Fraunhofer AAC codec.

License boilerplate update to follow.

Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5

1 files changed, 320 insertions, 0 deletions

diff --git a/libAACdec/src/aacdec_pns.cpp b/libAACdec/src/aacdec_pns.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: perceptual noise substitution 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_pns.h"
+
+
+#include "aac_ram.h"
+#include "aac_rom.h"
+#include "channelinfo.h"
+#include "block.h"
+#include "FDK_bitstream.h"
+
+#include "genericStds.h"
+
+
+#define NOISE_OFFSET 90           /* cf. ISO 14496-3 p. 175 */
+
+/*!
+  \brief Reset InterChannel and PNS data
+
+  The function resets the InterChannel and PNS data
+*/
+void CPns_ResetData(
+    CPnsData *pPnsData,
+    CPnsInterChannelData *pPnsInterChannelData
+    )
+{
+  /* Assign pointer always, since pPnsData is not persistent data */
+  pPnsData->pPnsInterChannelData = pPnsInterChannelData;
+  pPnsData->PnsActive = 0;
+  pPnsData->CurrentEnergy = 0;
+
+  FDKmemclear(pPnsData->pnsUsed,(8*16)*sizeof(UCHAR));
+  FDKmemclear(pPnsInterChannelData->correlated,(8*16)*sizeof(UCHAR));
+}
+
+/*!
+  \brief Initialize PNS data
+
+  The function initializes the PNS data
+*/
+void CPns_InitPns(
+    CPnsData *pPnsData,
+    CPnsInterChannelData *pPnsInterChannelData,
+    INT* currentSeed, INT* randomSeed)
+{
+  /* save pointer to inter channel data */
+  pPnsData->pPnsInterChannelData = pPnsInterChannelData;
+
+  /* use pointer because seed has to be
+     same, left and right channel ! */
+  pPnsData->currentSeed = currentSeed;
+  pPnsData->randomSeed  = randomSeed;
+}
+
+/*!
+  \brief Indicates if PNS is used
+
+  The function returns a value indicating whether PNS is used or not
+  acordding to the noise energy
+
+  \return  PNS used
+*/
+int CPns_IsPnsUsed (const CPnsData *pPnsData,
+                    const int group,
+                    const int band)
+{
+  unsigned pns_band = group*16+band;
+
+  return pPnsData->pnsUsed[pns_band] & (UCHAR)1;
+}
+
+/*!
+  \brief Set correlation
+
+  The function activates the noise correlation between the channel pair
+*/
+void CPns_SetCorrelation(CPnsData *pPnsData,
+                         const int group,
+                         const int band,
+                         const int outofphase)
+{
+  CPnsInterChannelData *pInterChannelData = pPnsData->pPnsInterChannelData;
+  unsigned pns_band = group*16+band;
+
+  pInterChannelData->correlated[pns_band] = (outofphase) ? 3 : 1;
+}
+
+/*!
+  \brief Indicates if correlation is used
+
+  The function indicates if the noise correlation between the channel pair
+  is activated
+
+  \return  PNS is correlated
+*/
+static
+int CPns_IsCorrelated(const CPnsData *pPnsData,
+                      const int group,
+                      const int band)
+{
+  CPnsInterChannelData *pInterChannelData = pPnsData->pPnsInterChannelData;
+  unsigned pns_band = group*16+band;
+
+  return (pInterChannelData->correlated[pns_band] & 0x01) ? 1 : 0;
+}
+
+/*!
+  \brief Indicates if correlated out of phase mode is used.
+
+  The function indicates if the noise correlation between the channel pair
+  is activated in out-of-phase mode.
+
+  \return  PNS is out-of-phase
+*/
+static
+int CPns_IsOutOfPhase(const CPnsData *pPnsData,
+                      const int group,
+                      const int band)
+{
+  CPnsInterChannelData *pInterChannelData = pPnsData->pPnsInterChannelData;
+  unsigned pns_band = group*16+band;
+
+  return (pInterChannelData->correlated[pns_band] & 0x02) ? 1 : 0;
+}
+
+/*!
+  \brief Read PNS information
+
+  The function reads the PNS information from the bitstream
+*/
+void CPns_Read (CPnsData *pPnsData,
+                HANDLE_FDK_BITSTREAM bs,
+                const CodeBookDescription *hcb,
+                SHORT *pScaleFactor,
+                UCHAR global_gain,
+                int band,
+                int group /* = 0 */)
+{
+  int delta ;
+  UINT pns_band = group*16+band;
+
+  if (pPnsData->PnsActive) {
+    /* Next PNS band case */
+    delta = CBlock_DecodeHuffmanWord (bs, hcb) - 60;
+  } else {
+    /* First PNS band case */
+    int noiseStartValue = FDKreadBits(bs,9);
+
+    delta = noiseStartValue - 256 ;
+    pPnsData->PnsActive = 1;
+    pPnsData->CurrentEnergy = global_gain - NOISE_OFFSET;
+  }
+
+  pPnsData->CurrentEnergy += delta ;
+  pScaleFactor[pns_band] = pPnsData->CurrentEnergy;
+
+  pPnsData->pnsUsed[pns_band] = 1;
+}
+
+
+/**
