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, 1217 insertions, 0 deletions

diff --git a/fdk-aac/libAACdec/src/rvlc.cpp b/fdk-aac/libAACdec/src/rvlc.cpp
new file mode 100644
index 0000000..b7a9be1
--- /dev/null
+++ b/fdk-aac/libAACdec/src/rvlc.cpp
@@ -0,0 +1,1217 @@
+/* -----------------------------------------------------------------------------
+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):
+
+   Description:
+
+*******************************************************************************/
+
+/*!
+  \file
+  \brief  RVLC Decoder
+  \author Robert Weidner
+*/
+
+#include "rvlc.h"
+
+#include "block.h"
+
+#include "aac_rom.h"
+#include "rvlcbit.h"
+#include "rvlcconceal.h"
+#include "aacdec_hcr.h"
+
+/*---------------------------------------------------------------------------------------------
+     function:     rvlcInit
+
+     description:  init RVLC by data from channelinfo, which was decoded
+previously and set up pointers
+-----------------------------------------------------------------------------------------------
+        input:     - pointer rvlc structure
+                   - pointer channel info structure
+                   - pointer bitstream structure
+-----------------------------------------------------------------------------------------------
+        return:    -
+--------------------------------------------------------------------------------------------
+*/
+
+static void rvlcInit(CErRvlcInfo *pRvlc,
+                     CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+                     HANDLE_FDK_BITSTREAM bs) {
+  /* RVLC common initialization part 2 of 2 */
+  SHORT *pScfEsc = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfEsc;
+  SHORT *pScfFwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd;
+  SHORT *pScfBwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd;
+  SHORT *pScaleFactor = pAacDecoderChannelInfo->pDynData->aScaleFactor;
+  int bnds;
+
+  pAacDecoderChannelInfo->pDynData->specificTo.aac.rvlcIntensityUsed = 0;
+
+  pRvlc->numDecodedEscapeWordsEsc = 0;
+  pRvlc->numDecodedEscapeWordsFwd = 0;
+  pRvlc->numDecodedEscapeWordsBwd = 0;
+
+  pRvlc->intensity_used = 0;
+  pRvlc->errorLogRvlc = 0;
+
+  pRvlc->conceal_max = CONCEAL_MAX_INIT;
+  pRvlc->conceal_min = CONCEAL_MIN_INIT;
+
+  pRvlc->conceal_max_esc = CONCEAL_MAX_INIT;
+  pRvlc->conceal_min_esc = CONCEAL_MIN_INIT;
+
+  pRvlc->pHuffTreeRvlcEscape = aHuffTreeRvlcEscape;
+  pRvlc->pHuffTreeRvlCodewds = aHuffTreeRvlCodewds;
+
+  /* init scf arrays (for savety (in case of there are only zero codebooks)) */
+  for (bnds = 0; bnds < RVLC_MAX_SFB; bnds++) {
+    pScfFwd[bnds] = 0;
+    pScfBwd[bnds] = 0;
+    pScfEsc[bnds] = 0;
+    pScaleFactor[bnds] = 0;
+  }
+
+  /* set base bitstream ptr to the RVL-coded part (start of RVLC data (ESC 2))
+   */
+  FDKsyncCache(bs);
+  pRvlc->bsAnchor = (INT)FDKgetValidBits(bs);
+
+  pRvlc->bitstreamIndexRvlFwd =
+      0; /* first bit within RVL coded block as start address for  forward
+            decoding */
+  pRvlc->bitstreamIndexRvlBwd =
+      pRvlc->length_of_rvlc_sf - 1; /* last bit within RVL coded block as start
+                                       address for backward decoding */
+
+  /* skip RVLC-bitstream-part -- pointing now to escapes (if present) or to TNS
+   * data (if present) */
+  FDKpushFor(bs, pRvlc->length_of_rvlc_sf);
+
+  if (pRvlc->sf_escapes_present != 0) {
+    /* locate internal bitstream ptr at escapes (which is the second part) */
+    FDKsyncCache(bs);
+    pRvlc->bitstreamIndexEsc = pRvlc->bsAnchor - (INT)FDKgetValidBits(bs);
+
+    /* skip escapeRVLC-bitstream-part -- pointing to TNS data (if present)   to
+     * make decoder continue */
+    /* decoding of RVLC should work despite this second pushFor during
+     * initialization because        */
+    /* bitstream initialization is valid for both ESC2 data parts (RVL-coded
+     * values and ESC-coded values) */
+    FDKpushFor(bs, pRvlc->length_of_rvlc_escapes);
+  }
+}
+
+/*---------------------------------------------------------------------------------------------
+     function:     rvlcCheckIntensityCb
+
+     description:  Check if a intensity codebook is used in the current channel.
+-----------------------------------------------------------------------------------------------
+        input:     - pointer rvlc structure
+                   - pointer channel info structure
+-----------------------------------------------------------------------------------------------
+        output:    - intensity_used: 0 no intensity codebook is used
+                                     1 intensity codebook is used
+-----------------------------------------------------------------------------------------------
+        return:    -
+--------------------------------------------------------------------------------------------
+*/
+
+static void rvlcCheckIntensityCb(
+    CErRvlcInfo *pRvlc, CAacDecoderChannelInfo *pAacDecoderChannelInfo) {
+  int group, band, bnds;
+
+  pRvlc->intensity_used = 0;
+
+  for (group = 0; group < pRvlc->numWindowGroups; group++) {
+    for (band = 0; band < pRvlc->maxSfbTransmitted; band++) {
+      bnds = 16 * group + band;
+      if ((pAacDecoderChannelInfo->pDynData->aCodeBook[bnds] ==
+           INTENSITY_HCB) ||
+          (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds] ==
+           INTENSITY_HCB2)) {
+        pRvlc->intensity_used = 1;
+        break;
+      }
+    }
+  }
+}
+
+/*---------------------------------------------------------------------------------------------
+     function:     rvlcDecodeEscapeWord
+
+     description:  Decode a huffman coded RVLC Escape-word. This value is part
+of a DPCM coded scalefactor.
