Include patched FDK-AAC in the repository

The initial idea was to get the DAB+ patch into upstream, but since
that follows the android source releases, there is no place for a custom
DAB+ patch there.

So instead of having to maintain a patched fdk-aac that has to have the
same .so version as the distribution package on which it is installed,
we prefer having a separate fdk-aac-dab library to avoid collision.

At that point, there's no reason to keep fdk-aac in a separate
repository, as odr-audioenc is the only tool that needs DAB+ encoding
support. Including it here simplifies installation, and makes it
consistent with toolame-dab, also shipped in this repository.

DAB+ decoding support (needed by ODR-SourceCompanion, dablin, etisnoop,
welle.io and others) can be done using upstream FDK-AAC.

1 files changed, 2095 insertions, 0 deletions

diff --git a/fdk-aac/libAACdec/src/conceal.cpp b/fdk-aac/libAACdec/src/conceal.cpp
new file mode 100644
index 0000000..5895cb8
--- /dev/null
+++ b/fdk-aac/libAACdec/src/conceal.cpp
@@ -0,0 +1,2095 @@
+/* -----------------------------------------------------------------------------
+Software License for The Fraunhofer FDK AAC Codec Library for Android
+
+© Copyright  1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
+Forschung e.V. All rights reserved.
+
+ 1.    INTRODUCTION
+The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
+that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
+scheme for digital audio. This FDK AAC Codec software is intended to be used on
+a wide variety of Android devices.
+
+AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
+general perceptual audio codecs. AAC-ELD is considered the best-performing
+full-bandwidth communications codec by independent studies and is widely
+deployed. AAC has been standardized by ISO and IEC as part of the MPEG
+specifications.
+
+Patent licenses for necessary patent claims for the FDK AAC Codec (including
+those of Fraunhofer) may be obtained through Via Licensing
+(www.vialicensing.com) or through the respective patent owners individually for
+the purpose of encoding or decoding bit streams in products that are compliant
+with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
+Android devices already license these patent claims through Via Licensing or
+directly from the patent owners, and therefore FDK AAC Codec software may
+already be covered under those patent licenses when it is used for those
+licensed purposes only.
+
+Commercially-licensed AAC software libraries, including floating-point versions
+with enhanced sound quality, are also available from Fraunhofer. Users are
+encouraged to check the Fraunhofer website for additional applications
+information and documentation.
+
+2.    COPYRIGHT LICENSE
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted without payment of copyright license fees provided that you
+satisfy the following conditions:
+
+You must retain the complete text of this software license in redistributions of
+the FDK AAC Codec or your modifications thereto in source code form.
+
+You must retain the complete text of this software license in the documentation
+and/or other materials provided with redistributions of the FDK AAC Codec or
+your modifications thereto in binary form. You must make available free of
+charge copies of the complete source code of the FDK AAC Codec and your
+modifications thereto to recipients of copies in binary form.
+
+The name of Fraunhofer may not be used to endorse or promote products derived
+from this library without prior written permission.
+
+You may not charge copyright license fees for anyone to use, copy or distribute
+the FDK AAC Codec software or your modifications thereto.
+
+Your modified versions of the FDK AAC Codec must carry prominent notices stating
+that you changed the software and the date of any change. For modified versions
+of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
+must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
+AAC Codec Library for Android."
+
+3.    NO PATENT LICENSE
+
+NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
+limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
+Fraunhofer provides no warranty of patent non-infringement with respect to this
+software.
+
+You may use this FDK AAC Codec software or modifications thereto only for
+purposes that are authorized by appropriate patent licenses.
+
+4.    DISCLAIMER
+
+This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
+holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
+including but not limited to the implied warranties of merchantability and
+fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
+or consequential damages, including but not limited to procurement of substitute
+goods or services; loss of use, data, or profits, or business interruption,
+however caused and on any theory of liability, whether in contract, strict
+liability, or tort (including negligence), arising in any way out of the use of
+this software, even if advised of the possibility of such damage.
+
+5.    CONTACT INFORMATION
+
+Fraunhofer Institute for Integrated Circuits IIS
+Attention: Audio and Multimedia Departments - FDK AAC LL
+Am Wolfsmantel 33
+91058 Erlangen, Germany
+
+www.iis.fraunhofer.de/amm
+amm-info@iis.fraunhofer.de
+----------------------------------------------------------------------------- */
+
+/**************************** AAC decoder library ******************************
+
+   Author(s):   Josef Hoepfl
+
+   Description: independent channel concealment
+
+*******************************************************************************/
+
+/*!
+  \page concealment AAC core concealment
+
+  This AAC core implementation includes a concealment function, which can be
+  enabled using the several defines during compilation.
+
+  There are various tests inside the core, starting with simple CRC tests and
+  ending in a variety of plausibility checks. If such a check indicates an
+  invalid bitstream, then concealment is applied.
+
+  Concealment is also applied when the calling main program indicates a
+  distorted or missing data frame using the frameOK flag. This is used for error
+  detection on the transport layer. (See below)
+
+  There are three concealment-modes:
+
+  1) Muting: The spectral data is simply set to zero in case of an detected
+  error.
+
+  2) Noise substitution: In case of an detected error, concealment copies the
+  last frame and adds attenuates the spectral data. For this mode you have to
+  set the #CONCEAL_NOISE define. Noise substitution adds no additional delay.
+
+  3) Interpolation: The interpolation routine swaps the spectral data from the
+  previous and the current frame just before the final frequency to time
+  conversion. In case a single frame is corrupted, concealmant interpolates
+  between the last good and the first good frame to create the spectral data for
+  the missing frame. If multiple frames are corrupted, concealment implements
+  first a fade out based on slightly modified spectral values from the last good
+     frame. As soon as good frames are available, concealmant fades in the new
+  spectral data. For this mode you have to set the #CONCEAL_INTER define. Note
+  that in this case, you also need to set #SBR_BS_DELAY_ENABLE, which basically
+  adds approriate delay in the SBR decoder. Note that the
+  Interpolating-Concealment increases the delay of your decoder by one frame and
+  that it does require additional resources such as memory and computational
+  complexity.
+
+  <h2>How concealment can be used with errors on the transport layer</h2>
+
+  Many errors can or have to be detected on the transport layer. For example in
+  IP based systems packet loss can occur. The transport protocol used should
+  indicate such packet loss by inserting an empty frame with frameOK=0.
+*/
+
+#include "conceal.h"
+
+#include "aac_rom.h"
+#include "genericStds.h"
+
+/* PNS (of block) */
+#include "aacdec_pns.h"
+#include "block.h"
+
+#define CONCEAL_DFLT_COMF_NOISE_LEVEL (0x100000)
+
+#define CONCEAL_NOT_DEFINED ((UCHAR)-1)
+
+/* default settings */
+#define CONCEAL_DFLT_FADEOUT_FRAMES (6)
+#define CONCEAL_DFLT_FADEIN_FRAMES (5)
+#define CONCEAL_DFLT_MUTE_RELEASE_FRAMES (0)
+
+#define CONCEAL_DFLT_FADE_FACTOR (0.707106781186548f) /* 1/sqrt(2) */
+
+/* some often used constants: */
+#define FIXP_ZERO FL2FXCONST_DBL(0.0f)
+#define FIXP_ONE FL2FXCONST_DBL(1.0f)
+#define FIXP_FL_CORRECTION FL2FXCONST_DBL(0.53333333333333333f)
+
+/* For parameter conversion */
+#define CONCEAL_PARAMETER_BITS (8)
+#define CONCEAL_MAX_QUANT_FACTOR ((1 << CONCEAL_PARAMETER_BITS) - 1)
+/*#define CONCEAL_MIN_ATTENUATION_FACTOR_025  ( FL2FXCONST_DBL(0.971627951577106174) )*/ /* -0.25 dB */
+#define CONCEAL_MIN_ATTENUATION_FACTOR_025_LD \
+  FL2FXCONST_DBL(-0.041524101186092029596853445212299)
+/*#define CONCEAL_MIN_ATTENUATION_FACTOR_050  ( FL2FXCONST_DBL(0.944060876285923380) )*/ /* -0.50 dB */
+#define CONCEAL_MIN_ATTENUATION_FACTOR_050_LD \
+  FL2FXCONST_DBL(-0.083048202372184059253597008145293)
+
+typedef enum {
+  CConcealment_NoExpand,
+  CConcealment_Expand,
+  CConcealment_Compress
+} CConcealmentExpandType;
+
+static const FIXP_SGL facMod4Table[4] = {
+    FL2FXCONST_SGL(0.500000000f), /* FIXP_SGL(0x4000),  2^-(1-0,00) */
+    FL2FXCONST_SGL(0.594603558f), /* FIXP_SGL(0x4c1b),  2^-(1-0,25) */
+    FL2FXCONST_SGL(0.707106781f), /* FIXP_SGL(0x5a82),  2^-(1-0,50) */
+    FL2FXCONST_SGL(0.840896415f)  /* FIXP_SGL(0x6ba2)   2^-(1-0,75) */
+};
+
+static void CConcealment_CalcBandEnergy(
+    FIXP_DBL *spectrum, const SamplingRateInfo *pSamplingRateInfo,
+    const int blockType, CConcealmentExpandType ex, int *sfbEnergy);
+
+static void CConcealment_InterpolateBuffer(FIXP_DBL *spectrum,
+                                           SHORT *pSpecScalePrev,
+                                           SHORT *pSpecScaleAct,
+                                           SHORT *pSpecScaleOut, int *enPrv,
+                                           int *enAct, int sfbCnt,
+                                           const SHORT *pSfbOffset);
+
+static int CConcealment_ApplyInter(
+    CConcealmentInfo *pConcealmentInfo,
+    CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+    const SamplingRateInfo *pSamplingRateInfo, const int samplesPerFrame,
+    const int improveTonal, const int frameOk, const int mute_release_active);
+
+static int CConcealment_ApplyNoise(
+    CConcealmentInfo *pConcealmentInfo,
+    CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
+    const SamplingRateInfo *pSamplingRateInfo, const int samplesPerFrame,
+    const UINT flags);
+
+static void CConcealment_UpdateState(
+    CConcealmentInfo *pConcealmentInfo, int frameOk,
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
+    const int samplesPerFrame, CAacDecoderChannelInfo *pAacDecoderChannelInfo);
+
+static void CConcealment_ApplyRandomSign(int iRandomPhase, FIXP_DBL *spec,
+                                         int samplesPerFrame);
+
+/* TimeDomainFading */
+static void CConcealment_TDFadePcmAtt(int start, int len, FIXP_DBL fadeStart,
+                                      FIXP_DBL fadeStop, FIXP_PCM *pcmdata);
+static void CConcealment_TDFadeFillFadingStations(FIXP_DBL *fadingStations,
+                                                  int *fadingSteps,
+                                                  FIXP_DBL fadeStop,
+                                                  FIXP_DBL fadeStart,
+                                                  TDfadingType fadingType);
+static void CConcealment_TDFading_doLinearFadingSteps(int *fadingSteps);
+
+/* Streamline the state machine */
+static int CConcealment_ApplyFadeOut(
+    int mode, CConcealmentInfo *pConcealmentInfo,
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
+    const int samplesPerFrame, CAacDecoderChannelInfo *pAacDecoderChannelInfo);
+
+static int CConcealment_TDNoise_Random(ULONG *seed);
+static void CConcealment_TDNoise_Apply(CConcealmentInfo *const pConcealmentInfo,
+                                       const int len, FIXP_PCM *const pcmdata);
+
+static BLOCK_TYPE CConcealment_GetWinSeq(int prevWinSeq) {
+  BLOCK_TYPE newWinSeq = BLOCK_LONG;
+
+  /* Try to have only long blocks */
+  if (prevWinSeq == BLOCK_START || prevWinSeq == BLOCK_SHORT) {
+    newWinSeq = BLOCK_STOP;
+  }
+
+  return (newWinSeq);
+}
+
+/*!
