/*--------------------------------------------------------------------------------------------- description: This function returns a bit from the bitstream according to read direction. It is called very often, therefore it makes sense to inline it (runtime). ----------------------------------------------------------------------------------------------- input: - handle to FDK bitstream - reference value marking start of bitfield - pLeftStartOfSegment - pRightStartOfSegment - readDirection ----------------------------------------------------------------------------------------------- return: - bit from bitstream -------------------------------------------------------------------------------------------- */ UINT HcrGetABitFromBitstream(HANDLE_FDK_BITSTREAM bs, const INT bsAnchor, INT *pLeftStartOfSegment, INT *pRightStartOfSegment, UCHAR readDirection) { UINT bit; INT readBitOffset; if (readDirection == FROM_LEFT_TO_RIGHT) { readBitOffset = (INT)FDKgetValidBits(bs) - bsAnchor + *pLeftStartOfSegment; if (readBitOffset) { FDKpushBiDirectional(bs, readBitOffset); } bit = FDKreadBits(bs, 1); *pLeftStartOfSegment += 1; } else { readBitOffset = (INT)FDKgetValidBits(bs) - bsAnchor + *pRightStartOfSegment; if (readBitOffset) { FDKpushBiDirectional(bs, readBitOffset); } /* to be replaced with a brother function of FDKreadBits() */ bit = FDKreadBits(bs, 1); FDKpushBack(bs, 2); *pRightStartOfSegment -= 1; } return (bit); }
TRANSPORTDEC_ERROR adifRead_DecodeHeader( CAdifHeader *pAdifHeader, CProgramConfig *pPce, HANDLE_FDK_BITSTREAM bs ) { int i; TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK; UINT startAnchor = FDKgetValidBits(bs); if ((INT)startAnchor < MIN_ADIF_HEADERLENGTH) { return (TRANSPORTDEC_NOT_ENOUGH_BITS); } if (FDKreadBits(bs,8) != 'A') { return (TRANSPORTDEC_SYNC_ERROR); } if (FDKreadBits(bs,8) != 'D') { return (TRANSPORTDEC_SYNC_ERROR); } if (FDKreadBits(bs,8) != 'I') { return (TRANSPORTDEC_SYNC_ERROR); } if (FDKreadBits(bs,8) != 'F') { return (TRANSPORTDEC_SYNC_ERROR); } if ( (pAdifHeader->CopyrightIdPresent = FDKreadBits(bs,1)) != 0 ) FDKpushBiDirectional(bs,72); /* CopyrightId */ pAdifHeader->OriginalCopy = FDKreadBits(bs,1); pAdifHeader->Home = FDKreadBits(bs,1); pAdifHeader->BitstreamType = FDKreadBits(bs,1); /* pAdifHeader->BitRate = FDKreadBits(bs, 23); */ pAdifHeader->BitRate = FDKreadBits(bs,16); pAdifHeader->BitRate <<= 7; pAdifHeader->BitRate |= FDKreadBits(bs,7); pAdifHeader->NumProgramConfigElements = FDKreadBits(bs,4) + 1; if (pAdifHeader->BitstreamType == 0) { FDKpushBiDirectional(bs,20); /* adif_buffer_fullness */ } /* Parse all PCEs but keep only one */ for (i=0; i < pAdifHeader->NumProgramConfigElements; i++) { CProgramConfig_Read(pPce, bs, startAnchor); } FDKbyteAlign(bs, startAnchor); return (ErrorStatus); }
