Fraunhofer AAC codec.

License boilerplate update to follow.

Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5

1 files changed, 350 insertions, 0 deletions

diff --git a/libAACdec/src/aacdec_tns.cpp b/libAACdec/src/aacdec_tns.cpp
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+++ b/libAACdec/src/aacdec_tns.cpp
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+/*****************************  MPEG-4 AAC Decoder  **************************
+
+                        (C) Copyright Fraunhofer IIS (2004)
+                               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.
+
+
+   $Id$
+   Author(s):   Josef Hoepfl
+   Description: temporal noise shaping tool
+
+   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 "aacdec_tns.h"
+#include "aac_rom.h"
+#include "FDK_bitstream.h"
+#include "channelinfo.h"
+
+
+
+/*!
+  \brief Reset tns data
+
+  The function resets the tns data
+
+  \return  none
+*/
+void CTns_Reset(CTnsData *pTnsData)
+{
+  /* Note: the following FDKmemclear should not be required. */
+  FDKmemclear(pTnsData->Filter, TNS_MAX_WINDOWS*TNS_MAXIMUM_FILTERS*sizeof(CFilter));
+  FDKmemclear(pTnsData->NumberOfFilters, TNS_MAX_WINDOWS*sizeof(UCHAR));
+  pTnsData->DataPresent = 0;
+  pTnsData->Active = 0;
+}
+
+void CTns_ReadDataPresentFlag(HANDLE_FDK_BITSTREAM bs,    /*!< pointer to bitstream */
+                              CTnsData *pTnsData)         /*!< pointer to aac decoder channel info */
+{
+  pTnsData->DataPresent = (UCHAR) FDKreadBits(bs,1);
+}
+
+/*!
+  \brief Read tns data from bitstream
+
+  The function reads the elements for tns from
+  the bitstream.
+
+  \return  none
+*/
+AAC_DECODER_ERROR CTns_Read(HANDLE_FDK_BITSTREAM bs,
+                            CTnsData *pTnsData,
+                            const CIcsInfo *pIcsInfo,
+                            const UINT flags)
+{
+  UCHAR n_filt,order;
+  UCHAR length,coef_res,coef_compress;
+  UCHAR window;
+  UCHAR wins_per_frame = GetWindowsPerFrame(pIcsInfo);
+  UCHAR isLongFlag = IsLongBlock(pIcsInfo);
+  AAC_DECODER_ERROR ErrorStatus = AAC_DEC_OK;
+
+  if (!pTnsData->DataPresent) {
+    return ErrorStatus;
+  }
+
+  for (window = 0; window < wins_per_frame; window++)
+  {
+    pTnsData->NumberOfFilters[window] = n_filt = (UCHAR) FDKreadBits(bs, isLongFlag ? 2 : 1);
+
+    if (pTnsData->NumberOfFilters[window] > TNS_MAXIMUM_FILTERS){
+        pTnsData->NumberOfFilters[window] = n_filt = TNS_MAXIMUM_FILTERS;
+    }
+
+    if (n_filt)
+    {
+      int index;
+      UCHAR nextstopband;
+
+      coef_res = (UCHAR) FDKreadBits(bs,1);
+
+      nextstopband = GetScaleFactorBandsTotal(pIcsInfo);
+
+      for (index=0; index < n_filt; index++)
+      {
+        CFilter *filter = &pTnsData->Filter[window][index];
+
+        length = (UCHAR)FDKreadBits(bs, isLongFlag ? 6 : 4);
+
+        if (length > nextstopband){
+          length = nextstopband;
+        }
+
+        filter->StartBand = nextstopband - length;
+        filter->StopBand  = nextstopband;
+        nextstopband = filter->StartBand;
+
+        {
+          filter->Order = order = (UCHAR) FDKreadBits(bs, isLongFlag ? 5 : 3);
+        }
+
+        if (filter->Order > TNS_MAXIMUM_ORDER){
+          filter->Order = order = TNS_MAXIMUM_ORDER;
+        }
+
+        if (order)
+        {
+          UCHAR coef,s_mask;
+          UCHAR i;
+          SCHAR n_mask;
+          static const UCHAR sgn_mask[] = {  0x2,  0x4,  0x8 };
+          static const SCHAR neg_mask[] = { ~0x3, ~0x7, ~0xF };
+
+          filter->Direction = FDKreadBits(bs,1) ? -1 : 1;
+
+          coef_compress = (UCHAR) FDKreadBits(bs,1);
+
+          filter->Resolution = coef_res + 3;
+
+          s_mask = sgn_mask[coef_res + 1 - coef_compress];
