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Diffstat (limited to 'libAACdec/src/channelinfo.cpp')
| -rw-r--r-- | libAACdec/src/channelinfo.cpp | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/libAACdec/src/channelinfo.cpp b/libAACdec/src/channelinfo.cpp new file mode 100644 index 0000000..6e520c0 --- /dev/null +++ b/libAACdec/src/channelinfo.cpp @@ -0,0 +1,276 @@ + +/* ----------------------------------------------------------------------------------------------------------- +Software License for The Fraunhofer FDK AAC Codec Library for Android + +© Copyright 1995 - 2012 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 +----------------------------------------------------------------------------------------------------------- */ + +/***************************** MPEG-4 AAC Decoder ************************** + + Author(s): Josef Hoepfl + Description: individual channel stream info + +******************************************************************************/ + +#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; +} |