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Diffstat (limited to 'libAACdec/src/channelinfo.cpp')
| -rw-r--r-- | libAACdec/src/channelinfo.cpp | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/libAACdec/src/channelinfo.cpp b/libAACdec/src/channelinfo.cpp new file mode 100644 index 0000000..5c113aa --- /dev/null +++ b/libAACdec/src/channelinfo.cpp @@ -0,0 +1,214 @@ +/***************************** MPEG-4 AAC Decoder ************************** + + (C) Copyright Fraunhofer IIS (2004) + All Rights Reserved + + Please be advised that this software and/or program delivery is + Confidential Information of Fraunhofer and subject to and covered by the + + Fraunhofer IIS Software Evaluation Agreement + between Google Inc. and Fraunhofer + effective and in full force since March 1, 2012. + + You may use this software and/or program only under the terms and + conditions described in the above mentioned Fraunhofer IIS Software + Evaluation Agreement. Any other and/or further use requires a separate agreement. + + + $Id$ + Author(s): Josef Hoepfl + Description: individual channel stream info + + This software and/or program is protected by copyright law and international + treaties. Any reproduction or distribution of this software and/or program, + or any portion of it, may result in severe civil and criminal penalties, and + will be prosecuted to the maximum extent possible under law. + +******************************************************************************/ + +#include "channelinfo.h" +#include "aac_rom.h" +#include "aac_ram.h" +#include "FDK_bitstream.h" + + +AAC_DECODER_ERROR IcsReadMaxSfb ( + HANDLE_FDK_BITSTREAM bs, + CIcsInfo *pIcsInfo, + const SamplingRateInfo *pSamplingRateInfo + ) +{ + AAC_DECODER_ERROR ErrorStatus = AAC_DEC_OK; + int nbits; + + if (IsLongBlock(pIcsInfo)) { + nbits = 6; + pIcsInfo->TotalSfBands = pSamplingRateInfo->NumberOfScaleFactorBands_Long; + } else { + nbits = 4; + pIcsInfo->TotalSfBands = pSamplingRateInfo->NumberOfScaleFactorBands_Short; + } + pIcsInfo->MaxSfBands = (UCHAR) FDKreadBits(bs, nbits); + + if (pIcsInfo->MaxSfBands > pIcsInfo->TotalSfBands){ + ErrorStatus = AAC_DEC_PARSE_ERROR; + } + + return ErrorStatus; +} + + + +AAC_DECODER_ERROR IcsRead(HANDLE_FDK_BITSTREAM bs, + CIcsInfo *pIcsInfo, + const SamplingRateInfo* pSamplingRateInfo, + const UINT flags) +{ + AAC_DECODER_ERROR ErrorStatus = AAC_DEC_OK; + + pIcsInfo->Valid = 0; + + if (flags & AC_ELD){ + pIcsInfo->WindowSequence = OnlyLongSequence; + pIcsInfo->WindowShape = 0; + } + else { + if ( !(flags & (AC_USAC|AC_RSVD50)) ) { + FDKreadBits(bs,1); + } + pIcsInfo->WindowSequence = (UCHAR) FDKreadBits(bs,2); + pIcsInfo->WindowShape = (UCHAR) FDKreadBits(bs,1); + if (flags & AC_LD) { + if (pIcsInfo->WindowShape) { + pIcsInfo->WindowShape = 2; /* select low overlap instead of KBD */ + } + } + } + + /* Sanity check */ + if ( (flags & (AC_ELD|AC_LD)) && pIcsInfo->WindowSequence != OnlyLongSequence) { + pIcsInfo->WindowSequence = OnlyLongSequence; + ErrorStatus = AAC_DEC_PARSE_ERROR; + goto bail; + } + + ErrorStatus = IcsReadMaxSfb(bs, pIcsInfo, pSamplingRateInfo); + if (ErrorStatus != AAC_DEC_OK) { + goto bail; + } + + if (IsLongBlock(pIcsInfo)) + { + if ( !(flags & (AC_ELD|AC_SCALABLE|AC_BSAC|AC_USAC|AC_RSVD50)) ) /* If not ELD nor Scalable nor BSAC nor USAC syntax then ... */ + { + if ((UCHAR)FDKreadBits(bs,1) != 0 ) /* UCHAR PredictorDataPresent */ + { + ErrorStatus = AAC_DEC_UNSUPPORTED_PREDICTION; + goto bail; + } + } + + pIcsInfo->WindowGroups = 1; + pIcsInfo->WindowGroupLength[0] = 1; + } + else + { + INT i; + UINT mask; + + pIcsInfo->ScaleFactorGrouping = (UCHAR) FDKreadBits(bs,7); + + pIcsInfo->WindowGroups = 0 ; + + for (i=0; i < (8-1); i++) + { + mask = 1 << (6 - i); + pIcsInfo->WindowGroupLength[i] = 1; + + if (pIcsInfo->ScaleFactorGrouping & mask) + { + pIcsInfo->WindowGroupLength[pIcsInfo->WindowGroups]++; + } + else + { + pIcsInfo->WindowGroups++; + } + } + + /* loop runs to i < 7 only */ + pIcsInfo->WindowGroupLength[8-1] = 1; + pIcsInfo->WindowGroups++; + } + + +bail: + if (ErrorStatus == AAC_DEC_OK) + pIcsInfo->Valid = 1; + + return ErrorStatus; +} + + +/* + interleave codebooks the following way + + 9 (84w) | 1 (51w) + 10 (82w) | 2 (39w) + SCL (65w) | 4 (38w) + 3 (39w) | 5 (41w) + | 6 (40w) + | 7 (31w) + | 8 (31w) + (270w) (271w) +*/ + + +/* + Table entries are sorted as following: + | num_swb_long_window | sfbands_long | num_swb_short_window | sfbands_short | +*/ +AAC_DECODER_ERROR getSamplingRateInfo( + SamplingRateInfo *t, + UINT samplesPerFrame, + UINT samplingRateIndex, + UINT samplingRate + ) +{ + int index = 0; + + + t->samplingRateIndex = samplingRateIndex; + t->samplingRate = samplingRate; + + switch (samplesPerFrame) { + case 1024: + index = 0; + break; + case 960: + index = 1; + break; + case 512: + index = 3; + break; + case 480: + index = 4; + break; + + default: + return AAC_DEC_UNSUPPORTED_FORMAT; + } + + t->ScaleFactorBands_Long = sfbOffsetTables[index][samplingRateIndex].sfbOffsetLong; + t->ScaleFactorBands_Short = sfbOffsetTables[index][samplingRateIndex].sfbOffsetShort; + t->NumberOfScaleFactorBands_Long = sfbOffsetTables[index][samplingRateIndex].numberOfSfbLong; + t->NumberOfScaleFactorBands_Short = sfbOffsetTables[index][samplingRateIndex].numberOfSfbShort; + + if (t->ScaleFactorBands_Long == NULL || t->NumberOfScaleFactorBands_Long == 0) { + return AAC_DEC_UNSUPPORTED_FORMAT; + } + + FDK_ASSERT(t->ScaleFactorBands_Long[t->NumberOfScaleFactorBands_Long] == samplesPerFrame); + FDK_ASSERT(t->ScaleFactorBands_Short == NULL || t->ScaleFactorBands_Short[t->NumberOfScaleFactorBands_Short]*8 == samplesPerFrame); + + return AAC_DEC_OK; +} |