+-----------------------------------------------------------------------------------------------
+        input:     - pointer rvlc structure
+-----------------------------------------------------------------------------------------------
+        return:    - a single RVLC-Escape value which had to be applied to a
+DPCM value (which has a absolute value of 7)
+--------------------------------------------------------------------------------------------
+*/
+
+static SCHAR rvlcDecodeEscapeWord(CErRvlcInfo *pRvlc, HANDLE_FDK_BITSTREAM bs) {
+  int i;
+  SCHAR value;
+  UCHAR carryBit;
+  UINT treeNode;
+  UINT branchValue;
+  UINT branchNode;
+
+  INT *pBitstreamIndexEsc;
+  const UINT *pEscTree;
+
+  pEscTree = pRvlc->pHuffTreeRvlcEscape;
+  pBitstreamIndexEsc = &(pRvlc->bitstreamIndexEsc);
+  treeNode = *pEscTree; /* init at starting node */
+
+  for (i = MAX_LEN_RVLC_ESCAPE_WORD - 1; i >= 0; i--) {
+    carryBit =
+        rvlcReadBitFromBitstream(bs, /* get next bit */
+                                 pRvlc->bsAnchor, pBitstreamIndexEsc, FWD);
+
+    CarryBitToBranchValue(carryBit, /* huffman decoding, do a single step in
+                                       huffman decoding tree */
+                          treeNode, &branchValue, &branchNode);
+
+    if ((branchNode & TEST_BIT_10) ==
+        TEST_BIT_10) { /* test bit 10 ; if set --> a RVLC-escape-word is
+                          completely decoded */
+      value = (SCHAR)branchNode & CLR_BIT_10;
+      pRvlc->length_of_rvlc_escapes -= (MAX_LEN_RVLC_ESCAPE_WORD - i);
+
+      if (pRvlc->length_of_rvlc_escapes < 0) {
+        pRvlc->errorLogRvlc |= RVLC_ERROR_ALL_ESCAPE_WORDS_INVALID;
+        value = -1;
+      }
+
+      return value;
+    } else {
+      treeNode = *(
+          pEscTree +
+          branchValue); /* update treeNode for further step in decoding tree */
+    }
+  }
+
+  pRvlc->errorLogRvlc |= RVLC_ERROR_ALL_ESCAPE_WORDS_INVALID;
+
+  return -1; /* should not be reached */
+}
+
+/*---------------------------------------------------------------------------------------------
+     function:     rvlcDecodeEscapes
+
+     description:  Decodes all huffman coded RVLC Escape Words.
+                   Here a difference to the pseudo-code-implementation from
+standard can be found. A while loop (and not two nested for loops) is used for
+two reasons:
+
+                   1. The plain huffman encoded escapes are decoded before the
+RVL-coded scalefactors. Therefore the escapes are present in the second step
+                      when decoding the RVL-coded-scalefactor values in forward
+and backward direction.
+
+                      When the RVL-coded scalefactors are decoded and there a
+escape is needed, then it is just taken out of the array in ascending order.
+
+                   2. It's faster.
+-----------------------------------------------------------------------------------------------
+        input:     - pointer rvlc structure
+                   - handle to FDK bitstream
+-----------------------------------------------------------------------------------------------
+        return:    - 0 ok     the decoded escapes seem to be valid
+                   - 1 error  there was a error detected during decoding escapes
+                              --> all escapes are invalid
+--------------------------------------------------------------------------------------------
+*/
+
+static void rvlcDecodeEscapes(CErRvlcInfo *pRvlc, SHORT *pEsc,
+                              HANDLE_FDK_BITSTREAM bs) {
+  SCHAR escWord;
+  SCHAR escCnt = 0;
+  SHORT *pEscBitCntSum;
+
+  pEscBitCntSum = &(pRvlc->length_of_rvlc_escapes);
+
+  /* Decode all RVLC-Escape words with a plain Huffman-Decoder */
+  while (*pEscBitCntSum > 0) {
+    escWord = rvlcDecodeEscapeWord(pRvlc, bs);
+
+    if (escWord >= 0) {
+      pEsc[escCnt] = escWord;
+      escCnt++;
+    } else {
+      pRvlc->errorLogRvlc |= RVLC_ERROR_ALL_ESCAPE_WORDS_INVALID;
+      pRvlc->numDecodedEscapeWordsEsc = escCnt;
+
+      return;
+    }
+  } /* all RVLC escapes decoded */
+
+  pRvlc->numDecodedEscapeWordsEsc = escCnt;
+}
+
+/*---------------------------------------------------------------------------------------------
+     function:     decodeRVLCodeword
+
+     description:  Decodes a RVL-coded dpcm-word (-part).
+-----------------------------------------------------------------------------------------------
+        input:     - FDK bitstream handle
+                   - pointer rvlc structure
+-----------------------------------------------------------------------------------------------
+        return:    - a dpcm value which is within range [0,1,..,14] in case of
+no errors. The offset of 7 must be subtracted to get a valid dpcm scalefactor
+value. In case of errors a forbidden codeword is detected --> returning -1
+--------------------------------------------------------------------------------------------
+*/
+
+SCHAR decodeRVLCodeword(HANDLE_FDK_BITSTREAM bs, CErRvlcInfo *pRvlc) {
+  int i;
+  SCHAR value;
+  UCHAR carryBit;
+  UINT branchValue;
+  UINT branchNode;
+
+  const UINT *pRvlCodeTree = pRvlc->pHuffTreeRvlCodewds;
+  UCHAR direction = pRvlc->direction;
+  INT *pBitstrIndxRvl = pRvlc->pBitstrIndxRvl_RVL;
+  UINT treeNode = *pRvlCodeTree;
+
+  for (i = MAX_LEN_RVLC_CODE_WORD - 1; i >= 0; i--) {
+    carryBit =
+        rvlcReadBitFromBitstream(bs, /* get next bit */
+                                 pRvlc->bsAnchor, pBitstrIndxRvl, direction);
+
+    CarryBitToBranchValue(carryBit, /* huffman decoding, do a single step in
+                                       huffman decoding tree */
+                          treeNode, &branchValue, &branchNode);
+
+    if ((branchNode & TEST_BIT_10) ==
+        TEST_BIT_10) { /* test bit 10 ; if set --> a
+                          RVLC-codeword is completely decoded
+                        */
+      value = (SCHAR)(branchNode & CLR_BIT_10);
+      *pRvlc->pRvlBitCnt_RVL -= (MAX_LEN_RVLC_CODE_WORD - i);
+
+      /* check available bits for decoding */
+      if (*pRvlc->pRvlBitCnt_RVL < 0) {
+        if (direction == FWD) {
+          pRvlc->errorLogRvlc |= RVLC_ERROR_RVL_SUM_BIT_COUNTER_BELOW_ZERO_FWD;
+        } else {
+          pRvlc->errorLogRvlc |= RVLC_ERROR_RVL_SUM_BIT_COUNTER_BELOW_ZERO_BWD;
+        }
+        value = -1; /* signalize an error in return value, because too many bits
+                       was decoded */
+      }
+
+      /* check max value of dpcm value */
+      if (value > MAX_ALLOWED_DPCM_INDEX) {
+        if (direction == FWD) {
+          pRvlc->errorLogRvlc |= RVLC_ERROR_FORBIDDEN_CW_DETECTED_FWD;
+        } else {
+          pRvlc->errorLogRvlc |= RVLC_ERROR_FORBIDDEN_CW_DETECTED_BWD;
+        }
+        value = -1; /* signalize an error in return value, because a forbidden
+                       cw was detected*/
+      }
+
+      return value; /* return a dpcm value with offset +7 or an error status */
+    } else {
+      treeNode = *(
+          pRvlCodeTree +
+          branchValue); /* update treeNode for further step in decoding tree */
+    }
+  }
+
+  return -1;
+}
+
+/*---------------------------------------------------------------------------------------------
+     function:     rvlcDecodeForward
+
+     description:  Decode RVL-coded codewords in forward direction.
