Replace obsolete SBR CRC with superior FDK CRC implementation. Fixes ELD SBR CRC decoding and prevents negative shift exponents in calcCRC().

Bug: 131430997
Test: atest DecoderTestXheAac ; atest DecoderTestAacDrc
Change-Id: I0c40609975de5854560643f3ce2c9fecf5973f73

3 files changed, 35 insertions, 382 deletions

diff --git a/libSBRdec/src/sbr_crc.cpp b/libSBRdec/src/sbr_crc.cpp
deleted file mode 100644
index ba0fd05..0000000
--- a/libSBRdec/src/sbr_crc.cpp
+++ /dev/null
@@ -1,192 +0,0 @@
-/* -----------------------------------------------------------------------------
-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
------------------------------------------------------------------------------ */
-
-/**************************** SBR decoder library ******************************
-
-   Author(s):
-
-   Description:
-
-*******************************************************************************/
-
-/*!
-  \file
-  \brief  CRC check coutines
-*/
-
-#include "sbr_crc.h"
-
-#include "FDK_bitstream.h"
-#include "transcendent.h"
-
-#define MAXCRCSTEP 16
-#define MAXCRCSTEP_LD 4
-
-/*!
-  \brief     crc calculation
-*/
-static ULONG calcCRC(HANDLE_CRC hCrcBuf, ULONG bValue, int nBits) {
-  int i;
-  ULONG bMask = (1UL << (nBits - 1));
-
-  for (i = 0; i < nBits; i++, bMask >>= 1) {
-    USHORT flag = (hCrcBuf->crcState & hCrcBuf->crcMask) ? 1 : 0;
-    USHORT flag1 = (bMask & bValue) ? 1 : 0;
-
-    flag ^= flag1;
-    hCrcBuf->crcState <<= 1;
-    if (flag) hCrcBuf->crcState ^= hCrcBuf->crcPoly;
-  }
-
-  return (hCrcBuf->crcState);
-}
-
-/*!
-  \brief     crc
-*/
-static int getCrc(HANDLE_FDK_BITSTREAM hBs, ULONG NrBits) {
-  int i;
-  CRC_BUFFER CrcBuf;
-
-  CrcBuf.crcState = SBR_CRC_START;
-  CrcBuf.crcPoly = SBR_CRC_POLY;
-  CrcBuf.crcMask = SBR_CRC_MASK;
-
-  int CrcStep = NrBits >> MAXCRCSTEP_LD;
-
-  int CrcNrBitsRest = (NrBits - CrcStep * MAXCRCSTEP);
-  ULONG bValue;
-
-  for (i = 0; i < CrcStep; i++) {
-    bValue = FDKreadBits(hBs, MAXCRCSTEP);
-    calcCRC(&CrcBuf, bValue, MAXCRCSTEP);
-  }
-
-  bValue = FDKreadBits(hBs, CrcNrBitsRest);
-  calcCRC(&CrcBuf, bValue, CrcNrBitsRest);
-
-  return (CrcBuf.crcState & SBR_CRC_RANGE);
-}
-
-/*!
-  \brief   crc interface
-  \return  1: CRC OK, 0: CRC check failure
-*/
-int SbrCrcCheck(HANDLE_FDK_BITSTREAM hBs, /*!< handle to bit-buffer  */
-                LONG NrBits)              /*!< max. CRC length       */
-{
-  int crcResult = 1;
-  ULONG NrCrcBits;
-  ULONG crcCheckResult;
-  LONG NrBitsAvailable;
-  ULONG crcCheckSum;
-
-  crcCheckSum = FDKreadBits(hBs, 10);
-
-  NrBitsAvailable = FDKgetValidBits(hBs);
-  if (NrBitsAvailable <= 0) {
-    return 0;
-  }
-
-  NrCrcBits = fixMin((INT)NrBits, (INT)NrBitsAvailable);
-
-  crcCheckResult = getCrc(hBs, NrCrcBits);
-  FDKpushBack(hBs, (NrBitsAvailable - FDKgetValidBits(hBs)));
-
-  if (crcCheckResult != crcCheckSum) {
-    crcResult = 0;
-  }
-
-  return (crcResult);
-}
diff --git a/libSBRdec/src/sbr_crc.h b/libSBRdec/src/sbr_crc.h
deleted file mode 100644
index 9633717..0000000
--- a/libSBRdec/src/sbr_crc.h
+++ /dev/null
@@ -1,138 +0,0 @@
-/* -----------------------------------------------------------------------------
-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
------------------------------------------------------------------------------ */
-
-/**************************** SBR decoder library ******************************
-
-   Author(s):
-
-   Description:
-
-*******************************************************************************/
-
-/*!
-  \file
-  \brief  CRC checking routines
-*/
-#ifndef SBR_CRC_H
-#define SBR_CRC_H
-
-#include "sbrdecoder.h"
-
-#include "FDK_bitstream.h"
-
-/* some useful crc polynoms:
-
-crc5: x^5+x^4+x^2+x^1+1
-crc6: x^6+x^5+x^3+x^2+x+1
-crc7: x^7+x^6+x^2+1
-crc8: x^8+x^2+x+x+1
-*/
-
-/* default SBR CRC */ /* G(x) = x^10 + x^9 + x^5 + x^4 + x + 1 */
-#define SBR_CRC_POLY 0x0233
-#define SBR_CRC_MASK 0x0200
-#define SBR_CRC_START 0x0000
-#define SBR_CRC_RANGE 0x03FF
-
-typedef struct {
-  USHORT crcState;
-  USHORT crcMask;
-  USHORT crcPoly;
-} CRC_BUFFER;
-
-typedef CRC_BUFFER *HANDLE_CRC;
-
-int SbrCrcCheck(HANDLE_FDK_BITSTREAM hBitBuf, LONG NrCrcBits);
-
-#endif
diff --git a/libSBRdec/src/sbrdecoder.cpp b/libSBRdec/src/sbrdecoder.cpp
index c827ced..52403f6 100644
--- a/libSBRdec/src/sbrdecoder.cpp
+++ b/libSBRdec/src/sbrdecoder.cpp
@@ -143,14 +143,12 @@ amm-info@iis.fraunhofer.de
 #include "env_extr.h"
 #include "sbr_dec.h"
 #include "env_dec.h"
-#include "sbr_crc.h"
+#include "FDK_crc.h"
 #include "sbr_ram.h"
 #include "sbr_rom.h"
 #include "lpp_tran.h"
 #include "transcendent.h"
 
