIXP_WTB *pWindowELD=NULL;
+ int i, N = frameLength, L = frameLength;
+
+ if (frameLength == 512) {
+ pWindowELD = ELDAnalysis512;
+ } else {
+ pWindowELD = ELDAnalysis480;
+ }
+
+ for(i=0;i<N/4;i++)
+ {
+ FIXP_DBL z0, outval;
+
+ z0 = (fMult((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N/2-1-i])<< (WTS0-1)) + (fMult((FIXP_PCM)timeData[L+N*3/4+i], pWindowELD[N/2+i])<< (WTS0-1));
+
+ outval = (fMultDiv2((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N+N/2-1-i]) >> (-WTS1));
+ outval += (fMultDiv2((FIXP_PCM)timeData[L+N*3/4+i], pWindowELD[N+N/2+i]) >> (-WTS1) );
+ outval += (fMultDiv2(overlapAddBuffer[N/2+i], pWindowELD[2*N+i])>> (-WTS2-1));
+
+ overlapAddBuffer[N/2+i] = overlapAddBuffer[i];
+
+ overlapAddBuffer[i] = z0;
+ mdctData[i] = overlapAddBuffer[N/2+i] + (fMultDiv2(overlapAddBuffer[N+N/2-1-i], pWindowELD[2*N+N/2+i]) >> (-WTS2-1));
+
+ mdctData[N-1-i] = outval;
+ overlapAddBuffer[N+N/2-1-i] = outval;
+ }
+
+ for(i=N/4;i<N/2;i++)
+ {
+ FIXP_DBL z0, outval;
+
+ z0 = fMult((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N/2-1-i]) << (WTS0-1);
+
+ outval = (fMultDiv2((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N+N/2-1-i]) >> (-WTS1)) ;
+ outval += (fMultDiv2(overlapAddBuffer[N/2+i], pWindowELD[2*N+i]) >> (-WTS2-1));
+
+ overlapAddBuffer[N/2+i] = overlapAddBuffer[i] + (fMult((FIXP_PCM)timeData[L-N/4+i], pWindowELD[N/2+i])<< (WTS0-1) );
+
+ overlapAddBuffer[i] = z0;
+ mdctData[i] = overlapAddBuffer[N/2+i] + (fMultDiv2(overlapAddBuffer[N+N/2-1-i], pWindowELD[2*N+N/2+i]) >> (-WTS2-1));
+
+ mdctData[N-1-i] = outval;
+ overlapAddBuffer[N+N/2-1-i] = outval;
+ }
+ }
+
+ dct_IV(mdctData, tl, mdctData_e);
+
+ *prevWindowShape = windowShape;
+
+ return 0;
+}
+