+  \brief Init common concealment information data
+
+  \param pConcealCommonData Pointer to the concealment common data structure.
+*/
+void CConcealment_InitCommonData(CConcealParams *pConcealCommonData) {
+  if (pConcealCommonData != NULL) {
+    int i;
+
+    /* Set default error concealment technique */
+    pConcealCommonData->method = ConcealMethodInter;
+
+    pConcealCommonData->numFadeOutFrames = CONCEAL_DFLT_FADEOUT_FRAMES;
+    pConcealCommonData->numFadeInFrames = CONCEAL_DFLT_FADEIN_FRAMES;
+    pConcealCommonData->numMuteReleaseFrames = CONCEAL_DFLT_MUTE_RELEASE_FRAMES;
+
+    pConcealCommonData->comfortNoiseLevel =
+        (FIXP_DBL)CONCEAL_DFLT_COMF_NOISE_LEVEL;
+
+    /* Init fade factors (symetric) */
+    pConcealCommonData->fadeOutFactor[0] =
+        FL2FXCONST_SGL(CONCEAL_DFLT_FADE_FACTOR);
+    pConcealCommonData->fadeInFactor[0] = pConcealCommonData->fadeOutFactor[0];
+
+    for (i = 1; i < CONCEAL_MAX_NUM_FADE_FACTORS; i++) {
+      pConcealCommonData->fadeOutFactor[i] =
+          FX_DBL2FX_SGL(fMult(pConcealCommonData->fadeOutFactor[i - 1],
+                              FL2FXCONST_SGL(CONCEAL_DFLT_FADE_FACTOR)));
+      pConcealCommonData->fadeInFactor[i] =
+          pConcealCommonData->fadeOutFactor[i];
+    }
+  }
+}
+
+/*!
+  \brief Get current concealment method.
+
+  \param pConcealCommonData Pointer to common concealment data (for all
+  channels)
+*/
+CConcealmentMethod CConcealment_GetMethod(CConcealParams *pConcealCommonData) {
+  CConcealmentMethod method = ConcealMethodNone;
+
+  if (pConcealCommonData != NULL) {
+    method = pConcealCommonData->method;
+  }
+
+  return (method);
+}
+
+/*!
+  \brief Init concealment information for each channel
+
+  \param pConcealChannelInfo Pointer to the channel related concealment info
+  structure to be initialized. \param pConcealCommonData  Pointer to common
+  concealment data (for all channels) \param initRenderMode      Initial render
+  mode to be set for the current channel. \param samplesPerFrame     The number
+  of samples per frame.
+*/
+void CConcealment_InitChannelData(CConcealmentInfo *pConcealChannelInfo,
+                                  CConcealParams *pConcealCommonData,
+                                  AACDEC_RENDER_MODE initRenderMode,
+                                  int samplesPerFrame) {
+  int i;
+  pConcealChannelInfo->TDNoiseSeed = 0;
+  FDKmemclear(pConcealChannelInfo->TDNoiseStates,
+              sizeof(pConcealChannelInfo->TDNoiseStates));
+  pConcealChannelInfo->TDNoiseCoef[0] = FL2FXCONST_SGL(0.05f);
+  pConcealChannelInfo->TDNoiseCoef[1] = FL2FXCONST_SGL(0.5f);
+  pConcealChannelInfo->TDNoiseCoef[2] = FL2FXCONST_SGL(0.45f);
+
+  pConcealChannelInfo->pConcealParams = pConcealCommonData;
+
+  pConcealChannelInfo->lastRenderMode = initRenderMode;
+
+  pConcealChannelInfo->windowShape = CONCEAL_NOT_DEFINED;
+  pConcealChannelInfo->windowSequence = BLOCK_LONG; /* default type */
+  pConcealChannelInfo->lastWinGrpLen = 1;
+
+  pConcealChannelInfo->concealState = ConcealState_Ok;
+
+  FDKmemclear(pConcealChannelInfo->spectralCoefficient,
+              1024 * sizeof(FIXP_CNCL));
+
+  for (i = 0; i < 8; i++) {
+    pConcealChannelInfo->specScale[i] = 0;
+  }
+
+  pConcealChannelInfo->iRandomPhase = 0;
+
+  pConcealChannelInfo->prevFrameOk[0] = 1;
+  pConcealChannelInfo->prevFrameOk[1] = 1;
+
+  pConcealChannelInfo->cntFadeFrames = 0;
+  pConcealChannelInfo->cntValidFrames = 0;
+  pConcealChannelInfo->fade_old = (FIXP_DBL)MAXVAL_DBL;
+  pConcealChannelInfo->winGrpOffset[0] = 0;
+  pConcealChannelInfo->winGrpOffset[1] = 0;
+  pConcealChannelInfo->attGrpOffset[0] = 0;
+  pConcealChannelInfo->attGrpOffset[1] = 0;
+}
+
+/*!
+  \brief Set error concealment parameters
+
+  \param concealParams
+  \param method
+  \param fadeOutSlope
+  \param fadeInSlope
+  \param muteRelease
+  \param comfNoiseLevel
+*/
+AAC_DECODER_ERROR
+CConcealment_SetParams(CConcealParams *concealParams, int method,
+                       int fadeOutSlope, int fadeInSlope, int muteRelease,
+                       FIXP_DBL comfNoiseLevel) {
+  /* set concealment technique */
+  if (method != AACDEC_CONCEAL_PARAM_NOT_SPECIFIED) {
+    switch ((CConcealmentMethod)method) {
+      case ConcealMethodMute:
+      case ConcealMethodNoise:
+      case ConcealMethodInter:
+        /* Be sure to enable delay adjustment of SBR decoder! */
+        if (concealParams == NULL) {
+          return AAC_DEC_INVALID_HANDLE;
+        } else {
+          /* set param */
+          concealParams->method = (CConcealmentMethod)method;
+        }
+        break;
+
+      default:
+        return AAC_DEC_SET_PARAM_FAIL;
+    }
+  }
+
+  /* set number of frames for fade-out slope */
+  if (fadeOutSlope != AACDEC_CONCEAL_PARAM_NOT_SPECIFIED) {
+    if ((fadeOutSlope < CONCEAL_MAX_NUM_FADE_FACTORS) && (fadeOutSlope >= 0)) {
+      if (concealParams == NULL) {
+        return AAC_DEC_INVALID_HANDLE;
+      } else {
+        /* set param */
+        concealParams->numFadeOutFrames = fadeOutSlope;
+      }
+    } else {
+      return AAC_DEC_SET_PARAM_FAIL;
+    }
+  }
+
+  /* set number of frames for fade-in slope */
+  if (fadeInSlope != AACDEC_CONCEAL_PARAM_NOT_SPECIFIED) {
+    if ((fadeInSlope < CONCEAL_MAX_NUM_FADE_FACTORS) && (fadeInSlope >= 0)) {
+      if (concealParams == NULL) {
+        return AAC_DEC_INVALID_HANDLE;
+      } else {
+        /* set param */
+        concealParams->numFadeInFrames = fadeInSlope;
+      }
+    } else {
+      return AAC_DEC_SET_PARAM_FAIL;
+    }
+  }
+
+  /* set number of error-free frames after which the muting will be released */
+  if (muteRelease != AACDEC_CONCEAL_PARAM_NOT_SPECIFIED) {
+    if ((muteRelease < (CONCEAL_MAX_NUM_FADE_FACTORS << 1)) &&
+        (muteRelease >= 0)) {
+      if (concealParams == NULL) {
+        return AAC_DEC_INVALID_HANDLE;
+      } else {
+        /* set param */
+        concealParams->numMuteReleaseFrames = muteRelease;
+      }
+    } else {
+      return AAC_DEC_SET_PARAM_FAIL;
+    }
+  }
+
+  /* set confort noise level which will be inserted while in state 'muting' */
+  if (comfNoiseLevel != (FIXP_DBL)AACDEC_CONCEAL_PARAM_NOT_SPECIFIED) {
+    if ((comfNoiseLevel < (FIXP_DBL)0) ||
+        (comfNoiseLevel > (FIXP_DBL)MAXVAL_DBL)) {
+      return AAC_DEC_SET_PARAM_FAIL;
+    }
+    if (concealParams == NULL) {
+      return AAC_DEC_INVALID_HANDLE;
+    } else {
+      concealParams->comfortNoiseLevel = (FIXP_DBL)comfNoiseLevel;
+    }
+  }
+
+  return (AAC_DEC_OK);
+}
+
+/*!
+  \brief Set fade-out/in attenuation factor vectors
+
+  \param concealParams
+  \param fadeOutAttenuationVector
+  \param fadeInAttenuationVector
+
+  \return 0 if OK all other values indicate errors
+*/
+AAC_DECODER_ERROR
+CConcealment_SetAttenuation(CConcealParams *concealParams,
+                            const SHORT *fadeOutAttenuationVector,
+                            const SHORT *fadeInAttenuationVector) {
+  if ((fadeOutAttenuationVector == NULL) && (fadeInAttenuationVector == NULL)) {
+    return AAC_DEC_SET_PARAM_FAIL;
+  }
+
+  /* Fade-out factors */
+  if (fadeOutAttenuationVector != NULL) {
+    int i;
+
+    /* check quantized factors first */
+    for (i = 0; i < CONCEAL_MAX_NUM_FADE_FACTORS; i++) {
+      if ((fadeOutAttenuationVector[i] < 0) ||
+          (fadeOutAttenuationVector[i] > CONCEAL_MAX_QUANT_FACTOR)) {
+        return AAC_DEC_SET_PARAM_FAIL;
+      }
+    }
+    if (concealParams == NULL) {
+      return AAC_DEC_INVALID_HANDLE;
+    }
+
+    /* now dequantize factors */
+    for (i = 0; i < CONCEAL_MAX_NUM_FADE_FACTORS; i++) {
+      concealParams->fadeOutFactor[i] =
+          FX_DBL2FX_SGL(fLdPow(CONCEAL_MIN_ATTENUATION_FACTOR_025_LD, 0,
+                               (FIXP_DBL)((INT)(FL2FXCONST_DBL(1.0 / 2.0) >>
+                                                (CONCEAL_PARAMETER_BITS - 1)) *
+                                          (INT)fadeOutAttenuationVector[i]),
+                               CONCEAL_PARAMETER_BITS));
+    }
+  }
+
+  /* Fade-in factors */
+  if (fadeInAttenuationVector != NULL) {
+    int i;
+
+    /* check quantized factors first */
+    for (i = 0; i < CONCEAL_MAX_NUM_FADE_FACTORS; i++) {
+      if ((fadeInAttenuationVector[i] < 0) ||
+          (fadeInAttenuationVector[i] > CONCEAL_MAX_QUANT_FACTOR)) {
+        return AAC_DEC_SET_PARAM_FAIL;
+      }
+    }
+    if (concealParams == NULL) {
+      return AAC_DEC_INVALID_HANDLE;
+    }
+
+    /* now dequantize factors */
+    for (i = 0; i < CONCEAL_MAX_NUM_FADE_FACTORS; i++) {
+      concealParams->fadeInFactor[i] = FX_DBL2FX_SGL(
+          fLdPow(CONCEAL_MIN_ATTENUATION_FACTOR_025_LD, 0,
+                 (FIXP_DBL)((INT)(FIXP_ONE >> CONCEAL_PARAMETER_BITS) *
+                            (INT)fadeInAttenuationVector[i]),
+                 CONCEAL_PARAMETER_BITS));
+    }
+  }
+
+  return (AAC_DEC_OK);
+}
+
+/*!
