| |
| /* ----------------------------------------------------------------------------------------------------------- |
| 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: joint stereo processing |
| |
| ******************************************************************************/ |
| |
| #include "stereo.h" |
| |
| |
| #include "aac_rom.h" |
| #include "FDK_bitstream.h" |
| #include "channelinfo.h" |
| |
| enum |
| { |
| L = 0, |
| R = 1 |
| }; |
| |
| |
| int CJointStereo_Read( |
| HANDLE_FDK_BITSTREAM bs, |
| CJointStereoData *pJointStereoData, |
| const int windowGroups, |
| const int scaleFactorBandsTransmitted, |
| const UINT flags |
| ) |
| { |
| int group,band; |
| |
| pJointStereoData->MsMaskPresent = (UCHAR) FDKreadBits(bs,2); |
| |
| FDKmemclear(pJointStereoData->MsUsed, scaleFactorBandsTransmitted*sizeof(UCHAR)); |
| |
| switch (pJointStereoData->MsMaskPresent) |
| { |
| case 0 : /* no M/S */ |
| /* all flags are already cleared */ |
| break ; |
| |
| case 1 : /* read ms_used */ |
| |
| for (group=0; group<windowGroups; group++) |
| { |
| for (band=0; band<scaleFactorBandsTransmitted; band++) |
| { |
| pJointStereoData->MsUsed[band] |= (FDKreadBits(bs,1) << group); |
| } |
| } |
| break ; |
| |
| case 2 : /* full spectrum M/S */ |
| |
| for (band=0; band<scaleFactorBandsTransmitted; band++) |
| { |
| pJointStereoData->MsUsed[band] = 255 ; /* set all flags to 1 */ |
| } |
| break ; |
| } |
| |
| return 0; |
| } |
| |
| void CJointStereo_ApplyMS( |
| CAacDecoderChannelInfo *pAacDecoderChannelInfo[2], |
| const SHORT *pScaleFactorBandOffsets, |
| const UCHAR *pWindowGroupLength, |
| const int windowGroups, |
| const int scaleFactorBandsTransmittedL, |
| const int scaleFactorBandsTransmittedR |
| ) |
| { |
| CJointStereoData *pJointStereoData = &pAacDecoderChannelInfo[L]->pComData->jointStereoData; |
| int window, group, scaleFactorBandsTransmitted; |
| |
| FDK_ASSERT(scaleFactorBandsTransmittedL == scaleFactorBandsTransmittedR); |
| scaleFactorBandsTransmitted = scaleFactorBandsTransmittedL; |
| for (window = 0, group = 0; group < windowGroups; group++) |
| { |
| UCHAR groupMask = 1 << group; |
| |
| for (int groupwin=0; groupwin<pWindowGroupLength[group]; groupwin++, window++) |
| { |
| int band; |
| FIXP_DBL *leftSpectrum, *rightSpectrum; |
| SHORT *leftScale = &pAacDecoderChannelInfo[L]->pDynData->aSfbScale[window*16]; |
| SHORT *rightScale = &pAacDecoderChannelInfo[R]->pDynData->aSfbScale[window*16]; |
| |
| leftSpectrum = SPEC(pAacDecoderChannelInfo[L]->pSpectralCoefficient, window, pAacDecoderChannelInfo[L]->granuleLength); |
| rightSpectrum = SPEC(pAacDecoderChannelInfo[R]->pSpectralCoefficient, window, pAacDecoderChannelInfo[R]->granuleLength); |
| |
| for (band=0; band<scaleFactorBandsTransmitted; band++) |
| { |
| if (pJointStereoData->MsUsed[band] & groupMask) |
| { |
| int lScale=leftScale[band]; |
| int rScale=rightScale[band]; |
| int commonScale=lScale > rScale ? lScale:rScale; |
| |
| /* ISO/IEC 14496-3 Chapter 4.6.8.1.1 : |
| M/S joint channel coding can only be used if common_window is 1. */ |
| FDK_ASSERT(GetWindowSequence(&pAacDecoderChannelInfo[L]->icsInfo) == GetWindowSequence(&pAacDecoderChannelInfo[R]->icsInfo)); |
| FDK_ASSERT(GetWindowShape(&pAacDecoderChannelInfo[L]->icsInfo) == GetWindowShape(&pAacDecoderChannelInfo[R]->icsInfo)); |
| |
| commonScale++; |
| leftScale[band]=commonScale; |
| rightScale[band]=commonScale; |
| |
| lScale = fMin(DFRACT_BITS-1, commonScale - lScale); |
| rScale = fMin(DFRACT_BITS-1, commonScale - rScale); |
| |
