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Diffstat (limited to 'libSBRdec/src/psbitdec.cpp')
| -rw-r--r-- | libSBRdec/src/psbitdec.cpp | 536 |
1 files changed, 536 insertions, 0 deletions
diff --git a/libSBRdec/src/psbitdec.cpp b/libSBRdec/src/psbitdec.cpp new file mode 100644 index 0000000..0a5687a --- /dev/null +++ b/libSBRdec/src/psbitdec.cpp @@ -0,0 +1,536 @@ +/**************************************************************************** + + (C) Copyright Fraunhofer IIS (2005) + 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. + + + 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. + + $Id$ + +*******************************************************************************/ + +#include "psbitdec.h" + + +#include "sbr_rom.h" +#include "huff_dec.h" + +/* PS dec privat functions */ +SBR_ERROR ResetPsDec(HANDLE_PS_DEC h_ps_d); +void ResetPsDeCor (HANDLE_PS_DEC h_ps_d); + +/***************************************************************************/ +/*! + \brief huffman decoding by codebook table + + \return index of huffman codebook table + +****************************************************************************/ +static SCHAR +decode_huff_cw (Huffman h, /*!< pointer to huffman codebook table */ + HANDLE_FDK_BITSTREAM hBitBuf, /*!< Handle to Bitbuffer */ + int *length) /*!< length of huffman codeword (or NULL) */ +{ + UCHAR bit = 0; + SCHAR index = 0; + UCHAR bitCount = 0; + + while (index >= 0) { + bit = FDKreadBits (hBitBuf, 1); + bitCount++; + index = h[index][bit]; + } + if (length) { + *length = bitCount; + } + return( index+64 ); /* Add offset */ +} + +/***************************************************************************/ +/*! + \brief helper function - limiting of value to min/max values + + \return limited value + +****************************************************************************/ + +static SCHAR +limitMinMax(SCHAR i, + SCHAR min, + SCHAR max) +{ + if (i<min) + return min; + else if (i>max) + return max; + else + return i; +} + +/***************************************************************************/ +/*! + \brief Decodes delta values in-place and updates + data buffers according to quantization classes. + + When delta coded in frequency the first element is deltacode from zero. + aIndex buffer is decoded from delta values to actual values. + + \return none + +****************************************************************************/ +static void +deltaDecodeArray(SCHAR enable, + SCHAR *aIndex, /*!< ICC/IID parameters */ + SCHAR *aPrevFrameIndex, /*!< ICC/IID parameters of previous frame */ + SCHAR DtDf, + UCHAR nrElements, /*!< as conveyed in bitstream */ + /*!< output array size: nrElements*stride */ + UCHAR stride, /*!