ref: 7f27198c6857096d755b592c7f55f7b1469c50ab
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 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 decoder void 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