+  \brief Get state of concealment module.
+
+  \param pConcealChannelInfo
+
+  \return Concealment state.
+*/
+CConcealmentState CConcealment_GetState(CConcealmentInfo *pConcealChannelInfo) {
+  CConcealmentState state = ConcealState_Ok;
+
+  if (pConcealChannelInfo != NULL) {
+    state = pConcealChannelInfo->concealState;
+  }
+
+  return (state);
+}
+
+/*!
+  \brief Store data for concealment techniques applied later
+
+  Interface function to store data for different concealment strategies
+ */
+void CConcealment_Store(
+    CConcealmentInfo *hConcealmentInfo,
+    CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo) {
+  UCHAR nbDiv = NB_DIV;
+
+  if (!(pAacDecoderChannelInfo->renderMode == AACDEC_RENDER_LPD &&
+        pAacDecoderChannelInfo->data.usac.mod[nbDiv - 1] == 0))
+
+  {
+    FIXP_DBL *pSpectralCoefficient =
+        SPEC_LONG(pAacDecoderChannelInfo->pSpectralCoefficient);
+    SHORT *pSpecScale = pAacDecoderChannelInfo->specScale;
+    CIcsInfo *pIcsInfo = &pAacDecoderChannelInfo->icsInfo;
+
+    SHORT tSpecScale[8];
+    UCHAR tWindowShape;
+    BLOCK_TYPE tWindowSequence;
+
+    /* store old window infos for swapping */
+    tWindowSequence = hConcealmentInfo->windowSequence;
+    tWindowShape = hConcealmentInfo->windowShape;
+
+    /* store old scale factors for swapping */
+    FDKmemcpy(tSpecScale, hConcealmentInfo->specScale, 8 * sizeof(SHORT));
+
+    /* store new window infos */
+    hConcealmentInfo->windowSequence = GetWindowSequence(pIcsInfo);
+    hConcealmentInfo->windowShape = GetWindowShape(pIcsInfo);
+    hConcealmentInfo->lastWinGrpLen =
+        *(GetWindowGroupLengthTable(pIcsInfo) + GetWindowGroups(pIcsInfo) - 1);
+
+    /* store new scale factors */
+    FDKmemcpy(hConcealmentInfo->specScale, pSpecScale, 8 * sizeof(SHORT));
+
+    if (hConcealmentInfo->pConcealParams->method < ConcealMethodInter) {
+    /* store new spectral bins */
+#if (CNCL_FRACT_BITS == DFRACT_BITS)
+      FDKmemcpy(hConcealmentInfo->spectralCoefficient, pSpectralCoefficient,
+                1024 * sizeof(FIXP_CNCL));
+#else
+      FIXP_CNCL *RESTRICT pCncl =
+          &hConcealmentInfo->spectralCoefficient[1024 - 1];
+      FIXP_DBL *RESTRICT pSpec = &pSpectralCoefficient[1024 - 1];
+      int i;
+      for (i = 1024; i != 0; i--) {
+        *pCncl-- = FX_DBL2FX_CNCL(*pSpec--);
+      }
+#endif
+    } else {
+    /* swap spectral data */
+#if (FIXP_CNCL == FIXP_DBL)
+      C_ALLOC_SCRATCH_START(pSpecTmp, FIXP_DBL, 1024);
+      FDKmemcpy(pSpecTmp, pSpectralCoefficient, 1024 * sizeof(FIXP_DBL));
+      FDKmemcpy(pSpectralCoefficient, hConcealmentInfo->spectralCoefficient,
+                1024 * sizeof(FIXP_DBL));
+      FDKmemcpy(hConcealmentInfo->spectralCoefficient, pSpecTmp,
+                1024 * sizeof(FIXP_DBL));
+      C_ALLOC_SCRATCH_END(pSpecTmp, FIXP_DBL, 1024);
+#else
+      FIXP_CNCL *RESTRICT pCncl =
+          &hConcealmentInfo->spectralCoefficient[1024 - 1];
+      FIXP_DBL *RESTRICT pSpec = &pSpectralCoefficient[1024 - 1];
+      FIXP_DBL tSpec;
+
+      for (int i = 1024; i != 0; i--) {
+        tSpec = *pSpec;
+        *pSpec-- = FX_CNCL2FX_DBL(*pCncl);
+        *pCncl-- = FX_DBL2FX_CNCL(tSpec);
+      }
+#endif
+
+      /* complete swapping of window infos */
+      pIcsInfo->WindowSequence = tWindowSequence;
+      pIcsInfo->WindowShape = tWindowShape;
+
+      /* complete swapping of scale factors */
+      FDKmemcpy(pSpecScale, tSpecScale, 8 * sizeof(SHORT));
+    }
+  }
+
+  if (pAacDecoderChannelInfo->renderMode == AACDEC_RENDER_LPD) {
+    /* Store LSF4 */
+    FDKmemcpy(hConcealmentInfo->lsf4, pAacDecoderStaticChannelInfo->lpc4_lsf,
+              sizeof(hConcealmentInfo->lsf4));
+    /* Store TCX gain */
+    hConcealmentInfo->last_tcx_gain =
+        pAacDecoderStaticChannelInfo->last_tcx_gain;
+    hConcealmentInfo->last_tcx_gain_e =
+        pAacDecoderStaticChannelInfo->last_tcx_gain_e;
+  }
+}
+
+/*!
+  \brief Apply concealment
+
+  Interface function to different concealment strategies
+ */
+int CConcealment_Apply(
+    CConcealmentInfo *hConcealmentInfo,
+    CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
+    const SamplingRateInfo *pSamplingRateInfo, const int samplesPerFrame,
+    const UCHAR lastLpdMode, const int frameOk, const UINT flags) {
+  int appliedProcessing = 0;
+  const int mute_release_active =
+      frameOk && (hConcealmentInfo->concealState >= ConcealState_Mute) &&
+      (hConcealmentInfo->cntValidFrames + 1 <=
+       hConcealmentInfo->pConcealParams->numMuteReleaseFrames);
+
+  if (hConcealmentInfo->windowShape == CONCEAL_NOT_DEFINED) {
+    /* Initialize window_shape with same value as in the current (parsed) frame.
+       Because section 4.6.11.3.2 (Windowing and block switching) of ISO/IEC
+       14496-3:2009 says: For the first raw_data_block() to be decoded the
+       window_shape of the left and right half of the window are identical. */
+    hConcealmentInfo->windowShape = pAacDecoderChannelInfo->icsInfo.WindowShape;
+  }
+
+  if (frameOk && !mute_release_active) {
+    /* Update render mode if frameOk except for ongoing mute release state. */
+    hConcealmentInfo->lastRenderMode =
+        (SCHAR)pAacDecoderChannelInfo->renderMode;
+
+    /* Rescue current data for concealment in future frames */
+    CConcealment_Store(hConcealmentInfo, pAacDecoderChannelInfo,
+                       pAacDecoderStaticChannelInfo);
+    /* Reset index to random sign vector to make sign calculation frame agnostic
+       (only depends on number of subsequently concealed spectral blocks) */
+    hConcealmentInfo->iRandomPhase = 0;
+  } else {
+    if (hConcealmentInfo->lastRenderMode == AACDEC_RENDER_INVALID) {
+      hConcealmentInfo->lastRenderMode = AACDEC_RENDER_IMDCT;
+    }
+    pAacDecoderChannelInfo->renderMode =
+        (AACDEC_RENDER_MODE)hConcealmentInfo->lastRenderMode;
+  }
+
+  /* hand current frame status to the state machine */
+  CConcealment_UpdateState(hConcealmentInfo, frameOk,
+                           pAacDecoderStaticChannelInfo, samplesPerFrame,
+                           pAacDecoderChannelInfo);
+
+  {
+    if (!frameOk && pAacDecoderChannelInfo->renderMode == AACDEC_RENDER_IMDCT) {
+      /* LPC extrapolation */
+      CLpc_Conceal(pAacDecoderChannelInfo->data.usac.lsp_coeff,
+                   pAacDecoderStaticChannelInfo->lpc4_lsf,
+                   pAacDecoderStaticChannelInfo->lsf_adaptive_mean,
+                   hConcealmentInfo->lastRenderMode == AACDEC_RENDER_IMDCT);
+      FDKmemcpy(hConcealmentInfo->lsf4, pAacDecoderStaticChannelInfo->lpc4_lsf,
+                sizeof(pAacDecoderStaticChannelInfo->lpc4_lsf));
+    }
+
+    /* Create data for signal rendering according to the selected concealment
+     * method and decoder operating mode. */
+
+    if ((!frameOk || mute_release_active) &&
+        (pAacDecoderChannelInfo->renderMode == AACDEC_RENDER_LPD)) {
+      /* Restore old LSF4 */
+      FDKmemcpy(pAacDecoderStaticChannelInfo->lpc4_lsf, hConcealmentInfo->lsf4,
+                sizeof(pAacDecoderStaticChannelInfo->lpc4_lsf));
+      /* Restore old TCX gain */
+      pAacDecoderStaticChannelInfo->last_tcx_gain =
+          hConcealmentInfo->last_tcx_gain;
+      pAacDecoderStaticChannelInfo->last_tcx_gain_e =
+          hConcealmentInfo->last_tcx_gain_e;
+    }
+
+    if (!(pAacDecoderChannelInfo->renderMode == AACDEC_RENDER_LPD &&
+          pAacDecoderStaticChannelInfo->last_lpd_mode == 0)) {
+      switch (hConcealmentInfo->pConcealParams->method) {
+        default:
+        case ConcealMethodMute:
+          if (!frameOk) {
+            /* Mute spectral data in case of errors */
+            FDKmemclear(pAacDecoderChannelInfo->pSpectralCoefficient,
+                        samplesPerFrame * sizeof(FIXP_DBL));
+            /* Set last window shape */
+            pAacDecoderChannelInfo->icsInfo.WindowShape =
+                hConcealmentInfo->windowShape;
+            appliedProcessing = 1;
+          }
+          break;
+
+        case ConcealMethodNoise:
+          /* Noise substitution error concealment technique */
+          appliedProcessing = CConcealment_ApplyNoise(
+              hConcealmentInfo, pAacDecoderChannelInfo,
+              pAacDecoderStaticChannelInfo, pSamplingRateInfo, samplesPerFrame,
+              flags);
+          break;
+
+        case ConcealMethodInter:
+          /* Energy interpolation concealment based on 3GPP */
+          appliedProcessing = CConcealment_ApplyInter(
+              hConcealmentInfo, pAacDecoderChannelInfo, pSamplingRateInfo,
+              samplesPerFrame, 0, /* don't use tonal improvement */
+              frameOk, mute_release_active);
+          break;
+      }
+    } else if (!frameOk || mute_release_active) {
+      /* simply restore the buffer */
+      FIXP_DBL *pSpectralCoefficient =
+          SPEC_LONG(pAacDecoderChannelInfo->pSpectralCoefficient);
+      SHORT *pSpecScale = pAacDecoderChannelInfo->specScale;
+      CIcsInfo *pIcsInfo = &pAacDecoderChannelInfo->icsInfo;
+#if (CNCL_FRACT_BITS != DFRACT_BITS)
+      FIXP_CNCL *RESTRICT pCncl =
+          &hConcealmentInfo->spectralCoefficient[1024 - 1];
+      FIXP_DBL *RESTRICT pSpec = &pSpectralCoefficient[1024 - 1];
+      int i;
+#endif
+
+      /* restore window infos (gri) do we need that? */
+      pIcsInfo->WindowSequence = hConcealmentInfo->windowSequence;
+      pIcsInfo->WindowShape = hConcealmentInfo->windowShape;
+
+      if (hConcealmentInfo->concealState != ConcealState_Mute) {
+        /* restore scale factors */
+        FDKmemcpy(pSpecScale, hConcealmentInfo->specScale, 8 * sizeof(SHORT));
+
+        /* restore spectral bins */
+#if (CNCL_FRACT_BITS == DFRACT_BITS)
+        FDKmemcpy(pSpectralCoefficient, hConcealmentInfo->spectralCoefficient,
+                  1024 * sizeof(FIXP_DBL));
+#else
+        for (i = 1024; i != 0; i--) {
+          *pSpec-- = FX_CNCL2FX_DBL(*pCncl--);
+        }
+#endif
+      } else {
+        /* clear scale factors */
+        FDKmemclear(pSpecScale, 8 * sizeof(SHORT));
+
+        /* clear buffer */
+        FDKmemclear(pSpectralCoefficient, 1024 * sizeof(FIXP_CNCL));
+      }
+    }
+  }
+  /* update history */
+  hConcealmentInfo->prevFrameOk[0] = hConcealmentInfo->prevFrameOk[1];
+  hConcealmentInfo->prevFrameOk[1] = frameOk;
+
+  return mute_release_active ? -1 : appliedProcessing;
+}
+
+/*!
