shithub: openh264

ref: 3022d4f6559596e0a6a1fae4d638f3c02f7d2a9e
dir: /codec/decoder/core/inc/cabac_decoder.h/

View raw version
/*!
 * \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	cabac_decoder.h
 *
 * \brief	Interfaces introduced for cabac decoder
 *
 * \date	10/10/2014 Created
 *
 *************************************************************************************
 */
#ifndef WELS_CABAC_DECODER_H__
#define WELS_CABAC_DECODER_H__

#include "decoder_context.h"
#include "error_code.h"
#include "wels_common_defs.h"
namespace WelsDec {
static const uint8_t g_kRenormTable256[256] = {
  6, 6, 6, 6, 6, 6, 6, 6,
  5, 5, 5, 5, 5, 5, 5, 5,
  4, 4, 4, 4, 4, 4, 4, 4,
  4, 4, 4, 4, 4, 4, 4, 4,
  3, 3, 3, 3, 3, 3, 3, 3,
  3, 3, 3, 3, 3, 3, 3, 3,
  3, 3, 3, 3, 3, 3, 3, 3,
  3, 3, 3, 3, 3, 3, 3, 3,
  2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2,
  2, 2, 2, 2, 2, 2, 2, 2,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1
};


//1. CABAC context initialization
void WelsCabacGlobalInit(PWelsDecoderContext pCabacCtx);
void WelsCabacContextInit (PWelsDecoderContext  pCtx, uint8_t eSliceType, int32_t iCabacInitIdc, int32_t iQp);

//2. decoding Engine initialization
int32_t InitCabacDecEngineFromBS (PWelsCabacDecEngine pDecEngine, SBitStringAux* pBsAux);
void RestoreCabacDecEngineToBS (PWelsCabacDecEngine pDecEngine, SBitStringAux* pBsAux);
//3. actual decoding
int32_t Read32BitsCabac (PWelsCabacDecEngine pDecEngine, uint32_t& uiValue, int32_t& iNumBitsRead);
int32_t DecodeBinCabac (PWelsCabacDecEngine pDecEngine, PWelsCabacCtx pBinCtx, uint32_t& uiBit);
int32_t DecodeBypassCabac (PWelsCabacDecEngine pDecEngine, uint32_t& uiBinVal);
int32_t  DecodeTerminateCabac (PWelsCabacDecEngine pDecEngine, uint32_t& uiBinVal);

//4. unary parsing
int32_t DecodeUnaryBinCabac (PWelsCabacDecEngine pDecEngine, PWelsCabacCtx pBinCtx, int32_t iCtxOffset,
                             uint32_t& uiSymVal);

//5. EXGk parsing
int32_t DecodeExpBypassCabac (PWelsCabacDecEngine pDecEngine, int32_t iCount, uint32_t& uiSymVal);
uint32_t DecodeUEGLevelCabac (PWelsCabacDecEngine pDecEngine, PWelsCabacCtx pBinCtx, uint32_t& uiBinVal);
int32_t DecodeUEGMvCabac (PWelsCabacDecEngine pDecEngine, PWelsCabacCtx pBinCtx, uint32_t iMaxC,  uint32_t& uiCode);

#define WELS_CABAC_HALF    0x01FE
#define WELS_CABAC_QUARTER 0x0100
#define WELS_CABAC_FALSE_RETURN(iErrorInfo) \
if(iErrorInfo) { \
  return iErrorInfo; \
}
}
#endif