Fraunhofer AAC codec.

License boilerplate update to follow.

Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5

1 files changed, 203 insertions, 0 deletions

diff --git a/libAACenc/src/transform.cpp b/libAACenc/src/transform.cpp
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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;
+}
+