UCHAR rvlcReadBitFromBitstream (HANDLE_FDK_BITSTREAM bs, USHORT *pPosition, UCHAR readDirection) { UINT bit; INT readBitOffset = *pPosition-FDKgetBitCnt(bs); if( readBitOffset ) { FDKpushBiDirectional(bs, readBitOffset); } if (readDirection == FWD) { bit = FDKreadBits(bs, 1); *pPosition += 1; } else { /* to be replaced with a brother function of FDKreadBits() */ bit = FDKreadBits(bs, 1); FDKpushBack(bs, 2); *pPosition -= 1; } return (bit); }
TRANSPORTDEC_ERROR transportDec_CrcCheck(HANDLE_TRANSPORTDEC pTp) { switch (pTp->transportFmt) { case TT_MP4_ADTS: if ( (pTp->parser.adts.bs.num_raw_blocks > 0) && (pTp->parser.adts.bs.protection_absent == 0) ) { HANDLE_FDK_BITSTREAM hBs = &pTp->bitStream[0]; int bitDiff; /* Calculate possible offset to CRC value. */ bitDiff = pTp->parser.adts.rawDataBlockDist[pTp->parser.adts.bs.num_raw_blocks-pTp->numberOfRawDataBlocks]<<3; bitDiff -= pTp->globalFramePos - FDKgetValidBits(hBs) + 16; FDKpushBiDirectional(hBs, bitDiff); pTp->parser.adts.crcReadValue = FDKreadBits(hBs, 16); } return adtsRead_CrcCheck(&pTp->parser.adts); default: return TRANSPORTDEC_OK; } }
/** * \brief adjust bit stream position and the end of an access unit. * \param hTp transport decoder handle. * \return error code. */ static TRANSPORTDEC_ERROR transportDec_AdjustEndOfAccessUnit(HANDLE_TRANSPORTDEC hTp) { HANDLE_FDK_BITSTREAM hBs = &hTp->bitStream[0]; TRANSPORTDEC_ERROR err = TRANSPORTDEC_OK; switch (hTp->transportFmt) { case TT_MP4_LOAS: case TT_MP4_LATM_MCP0: case TT_MP4_LATM_MCP1: if ( hTp->numberOfRawDataBlocks == 0 ) { /* Check global frame length */ if (hTp->transportFmt == TT_MP4_LOAS && hTp->parser.latm.m_audioMuxLengthBytes > 0) { int loasOffset; loasOffset = (hTp->parser.latm.m_audioMuxLengthBytes*8 + FDKgetValidBits(hBs)) - hTp->globalFramePos; if (loasOffset != 0) { FDKpushBiDirectional(hBs, loasOffset); /* For ELD and other payloads there is an unknown amount of padding, so ignore unread bits, but throw an error only if too many bits where read. */ if (loasOffset < 0) { err = TRANSPORTDEC_PARSE_ERROR; } } } /* Do global LOAS/LATM audioMuxElement byte alignment */ FDKbyteAlign(hBs, hTp->globalFramePos); } break; default: break; } return err; }
static TRANSPORTDEC_ERROR synchronization( HANDLE_TRANSPORTDEC hTp, INT *pHeaderBits ) { TRANSPORTDEC_ERROR err = TRANSPORTDEC_OK, errFirstFrame = TRANSPORTDEC_OK; HANDLE_FDK_BITSTREAM hBs = &hTp->bitStream[0]; INT syncLayerFrameBits = 0; /* Length of sync layer frame (i.e. LOAS) */ INT rawDataBlockLength = 0, rawDataBlockLengthPrevious; INT totalBits; INT headerBits = 0, headerBitsFirstFrame = 0, headerBitsPrevious; INT numFramesTraversed = 0, fTraverseMoreFrames, fConfigFound = 0, startPos, startPosFirstFrame = -1; INT numRawDataBlocksFirstFrame = 0, numRawDataBlocksPrevious, globalFramePosFirstFrame = 0, rawDataBlockLengthFirstFrame = 0; INT ignoreBufferFullness = hTp->flags & (TPDEC_IGNORE_BUFFERFULLNESS|TPDEC_SYNCOK); /* Synch parameters */ INT syncLength; /* Length of sync word in bits */ UINT syncWord; /* Sync word to be found */ UINT syncMask; /* Mask for sync word (for adding one bit, so comprising one bit less) */ C_ALLOC_SCRATCH_START(contextFirstFrame, transportdec_parser_t, 