+          n_mask = neg_mask[coef_res + 1 - coef_compress];
+
+          for (i=0; i < order; i++)
+          {
+            coef = (UCHAR) FDKreadBits(bs,filter->Resolution - coef_compress);
+            filter->Coeff[i] = (coef & s_mask) ? (coef | n_mask) : coef;
+          }
+        }
+      }
+    }
+  }
+
+  pTnsData->Active = 1;
+
+  return ErrorStatus;
+}
+
+
+static void CTns_Filter (FIXP_DBL *spec, int size, int inc, FIXP_TCC coeff [], int order)
+{
+  // - Simple all-pole filter of order "order" defined by
+  //   y(n) =  x(n) - a(2)*y(n-1) - ... - a(order+1)*y(n-order)
+  //
+  // - The state variables of the filter are initialized to zero every time
+  //
+  // - The output data is written over the input data ("in-place operation")
+  //
+  // - An input vector of "size" samples is processed and the index increment
+  //   to the next data sample is given by "inc"
+
+  int i,j,N;
+  FIXP_DBL *pSpec;
+  FIXP_DBL maxVal=FL2FXCONST_DBL(0.0);
+  INT s;
+
+  FDK_ASSERT(order <= TNS_MAXIMUM_ORDER);
+  C_ALLOC_SCRATCH_START(state, FIXP_DBL, TNS_MAXIMUM_ORDER);
+  FDKmemclear(state, order*sizeof(FIXP_DBL));
+
+  for (i=0; i<size; i++) {
+    maxVal = fixMax(maxVal,fixp_abs(spec[i]));
+  }
+
+  if ( maxVal > FL2FXCONST_DBL(0.03125*0.70710678118) )
+    s = fixMax(CntLeadingZeros(maxVal)-6,0);
+  else
+    s = fixMax(CntLeadingZeros(maxVal)-5,0);
+
+  s = fixMin(s,2);
+  s = s-1;
+
+  if (inc == -1)
+    pSpec = &spec[size - 1];
+  else
+    pSpec = &spec[0];
+
+  FIXP_TCC *pCoeff;
+
+#define FIRST_PART_FLTR                                              \
+    FIXP_DBL x, *pState = state;                                     \
+    pCoeff = coeff;                                                  \
+                                                                     \
+    if (s < 0)                                                       \
+      x = (pSpec [0]>>1) + fMultDiv2 (*pCoeff++, pState [0]) ;       \
+    else                                                             \
+      x = (pSpec [0]<<s) + fMultDiv2 (*pCoeff++, pState [0]) ;
+
+#define INNER_FLTR_INLINE                                            \
+      x = fMultAddDiv2 (x, *pCoeff, pState [1]);                     \
+      pState [0] = pState [1] - (fMultDiv2 (*pCoeff++, x) <<2) ;     \
+      pState++;
+
+#define LAST_PART_FLTR                                               \
+      if (s < 0)                                                     \
+        *pSpec = x << 1;                                             \
+      else                                                           \
+        *pSpec = x >> s;                                             \
+      *pState =(-x) << 1;                                            \
+      pSpec   += inc ;
+
+
+   if (order>8)
+   {
+      N = (order-1)&7;
+
+      for (i = size ; i != 0 ; i--)
+      {
+        FIRST_PART_FLTR
+
+        for (j = N; j > 0 ; j--) { INNER_FLTR_INLINE }
+
+        INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE
+        INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE
+
+        LAST_PART_FLTR
+      }
+
+   } else if (order>4) {
+
+      N = (order-1)&3;
+
+      for (i = size ; i != 0 ; i--)
+      {
+        FIRST_PART_FLTR
+        for (j = N; j > 0 ; j--) { INNER_FLTR_INLINE }
+
+        INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE
+
+        LAST_PART_FLTR
+      }
+
+   } else {
+
+      N = order-1;
+
+      for (i = size ; i != 0 ; i--)
+      {
+        FIRST_PART_FLTR
+
+        for (j = N; j > 0 ; j--) { INNER_FLTR_INLINE }
+
+        LAST_PART_FLTR
+      }
+   }
+
+   C_ALLOC_SCRATCH_END(state, FIXP_DBL, TNS_MAXIMUM_ORDER);
+}
+
+/*!