< 1=dflt, 2=half freq. resolution */ + SCHAR minIdx, + SCHAR maxIdx) +{ + int i; + + /* Delta decode */ + if ( enable==1 ) { + if (DtDf == 0) { /* Delta coded in freq */ + aIndex[0] = 0 + aIndex[0]; + aIndex[0] = limitMinMax(aIndex[0],minIdx,maxIdx); + for (i = 1; i < nrElements; i++) { + aIndex[i] = aIndex[i-1] + aIndex[i]; + aIndex[i] = limitMinMax(aIndex[i],minIdx,maxIdx); + } + } + else { /* Delta time */ + for (i = 0; i < nrElements; i++) { + aIndex[i] = aPrevFrameIndex[i*stride] + aIndex[i]; + aIndex[i] = limitMinMax(aIndex[i],minIdx,maxIdx); + } + } + } + else { /* No data is sent, set index to zero */ + for (i = 0; i < nrElements; i++) { + aIndex[i] = 0; + } + } + if (stride==2) { + for (i=nrElements*stride-1; i>0; i--) { + aIndex[i] = aIndex[i>>1]; + } + } +} + +/***************************************************************************/ +/*! + \brief Mapping of ICC/IID parameters to 20 stereo bands + + \return none + +****************************************************************************/ +static void map34IndexTo20 (SCHAR *aIndex, /*!< decoded ICC/IID parameters */ + UCHAR noBins) /*!< number of stereo bands */ +{ + aIndex[0] = (2*aIndex[0]+aIndex[1])/3; + aIndex[1] = (aIndex[1]+2*aIndex[2])/3; + aIndex[2] = (2*aIndex[3]+aIndex[4])/3; + aIndex[3] = (aIndex[4]+2*aIndex[5])/3; + aIndex[4] = (aIndex[6]+aIndex[7])/2; + aIndex[5] = (aIndex[8]+aIndex[9])/2; + aIndex[6] = aIndex[10]; + aIndex[7] = aIndex[11]; + aIndex[8] = (aIndex[12]+aIndex[13])/2; + aIndex[9] = (aIndex[14]+aIndex[15])/2; + aIndex[10] = aIndex[16]; + /* For IPD/OPD it stops here */ + + if (noBins == NO_HI_RES_BINS) + { + aIndex[11] = aIndex[17]; + aIndex[12] = aIndex[18]; + aIndex[13] = aIndex[19]; + aIndex[14] = (aIndex[20]+aIndex[21])/2; + aIndex[15] = (aIndex[22]+aIndex[23])/2; + aIndex[16] = (aIndex[24]+aIndex[25])/2; + aIndex[17] = (aIndex[26]+aIndex[27])/2; + aIndex[18] = (aIndex[28]+aIndex[29]+aIndex[30]+aIndex[31])/4; + aIndex[19] = (aIndex[32]+aIndex[33])/2; + } +} + +/***************************************************************************/ +/*! + \brief Decodes delta coded IID, ICC, IPD and OPD indices + + \return PS processing flag. If set to 1 + +****************************************************************************/ +int +DecodePs( struct PS_DEC *h_ps_d, /*!< PS handle */ + const UCHAR frameError ) /*!< Flag telling that frame had errors */ +{ + MPEG_PS_BS_DATA *pBsData; + UCHAR gr, env; + int bPsHeaderValid, bPsDataAvail; + + /* Shortcuts to avoid deferencing and keep the code readable */ + pBsData = &h_ps_d->bsData[h_ps_d->processSlot].mpeg; + bPsHeaderValid = pBsData->bPsHeaderValid; + bPsDataAvail = (h_ps_d->bPsDataAvail[h_ps_d->processSlot] == ppt_mpeg) ? 1 : 0; + + /*************************************************************************************** + * Decide whether to process or to conceal PS data or not. */ + + if ( ( h_ps_d->psDecodedPrv && !frameError && !bPsDataAvail) + || (!h_ps_d->psDecodedPrv && (frameError || !bPsDataAvail || !bPsHeaderValid)) ) { + /* Don't apply PS processing. + * Declare current PS header and bitstream data invalid. */ + pBsData->bPsHeaderValid = 0; + h_ps_d->bPsDataAvail[h_ps_d->processSlot] = ppt_none; + return (0); + } + + if (frameError || !bPsHeaderValid) + { /* no new PS data available (e.g. frame loss) */ + /* => keep latest data constant (i.e. FIX with noEnv=0) */ + pBsData->noEnv = 0; + } + + /*************************************************************************************** + * Decode