+\brief Apply concealment noise substitution
+
+  In case of frame lost this function produces a noisy frame with respect to the
+  energies values of past frame.
+ */
+static int CConcealment_ApplyNoise(
+    CConcealmentInfo *pConcealmentInfo,
+    CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
+    const SamplingRateInfo *pSamplingRateInfo, const int samplesPerFrame,
+    const UINT flags) {
+  FIXP_DBL *pSpectralCoefficient =
+      SPEC_LONG(pAacDecoderChannelInfo->pSpectralCoefficient);
+  CIcsInfo *pIcsInfo = &pAacDecoderChannelInfo->icsInfo;
+
+  int appliedProcessing = 0;
+
+  FDK_ASSERT(pConcealmentInfo != NULL);
+  FDK_ASSERT((samplesPerFrame >= 120) && (samplesPerFrame <= 1024));
+
+  switch (pConcealmentInfo->concealState) {
+    case ConcealState_Ok:
+      /* Nothing to do here! */
+      break;
+
+    case ConcealState_Single:
+    case ConcealState_FadeOut:
+      appliedProcessing = CConcealment_ApplyFadeOut(
+          /*mode =*/1, pConcealmentInfo, pAacDecoderStaticChannelInfo,
+          samplesPerFrame, pAacDecoderChannelInfo);
+      break;
+
+    case ConcealState_Mute: {
+      /* set dummy window parameters */
+      pIcsInfo->Valid = 0; /* Trigger the generation of a consitent IcsInfo */
+      pIcsInfo->WindowShape =
+          pConcealmentInfo->windowShape; /* Prevent an invalid WindowShape
+                                            (required for F/T transform) */
+      pIcsInfo->WindowSequence =
+          CConcealment_GetWinSeq(pConcealmentInfo->windowSequence);
+      pConcealmentInfo->windowSequence =
+          pIcsInfo->WindowSequence; /* Store for next frame
+                                       (spectrum in concealment
+                                       buffer can't be used at
+                                       all) */
+
+      /* mute spectral data */
+      FDKmemclear(pSpectralCoefficient, samplesPerFrame * sizeof(FIXP_DBL));
+      FDKmemclear(pConcealmentInfo->spectralCoefficient,
+                  samplesPerFrame * sizeof(FIXP_DBL));
+
+      appliedProcessing = 1;
+    } break;
+
+    case ConcealState_FadeIn: {
+      /* TimeDomainFading:                                        */
+      /* Attenuation of signal is done in CConcealment_TDFading() */
+
+      appliedProcessing = 1;
+    } break;
+
+    default:
+      /* we shouldn't come here anyway */
+      FDK_ASSERT(0);
+      break;
+  }
+
+  return appliedProcessing;
+}
+
+/*!
+  \brief Apply concealment interpolation
+
+  The function swaps the data from the current and the previous frame. If an
+  error has occured, frame interpolation is performed to restore the missing
+  frame. In case of multiple faulty frames, fade-in and fade-out is applied.
+*/
+static int CConcealment_ApplyInter(
+    CConcealmentInfo *pConcealmentInfo,
+    CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+    const SamplingRateInfo *pSamplingRateInfo, const int samplesPerFrame,
+    const int improveTonal, const int frameOk, const int mute_release_active) {
+#if defined(FDK_ASSERT_ENABLE)
+  CConcealParams *pConcealCommonData = pConcealmentInfo->pConcealParams;
+#endif
+
+  FIXP_DBL *pSpectralCoefficient =
+      SPEC_LONG(pAacDecoderChannelInfo->pSpectralCoefficient);
+  CIcsInfo *pIcsInfo = &pAacDecoderChannelInfo->icsInfo;
+  SHORT *pSpecScale = pAacDecoderChannelInfo->specScale;
+
+  int sfbEnergyPrev[64];
+  int sfbEnergyAct[64];
+
+  int i, appliedProcessing = 0;
+
+  /* clear/init */
+  FDKmemclear(sfbEnergyPrev, 64 * sizeof(int));
+  FDKmemclear(sfbEnergyAct, 64 * sizeof(int));
+
+  if (!frameOk || mute_release_active) {
+    /* Restore last frame from concealment buffer */
+    pIcsInfo->WindowShape = pConcealmentInfo->windowShape;
+    pIcsInfo->WindowSequence = pConcealmentInfo->windowSequence;
+
+    /* Restore spectral data */
+    for (i = 0; i < samplesPerFrame; i++) {
+      pSpectralCoefficient[i] =
+          FX_CNCL2FX_DBL(pConcealmentInfo->spectralCoefficient[i]);
+    }
+
+    /* Restore scale factors */
+    FDKmemcpy(pSpecScale, pConcealmentInfo->specScale, 8 * sizeof(SHORT));
+  }
+
+  /* if previous frame was not ok */
+  if (!pConcealmentInfo->prevFrameOk[1] || mute_release_active) {
+    /* if current frame (f_n) is ok and the last but one frame (f_(n-2))
+       was ok, too, then interpolate both frames in order to generate
+       the current output frame (f_(n-1)). Otherwise, use the last stored
+       frame (f_(n-2) or f_(n-3) or ...). */
+    if (frameOk && pConcealmentInfo->prevFrameOk[0] && !mute_release_active) {
+      appliedProcessing = 1;
+
+      /* Interpolate both frames in order to generate the current output frame
+       * (f_(n-1)). */
+      if (pIcsInfo->WindowSequence == BLOCK_SHORT) {
+        /* f_(n-2) == BLOCK_SHORT */
+        /* short--??????--short, short--??????--long interpolation */
+        /* short--short---short, short---long---long interpolation */
+
+        int wnd;
+
+        if (pConcealmentInfo->windowSequence ==
+            BLOCK_SHORT) { /* f_n == BLOCK_SHORT */
+          /* short--short---short interpolation */
+
+          int scaleFactorBandsTotal =
+              pSamplingRateInfo->NumberOfScaleFactorBands_Short;
+          const SHORT *pSfbOffset = pSamplingRateInfo->ScaleFactorBands_Short;
+          pIcsInfo->WindowShape = (samplesPerFrame <= 512) ? 2 : 1;
+          pIcsInfo->WindowSequence = BLOCK_SHORT;
+
+          for (wnd = 0; wnd < 8; wnd++) {
+            CConcealment_CalcBandEnergy(
+                &pSpectralCoefficient[wnd *
+                                      (samplesPerFrame / 8)], /* spec_(n-2) */
+                pSamplingRateInfo, BLOCK_SHORT, CConcealment_NoExpand,
+                sfbEnergyPrev);
+
+            CConcealment_CalcBandEnergy(
+                &pConcealmentInfo->spectralCoefficient[wnd * (samplesPerFrame /
+                                                              8)], /* spec_n */
+                pSamplingRateInfo, BLOCK_SHORT, CConcealment_NoExpand,
+                sfbEnergyAct);
+
+            CConcealment_InterpolateBuffer(
+                &pSpectralCoefficient[wnd *
+                                      (samplesPerFrame / 8)], /* spec_(n-1) */
+                &pSpecScale[wnd], &pConcealmentInfo->specScale[wnd],
+                &pSpecScale[wnd], sfbEnergyPrev, sfbEnergyAct,
+                scaleFactorBandsTotal, pSfbOffset);
+          }
+        } else { /* f_n != BLOCK_SHORT */
+          /* short---long---long interpolation */
+
+          int scaleFactorBandsTotal =
+              pSamplingRateInfo->NumberOfScaleFactorBands_Long;
+          const SHORT *pSfbOffset = pSamplingRateInfo->ScaleFactorBands_Long;
+          SHORT specScaleOut;
+
+          CConcealment_CalcBandEnergy(
+              &pSpectralCoefficient[samplesPerFrame -
+                                    (samplesPerFrame /
+                                     8)], /* [wnd] spec_(n-2) */
+              pSamplingRateInfo, BLOCK_SHORT, CConcealment_Expand,
+              sfbEnergyAct);
+
+          CConcealment_CalcBandEnergy(
+              pConcealmentInfo->spectralCoefficient, /* spec_n */
+              pSamplingRateInfo, BLOCK_LONG, CConcealment_NoExpand,
+              sfbEnergyPrev);
+
+          pIcsInfo->WindowShape = 0;
+          pIcsInfo->WindowSequence = BLOCK_STOP;
+
+          for (i = 0; i < samplesPerFrame; i++) {
+            pSpectralCoefficient[i] =
+                pConcealmentInfo->spectralCoefficient[i]; /* spec_n */
+          }
+
+          for (i = 0; i < 8; i++) { /* search for max(specScale) */
+            if (pSpecScale[i] > pSpecScale[0]) {
+              pSpecScale[0] = pSpecScale[i];
+            }
+          }
+
+          CConcealment_InterpolateBuffer(
+              pSpectralCoefficient, /* spec_(n-1) */
+              &pConcealmentInfo->specScale[0], &pSpecScale[0], &specScaleOut,
+              sfbEnergyPrev, sfbEnergyAct, scaleFactorBandsTotal, pSfbOffset);
+
+          pSpecScale[0] = specScaleOut;
+        }
+      } else {
+        /* long--??????--short, long--??????--long interpolation */
+        /* long---long---short, long---long---long interpolation */
+
+        int scaleFactorBandsTotal =
+            pSamplingRateInfo->NumberOfScaleFactorBands_Long;
+        const SHORT *pSfbOffset = pSamplingRateInfo->ScaleFactorBands_Long;
+        SHORT specScaleAct = pConcealmentInfo->specScale[0];
+
+        CConcealment_CalcBandEnergy(pSpectralCoefficient, /* spec_(n-2) */
+                                    pSamplingRateInfo, BLOCK_LONG,
+                                    CConcealment_NoExpand, sfbEnergyPrev);
+
+        if (pConcealmentInfo->windowSequence ==
+            BLOCK_SHORT) { /* f_n == BLOCK_SHORT */
+          /* long---long---short interpolation */
+
+          pIcsInfo->WindowShape = (samplesPerFrame <= 512) ? 2 : 1;
+          pIcsInfo->WindowSequence = BLOCK_START;
+
+          for (i = 1; i < 8; i++) { /* search for max(specScale) */
+            if (pConcealmentInfo->specScale[i] > specScaleAct) {