+-----------------------------------------------------------------------------------------------
+        input:     - pointer rvlc structure
+                   - pointer channel info structure
+                   - handle to FDK bitstream
+-----------------------------------------------------------------------------------------------
+        return:    -
+--------------------------------------------------------------------------------------------
+*/
+
+static void rvlcDecodeForward(CErRvlcInfo *pRvlc,
+                              CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+                              HANDLE_FDK_BITSTREAM bs) {
+  int band = 0;
+  int group = 0;
+  int bnds = 0;
+
+  SHORT dpcm;
+
+  SHORT factor =
+      pAacDecoderChannelInfo->pDynData->RawDataInfo.GlobalGain - SF_OFFSET;
+  SHORT position = -SF_OFFSET;
+  SHORT noisenrg = pAacDecoderChannelInfo->pDynData->RawDataInfo.GlobalGain -
+                   SF_OFFSET - 90 - 256;
+
+  SHORT *pScfFwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd;
+  SHORT *pScfEsc = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfEsc;
+  UCHAR *pEscFwdCnt = &(pRvlc->numDecodedEscapeWordsFwd);
+
+  pRvlc->pRvlBitCnt_RVL = &(pRvlc->length_of_rvlc_sf_fwd);
+  pRvlc->pBitstrIndxRvl_RVL = &(pRvlc->bitstreamIndexRvlFwd);
+
+  *pEscFwdCnt = 0;
+  pRvlc->direction = FWD;
+  pRvlc->noise_used = 0;
+  pRvlc->sf_used = 0;
+  pRvlc->lastScf = 0;
+  pRvlc->lastNrg = 0;
+  pRvlc->lastIs = 0;
+
+  rvlcCheckIntensityCb(pRvlc, pAacDecoderChannelInfo);
+
+  /* main loop fwd long */
+  for (group = 0; group < pRvlc->numWindowGroups; group++) {
+    for (band = 0; band < pRvlc->maxSfbTransmitted; band++) {
+      bnds = 16 * group + band;
+
+      switch (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds]) {
+        case ZERO_HCB:
+          pScfFwd[bnds] = 0;
+          break;
+
+        case INTENSITY_HCB2:
+        case INTENSITY_HCB:
+          /* store dpcm_is_position */
+          dpcm = decodeRVLCodeword(bs, pRvlc);
+          if (dpcm < 0) {
+            pRvlc->conceal_max = bnds;
+            return;
+          }
+          dpcm -= TABLE_OFFSET;
+          if ((dpcm == MIN_RVL) || (dpcm == MAX_RVL)) {
+            if (pRvlc->length_of_rvlc_escapes) {
+              pRvlc->conceal_max = bnds;
+              return;
+            } else {
+              if (dpcm == MIN_RVL) {
+                dpcm -= *pScfEsc++;
+              } else {
+                dpcm += *pScfEsc++;
+              }
+              (*pEscFwdCnt)++;
+              if (pRvlc->conceal_max_esc == CONCEAL_MAX_INIT) {
+                pRvlc->conceal_max_esc = bnds;
+              }
+            }
+          }
+          position += dpcm;
+          pScfFwd[bnds] = position;
+          pRvlc->lastIs = position;
+          break;
+
+        case NOISE_HCB:
+          if (pRvlc->noise_used == 0) {
+            pRvlc->noise_used = 1;
+            pRvlc->first_noise_band = bnds;
+            noisenrg += pRvlc->dpcm_noise_nrg;
+            pScfFwd[bnds] = 100 + noisenrg;
+            pRvlc->lastNrg = noisenrg;
+          } else {
+            dpcm = decodeRVLCodeword(bs, pRvlc);
+            if (dpcm < 0) {
+              pRvlc->conceal_max = bnds;
+              return;
+            }
+            dpcm -= TABLE_OFFSET;
+            if ((dpcm == MIN_RVL) || (dpcm == MAX_RVL)) {
+              if (pRvlc->length_of_rvlc_escapes) {
+                pRvlc->conceal_max = bnds;
+                return;
+              } else {
+                if (dpcm == MIN_RVL) {
+                  dpcm -= *pScfEsc++;
+                } else {
+                  dpcm += *pScfEsc++;
+                }
+                (*pEscFwdCnt)++;
+                if (pRvlc->conceal_max_esc == CONCEAL_MAX_INIT) {
+                  pRvlc->conceal_max_esc = bnds;
+                }
+              }
+            }
+            noisenrg += dpcm;
+            pScfFwd[bnds] = 100 + noisenrg;
+            pRvlc->lastNrg = noisenrg;
+          }
+          pAacDecoderChannelInfo->data.aac.PnsData.pnsUsed[bnds] = 1;
+          break;
+
+        default:
+          pRvlc->sf_used = 1;
+          dpcm = decodeRVLCodeword(bs, pRvlc);
+          if (dpcm < 0) {
+            pRvlc->conceal_max = bnds;
+            return;
+          }
+          dpcm -= TABLE_OFFSET;
+          if ((dpcm == MIN_RVL) || (dpcm == MAX_RVL)) {
+            if (pRvlc->length_of_rvlc_escapes) {
+              pRvlc->conceal_max = bnds;
+              return;
+            } else {
+              if (dpcm == MIN_RVL) {
+                dpcm -= *pScfEsc++;
+              } else {
+                dpcm += *pScfEsc++;
+              }
+              (*pEscFwdCnt)++;
+              if (pRvlc->conceal_max_esc == CONCEAL_MAX_INIT) {
+                pRvlc->conceal_max_esc = bnds;
+              }
+            }
+          }
+          factor += dpcm;
+          pScfFwd[bnds] = factor;