-#include "FDK_crc.h"
-
 #include "sbrdec_drc.h"
 
 #include "psbitdec.h"
@@ -1134,18 +1132,22 @@ SBR_ERROR sbrDecoder_Parse(HANDLE_SBRDECODER self, HANDLE_FDK_BITSTREAM hBs,
   SBR_HEADER_STATUS headerStatus = HEADER_NOT_PRESENT;
 
   INT startPos = FDKgetValidBits(hBs);
-  INT CRCLen = 0;
+  FDK_CRCINFO crcInfo;
+  INT crcReg = 0;
+  USHORT sbrCrc = 0;
+  UINT crcPoly;
+  UINT crcStartValue = 0;
+  UINT crcLen;
+
   HANDLE_FDK_BITSTREAM hBsOriginal = hBs;
   FDK_BITSTREAM bsBwd;
 
-  FDK_CRCINFO crcInfo;
-  INT crcReg = 0;
-  USHORT drmSbrCrc = 0;
   const int fGlobalIndependencyFlag = acFlags & AC_INDEP;
   const int bs_pvc = acElFlags[elementIndex] & AC_EL_USAC_PVC;
   const int bs_interTes = acElFlags[elementIndex] & AC_EL_USAC_ITES;
   int stereo;
   int fDoDecodeSbrData = 1;
+  int alignBits = 0;
 
   int lastSlot, lastHdrSlot = 0, thisHdrSlot = 0;
 