bitstream payload or prepare parameter for concealment: + */ + for (env=0; env<pBsData->noEnv; env++) { + SCHAR *aPrevIidIndex; + SCHAR *aPrevIccIndex; + + UCHAR noIidSteps = pBsData->bFineIidQ?NO_IID_STEPS_FINE:NO_IID_STEPS; + + if (env==0) { + aPrevIidIndex = h_ps_d->specificTo.mpeg.aIidPrevFrameIndex; + aPrevIccIndex = h_ps_d->specificTo.mpeg.aIccPrevFrameIndex; + } + else { + aPrevIidIndex = pBsData->aaIidIndex[env-1]; + aPrevIccIndex = pBsData->aaIccIndex[env-1]; + } + + deltaDecodeArray(pBsData->bEnableIid, + pBsData->aaIidIndex[env], + aPrevIidIndex, + pBsData->abIidDtFlag[env], + FDK_sbrDecoder_aNoIidBins[pBsData->freqResIid], + (pBsData->freqResIid)?1:2, + -noIidSteps, + noIidSteps); + + deltaDecodeArray(pBsData->bEnableIcc, + pBsData->aaIccIndex[env], + aPrevIccIndex, + pBsData->abIccDtFlag[env], + FDK_sbrDecoder_aNoIccBins[pBsData->freqResIcc], + (pBsData->freqResIcc)?1:2, + 0, + NO_ICC_STEPS-1); + } /* for (env=0; env<pBsData->noEnv; env++) */ + + /* handling of FIX noEnv=0 */ + if (pBsData->noEnv==0) { + /* set noEnv=1, keep last parameters or force 0 if not enabled */ + pBsData->noEnv = 1; + + if (pBsData->bEnableIid) { + for (gr = 0; gr < NO_HI_RES_IID_BINS; gr++) { + pBsData->aaIidIndex[pBsData->noEnv-1][gr] = + h_ps_d->specificTo.mpeg.aIidPrevFrameIndex[gr]; + } + } + else { + for (gr = 0; gr < NO_HI_RES_IID_BINS; gr++) { + pBsData->aaIidIndex[pBsData->noEnv-1][gr] = 0; + } + } + + if (pBsData->bEnableIcc) { + for (gr = 0; gr < NO_HI_RES_ICC_BINS; gr++) { + pBsData->aaIccIndex[pBsData->noEnv-1][gr] = + h_ps_d->specificTo.mpeg.aIccPrevFrameIndex[gr]; + } + } + else { + for (gr = 0; gr < NO_HI_RES_ICC_BINS; gr++) { + pBsData->aaIccIndex[pBsData->noEnv-1][gr] = 0; + } + } + } + + /* Update previous frame index buffers */ + for (gr = 0; gr < NO_HI_RES_IID_BINS; gr++) { + h_ps_d->specificTo.mpeg.aIidPrevFrameIndex[gr] = + pBsData->aaIidIndex[pBsData->noEnv-1][gr]; + } + for (gr = 0; gr < NO_HI_RES_ICC_BINS; gr++) { + h_ps_d->specificTo.mpeg.aIccPrevFrameIndex[gr] = + pBsData->aaIccIndex[pBsData->noEnv-1][gr]; + } + + /* PS data from bitstream (if avail) was decoded now */ + h_ps_d->bPsDataAvail[h_ps_d->processSlot] = ppt_none; + + /* handling of env borders for FIX & VAR */ + if (pBsData->bFrameClass == 0) { + /* FIX_BORDERS NoEnv=0,1,2,4 */ + pBsData->aEnvStartStop[0] = 0; + for (env=1; env<pBsData->noEnv; env++) { + pBsData->aEnvStartStop[env] = + (env * h_ps_d->noSubSamples) / pBsData->noEnv; + } + pBsData->aEnvStartStop[pBsData->noEnv] = h_ps_d->noSubSamples; + /* 1024 (32 slots) env borders: 0, 8, 16, 24, 32 */ + /* 960 (30 slots) env borders: 0, 7, 15, 22, 30 */ + } + else { /* if (h_ps_d->bFrameClass == 0) */ + /* VAR_BORDERS NoEnv=1,2,3,4 */ + pBsData->aEnvStartStop[0] = 0; + + /* handle case aEnvStartStop[noEnv]<noSubSample for VAR_BORDERS by + duplicating last PS parameters and incrementing noEnv */ + if (pBsData->aEnvStartStop[pBsData->noEnv] < h_ps_d->noSubSamples) { + for (gr = 0; gr < NO_HI_RES_IID_BINS; gr++) { + pBsData->aaIidIndex[pBsData->noEnv][gr] = + pBsData->aaIidIndex[pBsData->noEnv-1][gr]; + } + for (gr = 