+          pRvlc->lastScf = factor;
+          break;
+      }
+    }
+  }
+
+  /* postfetch fwd long */
+  if (pRvlc->intensity_used) {
+    dpcm = decodeRVLCodeword(bs, pRvlc); /* dpcm_is_last_position */
+    if (dpcm < 0) {
+      pRvlc->conceal_max = bnds;
+      return;
+    }
+    dpcm -= TABLE_OFFSET;
+    if ((dpcm == MIN_RVL) || (dpcm == MAX_RVL)) {
+      if (pRvlc->length_of_rvlc_escapes) {
+        pRvlc->conceal_max = bnds;
+        return;
+      } else {
+        if (dpcm == MIN_RVL) {
+          dpcm -= *pScfEsc++;
+        } else {
+          dpcm += *pScfEsc++;
+        }
+        (*pEscFwdCnt)++;
+        if (pRvlc->conceal_max_esc == CONCEAL_MAX_INIT) {
+          pRvlc->conceal_max_esc = bnds;
+        }
+      }
+    }
+    pRvlc->dpcm_is_last_position = dpcm;
+  }
+}
+
+/*---------------------------------------------------------------------------------------------
+     function:     rvlcDecodeBackward
+
+     description:  Decode RVL-coded codewords in backward direction.
+-----------------------------------------------------------------------------------------------
+        input:     - pointer rvlc structure
+                   - pointer channel info structure
+                   - handle FDK bitstream
+-----------------------------------------------------------------------------------------------
+        return:    -
+--------------------------------------------------------------------------------------------
+*/
+
+static void rvlcDecodeBackward(CErRvlcInfo *pRvlc,
+                               CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+                               HANDLE_FDK_BITSTREAM bs) {
+  SHORT band, group, dpcm, offset;
+  SHORT bnds = pRvlc->maxSfbTransmitted - 1;
+
+  SHORT factor = pRvlc->rev_global_gain - SF_OFFSET;
+  SHORT position = pRvlc->dpcm_is_last_position - SF_OFFSET;
+  SHORT noisenrg = pRvlc->rev_global_gain + pRvlc->dpcm_noise_last_position -
+                   SF_OFFSET - 90 - 256;
+
+  SHORT *pScfBwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd;
+  SHORT *pScfEsc = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfEsc;
+  UCHAR *pEscEscCnt = &(pRvlc->numDecodedEscapeWordsEsc);
+  UCHAR *pEscBwdCnt = &(pRvlc->numDecodedEscapeWordsBwd);
+
+  pRvlc->pRvlBitCnt_RVL = &(pRvlc->length_of_rvlc_sf_bwd);
+  pRvlc->pBitstrIndxRvl_RVL = &(pRvlc->bitstreamIndexRvlBwd);
+
+  *pEscBwdCnt = 0;
+  pRvlc->direction = BWD;
+  pScfEsc += *pEscEscCnt - 1; /* set pScfEsc to last entry */
+  pRvlc->firstScf = 0;
+  pRvlc->firstNrg = 0;
+  pRvlc->firstIs = 0;
+
+  /* prefetch long BWD */
+  if (pRvlc->intensity_used) {
+    dpcm = decodeRVLCodeword(bs, pRvlc); /* dpcm_is_last_position */
+    if (dpcm < 0) {
+      pRvlc->dpcm_is_last_position = 0;
+      pRvlc->conceal_min = bnds;
+      return;
+    }
+    dpcm -= TABLE_OFFSET;
+    if ((dpcm == MIN_RVL) || (dpcm == MAX_RVL)) {
+      if (pRvlc->length_of_rvlc_escapes) {
+        pRvlc->conceal_min = bnds;
+        return;
+      } else {
+        if (dpcm == MIN_RVL) {
+          dpcm -= *pScfEsc--;
+        } else {
+          dpcm += *pScfEsc--;
+        }
+        (*pEscBwdCnt)++;
+        if (pRvlc->conceal_min_esc == CONCEAL_MIN_INIT) {
+          pRvlc->conceal_min_esc = bnds;
+        }
+      }
+    }
+    pRvlc->dpcm_is_last_position = dpcm;
+  }
+
+  /* main loop long BWD */
+  for (group = pRvlc->numWindowGroups - 1; group >= 0; group--) {
+    for (band = pRvlc->maxSfbTransmitted - 1; band >= 0; band--) {
+      bnds = 16 * group + band;
+      if ((band == 0) && (pRvlc->numWindowGroups != 1))
+        offset = 16 - pRvlc->maxSfbTransmitted + 1;
+      else
+        offset = 1;
+
+      switch (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds]) {
+        case ZERO_HCB:
+          pScfBwd[bnds] = 0;
+          break;
+
+        case INTENSITY_HCB2:
+        case INTENSITY_HCB:
+          /* store dpcm_is_position */
+          dpcm = decodeRVLCodeword(bs, pRvlc);
+          if (dpcm < 0) {
+            pScfBwd[bnds] = position;
+            pRvlc->conceal_min = fMax(0, bnds - offset);
+            return;
+          }
+          dpcm -= TABLE_OFFSET;
+          if ((dpcm == MIN_RVL) || (dpcm == MAX_RVL)) {
+            if (pRvlc->length_of_rvlc_escapes) {
+              pScfBwd[bnds] = position;
+              pRvlc->conceal_min = fMax(0, bnds - offset);
+              return;
+            } else {
+              if (dpcm == MIN_RVL) {
+                dpcm -= *pScfEsc--;
+              } else {
+                dpcm += *pScfEsc--;
+              }
+              (*pEscBwdCnt)++;
+              if (pRvlc->conceal_min_esc == CONCEAL_MIN_INIT) {
+                pRvlc->conceal_min_esc = fMax(0, bnds - offset);
+              }
+            }
+          }
+          pScfBwd[bnds] = position;
+          position -= dpcm;
+          pRvlc->firstIs = position;
+          break;
+
+        case NOISE_HCB:
+          if (bnds == pRvlc->first_noise_band) {