@@ -1277,27 +1279,23 @@ SBR_ERROR sbrDecoder_Parse(HANDLE_SBRDECODER self, HANDLE_FDK_BITSTREAM hBs,
   if (fDoDecodeSbrData) {
     if (crcFlag) {
       switch (self->coreCodec) {
-        case AOT_ER_AAC_ELD:
-          FDKpushFor(hBs, 10);
-          /* check sbrcrc later: we don't know the payload length now */
-          break;
         case AOT_DRM_AAC:
         case AOT_DRM_SURROUND:
-          drmSbrCrc = (USHORT)FDKreadBits(hBs, 8);
-          /* Setup CRC decoder */
-          FDKcrcInit(&crcInfo, 0x001d, 0xFFFF, 8);
-          /* Start CRC region */
-          crcReg = FDKcrcStartReg(&crcInfo, hBs, 0);
+          crcPoly = 0x001d;
+          crcLen = 8;
+          crcStartValue = 0x000000ff;
           break;
         default:
-          CRCLen = bsPayLen - 10; /* change: 0 => i */
-          if (CRCLen < 0) {
-            fDoDecodeSbrData = 0;
-          } else {
-            fDoDecodeSbrData = SbrCrcCheck(hBs, CRCLen);
-          }
+          crcPoly = 0x0633;
+          crcLen = 10;
+          crcStartValue = 0x00000000;
           break;
       }
+      sbrCrc = (USHORT)FDKreadBits(hBs, crcLen);
+      /* Setup CRC decoder */
+      FDKcrcInit(&crcInfo, crcPoly, crcStartValue, crcLen);
+      /* Start CRC region */
+      crcReg = FDKcrcStartReg(&crcInfo, hBs, 0);
     }
   } /* if (fDoDecodeSbrData) */
 
@@ -1450,35 +1448,6 @@ SBR_ERROR sbrDecoder_Parse(HANDLE_SBRDECODER self, HANDLE_FDK_BITSTREAM hBs,
         valBits = (INT)FDKgetValidBits(hBs);
       }
 
-      if (crcFlag) {
-        switch (self->coreCodec) {
-          case AOT_ER_AAC_ELD: {
-            /* late crc check for eld */
-            INT payloadbits =
-                (INT)startPos - (INT)FDKgetValidBits(hBs) - startPos;
-            INT crcLen = payloadbits - 10;
-            FDKpushBack(hBs, payloadbits);
-            fDoDecodeSbrData = SbrCrcCheck(hBs, crcLen);
-            FDKpushFor(hBs, crcLen);
-          } break;
-          case AOT_DRM_AAC:
-          case AOT_DRM_SURROUND:
-            /* End CRC region */
-            FDKcrcEndReg(&crcInfo, hBs, crcReg);
-            /* Check CRC */
-            if ((FDKcrcGetCRC(&crcInfo) ^ 0xFF) != drmSbrCrc) {
-              fDoDecodeSbrData = 0;
-              if (headerStatus != HEADER_NOT_PRESENT) {
-                headerStatus = HEADER_ERROR;
-                hSbrHeader->syncState = SBR_NOT_INITIALIZED;
-              }
-            }
-            break;
-          default:
-            break;
-        }
-      }
-
       /* sanity check of remaining bits */
       if (valBits < 0) {
         fDoDecodeSbrData = 0;
@@ -1489,7 +1458,7 @@ SBR_ERROR sbrDecoder_Parse(HANDLE_SBRDECODER self, HANDLE_FDK_BITSTREAM hBs,
           case AOT_AAC_LC: {
             /* This sanity check is only meaningful with General Audio
              * bitstreams */
-            int alignBits = valBits & 0x7;
+            alignBits = valBits & 0x7;
 
             if (valBits > alignBits) {
               fDoDecodeSbrData = 0;
@@ -1508,6 +1477,20 @@ SBR_ERROR sbrDecoder_Parse(HANDLE_SBRDECODER self, HANDLE_FDK_BITSTREAM hBs,
     errorStatus = SBRDEC_PARSE_ERROR;
   }
 
+  if (crcFlag && (hSbrHeader->syncState >= SBR_HEADER) && fDoDecodeSbrData) {
+    FDKpushFor(hBs, alignBits);
+    FDKcrcEndReg(&crcInfo, hBs, crcReg); /* End CRC region */
+    FDKpushBack(hBs, alignBits);
+    /* Check CRC */
+    if ((FDKcrcGetCRC(&crcInfo) ^ crcStartValue) != sbrCrc) {
+      fDoDecodeSbrData = 0;
+      if (headerStatus != HEADER_NOT_PRESENT) {
+        headerStatus = HEADER_ERROR;
+        hSbrHeader->syncState = SBR_NOT_INITIALIZED;
+      }
+    }
+  }
+
   if (!fDoDecodeSbrData) {
     /* Set error flag for this slot to trigger concealment */
     setFrameErrorFlag(self->pSbrElement[elementIndex], FRAME_ERROR);