ref: e5b72f320832c060433adc97b44b02ca77083b14
dir: /codec/decoder/core/src/bit_stream.cpp/
/*! * \copy * Copyright (c) 2009-2013, Cisco Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 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 OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * * \file bit_stream.cpp * * \brief Reading / writing bit-stream * * \date 03/10/2009 Created * ************************************************************************************* */ #include "bit_stream.h" #include "error_code.h" namespace WelsDec { inline uint32_t GetValue4Bytes (uint8_t* pDstNal) { uint32_t uiValue = 0; uiValue = (pDstNal[0] << 24) | (pDstNal[1] << 16) | (pDstNal[2] << 8) | (pDstNal[3]); return uiValue; } int32_t InitReadBits (PBitStringAux pBitString, intX_t iEndOffset) { if (pBitString->pCurBuf >= (pBitString->pEndBuf - iEndOffset)) { return ERR_INFO_INVALID_ACCESS; } pBitString->uiCurBits = GetValue4Bytes (pBitString->pCurBuf); pBitString->pCurBuf += 4; pBitString->iLeftBits = -16; return ERR_NONE; } /*! * \brief input bits for decoder or initialize bitstream writing in encoder * * \param pBitString Bit string auxiliary pointer * \param kpBuf bit-stream buffer * \param kiSize size in bits for decoder; size in bytes for encoder * * \return 0: success, other: fail */ int32_t DecInitBits (PBitStringAux pBitString, const uint8_t* kpBuf, const int32_t kiSize) { const int32_t kiSizeBuf = (kiSize + 7) >> 3; uint8_t* pTmp = (uint8_t*)kpBuf; if (NULL == pTmp) return ERR_INFO_INVALID_ACCESS; pBitString->pStartBuf = pTmp; // buffer to start position pBitString->pEndBuf = pTmp + kiSizeBuf; // buffer + length pBitString->iBits = kiSize; // count bits of overall bitstreaming inputindex; pBitString->pCurBuf = pBitString->pStartBuf; int32_t iErr = InitReadBits (pBitString, 0); if (iErr) { return iErr; } return ERR_NONE; } void RBSP2EBSP (uint8_t* pDstBuf, uint8_t* pSrcBuf, const int32_t kiSize) { uint8_t* pSrcPointer = pSrcBuf; uint8_t* pDstPointer = pDstBuf; uint8_t* pSrcEnd = pSrcBuf + kiSize; int32_t iZeroCount = 0; while (pSrcPointer < pSrcEnd) { if (iZeroCount == 2 && *pSrcPointer <= 3) { //add the code 0x03 *pDstPointer++ = 3; iZeroCount = 0; } if (*pSrcPointer == 0) { ++ iZeroCount; } else { iZeroCount = 0; } *pDstPointer++ = *pSrcPointer++; } } } // namespace WelsDec