+            pScfBwd[bnds] =
+                pRvlc->dpcm_noise_nrg +
+                pAacDecoderChannelInfo->pDynData->RawDataInfo.GlobalGain -
+                SF_OFFSET - 90 - 256;
+            pRvlc->firstNrg = pScfBwd[bnds];
+          } else {
+            dpcm = decodeRVLCodeword(bs, pRvlc);
+            if (dpcm < 0) {
+              pScfBwd[bnds] = noisenrg;
+              pRvlc->conceal_min = fMax(0, bnds - offset);
+              return;
+            }
+            dpcm -= TABLE_OFFSET;
+            if ((dpcm == MIN_RVL) || (dpcm == MAX_RVL)) {
+              if (pRvlc->length_of_rvlc_escapes) {
+                pScfBwd[bnds] = noisenrg;
+                pRvlc->conceal_min = fMax(0, bnds - offset);
+                return;
+              } else {
+                if (dpcm == MIN_RVL) {
+                  dpcm -= *pScfEsc--;
+                } else {
+                  dpcm += *pScfEsc--;
+                }
+                (*pEscBwdCnt)++;
+                if (pRvlc->conceal_min_esc == CONCEAL_MIN_INIT) {
+                  pRvlc->conceal_min_esc = fMax(0, bnds - offset);
+                }
+              }
+            }
+            pScfBwd[bnds] = noisenrg;
+            noisenrg -= dpcm;
+            pRvlc->firstNrg = noisenrg;
+          }
+          break;
+
+        default:
+          dpcm = decodeRVLCodeword(bs, pRvlc);
+          if (dpcm < 0) {
+            pScfBwd[bnds] = factor;
+            pRvlc->conceal_min = fMax(0, bnds - offset);
+            return;
+          }
+          dpcm -= TABLE_OFFSET;
+          if ((dpcm == MIN_RVL) || (dpcm == MAX_RVL)) {
+            if (pRvlc->length_of_rvlc_escapes) {
+              pScfBwd[bnds] = factor;
+              pRvlc->conceal_min = fMax(0, bnds - offset);
+              return;
+            } else {
+              if (dpcm == MIN_RVL) {
+                dpcm -= *pScfEsc--;
+              } else {
+                dpcm += *pScfEsc--;
+              }
+              (*pEscBwdCnt)++;
+              if (pRvlc->conceal_min_esc == CONCEAL_MIN_INIT) {
+                pRvlc->conceal_min_esc = fMax(0, bnds - offset);
+              }
+            }
+          }
+          pScfBwd[bnds] = factor;
+          factor -= dpcm;
+          pRvlc->firstScf = factor;
+          break;
+      }
+    }
+  }
+}
+
+/*---------------------------------------------------------------------------------------------
+     function:     rvlcFinalErrorDetection
+
+     description:  Call RVLC concealment if error was detected in decoding
+process
+-----------------------------------------------------------------------------------------------
+        input:     - pointer rvlc structure
+                   - pointer channel info structure
+-----------------------------------------------------------------------------------------------
+        return:    -
+--------------------------------------------------------------------------------------------
+*/
+
+static void rvlcFinalErrorDetection(
+    CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo) {
+  CErRvlcInfo *pRvlc =
+      &pAacDecoderChannelInfo->pComData->overlay.aac.erRvlcInfo;
+  UCHAR ErrorStatusComplete = 0;
+  UCHAR ErrorStatusLengthFwd = 0;
+  UCHAR ErrorStatusLengthBwd = 0;
+  UCHAR ErrorStatusLengthEscapes = 0;
+  UCHAR ErrorStatusFirstScf = 0;
+  UCHAR ErrorStatusLastScf = 0;
+  UCHAR ErrorStatusFirstNrg = 0;
+  UCHAR ErrorStatusLastNrg = 0;
+  UCHAR ErrorStatusFirstIs = 0;
+  UCHAR ErrorStatusLastIs = 0;
+  UCHAR ErrorStatusForbiddenCwFwd = 0;
+  UCHAR ErrorStatusForbiddenCwBwd = 0;
+  UCHAR ErrorStatusNumEscapesFwd = 0;
+  UCHAR ErrorStatusNumEscapesBwd = 0;
+  UCHAR ConcealStatus = 1;
+  UCHAR currentBlockType; /* short: 0, not short: 1*/
+
+  pAacDecoderChannelInfo->pDynData->specificTo.aac.rvlcCurrentScaleFactorOK = 1;
+
+  /* invalid escape words, bit counter unequal zero, forbidden codeword detected
+   */
+  if (pRvlc->errorLogRvlc & RVLC_ERROR_FORBIDDEN_CW_DETECTED_FWD)
+    ErrorStatusForbiddenCwFwd = 1;
+
+  if (pRvlc->errorLogRvlc & RVLC_ERROR_FORBIDDEN_CW_DETECTED_BWD)
+    ErrorStatusForbiddenCwBwd = 1;
+
+  /* bit counter forward unequal zero */
+  if (pRvlc->length_of_rvlc_sf_fwd) ErrorStatusLengthFwd = 1;
+
+  /* bit counter backward unequal zero */
+  if (pRvlc->length_of_rvlc_sf_bwd) ErrorStatusLengthBwd = 1;
+
+  /* bit counter escape sequences unequal zero */
+  if (pRvlc->sf_escapes_present)
+    if (pRvlc->length_of_rvlc_escapes) ErrorStatusLengthEscapes = 1;
+
+  if (pRvlc->sf_used) {
+    /* first decoded scf does not match to global gain in backward direction */
+    if (pRvlc->firstScf !=
+        (pAacDecoderChannelInfo->pDynData->RawDataInfo.GlobalGain - SF_OFFSET))
+      ErrorStatusFirstScf = 1;
+
+    /* last decoded scf does not match to rev global gain in forward direction
+     */
+    if (pRvlc->lastScf != (pRvlc->rev_global_gain - SF_OFFSET))
+      ErrorStatusLastScf = 1;
+  }
+