1); totalBits = (INT)FDKgetValidBits(hBs); if (totalBits <= 0) { /* Return sync error, because this happens only in case of severly damaged bit streams. Returning TRANSPORTDEC_NOT_ENOUGH_BITS here is very dangerous. */ /* numberOfRawDataBlocks must be always reset in case of sync errors. */ hTp->numberOfRawDataBlocks = 0; goto bail; } fTraverseMoreFrames = (hTp->flags & (TPDEC_MINIMIZE_DELAY|TPDEC_EARLY_CONFIG)) && ! (hTp->flags & TPDEC_SYNCOK); /* Set transport specific sync parameters */ switch (hTp->transportFmt) { case TT_MP4_ADTS: syncWord = ADTS_SYNCWORD; syncLength = ADTS_SYNCLENGTH; break; case TT_MP4_LOAS: syncWord = 0x2B7; syncLength = 11; break; default: syncWord = 0; syncLength = 0; break; } syncMask = (1<<syncLength)-1; do { INT bitsAvail = 0; /* Bits available in bitstream buffer */ INT checkLengthBits; /* Helper to check remaining bits and buffer boundaries */ UINT synch; /* Current sync word read from bitstream */ headerBitsPrevious = headerBits; bitsAvail = (INT)FDKgetValidBits(hBs); if (hTp->numberOfRawDataBlocks == 0) { /* search synchword */ FDK_ASSERT( (bitsAvail % TPDEC_SYNCSKIP) == 0); if ((bitsAvail-syncLength) < TPDEC_SYNCSKIP) { err = TRANSPORTDEC_NOT_ENOUGH_BITS; headerBits = 0; } else { synch = FDKreadBits(hBs, syncLength); if ( !(hTp->flags & TPDEC_SYNCOK) ) { for (; (bitsAvail-syncLength) >= TPDEC_SYNCSKIP; bitsAvail-=TPDEC_SYNCSKIP) { if (synch == syncWord) { break; } synch = ((synch << TPDEC_SYNCSKIP) & syncMask) | FDKreadBits(hBs, TPDEC_SYNCSKIP); } } if (synch != syncWord) { /* No correct syncword found. */ err = TRANSPORTDEC_SYNC_ERROR; } else { err = TRANSPORTDEC_OK; } headerBits = syncLength; } } else { headerBits = 0; } /* Save previous raw data block data */ rawDataBlockLengthPrevious = rawDataBlockLength; numRawDataBlocksPrevious = hTp->numberOfRawDataBlocks; /* Parse transport header (raw data block granularity) */ startPos = FDKgetValidBits(hBs); if (err == TRANSPORTDEC_OK ) { switch (hTp->transportFmt) { case TT_MP4_ADTS: if (hTp->numberOfRawDataBlocks <= 0) { int errC; /* Parse ADTS header */ err = adtsRead_DecodeHeader( &hTp->parser.adts, &hTp->asc[0], hBs, ignoreBufferFullness ); if (err != TRANSPORTDEC_OK) { if (err != TRANSPORTDEC_NOT_ENOUGH_BITS) { err = TRANSPORTDEC_SYNC_ERROR; } } else { errC = hTp->callbacks.cbUpdateConfig(hTp->callbacks.cbUpdateConfigData, &hTp->asc[0]); if (errC != 0) { err = TRANSPORTDEC_SYNC_ERROR; } else { hTp->numberOfRawDataBlocks = hTp->parser.adts.bs.num_raw_blocks+1; /* CAUTION: The PCE (if available) is declared to be a part of the header! */ hTp->globalFramePos = FDKgetValidBits(hBs) + hTp->parser.adts.bs.num_pce_bits; } } } else { /* Reset CRC because the next bits are the beginning of a raw_data_block() */ FDKcrcReset(&hTp->parser.adts.crcInfo); hTp->globalFramePos = FDKgetValidBits(hBs); } if (err == TRANSPORTDEC_OK) { hTp->numberOfRawDataBlocks--; rawDataBlockLength = adtsRead_GetRawDataBlockLength(&hTp->parser.adts, (hTp->parser.adts.bs.num_raw_blocks-hTp->numberOfRawDataBlocks)); syncLayerFrameBits = (hTp->parser.adts.bs.frame_length<<3) - (startPos - FDKgetValidBits(hBs)) - syncLength; if (syncLayerFrameBits <= 0) { err = TRANSPORTDEC_SYNC_ERROR; } } else { hTp->numberOfRawDataBlocks = 0; } break; case TT_MP4_LOAS: if (hTp->numberOfRawDataBlocks <= 0) { syncLayerFrameBits = FDKreadBits(hBs, 13); hTp->parser.latm.m_audioMuxLengthBytes = syncLayerFrameBits; syncLayerFrameBits <<= 3; } case TT_MP4_LATM_MCP1: case TT_MP4_LATM_MCP0: if (hTp->numberOfRawDataBlocks <= 0) { hTp->globalFramePos = FDKgetValidBits(hBs); err = CLatmDemux_Read( hBs, &hTp->parser.latm, hTp->transportFmt, &hTp->callbacks, hTp->asc, ignoreBufferFullness); if (err != TRANSPORTDEC_OK) { if (err != TRANSPORTDEC_NOT_ENOUGH_BITS) { err = TRANSPORTDEC_SYNC_ERROR; } } else { hTp->numberOfRawDataBlocks = CLatmDemux_GetNrOfSubFrames(&hTp->parser.latm); syncLayerFrameBits -= startPos - FDKgetValidBits(hBs) - (13); } } else { err = CLatmDemux_ReadPayloadLengthInfo(hBs, &hTp->parser.latm); if (err != TRANSPORTDEC_OK) { err = TRANSPORTDEC_SYNC_ERROR; } } if (err == TRANSPORTDEC_OK) { rawDataBlockLength = CLatmDemux_GetFrameLengthInBits(&hTp->parser.latm); hTp->numberOfRawDataBlocks--; } else { hTp->numberOfRawDataBlocks = 0; } break; default: { syncLayerFrameBits = 0; } break; } } headerBits += startPos - (INT)FDKgetValidBits(hBs); bitsAvail -= headerBits; checkLengthBits = syncLayerFrameBits; /* Check if the whole frame would fit the bitstream buffer */ if (err == TRANSPORTDEC_OK) { if ( (checkLengthBits+headerBits) > ((TRANSPORTDEC_INBUF_SIZE<<3)-7) ) { /* We assume that the size of the transport bit buffer has been chosen to meet all system requirements, thus this condition is considered a synchronisation error. */ err = TRANSPORTDEC_SYNC_ERROR; } else { if ( bitsAvail < checkLengthBits ) { err = TRANSPORTDEC_NOT_ENOUGH_BITS; } } } if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) { break; } if (err == TRANSPORTDEC_SYNC_ERROR) { int bits; /* Enforce re-sync of transport headers. */ hTp->numberOfRawDataBlocks = 0; /* Ensure that the bit amount lands and a multiple of TPDEC_SYNCSKIP */ bits = (bitsAvail + headerBits) % TPDEC_SYNCSKIP; /* Rewind - TPDEC_SYNCSKIP, in order to look for a synch one bit ahead next time. */ FDKpushBiDirectional(hBs, -(headerBits - TPDEC_SYNCSKIP) + bits); bitsAvail += headerBits - TPDEC_SYNCSKIP - bits; headerBits = 0; } /* Frame traversal */ if ( fTraverseMoreFrames ) { /* Save parser context for early config discovery "rewind all frames" */ if ( (hTp->flags & TPDEC_EARLY_CONFIG) && !