+              specScaleAct = pConcealmentInfo->specScale[i];
+            }
+          }
+
+          /* Expand first short spectrum */
+          CConcealment_CalcBandEnergy(
+              pConcealmentInfo->spectralCoefficient,               /* spec_n */
+              pSamplingRateInfo, BLOCK_SHORT, CConcealment_Expand, /* !!! */
+              sfbEnergyAct);
+        } else {
+          /* long---long---long interpolation */
+
+          pIcsInfo->WindowShape = 0;
+          pIcsInfo->WindowSequence = BLOCK_LONG;
+
+          CConcealment_CalcBandEnergy(
+              pConcealmentInfo->spectralCoefficient, /* spec_n */
+              pSamplingRateInfo, BLOCK_LONG, CConcealment_NoExpand,
+              sfbEnergyAct);
+        }
+
+        CConcealment_InterpolateBuffer(
+            pSpectralCoefficient, /* spec_(n-1) */
+            &pSpecScale[0], &specScaleAct, &pSpecScale[0], sfbEnergyPrev,
+            sfbEnergyAct, scaleFactorBandsTotal, pSfbOffset);
+      }
+    }
+
+    /* Noise substitution of sign of the output spectral coefficients */
+    CConcealment_ApplyRandomSign(pConcealmentInfo->iRandomPhase,
+                                 pSpectralCoefficient, samplesPerFrame);
+    /* Increment random phase index to avoid repetition artifacts. */
+    pConcealmentInfo->iRandomPhase =
+        (pConcealmentInfo->iRandomPhase + 1) & (AAC_NF_NO_RANDOM_VAL - 1);
+  }
+
+  /* scale spectrum according to concealment state */
+  switch (pConcealmentInfo->concealState) {
+    case ConcealState_Single:
+      appliedProcessing = 1;
+      break;
+
+    case ConcealState_FadeOut: {
+      FDK_ASSERT(pConcealmentInfo->cntFadeFrames >= 0);
+      FDK_ASSERT(pConcealmentInfo->cntFadeFrames <
+                 CONCEAL_MAX_NUM_FADE_FACTORS);
+      FDK_ASSERT(pConcealmentInfo->cntFadeFrames <
+                 pConcealCommonData->numFadeOutFrames);
+
+      /* TimeDomainFading:                                        */
+      /* Attenuation of signal is done in CConcealment_TDFading() */
+
+      appliedProcessing = 1;
+    } break;
+
+    case ConcealState_FadeIn: {
+      FDK_ASSERT(pConcealmentInfo->cntFadeFrames >= 0);
+      FDK_ASSERT(pConcealmentInfo->cntFadeFrames <
+                 CONCEAL_MAX_NUM_FADE_FACTORS);
+      FDK_ASSERT(pConcealmentInfo->cntFadeFrames <
+                 pConcealCommonData->numFadeInFrames);
+
+      /* TimeDomainFading:                                        */
+      /* Attenuation of signal is done in CConcealment_TDFading() */
+
+      appliedProcessing = 1;
+    } break;
+
+    case ConcealState_Mute: {
+      /* set dummy window parameters */
+      pIcsInfo->Valid = 0; /* Trigger the generation of a consitent IcsInfo */
+      pIcsInfo->WindowShape =
+          pConcealmentInfo->windowShape; /* Prevent an invalid WindowShape
+                                            (required for F/T transform) */
+      pIcsInfo->WindowSequence =
+          CConcealment_GetWinSeq(pConcealmentInfo->windowSequence);
+      pConcealmentInfo->windowSequence =
+          pIcsInfo->WindowSequence; /* Store for next frame
+                                       (spectrum in concealment
+                                       buffer can't be used at
+                                       all) */
+
+      /* mute spectral data */
+      FDKmemclear(pSpectralCoefficient, samplesPerFrame * sizeof(FIXP_DBL));
+
+      appliedProcessing = 1;
+    } break;
+
+    default:
+      /* nothing to do here */
+      break;
+  }
+
+  return appliedProcessing;
+}
+
+/*!
+  \brief Calculate the spectral energy
+
+  The function calculates band-wise the spectral energy. This is used for
+  frame interpolation.
+*/
+static void CConcealment_CalcBandEnergy(
+    FIXP_DBL *spectrum, const SamplingRateInfo *pSamplingRateInfo,
+    const int blockType, CConcealmentExpandType expandType, int *sfbEnergy) {
+  const SHORT *pSfbOffset;
+  int line, sfb, scaleFactorBandsTotal = 0;
+
+  /* In the following calculations, enAccu is initialized with LSB-value in
+   * order to avoid zero energy-level */
+
+  line = 0;
+
+  switch (blockType) {
+    case BLOCK_LONG:
+    case BLOCK_START:
+    case BLOCK_STOP:
+
+      if (expandType == CConcealment_NoExpand) {
+        /* standard long calculation */
+        scaleFactorBandsTotal =
+            pSamplingRateInfo->NumberOfScaleFactorBands_Long;
+        pSfbOffset = pSamplingRateInfo->ScaleFactorBands_Long;
+
+        for (sfb = 0; sfb < scaleFactorBandsTotal; sfb++) {
+          FIXP_DBL enAccu = (FIXP_DBL)(LONG)1;
+          int sfbScale =
+              (sizeof(LONG) << 3) -
+              CntLeadingZeros(pSfbOffset[sfb + 1] - pSfbOffset[sfb]) - 1;
+          /* scaling depends on sfb width. */
+          for (; line < pSfbOffset[sfb + 1]; line++) {
+            enAccu += fPow2Div2(*(spectrum + line)) >> sfbScale;
+          }
+          *(sfbEnergy + sfb) = CntLeadingZeros(enAccu) - 1;
+        }
+      } else {
+        /* compress long to short */
+        scaleFactorBandsTotal =
+            pSamplingRateInfo->NumberOfScaleFactorBands_Short;
+        pSfbOffset = pSamplingRateInfo->ScaleFactorBands_Short;
+
+        for (sfb = 0; sfb < scaleFactorBandsTotal; sfb++) {
+          FIXP_DBL enAccu = (FIXP_DBL)(LONG)1;
+          int sfbScale =
+              (sizeof(LONG) << 3) -
+              CntLeadingZeros(pSfbOffset[sfb + 1] - pSfbOffset[sfb]) - 1;
+          /* scaling depends on sfb width. */
+          for (; line < pSfbOffset[sfb + 1] << 3; line++) {
+            enAccu +=
+                (enAccu + (fPow2Div2(*(spectrum + line)) >> sfbScale)) >> 3;
+          }
+          *(sfbEnergy + sfb) = CntLeadingZeros(enAccu) - 1;
+        }
+      }
+      break;
+
+    case BLOCK_SHORT:
+
+      if (expandType == CConcealment_NoExpand) {
+        /*   standard short calculation */
+        scaleFactorBandsTotal =
+            pSamplingRateInfo->NumberOfScaleFactorBands_Short;
+        pSfbOffset = pSamplingRateInfo->ScaleFactorBands_Short;
+
+        for (sfb = 0; sfb < scaleFactorBandsTotal; sfb++) {
+          FIXP_DBL enAccu = (FIXP_DBL)(LONG)1;
+          int sfbScale =
+              (sizeof(LONG) << 3) -
+              CntLeadingZeros(pSfbOffset[sfb + 1] - pSfbOffset[sfb]) - 1;
+          /* scaling depends on sfb width. */
+          for (; line < pSfbOffset[sfb + 1]; line++) {
+            enAccu += fPow2Div2(*(spectrum + line)) >> sfbScale;
+          }
+          *(sfbEnergy + sfb) = CntLeadingZeros(enAccu) - 1;
+        }
+      } else {
+        /*  expand short to long spectrum */
+        scaleFactorBandsTotal =
+            pSamplingRateInfo->NumberOfScaleFactorBands_Long;
+        pSfbOffset = pSamplingRateInfo->ScaleFactorBands_Long;
+
+        for (sfb = 0; sfb < scaleFactorBandsTotal; sfb++) {
+          FIXP_DBL enAccu = (FIXP_DBL)(LONG)1;
+          int sfbScale =
+              (sizeof(LONG) << 3) -
+              CntLeadingZeros(pSfbOffset[sfb + 1] - pSfbOffset[sfb]) - 1;
+          /* scaling depends on sfb width. */
+          for (; line < pSfbOffset[sfb + 1]; line++) {
+            enAccu += fPow2Div2(*(spectrum + (line >> 3))) >> sfbScale;
+          }
+          *(sfbEnergy + sfb) = CntLeadingZeros(enAccu) - 1;
+        }
+      }
+      break;
+  }
+}
+
+/*!
+  \brief Interpolate buffer
+
+  The function creates the interpolated spectral data according to the
+  energy of the last good frame and the current (good) frame.
+*/
+static void CConcealment_InterpolateBuffer(FIXP_DBL *spectrum,
+                                           SHORT *pSpecScalePrv,
+                                           SHORT *pSpecScaleAct,
+                                           SHORT *pSpecScaleOut, int *enPrv,
+                                           int *enAct, int sfbCnt,
+                                           const SHORT *pSfbOffset) {
+  int sfb, line = 0;
+  int fac_shift;
+  int fac_mod;
+  FIXP_DBL accu;
+
+  for (sfb = 0; sfb < sfbCnt; sfb++) {
+    fac_shift =
+        enPrv[sfb] - enAct[sfb] + ((*pSpecScaleAct - *pSpecScalePrv) << 1);
+    fac_mod = fac_shift & 3;
+    fac_shift = (fac_shift >> 2) + 1;
+    fac_shift += *pSpecScalePrv - fixMax(*pSpecScalePrv, *pSpecScaleAct);
+
+    for (; line < pSfbOffset[sfb + 1]; line++) {
+      accu = fMult(*(spectrum + line), facMod4Table[fac_mod]);
+      if (fac_shift < 0) {
+        accu >>= -fac_shift;
+      } else {
+        accu <<= fac_shift;
+      }
+      *(spectrum + line) = accu;
+    }
+  }
+  *pSpecScaleOut = fixMax(*pSpecScalePrv, *pSpecScaleAct);
+}
+
+/*!
+  \brief Find next fading frame in case of changing fading direction
+
+  \param pConcealCommonData Pointer to the concealment common data structure.
+  \param actFadeIndex Last index used for fading
+  \param direction Direction of change: 0 : change from FADE-OUT to FADE-IN,  1
+  : change from FADE-IN to FADE-OUT
+
+  This function determines the next fading index to be used for the fading
+  direction to be changed to.