+  if (pRvlc->noise_used) {
+    /* first decoded nrg does not match to dpcm_noise_nrg in backward direction
+     */
+    if (pRvlc->firstNrg !=
+        (pAacDecoderChannelInfo->pDynData->RawDataInfo.GlobalGain +
+         pRvlc->dpcm_noise_nrg - SF_OFFSET - 90 - 256))
+      ErrorStatusFirstNrg = 1;
+
+    /* last decoded nrg does not match to dpcm_noise_last_position in forward
+     * direction */
+    if (pRvlc->lastNrg !=
+        (pRvlc->rev_global_gain + pRvlc->dpcm_noise_last_position - SF_OFFSET -
+         90 - 256))
+      ErrorStatusLastNrg = 1;
+  }
+
+  if (pRvlc->intensity_used) {
+    /* first decoded is position does not match in backward direction */
+    if (pRvlc->firstIs != (-SF_OFFSET)) ErrorStatusFirstIs = 1;
+
+    /* last decoded is position does not match in forward direction */
+    if (pRvlc->lastIs != (pRvlc->dpcm_is_last_position - SF_OFFSET))
+      ErrorStatusLastIs = 1;
+  }
+
+  /* decoded escapes and used escapes in forward direction do not fit */
+  if ((pRvlc->numDecodedEscapeWordsFwd != pRvlc->numDecodedEscapeWordsEsc) &&
+      (pRvlc->conceal_max == CONCEAL_MAX_INIT)) {
+    ErrorStatusNumEscapesFwd = 1;
+  }
+
+  /* decoded escapes and used escapes in backward direction do not fit */
+  if ((pRvlc->numDecodedEscapeWordsBwd != pRvlc->numDecodedEscapeWordsEsc) &&
+      (pRvlc->conceal_min == CONCEAL_MIN_INIT)) {
+    ErrorStatusNumEscapesBwd = 1;
+  }
+
+  if (ErrorStatusLengthEscapes ||
+      (((pRvlc->conceal_max == CONCEAL_MAX_INIT) &&
+        (pRvlc->numDecodedEscapeWordsFwd != pRvlc->numDecodedEscapeWordsEsc) &&
+        (ErrorStatusLastScf || ErrorStatusLastNrg || ErrorStatusLastIs))
+
+       &&
+
+       ((pRvlc->conceal_min == CONCEAL_MIN_INIT) &&
+        (pRvlc->numDecodedEscapeWordsBwd != pRvlc->numDecodedEscapeWordsEsc) &&
+        (ErrorStatusFirstScf || ErrorStatusFirstNrg || ErrorStatusFirstIs))) ||
+      ((pRvlc->conceal_max == CONCEAL_MAX_INIT) &&
+       ((pRvlc->rev_global_gain - SF_OFFSET - pRvlc->lastScf) < -15)) ||
+      ((pRvlc->conceal_min == CONCEAL_MIN_INIT) &&
+       ((pAacDecoderChannelInfo->pDynData->RawDataInfo.GlobalGain - SF_OFFSET -
+         pRvlc->firstScf) < -15))) {
+    if ((pRvlc->conceal_max == CONCEAL_MAX_INIT) ||
+        (pRvlc->conceal_min == CONCEAL_MIN_INIT)) {
+      pRvlc->conceal_max = 0;
+      pRvlc->conceal_min = fMax(
+          0, (pRvlc->numWindowGroups - 1) * 16 + pRvlc->maxSfbTransmitted - 1);
+    } else {
+      pRvlc->conceal_max = fMin(pRvlc->conceal_max, pRvlc->conceal_max_esc);
+      pRvlc->conceal_min = fMax(pRvlc->conceal_min, pRvlc->conceal_min_esc);
+    }
+  }
+
+  ErrorStatusComplete = ErrorStatusLastScf || ErrorStatusFirstScf ||
+                        ErrorStatusLastNrg || ErrorStatusFirstNrg ||
+                        ErrorStatusLastIs || ErrorStatusFirstIs ||
+                        ErrorStatusForbiddenCwFwd ||
+                        ErrorStatusForbiddenCwBwd || ErrorStatusLengthFwd ||
+                        ErrorStatusLengthBwd || ErrorStatusLengthEscapes ||
+                        ErrorStatusNumEscapesFwd || ErrorStatusNumEscapesBwd;
+
+  currentBlockType =
+      (GetWindowSequence(&pAacDecoderChannelInfo->icsInfo) == BLOCK_SHORT) ? 0
+                                                                           : 1;
+
+  if (!ErrorStatusComplete) {
+    int band;
+    int group;
+    int bnds;
+    int lastSfbIndex;
+
+    lastSfbIndex = (pRvlc->numWindowGroups > 1) ? 16 : 64;
+
+    for (group = 0; group < pRvlc->numWindowGroups; group++) {
+      for (band = 0; band < pRvlc->maxSfbTransmitted; band++) {
+        bnds = 16 * group + band;
+        pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] =
+            pAacDecoderStaticChannelInfo->concealmentInfo
+                .aRvlcPreviousScaleFactor[bnds] =
+                pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds];
+      }
+    }
+
+    for (group = 0; group < pRvlc->numWindowGroups; group++) {
+      for (band = 0; band < pRvlc->maxSfbTransmitted; band++) {
+        bnds = 16 * group + band;
+        pAacDecoderStaticChannelInfo->concealmentInfo
+            .aRvlcPreviousCodebook[bnds] =
+            pAacDecoderChannelInfo->pDynData->aCodeBook[bnds];
+      }
+      for (; band < lastSfbIndex; band++) {
+        bnds = 16 * group + band;
+        FDK_ASSERT(bnds >= 0 && bnds < RVLC_MAX_SFB);
+        pAacDecoderStaticChannelInfo->concealmentInfo
+            .aRvlcPreviousCodebook[bnds] = ZERO_HCB;
+      }
+    }
+  } else {
+    int band;
+    int group;
+
+    /* A single bit error was detected in decoding of dpcm values. It also could
+       be an error with more bits in decoding of escapes and dpcm values whereby
+       an illegal codeword followed not directly after the corrupted bits but
+       just after decoding some more (wrong) scalefactors. Use the smaller
+       scalefactor from forward decoding, backward decoding and previous frame.