(hTp->flags & TPDEC_MINIMIZE_DELAY)) { /* ignore buffer fullness if just traversing additional frames for ECD */ ignoreBufferFullness = 1; /* Save context in order to return later */ if ( err == TRANSPORTDEC_OK && startPosFirstFrame == -1 ) { startPosFirstFrame = FDKgetValidBits(hBs); numRawDataBlocksFirstFrame = hTp->numberOfRawDataBlocks; globalFramePosFirstFrame = hTp->globalFramePos; rawDataBlockLengthFirstFrame = rawDataBlockLength; headerBitsFirstFrame = headerBits; errFirstFrame = err; FDKmemcpy(contextFirstFrame, &hTp->parser, sizeof(transportdec_parser_t)); } /* Break when config was found or it is not possible anymore to find a config */ if (startPosFirstFrame != -1 && (fConfigFound || err != TRANSPORTDEC_OK)) { break; } } if (err == TRANSPORTDEC_OK) { FDKpushFor(hBs, rawDataBlockLength); bitsAvail -= rawDataBlockLength; numFramesTraversed++; /* Ignore error here itentionally. */ transportDec_AdjustEndOfAccessUnit(hTp); } } } while ( fTraverseMoreFrames || (err == TRANSPORTDEC_SYNC_ERROR && !(hTp->flags & TPDEC_SYNCOK))); /* Restore context in case of ECD frame traversal */ if ( startPosFirstFrame != -1 && (fConfigFound || err != TRANSPORTDEC_OK) ) { FDKpushBiDirectional(hBs, FDKgetValidBits(hBs) - startPosFirstFrame); FDKmemcpy(&hTp->parser, contextFirstFrame, sizeof(transportdec_parser_t)); hTp->numberOfRawDataBlocks = numRawDataBlocksFirstFrame; hTp->globalFramePos = globalFramePosFirstFrame; rawDataBlockLength = rawDataBlockLengthFirstFrame; headerBits = headerBitsFirstFrame; err = errFirstFrame; numFramesTraversed = 0; } /* Additional burst data mode buffer fullness check. */ if ( !(hTp->flags & (TPDEC_IGNORE_BUFFERFULLNESS|TPDEC_SYNCOK)) && err == TRANSPORTDEC_OK) { err = additionalHoldOffNeeded(hTp, transportDec_GetBufferFullness(hTp), FDKgetValidBits(hBs) - syncLayerFrameBits); if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) { hTp->holdOffFrames++; } } /* Rewind for retry because of not enough bits */ if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) { FDKpushBack(hBs, headerBits); headerBits = 0; } else { /* reset hold off frame counter */ hTp->holdOffFrames = 0; } /* Return to last good frame in case of frame traversal but not ECD. */ if (numFramesTraversed > 0) { FDKpushBack(hBs, rawDataBlockLengthPrevious); if (err != TRANSPORTDEC_OK) { hTp->numberOfRawDataBlocks = numRawDataBlocksPrevious; headerBits = headerBitsPrevious; } err = TRANSPORTDEC_OK; } bail: hTp->auLength[0] = rawDataBlockLength; if (err == TRANSPORTDEC_OK) { hTp->flags |= TPDEC_SYNCOK; } if (pHeaderBits != NULL) { *pHeaderBits = headerBits; } if (err == TRANSPORTDEC_SYNC_ERROR) { hTp->flags &= ~TPDEC_SYNCOK; } C_ALLOC_SCRATCH_END(contextFirstFrame, transportdec_parser_t, 1); return err; }
static TRANSPORTDEC_ERROR synchronization( HANDLE_TRANSPORTDEC hTp, INT *pHeaderBits ) { TRANSPORTDEC_ERROR err = TRANSPORTDEC_OK, errFirstFrame = TRANSPORTDEC_OK; HANDLE_FDK_BITSTREAM hBs = &hTp->bitStream[0]; INT syncLayerFrameBits = 0; /* Length of sync layer frame (i.e. LOAS) */ INT rawDataBlockLength = 0, rawDataBlockLengthPrevious; INT totalBits; INT headerBits = 0, headerBitsFirstFrame = 0, headerBitsPrevious; INT numFramesTraversed = 0, fTraverseMoreFrames, fConfigFound = (hTp->flags & TPDEC_CONFIG_FOUND), startPosFirstFrame = -1; INT numRawDataBlocksFirstFrame = 0, numRawDataBlocksPrevious, globalFramePosFirstFrame = 0, rawDataBlockLengthFirstFrame = 0; INT ignoreBufferFullness = hTp->flags & (TPDEC_LOST_FRAMES_PENDING|TPDEC_IGNORE_BUFFERFULLNESS|TPDEC_SYNCOK); /* Synch parameters */ INT syncLength; /* Length of sync word in bits */ UINT syncWord; /* Sync word to be found */ UINT syncMask; /* Mask for sync word (for adding one bit, so comprising one bit less) */ C_ALLOC_SCRATCH_START(contextFirstFrame, transportdec_parser_t, 1); totalBits = (INT)FDKgetValidBits(hBs); if (totalBits <= 0) { err = TRANSPORTDEC_NOT_ENOUGH_BITS; goto bail; } fTraverseMoreFrames = (hTp->flags & (TPDEC_MINIMIZE_DELAY|TPDEC_EARLY_CONFIG)) && ! (hTp->flags & TPDEC_SYNCOK); /* Set transport specific sync parameters */ switch (hTp->transportFmt) { case TT_MP4_ADTS: syncWord = ADTS_SYNCWORD; syncLength = ADTS_SYNCLENGTH; break; case TT_MP4_LOAS: syncWord = 0x2B7; syncLength = 11; break; default: syncWord = 0; syncLength = 0; break; } syncMask = (1<<syncLength)-1; do { INT bitsAvail = 0; /* Bits available in bitstream buffer */ INT checkLengthBits; /* Helper to check remaining bits and buffer boundaries */ UINT synch; /* Current sync word read from bitstream */ headerBitsPrevious = headerBits; bitsAvail = (INT)FDKgetValidBits(hBs); if (hTp->numberOfRawDataBlocks == 0) { /* search synchword */ FDK_ASSERT( (bitsAvail % TPDEC_SYNCSKIP) == 0); if ((bitsAvail-syncLength) < TPDEC_SYNCSKIP) { err = TRANSPORTDEC_NOT_ENOUGH_BITS; headerBits = 0; } else { synch = FDKreadBits(hBs, syncLength); if ( !(hTp->flags & TPDEC_SYNCOK) ) { for (; (bitsAvail-syncLength) >= TPDEC_SYNCSKIP; bitsAvail-=TPDEC_SYNCSKIP) { if (synch == syncWord) { break; } synch = ((synch << TPDEC_SYNCSKIP) & syncMask) | FDKreadBits(hBs, TPDEC_SYNCSKIP); } } if (synch != syncWord) { /* No correct syncword found. */ err = TRANSPORTDEC_SYNC_ERROR; } else { err = TRANSPORTDEC_OK; } headerBits = syncLength; } } else { headerBits = 0; } /* Save previous raw data block data */ rawDataBlockLengthPrevious = rawDataBlockLength; numRawDataBlocksPrevious = hTp->numberOfRawDataBlocks; /* Parse transport header (raw data block granularity) */ if (err == TRANSPORTDEC_OK ) { err = transportDec_readHeader( hTp, hBs, syncLength, ignoreBufferFullness, &rawDataBlockLength, &fTraverseMoreFrames, &syncLayerFrameBits, &fConfigFound, &headerBits ); } bitsAvail -= headerBits; checkLengthBits = syncLayerFrameBits; /* Check if the whole frame would fit the bitstream buffer */ if (err == TRANSPORTDEC_OK) { if ( (checkLengthBits+headerBits) > ((TRANSPORTDEC_INBUF_SIZE<<3)-7) ) { /* We assume that the size of the transport bit buffer has been chosen to meet all system requirements, thus this condition is considered a synchronisation error. */ err = TRANSPORTDEC_SYNC_ERROR; } else { if ( bitsAvail < checkLengthBits ) { err = TRANSPORTDEC_NOT_ENOUGH_BITS; } } } if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) { break; } if (err == TRANSPORTDEC_SYNC_ERROR) { int bits; /* Enforce re-sync of transport headers. */ hTp->numberOfRawDataBlocks = 0; /* Ensure that the bit amount lands at a multiple of TPDEC_SYNCSKIP */ bits = (bitsAvail + headerBits) % TPDEC_SYNCSKIP; /* Rewind - TPDEC_SYNCSKIP, in order to look for a synch one bit ahead next time. */ FDKpushBiDirectional(hBs, -(headerBits - TPDEC_SYNCSKIP) + bits); bitsAvail += headerBits - TPDEC_SYNCSKIP - bits; headerBits = 0; } /* Frame traversal */ if ( fTraverseMoreFrames ) { /* Save parser context for early config discovery "rewind all frames" */ if ( (hTp->flags & TPDEC_EARLY_CONFIG) && !(hTp->flags & TPDEC_MINIMIZE_DELAY)) { /* ignore buffer fullness if just traversing additional frames for ECD */ ignoreBufferFullness = 1; /* Save context in order to return later */ if ( err == TRANSPORTDEC_OK && startPosFirstFrame == -1 ) { startPosFirstFrame = FDKgetValidBits(hBs); numRawDataBlocksFirstFrame = hTp->numberOfRawDataBlocks; globalFramePosFirstFrame = hTp->globalFramePos; rawDataBlockLengthFirstFrame = rawDataBlockLength; headerBitsFirstFrame = headerBits; errFirstFrame = err; FDKmemcpy(contextFirstFrame, &hTp->parser, sizeof(transportdec_parser_t)); } /* Break when config was found or it is not possible anymore to find a config */ if (startPosFirstFrame != -1 && (fConfigFound || err != TRANSPORTDEC_OK)) { /* In case of ECD and sync error, do not rewind anywhere. */ if (err == TRANSPORTDEC_SYNC_ERROR) { startPosFirstFrame = -1; fConfigFound = 0; numFramesTraversed = 0; } break; } } if (err == TRANSPORTDEC_OK) { FDKpushFor(hBs, rawDataBlockLength); bitsAvail -= rawDataBlockLength; numFramesTraversed++; /* Ignore error here itentionally. */ transportDec_AdjustEndOfAccessUnit(hTp); } } } while ( fTraverseMoreFrames || (err == TRANSPORTDEC_SYNC_ERROR && !(hTp->flags & TPDEC_SYNCOK))); /* Restore context in case of ECD frame traversal */ if ( startPosFirstFrame != -1 && (fConfigFound || err != TRANSPORTDEC_OK) ) { FDKpushBiDirectional(hBs, FDKgetValidBits(hBs) - startPosFirstFrame); FDKmemcpy(&hTp->parser, contextFirstFrame, sizeof(transportdec_parser_t)); hTp->numberOfRawDataBlocks = numRawDataBlocksFirstFrame; hTp->globalFramePos = globalFramePosFirstFrame; rawDataBlockLength = rawDataBlockLengthFirstFrame; headerBits = headerBitsFirstFrame; err = errFirstFrame; numFramesTraversed = 0; } /* Additional burst data mode buffer fullness check. */ if ( !(hTp->flags & (TPDEC_LOST_FRAMES_PENDING|TPDEC_IGNORE_BUFFERFULLNESS|TPDEC_SYNCOK)) && err == TRANSPORTDEC_OK) { err = additionalHoldOffNeeded(hTp, transportDec_GetBufferFullness(hTp), FDKgetValidBits(hBs) - syncLayerFrameBits); if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) { hTp->holdOffFrames++; } } /* Rewind for retry because of not enough bits */ if (err == TRANSPORTDEC_NOT_ENOUGH_BITS) { FDKpushBack(hBs, headerBits); headerBits = 0; } else { /* reset hold off frame counter */ hTp->holdOffFrames = 0; } /* Return to last good frame in case of frame traversal but not ECD. */ if (numFramesTraversed > 0) { FDKpushBack(hBs, rawDataBlockLengthPrevious); if (err != TRANSPORTDEC_OK) { hTp->numberOfRawDataBlocks = numRawDataBlocksPrevious; headerBits = headerBitsPrevious; } err = TRANSPORTDEC_OK; } bail: hTp->auLength[0] = rawDataBlockLength; /* Detect pointless TRANSPORTDEC_NOT_ENOUGH_BITS error case, were the bit buffer is already full, or no new burst packet fits. Recover by advancing the bit buffer. */ if ( (TRANSPORTDEC_NOT_ENOUGH_BITS == err) && (FDKgetValidBits(hBs) >= ((TRANSPORTDEC_INBUF_SIZE*8 - ((hTp->avgBitRate*hTp->burstPeriod)/1000)) - 7)) ) { FDKpushFor(hBs, TPDEC_SYNCSKIP); err = TRANSPORTDEC_SYNC_ERROR; } if (err == TRANSPORTDEC_OK) { hTp->flags |= TPDEC_SYNCOK; } if (fConfigFound) { hTp->flags |= TPDEC_CONFIG_FOUND; } if (pHeaderBits != NULL) { *pHeaderBits = headerBits; } if (err == TRANSPORTDEC_SYNC_ERROR) { hTp->flags &= ~TPDEC_SYNCOK; } C_ALLOC_SCRATCH_END(contextFirstFrame, transportdec_parser_t, 1); return err; }
/** * \brief adjust bit stream position and the end of an access unit. * \param hTp transport decoder handle. * \return error code. */ static TRANSPORTDEC_ERROR transportDec_AdjustEndOfAccessUnit(HANDLE_TRANSPORTDEC hTp) { HANDLE_FDK_BITSTREAM hBs = &hTp->bitStream[0]; TRANSPORTDEC_ERROR err = TRANSPORTDEC_OK; switch (hTp->transportFmt) { case TT_MP4_LOAS: case TT_MP4_LATM_MCP0: case TT_MP4_LATM_MCP1: if ( hTp->numberOfRawDataBlocks == 0 ) { /* Do byte align at the end of AudioMuxElement. */ FDKbyteAlign(hBs, hTp->globalFramePos); /* Check global frame length */ if (hTp->transportFmt == TT_MP4_LOAS && hTp->parser.latm.m_audioMuxLengthBytes > 0) { int loasOffset; loasOffset = (hTp->parser.latm.m_audioMuxLengthBytes*8 + FDKgetValidBits(hBs)) - hTp->globalFramePos; if (loasOffset != 0) { FDKpushBiDirectional(hBs, loasOffset); /* For ELD and other payloads there is an unknown amount of padding, so ignore unread bits, but throw an error only if too many bits where read. */ if (loasOffset < 0) { err = TRANSPORTDEC_PARSE_ERROR; } } } } break; case TT_MP4_ADTS: if (hTp->parser.adts.bs.protection_absent == 0) { int offset; /* Calculate offset to end of AU */ offset = hTp->parser.adts.rawDataBlockDist[hTp->parser.adts.bs.num_raw_blocks-hTp->numberOfRawDataBlocks]<<3; /* CAUTION: The PCE (if available) is declared to be a part of the header! */ offset -= hTp->accessUnitAnchor[0] - FDKgetValidBits(hBs) + 16 + hTp->parser.adts.bs.num_pce_bits; FDKpushBiDirectional(hBs, offset); } if (hTp->parser.adts.bs.num_raw_blocks > 0 && hTp->parser.adts.bs.protection_absent == 0) { /* Note this CRC read currently happens twice because of transportDec_CrcCheck() */ hTp->parser.adts.crcReadValue = FDKreadBits(hBs, 16); } if ( hTp->numberOfRawDataBlocks == 0 ) { /* Check global frame length */ if (hTp->parser.adts.bs.protection_absent == 0) { int offset; offset = (hTp->parser.adts.bs.frame_length*8 - ADTS_SYNCLENGTH + FDKgetValidBits(hBs)) - hTp->globalFramePos; if (offset != 0) { FDKpushBiDirectional(hBs, offset); } } } break; default: break; } return err; }