+*/
+
+static INT findEquiFadeFrame(CConcealParams *pConcealCommonData,
+                             INT actFadeIndex, int direction) {
+  FIXP_SGL *pFactor;
+  FIXP_SGL referenceVal;
+  FIXP_SGL minDiff = (FIXP_SGL)MAXVAL_SGL;
+
+  INT nextFadeIndex = 0;
+
+  int i;
+
+  /* init depending on direction */
+  if (direction == 0) { /* FADE-OUT => FADE-IN */
+    if (actFadeIndex < 0) {
+      referenceVal = (FIXP_SGL)MAXVAL_SGL;
+    } else {
+      referenceVal = pConcealCommonData->fadeOutFactor[actFadeIndex] >> 1;
+    }
+    pFactor = pConcealCommonData->fadeInFactor;
+  } else { /* FADE-IN => FADE-OUT */
+    if (actFadeIndex < 0) {
+      referenceVal = (FIXP_SGL)MAXVAL_SGL;
+    } else {
+      referenceVal = pConcealCommonData->fadeInFactor[actFadeIndex] >> 1;
+    }
+    pFactor = pConcealCommonData->fadeOutFactor;
+  }
+
+  /* search for minimum difference */
+  for (i = 0; i < CONCEAL_MAX_NUM_FADE_FACTORS; i++) {
+    FIXP_SGL diff = fixp_abs((pFactor[i] >> 1) - referenceVal);
+    if (diff < minDiff) {
+      minDiff = diff;
+      nextFadeIndex = i;
+    }
+  }
+
+  /* check and adjust depending on direction */
+  if (direction == 0) { /* FADE-OUT => FADE-IN */
+    if (nextFadeIndex > pConcealCommonData->numFadeInFrames) {
+      nextFadeIndex = fMax(pConcealCommonData->numFadeInFrames - 1, 0);
+    }
+    if (((pFactor[nextFadeIndex] >> 1) <= referenceVal) &&
+        (nextFadeIndex > 0)) {
+      nextFadeIndex -= 1;
+    }
+  } else { /* FADE-IN => FADE-OUT */
+    if (((pFactor[nextFadeIndex] >> 1) >= referenceVal) &&
+        (nextFadeIndex < CONCEAL_MAX_NUM_FADE_FACTORS - 1)) {
+      nextFadeIndex += 1;
+    }
+  }
+
+  return (nextFadeIndex);
+}
+
+/*!
+  \brief Update the concealment state
+
+  The function updates the state of the concealment state-machine. The
+  states are: mute, fade-in, fade-out, interpolate and frame-ok.
+*/
+static void CConcealment_UpdateState(
+    CConcealmentInfo *pConcealmentInfo, int frameOk,
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
+    const int samplesPerFrame, CAacDecoderChannelInfo *pAacDecoderChannelInfo) {
+  CConcealParams *pConcealCommonData = pConcealmentInfo->pConcealParams;
+
+  switch (pConcealCommonData->method) {
+    case ConcealMethodNoise: {
+      if (pConcealmentInfo->concealState != ConcealState_Ok) {
+        /* count the valid frames during concealment process */
+        if (frameOk) {
+          pConcealmentInfo->cntValidFrames += 1;
+        } else {
+          pConcealmentInfo->cntValidFrames = 0;
+        }
+      }
+
+      /* -- STATE MACHINE for Noise Substitution -- */
+      switch (pConcealmentInfo->concealState) {
+        case ConcealState_Ok:
+          if (!frameOk) {
+            pConcealmentInfo->cntFadeFrames = 0;
+            pConcealmentInfo->cntValidFrames = 0;
+            pConcealmentInfo->attGrpOffset[0] = 0;
+            pConcealmentInfo->attGrpOffset[1] = 0;
+            pConcealmentInfo->winGrpOffset[0] = 0;
+            pConcealmentInfo->winGrpOffset[1] = 0;
+            if (pConcealCommonData->numFadeOutFrames > 0) {
+              /* change to state SINGLE-FRAME-LOSS */
+              pConcealmentInfo->concealState = ConcealState_Single;
+              /* mode 0 just updates the Fading counter */
+              CConcealment_ApplyFadeOut(
+                  /*mode =*/0, pConcealmentInfo, pAacDecoderStaticChannelInfo,
+                  samplesPerFrame, pAacDecoderChannelInfo);
+
+            } else {
+              /* change to state MUTE */
+              pConcealmentInfo->concealState = ConcealState_Mute;
+            }
+          }
+          break;
+
+        case ConcealState_Single: /* Just a pre-stage before fade-out begins.
+                                     Stay here only one frame! */
+          if (frameOk) {
+            /* change to state OK */
+            pConcealmentInfo->concealState = ConcealState_Ok;
+          } else {
+            if (pConcealmentInfo->cntFadeFrames >=
+                pConcealCommonData->numFadeOutFrames) {
+              /* change to state MUTE */
+              pConcealmentInfo->concealState = ConcealState_Mute;
+            } else {
+              /* change to state FADE-OUT */
+              pConcealmentInfo->concealState = ConcealState_FadeOut;
+              /* mode 0 just updates the Fading counter */
+              CConcealment_ApplyFadeOut(
+                  /*mode =*/0, pConcealmentInfo, pAacDecoderStaticChannelInfo,
+                  samplesPerFrame, pAacDecoderChannelInfo);
+            }
+          }
+          break;
+
+        case ConcealState_FadeOut:
+          if (pConcealmentInfo->cntValidFrames >
+              pConcealCommonData->numMuteReleaseFrames) {
+            if (pConcealCommonData->numFadeInFrames > 0) {
+              /* change to state FADE-IN */
+              pConcealmentInfo->concealState = ConcealState_FadeIn;
+              pConcealmentInfo->cntFadeFrames = findEquiFadeFrame(
+                  pConcealCommonData, pConcealmentInfo->cntFadeFrames,
+                  0 /* FadeOut -> FadeIn */);
+            } else {
+              /* change to state OK */
+              pConcealmentInfo->concealState = ConcealState_Ok;
+            }
+          } else {
+            if (frameOk) {
+              /* we have good frame information but stay fully in concealment -
+               * reset winGrpOffset/attGrpOffset */
+              pConcealmentInfo->winGrpOffset[0] = 0;
+              pConcealmentInfo->winGrpOffset[1] = 0;
+              pConcealmentInfo->attGrpOffset[0] = 0;
+              pConcealmentInfo->attGrpOffset[1] = 0;
+            }
+            if (pConcealmentInfo->cntFadeFrames >=
+                pConcealCommonData->numFadeOutFrames) {
+              /* change to state MUTE */
+              pConcealmentInfo->concealState = ConcealState_Mute;
+            } else /* Stay in FADE-OUT */
+            {
+              /* mode 0 just updates the Fading counter */
+              CConcealment_ApplyFadeOut(
+                  /*mode =*/0, pConcealmentInfo, pAacDecoderStaticChannelInfo,
+                  samplesPerFrame, pAacDecoderChannelInfo);
+            }
+          }
+          break;
+
+        case ConcealState_Mute:
+          if (pConcealmentInfo->cntValidFrames >
+              pConcealCommonData->numMuteReleaseFrames) {
+            if (pConcealCommonData->numFadeInFrames > 0) {
+              /* change to state FADE-IN */
+              pConcealmentInfo->concealState = ConcealState_FadeIn;
+              pConcealmentInfo->cntFadeFrames =
+                  pConcealCommonData->numFadeInFrames - 1;
+            } else {
+              /* change to state OK */
+              pConcealmentInfo->concealState = ConcealState_Ok;
+            }
+          } else {
+            if (frameOk) {
+              /* we have good frame information but stay fully in concealment -
+               * reset winGrpOffset/attGrpOffset */
+              pConcealmentInfo->winGrpOffset[0] = 0;
+              pConcealmentInfo->winGrpOffset[1] = 0;
+              pConcealmentInfo->attGrpOffset[0] = 0;
+              pConcealmentInfo->attGrpOffset[1] = 0;
+            }
+          }
+          break;
+
+        case ConcealState_FadeIn:
+          pConcealmentInfo->cntFadeFrames -= 1;
+          if (frameOk) {
+            if (pConcealmentInfo->cntFadeFrames < 0) {
+              /* change to state OK */
+              pConcealmentInfo->concealState = ConcealState_Ok;
+            }
+          } else {
+            if (pConcealCommonData->numFadeOutFrames > 0) {
+              /* change to state FADE-OUT */
+              pConcealmentInfo->concealState = ConcealState_FadeOut;
+              pConcealmentInfo->cntFadeFrames = findEquiFadeFrame(
+                  pConcealCommonData, pConcealmentInfo->cntFadeFrames + 1,
+                  1 /* FadeIn -> FadeOut */);
+              pConcealmentInfo->winGrpOffset[0] = 0;
+              pConcealmentInfo->winGrpOffset[1] = 0;
+              pConcealmentInfo->attGrpOffset[0] = 0;
+              pConcealmentInfo->attGrpOffset[1] = 0;
+
+              pConcealmentInfo
+                  ->cntFadeFrames--; /* decrease because
+                                        CConcealment_ApplyFadeOut() will
+                                        increase, accordingly */
+              /* mode 0 just updates the Fading counter */
+              CConcealment_ApplyFadeOut(
+                  /*mode =*/0, pConcealmentInfo, pAacDecoderStaticChannelInfo,
+                  samplesPerFrame, pAacDecoderChannelInfo);
+            } else {
+              /* change to state MUTE */
+              pConcealmentInfo->concealState = ConcealState_Mute;
+            }
+          }
+          break;
+
+        default:
+          FDK_ASSERT(0);
+          break;
+      }
+    } break;
+
+    case ConcealMethodInter:
+    case ConcealMethodTonal: {
+      if (pConcealmentInfo->concealState != ConcealState_Ok) {
+        /* count the valid frames during concealment process */
+        if (pConcealmentInfo->prevFrameOk[1] ||
+            (pConcealmentInfo->prevFrameOk[0] &&
+             !pConcealmentInfo->prevFrameOk[1] && frameOk)) {
+          /* The frame is OK even if it can be estimated by the energy
+           * interpolation algorithm */
+          pConcealmentInfo->cntValidFrames += 1;
+        } else {
+          pConcealmentInfo->cntValidFrames = 0;
+        }
+      }
+
+      /* -- STATE MACHINE for energy interpolation -- */
+      switch (pConcealmentInfo->concealState) {
+        case ConcealState_Ok:
+          if (!(pConcealmentInfo->prevFrameOk[1] ||
+                (pConcealmentInfo->prevFrameOk[0] &&
+                 !pConcealmentInfo->prevFrameOk[1] && frameOk))) {
+            if (pConcealCommonData->numFadeOutFrames > 0) {
+              /* Fade out only if the energy interpolation algorithm can not be
+               * applied! */
+              pConcealmentInfo->concealState = ConcealState_FadeOut;
+            } else {
+              /* change to state MUTE */
+              pConcealmentInfo->concealState = ConcealState_Mute;
+            }
+            pConcealmentInfo->cntFadeFrames = 0;
+            pConcealmentInfo->cntValidFrames = 0;
+          }
+          break;
+
+        case ConcealState_Single:
+          pConcealmentInfo->concealState = ConcealState_Ok;
+          break;
+
+        case ConcealState_FadeOut:
+          pConcealmentInfo->cntFadeFrames += 1;
+
+          if (pConcealmentInfo->cntValidFrames >
+              pConcealCommonData->numMuteReleaseFrames) {
+            if (pConcealCommonData->numFadeInFrames > 0) {
+              /* change to state FADE-IN */
+              pConcealmentInfo->concealState = ConcealState_FadeIn;
+              pConcealmentInfo->cntFadeFrames = findEquiFadeFrame(
+                  pConcealCommonData, pConcealmentInfo->cntFadeFrames - 1,
+                  0 /* FadeOut -> FadeIn */);
+            } else {
+              /* change to state OK */
+              pConcealmentInfo->concealState = ConcealState_Ok;
+            }
+          } else {
+            if (pConcealmentInfo->cntFadeFrames >=
+                pConcealCommonData->numFadeOutFrames) {
+              /* change to state MUTE */
+              pConcealmentInfo->concealState = ConcealState_Mute;
+            }
+          }
+          break;
+
+        case ConcealState_Mute:
+          if (pConcealmentInfo->cntValidFrames >
+              pConcealCommonData->numMuteReleaseFrames) {
+            if (pConcealCommonData->numFadeInFrames > 0) {
+              /* change to state FADE-IN */
+              pConcealmentInfo->concealState = ConcealState_FadeIn;
+              pConcealmentInfo->cntFadeFrames =
+                  pConcealCommonData->numFadeInFrames - 1;
+            } else {
+              /* change to state OK */
+              pConcealmentInfo->concealState = ConcealState_Ok;
+            }
+          }
+          break;
+
+        case ConcealState_FadeIn:
+          pConcealmentInfo->cntFadeFrames -=
+              1; /* used to address the fade-in factors */
+
+          if (frameOk || pConcealmentInfo->prevFrameOk[1]) {
+            if (pConcealmentInfo->cntFadeFrames < 0) {
+              /* change to state OK */
+              pConcealmentInfo->concealState = ConcealState_Ok;
+            }
+          } else {
+            if (pConcealCommonData->numFadeOutFrames > 0) {
+              /* change to state FADE-OUT */
+              pConcealmentInfo->concealState = ConcealState_FadeOut;
+              pConcealmentInfo->cntFadeFrames = findEquiFadeFrame(
+                  pConcealCommonData, pConcealmentInfo->cntFadeFrames + 1,
+                  1 /* FadeIn -> FadeOut */);
+            } else {
+              /* change to state MUTE */
+              pConcealmentInfo->concealState = ConcealState_Mute;
+            }
+          }
+          break;
+      } /* End switch(pConcealmentInfo->concealState) */
+    } break;
+
+    default:
+      /* Don't need a state machine for other concealment methods. */
+      break;
+  }
+}
+
+/*!