+     */
+    if (((pRvlc->conceal_min != CONCEAL_MIN_INIT) ||
+         (pRvlc->conceal_max != CONCEAL_MAX_INIT)) &&
+        (pRvlc->conceal_min <= pRvlc->conceal_max) &&
+        (pAacDecoderStaticChannelInfo->concealmentInfo.rvlcPreviousBlockType ==
+         currentBlockType) &&
+        pAacDecoderStaticChannelInfo->concealmentInfo
+            .rvlcPreviousScaleFactorOK &&
+        pRvlc->sf_concealment && ConcealStatus) {
+      BidirectionalEstimation_UseScfOfPrevFrameAsReference(
+          pAacDecoderChannelInfo, pAacDecoderStaticChannelInfo);
+      ConcealStatus = 0;
+    }
+
+    /* A single bit error was detected in decoding of dpcm values. It also could
+       be an error with more bits in decoding of escapes and dpcm values whereby
+       an illegal codeword followed not directly after the corrupted bits but
+       just after decoding some more (wrong) scalefactors. Use the smaller
+       scalefactor from forward and backward decoding. */
+    if ((pRvlc->conceal_min <= pRvlc->conceal_max) &&
+        ((pRvlc->conceal_min != CONCEAL_MIN_INIT) ||
+         (pRvlc->conceal_max != CONCEAL_MAX_INIT)) &&
+        !(pAacDecoderStaticChannelInfo->concealmentInfo
+              .rvlcPreviousScaleFactorOK &&
+          pRvlc->sf_concealment &&
+          (pAacDecoderStaticChannelInfo->concealmentInfo
+               .rvlcPreviousBlockType == currentBlockType)) &&
+        ConcealStatus) {
+      BidirectionalEstimation_UseLowerScfOfCurrentFrame(pAacDecoderChannelInfo);
+      ConcealStatus = 0;
+    }
+
+    /* No errors were detected in decoding of escapes and dpcm values however
+       the first and last value of a group (is,nrg,sf) is incorrect */
+    if ((pRvlc->conceal_min <= pRvlc->conceal_max) &&
+        ((ErrorStatusLastScf && ErrorStatusFirstScf) ||
+         (ErrorStatusLastNrg && ErrorStatusFirstNrg) ||
+         (ErrorStatusLastIs && ErrorStatusFirstIs)) &&
+        !(ErrorStatusForbiddenCwFwd || ErrorStatusForbiddenCwBwd ||
+          ErrorStatusLengthEscapes) &&
+        ConcealStatus) {
+      StatisticalEstimation(pAacDecoderChannelInfo);
+      ConcealStatus = 0;
+    }
+
+    /* A error with more bits in decoding of escapes and dpcm values was
+       detected. Use the smaller scalefactor from forward decoding, backward
+       decoding and previous frame. */
+    if ((pRvlc->conceal_min <= pRvlc->conceal_max) &&
+        pAacDecoderStaticChannelInfo->concealmentInfo
+            .rvlcPreviousScaleFactorOK &&
+        pRvlc->sf_concealment &&
+        (pAacDecoderStaticChannelInfo->concealmentInfo.rvlcPreviousBlockType ==
+         currentBlockType) &&
+        ConcealStatus) {
+      PredictiveInterpolation(pAacDecoderChannelInfo,
+                              pAacDecoderStaticChannelInfo);
+      ConcealStatus = 0;
+    }
+
+    /* Call frame concealment, because no better strategy was found. Setting the
+       scalefactors to zero is done for debugging purposes */
+    if (ConcealStatus) {
+      for (group = 0; group < pRvlc->numWindowGroups; group++) {
+        for (band = 0; band < pRvlc->maxSfbTransmitted; band++) {
+          pAacDecoderChannelInfo->pDynData->aScaleFactor[16 * group + band] = 0;
+        }
+      }
+      pAacDecoderChannelInfo->pDynData->specificTo.aac
+          .rvlcCurrentScaleFactorOK = 0;
+    }
+  }
+}
+
+/*---------------------------------------------------------------------------------------------
+     function:     CRvlc_Read
+
+     description:  Read RVLC ESC1 data (side info) from bitstream.
+-----------------------------------------------------------------------------------------------
+        input:     - pointer rvlc structure
+                   - pointer channel info structure
+                   - pointer bitstream structure
+-----------------------------------------------------------------------------------------------
+        return:    -
+--------------------------------------------------------------------------------------------
+*/
+
+void CRvlc_Read(CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+                HANDLE_FDK_BITSTREAM bs) {
+  CErRvlcInfo *pRvlc =
+      &pAacDecoderChannelInfo->pComData->overlay.aac.erRvlcInfo;
+
+  int group, band;
+
+  /* RVLC long specific initialization  Init part 1 of 2 */
+  pRvlc->numWindowGroups = GetWindowGroups(&pAacDecoderChannelInfo->icsInfo);
+  pRvlc->maxSfbTransmitted =
+      GetScaleFactorBandsTransmitted(&pAacDecoderChannelInfo->icsInfo);
+  pRvlc->noise_used = 0;               /* noise detection */
+  pRvlc->dpcm_noise_nrg = 0;           /* only for debugging */
+  pRvlc->dpcm_noise_last_position = 0; /* only for debugging */
+  pRvlc->length_of_rvlc_escapes =
+      -1; /* default value is used for error detection and concealment */
+
+  /* read only error sensitivity class 1 data (ESC 1 - data) */
+  pRvlc->sf_concealment = FDKreadBits(bs, 1);  /* #1 */
+  pRvlc->rev_global_gain = FDKreadBits(bs, 8); /* #2 */
+
+  if (GetWindowSequence(&pAacDecoderChannelInfo->icsInfo) == BLOCK_SHORT) {
+    pRvlc->length_of_rvlc_sf = FDKreadBits(bs, 11); /* #3 */
+  } else {
+    pRvlc->length_of_rvlc_sf = FDKreadBits(bs, 9); /* #3 */
+  }
+
+  /* check if noise codebook is used */
+  for (group = 0; group < pRvlc->numWindowGroups; group++) {
+    for (band = 0; band < pRvlc->maxSfbTransmitted; band++) {
+      if (pAacDecoderChannelInfo->pDynData->aCodeBook[16 * group + band] ==
+          NOISE_HCB) {
+        pRvlc->noise_used = 1;
+        break;
+      }
+    }
+  }
+
+  if (pRvlc->noise_used)
+    pRvlc->dpcm_noise_nrg = FDKreadBits(bs, 9); /* #4  PNS */
+
+  pRvlc->sf_escapes_present = FDKreadBits(bs, 1); /* #5      */
+
+  if (pRvlc->sf_escapes_present) {
+    pRvlc->length_of_rvlc_escapes = FDKreadBits(bs, 8); /* #6      */
+  }
+
+  if (pRvlc->noise_used) {
+    pRvlc->dpcm_noise_last_position = FDKreadBits(bs, 9); /* #7  PNS */
+    pRvlc->length_of_rvlc_sf -= 9;
+  }
+
+  pRvlc->length_of_rvlc_sf_fwd = pRvlc->length_of_rvlc_sf;
+  pRvlc->length_of_rvlc_sf_bwd = pRvlc->length_of_rvlc_sf;
+}
+
+/*---------------------------------------------------------------------------------------------
+     function:     CRvlc_Decode
+
+     description:  Decode rvlc data
+                   The function reads both the escape sequences and the
+scalefactors in forward and backward direction. If an error occured during
+decoding process which can not be concealed with the rvlc concealment frame
+concealment will be initiated. Then the element "rvlcCurrentScaleFactorOK" in
+the decoder channel info is set to 0 otherwise it is set to 1.