0; gr < NO_HI_RES_ICC_BINS; gr++) { + pBsData->aaIccIndex[pBsData->noEnv][gr] = + pBsData->aaIccIndex[pBsData->noEnv-1][gr]; + } + pBsData->noEnv++; + pBsData->aEnvStartStop[pBsData->noEnv] = h_ps_d->noSubSamples; + } + + /* enforce strictly monotonic increasing borders */ + for (env=1; env<pBsData->noEnv; env++) { + UCHAR thr; + thr = (UCHAR)h_ps_d->noSubSamples - (pBsData->noEnv - env); + if (pBsData->aEnvStartStop[env] > thr) { + pBsData->aEnvStartStop[env] = thr; + } + else { + thr = pBsData->aEnvStartStop[env-1]+1; + if (pBsData->aEnvStartStop[env] < thr) { + pBsData->aEnvStartStop[env] = thr; + } + } + } + } /* if (h_ps_d->bFrameClass == 0) ... else */ + + /* copy data prior to possible 20<->34 in-place mapping */ + for (env=0; env<pBsData->noEnv; env++) { + UCHAR i; + for (i=0; i<NO_HI_RES_IID_BINS; i++) { + h_ps_d->specificTo.mpeg.coef.aaIidIndexMapped[env][i] = pBsData->aaIidIndex[env][i]; + } + for (i=0; i<NO_HI_RES_ICC_BINS; i++) { + h_ps_d->specificTo.mpeg.coef.aaIccIndexMapped[env][i] = pBsData->aaIccIndex[env][i]; + } + } + + + /* MPEG baseline PS */ + /* Baseline version of PS always uses the hybrid filter structure with 20 stereo bands. */ + /* If ICC/IID parameters for 34 stereo bands are decoded they have to be mapped to 20 */ + /* stereo bands. */ + /* Additionaly the IPD/OPD parameters won't be used. */ + + for (env=0; env<pBsData->noEnv; env++) { + if (pBsData->freqResIid == 2) + map34IndexTo20 (h_ps_d->specificTo.mpeg.coef.aaIidIndexMapped[env], NO_HI_RES_IID_BINS); + if (pBsData->freqResIcc == 2) + map34IndexTo20 (h_ps_d->specificTo.mpeg.coef.aaIccIndexMapped[env], NO_HI_RES_ICC_BINS); + + /* IPD/OPD is disabled in baseline version and thus was removed here */ + } + + return (1); +} + + +/***************************************************************************/ +/*! + + \brief Reads parametric stereo data from bitstream + + \return + +****************************************************************************/ +unsigned int +ReadPsData (HANDLE_PS_DEC h_ps_d, /*!< handle to struct PS_DEC */ + HANDLE_FDK_BITSTREAM hBitBuf, /*!< handle to struct BIT_BUF */ + int nBitsLeft /*!< max number of bits available */ + ) +{ + MPEG_PS_BS_DATA *pBsData; + + UCHAR gr, env; + SCHAR dtFlag; + INT startbits; + Huffman CurrentTable; + SCHAR bEnableHeader; + + if (!h_ps_d) + return 0; + + pBsData = &h_ps_d->bsData[h_ps_d->bsReadSlot].mpeg; + + if (h_ps_d->bsReadSlot != h_ps_d->bsLastSlot) { + /* Copy last header data */ + FDKmemcpy(pBsData, &h_ps_d->bsData[h_ps_d->bsLastSlot].mpeg, sizeof(MPEG_PS_BS_DATA)); + } + + + startbits = (INT) FDKgetValidBits(hBitBuf); + + bEnableHeader = (SCHAR) FDKreadBits (hBitBuf, 1); + + /* Read header */ + if (bEnableHeader) { + pBsData->bPsHeaderValid = 1; + pBsData->bEnableIid = (UCHAR) FDKreadBits (hBitBuf, 1); + if (pBsData->bEnableIid) { + pBsData->modeIid = (UCHAR) FDKreadBits (hBitBuf, 3); + } + + pBsData->bEnableIcc = (UCHAR) FDKreadBits (hBitBuf, 1); + if (pBsData->bEnableIcc) { + pBsData->modeIcc = (UCHAR) FDKreadBits (hBitBuf, 3); + } + + pBsData->bEnableExt = (UCHAR) FDKreadBits (hBitBuf, 