+\brief Randomizes the sign of the spectral data
+
+  The function toggles the sign of the spectral data randomly. This is
+  useful to ensure the quality of the concealed frames.
+ */
+static void CConcealment_ApplyRandomSign(int randomPhase, FIXP_DBL *spec,
+                                         int samplesPerFrame) {
+  int i;
+  USHORT packedSign = 0;
+
+  /* random table 512x16bit has been reduced to 512 packed sign bits = 32x16 bit
+   */
+
+  /* read current packed sign word */
+  packedSign = AacDec_randomSign[randomPhase >> 4];
+  packedSign >>= (randomPhase & 0xf);
+
+  for (i = 0; i < samplesPerFrame; i++) {
+    if ((randomPhase & 0xf) == 0) {
+      packedSign = AacDec_randomSign[randomPhase >> 4];
+    }
+
+    if (packedSign & 0x1) {
+      spec[i] = -spec[i];
+    }
+    packedSign >>= 1;
+
+    randomPhase = (randomPhase + 1) & (AAC_NF_NO_RANDOM_VAL - 1);
+  }
+}
+
+/*!
+  \brief Get fadeing factor for current concealment state.
+
+  The function returns the state (ok or not) of the previous frame.
+  If called before the function CConcealment_Apply() set the fBeforeApply
+  flag to get the correct value.
+
+  \return Frame OK flag of previous frame.
+ */
+int CConcealment_GetLastFrameOk(CConcealmentInfo *hConcealmentInfo,
+                                const int fBeforeApply) {
+  int prevFrameOk = 1;
+
+  if (hConcealmentInfo != NULL) {
+    prevFrameOk = hConcealmentInfo->prevFrameOk[fBeforeApply & 0x1];
+  }
+
+  return prevFrameOk;
+}
+
+/*!
+  \brief Get the number of delay frames introduced by concealment technique.
+
+  \return Number of delay frames.
+ */
+UINT CConcealment_GetDelay(CConcealParams *pConcealCommonData) {
+  UINT frameDelay = 0;
+
+  if (pConcealCommonData != NULL) {
+    switch (pConcealCommonData->method) {
+      case ConcealMethodTonal:
+      case ConcealMethodInter:
+        frameDelay = 1;
+        break;
+      default:
+        break;
+    }
+  }
+
+  return frameDelay;
+}
+
+static int CConcealment_ApplyFadeOut(
+    int mode, CConcealmentInfo *pConcealmentInfo,
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
+    const int samplesPerFrame, CAacDecoderChannelInfo *pAacDecoderChannelInfo) {
+  /* mode 1 = apply RandomSign and mute spectral coefficients if necessary,  *
+   * mode 0 = Update cntFadeFrames                                            */
+
+  /* restore frequency coefficients from buffer with a specific muting */
+  int srcWin, dstWin, numWindows = 1;
+  int windowLen = samplesPerFrame;
+  int srcGrpStart = 0;
+  int winIdxStride = 1;
+  int numWinGrpPerFac, attIdx, attIdxStride;
+  int i;
+  int appliedProcessing = 0;
+
+  CIcsInfo *pIcsInfo = &pAacDecoderChannelInfo->icsInfo;
+  FIXP_DBL *pSpectralCoefficient =
+      SPEC_LONG(pAacDecoderChannelInfo->pSpectralCoefficient);
+  SHORT *pSpecScale = pAacDecoderChannelInfo->specScale;
+
+  /* set old window parameters */
+  if (pConcealmentInfo->lastRenderMode == AACDEC_RENDER_LPD) {
+    switch (pAacDecoderStaticChannelInfo->last_lpd_mode) {
+      case 1:
+        numWindows = 4;
+        srcGrpStart = 3;
+        windowLen = samplesPerFrame >> 2;
+        break;
+      case 2:
+        numWindows = 2;
+        srcGrpStart = 1;
+        windowLen = samplesPerFrame >> 1;
+        winIdxStride = 2;
+        break;
+      case 3:
+        numWindows = 1;
+        srcGrpStart = 0;
+        windowLen = samplesPerFrame;
+        winIdxStride = 4;
+        break;
+    }
+    pConcealmentInfo->lastWinGrpLen = 1;
+  } else {
+    pIcsInfo->WindowShape = pConcealmentInfo->windowShape;
+    pIcsInfo->WindowSequence = pConcealmentInfo->windowSequence;
+
+    if (pConcealmentInfo->windowSequence == BLOCK_SHORT) {
+      /* short block handling */
+      numWindows = 8;
+      windowLen = samplesPerFrame >> 3;
+      srcGrpStart = numWindows - pConcealmentInfo->lastWinGrpLen;
+    }
+  }
+
+  attIdxStride =
+      fMax(1, (int)(numWindows / (pConcealmentInfo->lastWinGrpLen + 1)));
+
+  /* load last state */
+  attIdx = pConcealmentInfo->cntFadeFrames;
+  numWinGrpPerFac = pConcealmentInfo->attGrpOffset[mode];
+  srcWin = srcGrpStart + pConcealmentInfo->winGrpOffset[mode];
+
+  FDK_ASSERT((srcGrpStart * windowLen + windowLen) <= samplesPerFrame);
+  FDK_ASSERT((srcWin * windowLen + windowLen) <= 1024);
+
+  for (dstWin = 0; dstWin < numWindows; dstWin += 1) {
+    FIXP_CNCL *pCncl =
+        pConcealmentInfo->spectralCoefficient + (srcWin * windowLen);
+    FIXP_DBL *pOut = pSpectralCoefficient + (dstWin * windowLen);
+
+    if (mode == 1) {
+      /* mute if attIdx gets large enaugh */
+      if (attIdx > pConcealmentInfo->pConcealParams->numFadeOutFrames) {
+        FDKmemclear(pCncl, sizeof(FIXP_DBL) * windowLen);
+      }
+
+      /* restore frequency coefficients from buffer - attenuation is done later
+       */
+      for (i = 0; i < windowLen; i++) {
+        pOut[i] = pCncl[i];
+      }
+
+      /* apply random change of sign for spectral coefficients */
+      CConcealment_ApplyRandomSign(pConcealmentInfo->iRandomPhase, pOut,
+                                   windowLen);
+
+      /* Increment random phase index to avoid repetition artifacts. */
+      pConcealmentInfo->iRandomPhase =
+          (pConcealmentInfo->iRandomPhase + 1) & (AAC_NF_NO_RANDOM_VAL - 1);
+
+      /* set old scale factors */
+      pSpecScale[dstWin * winIdxStride] =
+          pConcealmentInfo->specScale[srcWin * winIdxStride];
+    }
+
+    srcWin += 1;
+
+    if (srcWin >= numWindows) {
+      /* end of sequence -> rewind to first window of group */
+      srcWin = srcGrpStart;
+      numWinGrpPerFac += 1;
+      if (numWinGrpPerFac >= attIdxStride) {
+        numWinGrpPerFac = 0;
+        attIdx += 1;
+      }
+    }
+  }
+
+  /* store current state */
+
+  pConcealmentInfo->winGrpOffset[mode] = srcWin - srcGrpStart;
+  FDK_ASSERT((pConcealmentInfo->winGrpOffset[mode] >= 0) &&
+             (pConcealmentInfo->winGrpOffset[mode] < 8));
+  pConcealmentInfo->attGrpOffset[mode] = numWinGrpPerFac;
+  FDK_ASSERT((pConcealmentInfo->attGrpOffset[mode] >= 0) &&
+             (pConcealmentInfo->attGrpOffset[mode] < attIdxStride));
+
+  if (mode == 0) {
+    pConcealmentInfo->cntFadeFrames = attIdx;
+  }
+
+  appliedProcessing = 1;
+
+  return appliedProcessing;
+}
+
+/*!
+  \brief Do Time domain fading (TDFading) in concealment case
+
+  In case of concealment, this function takes care of the fading, after time
+domain signal has been rendered by the respective signal rendering functions.
+  The fading out in case of ACELP decoding is not done by this function but by
+the ACELP decoder for the first concealed frame if CONCEAL_CORE_IGNORANT_FADE is
+not set.
+
+  TimeDomain fading never creates jumps in energy / discontinuities, it always
+does a continuous fading. To achieve this, fading is always done from a starting
+point to a target point, while the starting point is always determined to be the
+last target point. By varying the target point of a fading, the fading slope can
+be controlled.
+
+  This principle is applied to the fading within a frame and the fading from
+frame to frame.
+
+  One frame is divided into 8 subframes to obtain 8 parts of fading slopes
+within a frame, each maybe with its own gradient.
+
+  Workflow:
+  1.) Determine Fading behavior and end-of-frame target fading level, based on
+concealmentState (determined by CConcealment_UpdateState()) and the core mode.
+        - By _DEFAULT_,
+          The target fading level is determined by fadeOutFactor[cntFadeFrames]
+in case of fadeOut, or fadeInFactor[cntFadeFrames] in case of fadeIn.
+          --> fading type is FADE_TIMEDOMAIN in this case. Target fading level
+is determined by fading index cntFadeFrames.
+
+        - If concealmentState is signalling a _MUTED SIGNAL_,
+          TDFading decays to 0 within 1/8th of a frame if numFadeOutFrames == 0.
+          --> fading type is FADE_TIMEDOMAIN_TOSPECTRALMUTE in this case.
+
+        - If concealmentState is signalling the _END OF MUTING_,
+          TDFading fades to target fading level within 1/8th of a frame if
+numFadeInFrames == 0.
+          --> fading type is FADE_TIMEDOMAIN_FROMSPECTRALMUTE in this case.
+Target fading level is determined by fading index cntFadeFrames.
+
+#ifndef CONCEAL_CORE_IGNORANT_FADE
+        - In case of an _ACELP FADEOUT_,
+          TDFading leaves fading control to ACELP decoder for 1/2 frame.
+          --> fading type is FADE_ACELPDOMAIN in this case.
+#endif
+
+  2.) Render fading levels within current frame and do the final fading:
+      Map Fading slopes to fading levels and apply to time domain signal.