+-----------------------------------------------------------------------------------------------
+        input:     - pointer rvlc structure
+                   - pointer channel info structure
+                   - pointer to persistent channel info structure
+                   - pointer bitstream structure
+-----------------------------------------------------------------------------------------------
+        return:    ErrorStatus = AAC_DEC_OK
+--------------------------------------------------------------------------------------------
+*/
+
+void CRvlc_Decode(CAacDecoderChannelInfo *pAacDecoderChannelInfo,
+                  CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
+                  HANDLE_FDK_BITSTREAM bs) {
+  CErRvlcInfo *pRvlc =
+      &pAacDecoderChannelInfo->pComData->overlay.aac.erRvlcInfo;
+  INT bitCntOffst;
+  INT saveBitCnt;
+
+  rvlcInit(pRvlc, pAacDecoderChannelInfo, bs);
+
+  /* save bitstream position */
+  saveBitCnt = (INT)FDKgetValidBits(bs);
+
+  if (pRvlc->sf_escapes_present)
+    rvlcDecodeEscapes(
+        pRvlc, pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfEsc, bs);
+
+  rvlcDecodeForward(pRvlc, pAacDecoderChannelInfo, bs);
+  rvlcDecodeBackward(pRvlc, pAacDecoderChannelInfo, bs);
+  rvlcFinalErrorDetection(pAacDecoderChannelInfo, pAacDecoderStaticChannelInfo);
+
+  pAacDecoderChannelInfo->pDynData->specificTo.aac.rvlcIntensityUsed =
+      pRvlc->intensity_used;
+  pAacDecoderChannelInfo->data.aac.PnsData.PnsActive = pRvlc->noise_used;
+
+  /* restore bitstream position */
+  bitCntOffst = (INT)FDKgetValidBits(bs) - saveBitCnt;
+  if (bitCntOffst) {
+    FDKpushBiDirectional(bs, bitCntOffst);
+  }
+}
+
+void CRvlc_ElementCheck(
+    CAacDecoderChannelInfo *pAacDecoderChannelInfo[],
+    CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo[],
+    const UINT flags, const INT elChannels) {
+  int ch;
+
+  /* Required for MPS residuals. */
+  if (pAacDecoderStaticChannelInfo == NULL) {
+    return;
+  }
+
+  /* RVLC specific sanity checks */
+  if ((flags & AC_ER_RVLC) && (elChannels == 2)) { /* to be reviewed */
+    if (((pAacDecoderChannelInfo[0]
+              ->pDynData->specificTo.aac.rvlcCurrentScaleFactorOK == 0) ||
+         (pAacDecoderChannelInfo[1]
+              ->pDynData->specificTo.aac.rvlcCurrentScaleFactorOK == 0)) &&
+        pAacDecoderChannelInfo[0]->pComData->jointStereoData.MsMaskPresent) {
+      pAacDecoderChannelInfo[0]
+          ->pDynData->specificTo.aac.rvlcCurrentScaleFactorOK = 0;
+      pAacDecoderChannelInfo[1]
+          ->pDynData->specificTo.aac.rvlcCurrentScaleFactorOK = 0;
+    }
+
+    if ((pAacDecoderChannelInfo[0]
+             ->pDynData->specificTo.aac.rvlcCurrentScaleFactorOK == 0) &&
+        (pAacDecoderChannelInfo[1]
+             ->pDynData->specificTo.aac.rvlcCurrentScaleFactorOK == 1) &&
+        (pAacDecoderChannelInfo[1]
+             ->pDynData->specificTo.aac.rvlcIntensityUsed == 1)) {
+      pAacDecoderChannelInfo[1]
+          ->pDynData->specificTo.aac.rvlcCurrentScaleFactorOK = 0;
+    }
+  }
+
+  for (ch = 0; ch < elChannels; ch++) {
+    pAacDecoderStaticChannelInfo[ch]->concealmentInfo.rvlcPreviousBlockType =
+        (GetWindowSequence(&pAacDecoderChannelInfo[ch]->icsInfo) == BLOCK_SHORT)
+            ? 0
+            : 1;
+    if (flags & AC_ER_RVLC) {
+      pAacDecoderStaticChannelInfo[ch]
+          ->concealmentInfo.rvlcPreviousScaleFactorOK =
+          pAacDecoderChannelInfo[ch]
+              ->pDynData->specificTo.aac.rvlcCurrentScaleFactorOK;
+    } else {
+      pAacDecoderStaticChannelInfo[ch]
+          ->concealmentInfo.rvlcPreviousScaleFactorOK = 0;
+    }
+  }
+}