Decode parametric stereo even with invalid channel config

AAC decoder: Allow decoding of Parametric Stereo (AOT 29) bitstreams
   with invalid channel config 2.

Bug 9428126

Change-Id: I1e8b801dfc0e6b1706421342d4985512e83f0dbe

3 files changed, 8 insertions, 7 deletions

diff --git a/libAACdec/include/aacdecoder_lib.h b/libAACdec/include/aacdecoder_lib.h
index d275644..60efe8d 100644
--- a/libAACdec/include/aacdecoder_lib.h
+++ b/libAACdec/include/aacdecoder_lib.h
@@ -504,7 +504,8 @@ typedef struct
   INT               aacSamplesPerFrame;  /*!< Samples per frame for the AAC core (from ASC). \n
                                               1024 or 960 for AAC-LC \n
                                               512 or 480 for AAC-LD and AAC-ELD         */
-
+  INT               aacNumChannels;      /*!< The number of audio channels after AAC core processing (before PS or MPS processing).
+                                              CAUTION: This are not the final number of output channels! */
   AUDIO_OBJECT_TYPE extAot;              /*!< Extension Audio Object Type (from ASC)   */
   INT               extSamplingRate;     /*!< Extension sampling rate in Hz (from ASC) */
 
diff --git a/libAACdec/src/aacdecoder.cpp b/libAACdec/src/aacdecoder.cpp
index 20c7f60..3d00d34 100644
--- a/libAACdec/src/aacdecoder.cpp
+++ b/libAACdec/src/aacdecoder.cpp
@@ -183,7 +183,7 @@ void CAacDecoder_SyncQmfMode(HANDLE_AACDECODER self)
   if ( self->qmfModeCurr == NOT_DEFINED )
   {
     if ( (IS_LOWDELAY(self->streamInfo.aot) && (self->flags & AC_MPS_PRESENT))
-      || ( (self->ascChannels == 1)
+      || ( (self->streamInfo.aacNumChannels == 1)
         && ( (CAN_DO_PS(self->streamInfo.aot) && !(self->flags & AC_MPS_PRESENT))
           || (  IS_USAC(self->streamInfo.aot) &&  (self->flags & AC_MPS_PRESENT)) ) ) )
     {
@@ -196,7 +196,7 @@ void CAacDecoder_SyncQmfMode(HANDLE_AACDECODER self)
 
   /* Set SBR to current QMF mode. Error does not matter. */
   sbrDecoder_SetParam(self->hSbrDecoder, SBR_QMF_MODE, (self->qmfModeCurr == MODE_LP));
-  self->psPossible = ((CAN_DO_PS(self->streamInfo.aot) && self->aacChannels == 1 && ! (self->flags & AC_MPS_PRESENT))) && self->qmfModeCurr == MODE_HQ ;
+  self->psPossible = ((CAN_DO_PS(self->streamInfo.aot) && self->streamInfo.aacNumChannels == 1 && ! (self->flags & AC_MPS_PRESENT))) && self->qmfModeCurr == MODE_HQ ;
   FDK_ASSERT( ! ( (self->flags & AC_MPS_PRESENT) && self->psPossible ) );
 }
 
@@ -1573,7 +1573,7 @@ LINKSPEC_CPP AAC_DECODER_ERROR CAacDecoder_DecodeFrame(
   }
 
   /* Update number of output channels */
-  self->streamInfo.numChannels = aacChannels;
+  self->streamInfo.aacNumChannels = aacChannels;
 
  #ifdef TP_PCE_ENABLE
   if (pceRead == 1 && CProgramConfig_IsValid(pce)) {
diff --git a/libAACdec/src/aacdecoder_lib.cpp b/libAACdec/src/aacdecoder_lib.cpp
index 1dedf68..5f0be30 100644
--- a/libAACdec/src/aacdecoder_lib.cpp
+++ b/libAACdec/src/aacdecoder_lib.cpp
@@ -110,7 +110,7 @@ amm-info@iis.fraunhofer.de
 /* Decoder library info */
 #define AACDECODER_LIB_VL0 2
 #define AACDECODER_LIB_VL1 5
-#define AACDECODER_LIB_VL2 1
+#define AACDECODER_LIB_VL2 2
 #define AACDECODER_LIB_TITLE "AAC Decoder Lib"
 #define AACDECODER_LIB_BUILD_DATE __DATE__
 #define AACDECODER_LIB_BUILD_TIME __TIME__
@@ -794,8 +794,8 @@ LINKSPEC_CPP AAC_DECODER_ERROR aacDecoder_DecodeFrame(
       /* Export data into streaminfo structure */
       self->streamInfo.sampleRate = self->streamInfo.aacSampleRate;
       self->streamInfo.frameSize  = self->streamInfo.aacSamplesPerFrame;
-      self->streamInfo.numChannels = self->aacChannels;
     }
+    self->streamInfo.numChannels = self->streamInfo.aacNumChannels;
 
 
 
@@ -832,7 +832,7 @@ LINKSPEC_CPP AAC_DECODER_ERROR aacDecoder_DecodeFrame(
                                     pTimeData,
                                    &self->streamInfo.numChannels,
                                    &self->streamInfo.sampleRate,
-                                    self->channelOutputMapping[self->aacChannels-1],
+                                    self->channelOutputMapping[self->streamInfo.numChannels-1],
                                     interleaved,
                                     self->frameOK,
                                    &self->psPossible);