/*! * \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 InitBits (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;} //Following for write bs in decodervoid DecInitBitsForEncoding (PBitStringAux pBitString, uint8_t* pBuf, const int32_t kiSize) {  uint8_t* pPtr = pBuf;  pBitString->pStartBuf = pPtr;  pBitString->pCurBuf = pPtr;  pBitString->pEndBuf = pPtr + kiSize;  pBitString->iLeftBits = 32;  pBitString->uiCurBits = 0;} #define WRITE_BE_32(ptr, val) do { \    (ptr)[0] = (val) >> 24; \    (ptr)[1] = (val) >> 16; \    (ptr)[2] = (val) >>  8; \    (ptr)[3] = (val) >>  0; \  } while (0); int32_t DecBsWriteBits (PBitStringAux pBitString, int32_t iLen, const uint32_t kuiValue) {  if (iLen < pBitString->iLeftBits) {    pBitString->uiCurBits = (pBitString->uiCurBits << iLen) | kuiValue;    pBitString->iLeftBits -= iLen;  } else {    iLen -= pBitString->iLeftBits;    pBitString->uiCurBits = (pBitString->uiCurBits << pBitString->iLeftBits) | (kuiValue >> iLen);    WRITE_BE_32 (pBitString->pCurBuf, pBitString->uiCurBits);    pBitString->pCurBuf += 4;    pBitString->uiCurBits = kuiValue & ((1 << iLen) - 1);    pBitString->iLeftBits = 32 - iLen;  }  return 0;} int32_t DecBsWriteOneBit (PBitStringAux pBitString, const uint32_t kuiValue) {  DecBsWriteBits (pBitString, 1, kuiValue);  return 0;} int32_t DecBsFlush (PBitStringAux pBitString) {  WRITE_BE_32 (pBitString->pCurBuf, pBitString->uiCurBits << pBitString->iLeftBits);  pBitString->pCurBuf += 4 - pBitString->iLeftBits / 8;  pBitString->iLeftBits = 32;  pBitString->uiCurBits = 0;  return 0;} const uint32_t g_kuiDecGolombUELength[256] = {  1,  3,  3,  5,  5,  5,  5,  7,  7,  7,  7,  7,  7,  7,  7,     //14  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9,  9, //30  11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,//46  11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,//62  13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,//  13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,  13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,  13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,  17}; int32_t DecBsWriteUe (PBitStringAux pBitString, const uint32_t kuiValue) {  uint32_t iTmpValue = kuiValue + 1;  if (256 > kuiValue) {    DecBsWriteBits (pBitString, g_kuiDecGolombUELength[kuiValue], kuiValue + 1);  } else {    uint32_t n = 0;    if (iTmpValue & 0xffff0000) {      iTmpValue >>= 16;      n += 16;    }    if (iTmpValue & 0xff) {      iTmpValue >>= 8;      n += 8;    }     //n += (g_kuiDecGolombUELength[iTmpValue] >> 1);     n += (g_kuiDecGolombUELength[iTmpValue - 1] >> 1);    DecBsWriteBits (pBitString, (n << 1) + 1, kuiValue + 1);  }  return 0;} int32_t DecBsWriteSe (PBitStringAux pBitString, const int32_t kiValue) {  uint32_t iTmpValue;  if (0 == kiValue) {    DecBsWriteOneBit (pBitString, 1);  } else if (0 < kiValue) {    iTmpValue = (kiValue << 1) - 1;    DecBsWriteUe (pBitString, iTmpValue);  } else {    iTmpValue = ((-kiValue) << 1);    DecBsWriteUe (pBitString, iTmpValue);  }  return 0;} int32_t DecBsRbspTrailingBits (PBitStringAux pBitString) {  DecBsWriteOneBit (pBitString, 1);  DecBsFlush (pBitString);   return 0;} 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