| FDK_ASSERT(lScale >= 0 && rScale >= 0); |
| |
| for (int index=pScaleFactorBandOffsets[band]; index<pScaleFactorBandOffsets[band+1]; index++) |
| { |
| FIXP_DBL leftCoefficient = leftSpectrum [index] ; |
| FIXP_DBL rightCoefficient = rightSpectrum [index] ; |
| |
| leftCoefficient >>= lScale ; |
| rightCoefficient >>= rScale ; |
| |
| leftSpectrum [index] = leftCoefficient + rightCoefficient ; |
| rightSpectrum [index] = leftCoefficient - rightCoefficient ; |
| } |
| } |
| } |
| } |
| } |
| |
| /* Reset MsUsed flags if no explicit signalling was transmitted. Necessary for intensity coding. |
| PNS correlation signalling was mapped before calling CJointStereo_ApplyMS(). */ |
| if (pJointStereoData->MsMaskPresent == 2) { |
| FDKmemclear(pJointStereoData->MsUsed, JointStereoMaximumBands * sizeof(UCHAR)); |
| } |
| } |
| |
| void CJointStereo_ApplyIS( |
| CAacDecoderChannelInfo *pAacDecoderChannelInfo[2], |
| const SHORT *pScaleFactorBandOffsets, |
| const UCHAR *pWindowGroupLength, |
| const int windowGroups, |
| const int scaleFactorBandsTransmitted, |
| const UINT CommonWindow |
| ) |
| { |
| CJointStereoData *pJointStereoData = &pAacDecoderChannelInfo[L]->pComData->jointStereoData; |
| |
| for (int window=0,group=0; group<windowGroups; group++) |
| { |
| UCHAR *CodeBook; |
| SHORT *ScaleFactor; |
| UCHAR groupMask = 1 << group; |
| |
| CodeBook = &pAacDecoderChannelInfo[R]->pDynData->aCodeBook[group*16]; |
| ScaleFactor = &pAacDecoderChannelInfo[R]->pDynData->aScaleFactor[group*16]; |
| |
| for (int groupwin=0; groupwin<pWindowGroupLength[group]; groupwin++, window++) |
| { |
| FIXP_DBL *leftSpectrum, *rightSpectrum; |
| SHORT *leftScale = &pAacDecoderChannelInfo[L]->pDynData->aSfbScale[window*16]; |
| SHORT *rightScale = &pAacDecoderChannelInfo[R]->pDynData->aSfbScale[window*16]; |
| int band; |
| |
| leftSpectrum = SPEC(pAacDecoderChannelInfo[L]->pSpectralCoefficient, window, pAacDecoderChannelInfo[L]->granuleLength); |
| rightSpectrum = SPEC(pAacDecoderChannelInfo[R]->pSpectralCoefficient, window, pAacDecoderChannelInfo[R]->granuleLength); |
| |
| for (band=0; band<scaleFactorBandsTransmitted; band++) |
| { |
| if ((CodeBook [band] == INTENSITY_HCB) || |
| (CodeBook [band] == INTENSITY_HCB2)) |
| { |
| int bandScale = -(ScaleFactor [band] + 100) ; |
| |
| int msb = bandScale >> 2 ; |
| int lsb = bandScale & 0x03 ; |
| |
| /* exponent of MantissaTable[lsb][0] is 1, thus msb+1 below. */ |
| FIXP_DBL scale = MantissaTable[lsb][0]; |
| |
| /* ISO/IEC 14496-3 Chapter 4.6.8.2.3 : |
| The use of intensity stereo coding is signaled by the use of the pseudo codebooks |
| INTENSITY_HCB and INTENSITY_HCB2 (15 and 14) only in the right channel of a |
| channel_pair_element() having a common ics_info() (common_window == 1). */ |
| FDK_ASSERT(GetWindowSequence(&pAacDecoderChannelInfo[L]->icsInfo) == GetWindowSequence(&pAacDecoderChannelInfo[R]->icsInfo)); |
| FDK_ASSERT(GetWindowShape(&pAacDecoderChannelInfo[L]->icsInfo) == GetWindowShape(&pAacDecoderChannelInfo[R]->icsInfo)); |
| |
| rightScale[band] = leftScale[band]+msb+1; |
| |
| if (CommonWindow && (pJointStereoData->MsUsed[band] & groupMask)) |
| { |
| |
| if (CodeBook[band] == INTENSITY_HCB) /* _NOT_ in-phase */ |
| { |
| scale = -scale ; |
| } |
| } |
| else |
| { |
| if (CodeBook[band] == INTENSITY_HCB2) /* out-of-phase */ |
| { |
| scale = -scale ; |
| } |
| } |
| |
| for (int index=pScaleFactorBandOffsets[band]; index<pScaleFactorBandOffsets[band+1]; index++) |
| { |
| rightSpectrum[index] = fMult(leftSpectrum[index],scale); |
| } |
| } |
| } |
| } |
| } |
| } |