1); + } + + pBsData->bFrameClass = (UCHAR) FDKreadBits (hBitBuf, 1); + if (pBsData->bFrameClass == 0) { + /* FIX_BORDERS NoEnv=0,1,2,4 */ + pBsData->noEnv = FDK_sbrDecoder_aFixNoEnvDecode[(UCHAR) FDKreadBits (hBitBuf, 2)]; + /* all additional handling of env borders is now in DecodePs() */ + } + else { + /* VAR_BORDERS NoEnv=1,2,3,4 */ + pBsData->noEnv = 1+(UCHAR) FDKreadBits (hBitBuf, 2); + for (env=1; env<pBsData->noEnv+1; env++) + pBsData->aEnvStartStop[env] = ((UCHAR) FDKreadBits (hBitBuf, 5)) + 1; + /* all additional handling of env borders is now in DecodePs() */ + } + + /* verify that IID & ICC modes (quant grid, freq res) are supported */ + if ((pBsData->modeIid > 5) || (pBsData->modeIcc > 5)) { + /* no useful PS data could be read from bitstream */ + h_ps_d->bPsDataAvail[h_ps_d->bsReadSlot] = ppt_none; + /* discard all remaining bits */ + nBitsLeft -= startbits - FDKgetValidBits(hBitBuf); + while (nBitsLeft) { + int i = nBitsLeft; + if (i>8) { + i = 8; + } + FDKreadBits (hBitBuf, i); + nBitsLeft -= i; + } + return (startbits - FDKgetValidBits(hBitBuf)); + } + + if (pBsData->modeIid > 2){ + pBsData->freqResIid = pBsData->modeIid-3; + pBsData->bFineIidQ = 1; + } + else{ + pBsData->freqResIid = pBsData->modeIid; + pBsData->bFineIidQ = 0; + } + + if (pBsData->modeIcc > 2){ + pBsData->freqResIcc = pBsData->modeIcc-3; + } + else{ + pBsData->freqResIcc = pBsData->modeIcc; + } + + + /* Extract IID data */ + if (pBsData->bEnableIid) { + for (env=0; env<pBsData->noEnv; env++) { + dtFlag = (SCHAR)FDKreadBits (hBitBuf, 1); + if (!dtFlag) + { + if (pBsData->bFineIidQ) + CurrentTable = (Huffman)&aBookPsIidFineFreqDecode; + else + CurrentTable = (Huffman)&aBookPsIidFreqDecode; + } + else + { + if (pBsData->bFineIidQ) + CurrentTable = (Huffman)&aBookPsIidFineTimeDecode; + else + CurrentTable = (Huffman)&aBookPsIidTimeDecode; + } + + for (gr = 0; gr < FDK_sbrDecoder_aNoIidBins[pBsData->freqResIid]; gr++) + pBsData->aaIidIndex[env][gr] = decode_huff_cw(CurrentTable,hBitBuf,NULL); + pBsData->abIidDtFlag[env] = dtFlag; + } + } + + /* Extract ICC data */ + if (pBsData->bEnableIcc) { + for (env=0; env<pBsData->noEnv; env++) { + dtFlag = (SCHAR)FDKreadBits (hBitBuf, 1); + if (!dtFlag) + CurrentTable = (Huffman)&aBookPsIccFreqDecode; + else + CurrentTable = (Huffman)&aBookPsIccTimeDecode; + + for (gr = 0; gr < FDK_sbrDecoder_aNoIccBins[pBsData->freqResIcc]; gr++) + pBsData->aaIccIndex[env][gr] = decode_huff_cw(CurrentTable,hBitBuf,NULL); + pBsData->abIccDtFlag[env] = dtFlag; + } + } + + if (pBsData->bEnableExt) { + + /*! + Decoders that support only the baseline version of the PS tool are allowed + to ignore the IPD/OPD data, but according header data has to be parsed. + ISO/IEC 14496-3 Subpart 8 Annex 4 + */ + + int cnt = FDKreadBits(hBitBuf, PS_EXTENSION_SIZE_BITS); + if (cnt == (1<<PS_EXTENSION_SIZE_BITS)-1) { + cnt += FDKreadBits(hBitBuf, PS_EXTENSION_ESC_COUNT_BITS); + } + while (cnt--) + FDKreadBits(hBitBuf, 8); + } + + + /* new PS data was read from bitstream */ + h_ps_d->bPsDataAvail[h_ps_d->bsReadSlot] = ppt_mpeg; + + + + return (startbits - FDKgetValidBits(hBitBuf)); +} + |