+ * \brief Generate a vector of noise of given length. The noise values are
+ *        scaled in order to yield a noise energy of 1.0
+ * \param spec pointer to were the noise values will be written to.
+ * \param size amount of noise values to be generated.
+ * \param pRandomState pointer to the state of the random generator being used.
+ * \return exponent of generated noise vector.
+ */
+static int GenerateRandomVector (FIXP_DBL *RESTRICT spec,
+                                  int size,
+                                  int *pRandomState)
+{
+  int i, invNrg_e = 0, nrg_e = 0;
+  FIXP_DBL invNrg_m, nrg_m = FL2FXCONST_DBL(0.0f) ;
+  FIXP_DBL *RESTRICT ptr = spec;
+  int randomState = *pRandomState;
+
+#define GEN_NOISE_NRG_SCALE 7
+
+  /* Generate noise and calculate energy. */
+  for (i=0; i<size; i++)
+  {
+    randomState = (1664525L * randomState) + 1013904223L; // Numerical Recipes
+    nrg_m = fPow2AddDiv2(nrg_m, (FIXP_DBL)randomState>>GEN_NOISE_NRG_SCALE);
+    *ptr++ = (FIXP_DBL)randomState;
+  }
+  nrg_e = GEN_NOISE_NRG_SCALE*2 + 1;
+
+  /* weight noise with = 1 / sqrt_nrg; */
+  invNrg_m = invSqrtNorm2(nrg_m<<1, &invNrg_e);
+  invNrg_e += -((nrg_e-1)>>1);
+
+  for (i=size; i--; )
+  {
+    spec[i] = fMult(spec[i], invNrg_m);
+  }
+
+  /* Store random state */
+  *pRandomState = randomState;
+
+  return invNrg_e;
+}
+
+static void ScaleBand (FIXP_DBL *RESTRICT spec, int size, int scaleFactor, int specScale, int noise_e, int out_of_phase)
+{
+  int i, shift, sfExponent;
+  FIXP_DBL sfMatissa;
+
+  /* Get gain from scale factor value = 2^(scaleFactor * 0.25) */
+  sfMatissa = MantissaTable[scaleFactor & 0x03][0];
+  /* sfExponent = (scaleFactor >> 2) + ExponentTable[scaleFactor & 0x03][0]; */
+  /* Note:  ExponentTable[scaleFactor & 0x03][0] is always 1. */
+  sfExponent = (scaleFactor >> 2) + 1;
+
+  if (out_of_phase != 0) {
+    sfMatissa = -sfMatissa;
+  }
+
+  /* +1 because of fMultDiv2 below. */
+  shift = sfExponent - specScale + 1 + noise_e;
+
+  /* Apply gain to noise values */
+  if (shift>=0) {
+    shift = fixMin( shift, DFRACT_BITS-1 );
+    for (i = size ; i-- != 0; ) {
+      spec [i] = fMultDiv2 (spec [i], sfMatissa) << shift;
+    }
+  } else {
+    shift = fixMin( -shift, DFRACT_BITS-1 );
+    for (i = size ; i-- != 0; ) {
+      spec [i] = fMultDiv2 (spec [i], sfMatissa) >> shift;
+    }
+  }
+}
+
+
+/*!
+  \brief Apply PNS
+
+  The function applies PNS (i.e. it generates noise) on the bands
+  flagged as noisy bands
+
+*/
+void CPns_Apply (const CPnsData *pPnsData,
+                 const CIcsInfo *pIcsInfo,
+                 SPECTRAL_PTR pSpectrum,
+                 const SHORT    *pSpecScale,
+                 const SHORT    *pScaleFactor,
+                 const SamplingRateInfo *pSamplingRateInfo,
+                 const INT granuleLength,
+                 const int channel)
+{
+  if (pPnsData->PnsActive) {
+    const short *BandOffsets = GetScaleFactorBandOffsets(pIcsInfo, pSamplingRateInfo);
+
+    int ScaleFactorBandsTransmitted = GetScaleFactorBandsTransmitted(pIcsInfo);
+
+    for (int window = 0, group = 0; group < GetWindowGroups(pIcsInfo); group++) {
+      for (int groupwin = 0; groupwin < GetWindowGroupLength(pIcsInfo, group); groupwin++, window++) {
+        FIXP_DBL *spectrum = SPEC(pSpectrum, window, granuleLength);
+
+        for (int band = 0 ; band < ScaleFactorBandsTransmitted; band++) {
+          if (CPns_IsPnsUsed (pPnsData, group, band)) {
+            UINT pns_band = group*16+band;
+
+            int bandWidth = BandOffsets [band + 1] - BandOffsets [band] ;
+            int noise_e;
+
+            FDK_ASSERT(bandWidth >= 0);
+
+            if (channel > 0 && CPns_IsCorrelated(pPnsData, group, band))
+            {
+              noise_e = GenerateRandomVector (spectrum + BandOffsets [band], bandWidth,
+                                    &pPnsData->randomSeed [pns_band]) ;
+            }
+            else
+            {
+              pPnsData->randomSeed [pns_band] = *pPnsData->currentSeed ;
+
+              noise_e = GenerateRandomVector (spectrum + BandOffsets [band], bandWidth,
+                                    pPnsData->currentSeed) ;
+            }
+
+            int outOfPhase  = CPns_IsOutOfPhase (pPnsData, group, band);
+
+            ScaleBand (spectrum + BandOffsets [band], bandWidth,
+                       pScaleFactor[pns_band],
+                       pSpecScale[window], noise_e, outOfPhase) ;
+          }
+        }
+      }
+    }
+  }
+}