+
+
+*/
+
+INT CConcealment_TDFading(
+    int len, CAacDecoderStaticChannelInfo **ppAacDecoderStaticChannelInfo,
+    FIXP_PCM *pcmdata, FIXP_PCM *pcmdata_1) {
+  /*
+  Do the fading in Time domain based on concealment states and core mode
+  */
+  FIXP_DBL fadeStop, attMute = (FIXP_DBL)0;
+  int idx = 0, ii;
+  CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo =
+      *ppAacDecoderStaticChannelInfo;
+  CConcealmentInfo *pConcealmentInfo =
+      &pAacDecoderStaticChannelInfo->concealmentInfo;
+  CConcealParams *pConcealParams = pConcealmentInfo->pConcealParams;
+  const CConcealmentState concealState = pConcealmentInfo->concealState;
+  TDfadingType fadingType;
+  FIXP_DBL fadingStations[9] = {0};
+  int fadingSteps[8] = {0};
+  const FIXP_DBL fadeStart =
+      pConcealmentInfo
+          ->fade_old; /* start fading at last end-of-frame attenuation */
+  FIXP_SGL *fadeFactor = pConcealParams->fadeOutFactor;
+  const INT cntFadeFrames = pConcealmentInfo->cntFadeFrames;
+  int TDFadeOutStopBeforeMute = 1;
+  int TDFadeInStopBeforeFullLevel = 1;
+
+  /*
+  determine Fading behaviour (end-of-frame attenuation and fading type) (1.)
+  */
+
+  switch (concealState) {
+    case ConcealState_Single:
+    case ConcealState_Mute:
+    case ConcealState_FadeOut:
+      idx = (pConcealParams->method == ConcealMethodNoise) ? cntFadeFrames - 1
+                                                           : cntFadeFrames;
+      fadingType = FADE_TIMEDOMAIN;
+
+      if (concealState == ConcealState_Mute ||
+          (cntFadeFrames + TDFadeOutStopBeforeMute) >
+              pConcealmentInfo->pConcealParams->numFadeOutFrames) {
+        fadingType = FADE_TIMEDOMAIN_TOSPECTRALMUTE;
+      }
+
+      break;
+    case ConcealState_FadeIn:
+      idx = cntFadeFrames;
+      idx -= TDFadeInStopBeforeFullLevel;
+      FDK_FALLTHROUGH;
+    case ConcealState_Ok:
+      fadeFactor = pConcealParams->fadeInFactor;
+      idx = (concealState == ConcealState_Ok) ? -1 : idx;
+      fadingType = (pConcealmentInfo->concealState_old == ConcealState_Mute)
+                       ? FADE_TIMEDOMAIN_FROMSPECTRALMUTE
+                       : FADE_TIMEDOMAIN;
+      break;
+    default:
+      FDK_ASSERT(0);
+      fadingType = FADE_TIMEDOMAIN_TOSPECTRALMUTE;
+      break;
+  }
+
+  /* determine Target end-of-frame fading level and fading slope */
+  switch (fadingType) {
+    case FADE_TIMEDOMAIN_FROMSPECTRALMUTE:
+      fadeStop =
+          (idx < 0) ? (FIXP_DBL)MAXVAL_DBL : FX_SGL2FX_DBL(fadeFactor[idx]);
+      if (pConcealmentInfo->pConcealParams->numFadeInFrames == 0) {
+        /* do step as fast as possible */
+        fadingSteps[0] = 1;
+        break;
+      }
+      CConcealment_TDFading_doLinearFadingSteps(&fadingSteps[0]);
+      break;
+    case FADE_TIMEDOMAIN:
+      fadeStop =
+          (idx < 0) ? (FIXP_DBL)MAXVAL_DBL : FX_SGL2FX_DBL(fadeFactor[idx]);
+      CConcealment_TDFading_doLinearFadingSteps(&fadingSteps[0]);
+      break;
+    case FADE_TIMEDOMAIN_TOSPECTRALMUTE:
+      fadeStop = attMute;
+      if (pConcealmentInfo->pConcealParams->numFadeOutFrames == 0) {
+        /* do step as fast as possible */
+        fadingSteps[0] = 1;
+        break;
+      }
+      CConcealment_TDFading_doLinearFadingSteps(&fadingSteps[0]);
+      break;
+  }
+
+  /*
+  Render fading levels within current frame and do the final fading (2.)
+  */
+
+  len >>= 3;
+  CConcealment_TDFadeFillFadingStations(fadingStations, fadingSteps, fadeStop,
+                                        fadeStart, fadingType);
+
+  if ((fadingStations[8] != (FIXP_DBL)MAXVAL_DBL) ||
+      (fadingStations[7] != (FIXP_DBL)MAXVAL_DBL) ||
+      (fadingStations[6] != (FIXP_DBL)MAXVAL_DBL) ||
+      (fadingStations[5] != (FIXP_DBL)MAXVAL_DBL) ||
+      (fadingStations[4] != (FIXP_DBL)MAXVAL_DBL) ||
+      (fadingStations[3] != (FIXP_DBL)MAXVAL_DBL) ||
+      (fadingStations[2] != (FIXP_DBL)MAXVAL_DBL) ||
+      (fadingStations[1] != (FIXP_DBL)MAXVAL_DBL) ||
+      (fadingStations[0] !=
+       (FIXP_DBL)MAXVAL_DBL)) /* if there's something to fade */
+  {
+    int start = 0;
+    for (ii = 0; ii < 8; ii++) {
+      CConcealment_TDFadePcmAtt(start, len, fadingStations[ii],
+                                fadingStations[ii + 1], pcmdata);
+      start += len;
+    }
+  }
+  CConcealment_TDNoise_Apply(pConcealmentInfo, len, pcmdata);
+
+  /* Save end-of-frame attenuation and fading type */
+  pConcealmentInfo->lastFadingType = fadingType;
+  pConcealmentInfo->fade_old = fadeStop;
+  pConcealmentInfo->concealState_old = concealState;
+
+  return 1;
+}
+
+/* attenuate pcmdata in Time Domain Fading process */
+static void CConcealment_TDFadePcmAtt(int start, int len, FIXP_DBL fadeStart,
+                                      FIXP_DBL fadeStop, FIXP_PCM *pcmdata) {
+  int i;
+  FIXP_DBL dStep;
+  FIXP_DBL dGain;
+  FIXP_DBL dGain_apply;
+  int bitshift = (DFRACT_BITS - SAMPLE_BITS);
+
+  /* set start energy */
+  dGain = fadeStart;
+  /* determine energy steps from sample to sample */
+  dStep = (FIXP_DBL)((int)((fadeStart >> 1) - (fadeStop >> 1)) / len) << 1;
+
+  for (i = start; i < (start + len); i++) {
+    dGain -= dStep;
+    /* prevent gain from getting negative due to possible fixpoint inaccuracies
+     */
+    dGain_apply = fMax((FIXP_DBL)0, dGain);
+    /* finally, attenuate samples */
+    pcmdata[i] = (FIXP_PCM)((fMult(pcmdata[i], (dGain_apply))) >> bitshift);
+  }
+}
+
+/*
+\brief Fill FadingStations
+
+The fadingstations are the attenuation factors, being applied to its dedicated
+portions of pcm data. They are calculated using the fadingsteps. One fadingstep
+is the weighted contribution to the fading slope within its dedicated portion of
+pcm data.
+
+*Fadingsteps  :      0  0  0  1  0  1  2  0
+
+                  |<-  1 Frame pcm data ->|
+      fadeStart-->|__________             |
+                  ^  ^  ^  ^ \____        |
+ Attenuation  :   |  |  |  |  ^  ^\__     |
+                  |  |  |  |  |  |  ^\    |
+                  |  |  |  |  |  |  | \___|<-- fadeStop
+                  |  |  |  |  |  |  |  ^  ^
+                  |  |  |  |  |  |  |  |  |
+Fadingstations:  [0][1][2][3][4][5][6][7][8]
+
+(Fadingstations "[0]" is "[8] from previous frame", therefore its not meaningful
+to be edited)
+
+*/
+static void CConcealment_TDFadeFillFadingStations(FIXP_DBL *fadingStations,
+                                                  int *fadingSteps,
+                                                  FIXP_DBL fadeStop,
+                                                  FIXP_DBL fadeStart,
+                                                  TDfadingType fadingType) {
+  int i;
+  INT fadingSteps_sum = 0;
+  INT fadeDiff;
+
+  fadingSteps_sum = fadingSteps[0] + fadingSteps[1] + fadingSteps[2] +
+                    fadingSteps[3] + fadingSteps[4] + fadingSteps[5] +
+                    fadingSteps[6] + fadingSteps[7];
+  fadeDiff = ((INT)(fadeStop - fadeStart) / fMax(fadingSteps_sum, (INT)1));
+  fadingStations[0] = fadeStart;
+  for (i = 1; i < 8; i++) {
+    fadingStations[i] =
+        fadingStations[i - 1] + (FIXP_DBL)(fadeDiff * fadingSteps[i - 1]);
+  }
+  fadingStations[8] = fadeStop;
+}
+
+static void CConcealment_TDFading_doLinearFadingSteps(int *fadingSteps) {
+  fadingSteps[0] = fadingSteps[1] = fadingSteps[2] = fadingSteps[3] =
+      fadingSteps[4] = fadingSteps[5] = fadingSteps[6] = fadingSteps[7] = 1;
+}
+
+/* end of TimeDomainFading functions */
+
+/* derived from int UsacRandomSign() */
+static int CConcealment_TDNoise_Random(ULONG *seed) {
+  *seed = (ULONG)(((UINT64)(*seed) * 69069) + 5);
+  return (int)(*seed);
+}
+
+static void CConcealment_TDNoise_Apply(CConcealmentInfo *const pConcealmentInfo,
+                                       const int len, FIXP_PCM *const pcmdata) {
+  FIXP_PCM *states = pConcealmentInfo->TDNoiseStates;
+  FIXP_PCM noiseVal;
+  FIXP_DBL noiseValLong;
+  FIXP_SGL *coef = pConcealmentInfo->TDNoiseCoef;
+  FIXP_DBL TDNoiseAtt;
+  ULONG seed = pConcealmentInfo->TDNoiseSeed =
+      (ULONG)CConcealment_TDNoise_Random(&pConcealmentInfo->TDNoiseSeed) + 1;
+
+  TDNoiseAtt = pConcealmentInfo->pConcealParams->comfortNoiseLevel;
+
+  int ii;
+
+  if ((pConcealmentInfo->concealState != ConcealState_Ok ||
+       pConcealmentInfo->concealState_old != ConcealState_Ok) &&
+      TDNoiseAtt != (FIXP_DBL)0) {
+    for (ii = 0; ii < (len << 3); ii++) {
+      /* create filtered noise */
+      states[2] = states[1];
+      states[1] = states[0];
+      states[0] = ((FIXP_PCM)CConcealment_TDNoise_Random(&seed));
+      noiseValLong = fMult(states[0], coef[0]) + fMult(states[1], coef[1]) +
+                     fMult(states[2], coef[2]);
+      noiseVal = FX_DBL2FX_PCM(fMult(noiseValLong, TDNoiseAtt));
+
+      /* add filtered noise - check for clipping, before */
+      if (noiseVal > (FIXP_PCM)0 &&
+          pcmdata[ii] > (FIXP_PCM)MAXVAL_FIXP_PCM - noiseVal) {
+        noiseVal = noiseVal * (FIXP_PCM)-1;
+      } else if (noiseVal < (FIXP_PCM)0 &&
+                 pcmdata[ii] < (FIXP_PCM)MINVAL_FIXP_PCM - noiseVal) {
+        noiseVal = noiseVal * (FIXP_PCM)-1;
+      }
+
+      pcmdata[ii] += noiseVal;
+    }
+  }
+}