+  \brief Apply tns to spectral lines
+
+  The function applies the tns to the spectrum,
+
+  \return  none
+*/
+void CTns_Apply (
+        CTnsData *RESTRICT pTnsData, /*!< pointer to aac decoder info */
+        const CIcsInfo *pIcsInfo,
+        SPECTRAL_PTR pSpectralCoefficient,
+        const SamplingRateInfo *pSamplingRateInfo,
+        const INT granuleLength
+        )
+{
+  int window,index,start,stop,size;
+
+
+  if (pTnsData->Active)
+  {
+      C_AALLOC_SCRATCH_START(coeff, FIXP_TCC, TNS_MAXIMUM_ORDER);
+
+      for (window=0; window < GetWindowsPerFrame(pIcsInfo); window++)
+      {
+        FIXP_DBL *pSpectrum = SPEC(pSpectralCoefficient, window, granuleLength);
+
+        for (index=0; index < pTnsData->NumberOfFilters[window]; index++)
+        {
+          CFilter *RESTRICT filter = &pTnsData->Filter[window][index];
+
+          if (filter->Order > 0)
+          {
+             FIXP_TCC *pCoeff;
+             int tns_max_bands;
+
+             pCoeff = &coeff[filter->Order-1];
+             if (filter->Resolution == 3)
+             {
+               int i;
+               for (i=0; i < filter->Order; i++)
+                 *pCoeff-- = FDKaacDec_tnsCoeff3[filter->Coeff[i]+4];
+             }
+             else
+             {
+               int i;
+               for (i=0; i < filter->Order; i++)
+                 *pCoeff-- = FDKaacDec_tnsCoeff4[filter->Coeff[i]+8];
+             }
+
+             switch (granuleLength) {
+               case 480:
+                 tns_max_bands = tns_max_bands_tbl_480[pSamplingRateInfo->samplingRateIndex-3];
+                 break;
+               case 512:
+                 tns_max_bands = tns_max_bands_tbl_512[pSamplingRateInfo->samplingRateIndex-3];
+                 break;
+               default:
+                 tns_max_bands = GetMaximumTnsBands(pIcsInfo, pSamplingRateInfo->samplingRateIndex);
+                 break;
+             }
+
+             start = fixMin( fixMin(filter->StartBand, tns_max_bands),
+                             GetScaleFactorBandsTransmitted(pIcsInfo) );
+
+             start = GetScaleFactorBandOffsets(pIcsInfo, pSamplingRateInfo)[start];
+
+             stop = fixMin( fixMin(filter->StopBand, tns_max_bands),
+                            GetScaleFactorBandsTransmitted(pIcsInfo) );
+
+             stop = GetScaleFactorBandOffsets(pIcsInfo, pSamplingRateInfo)[stop];
+
+             size = stop - start;
+
+             if (size > 0) {
+               CTns_Filter(&pSpectrum[start],
+                            size,
+                            filter->Direction,
+                            coeff,
+                            filter->Order );
+             }
+          }
+        }
+      }
+      C_AALLOC_SCRATCH_END(coeff, FIXP_TCC, TNS_MAXIMUM_ORDER);
+  }
+
+}