www.pudn.com > AvsVideoCodec.rar > golomb_dec.c

/* 
***************************************************************************** 
* COPYRIGHT AND WARRANTY INFORMATION 
* 
* Copyright 2003, Advanced Audio Video Coding Standard, Part II 
* 
* DISCLAIMER OF WARRANTY 
* 
* The contents of this file are subject to the Mozilla Public License 
* Version 1.1 (the "License"); you may not use this file except in 
* compliance with the License. You may obtain a copy of the License at 
* http://www.mozilla.org/MPL/ 
* 
* Software distributed under the License is distributed on an "AS IS" 
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the 
* License for the specific language governing rights and limitations under 
* the License. 
*                      
* THIS IS NOT A GRANT OF PATENT RIGHTS - SEE THE AVS PATENT POLICY. 
* The AVS Working Group doesn't represent or warrant that the programs 
* furnished here under are free of infringement of any third-party patents. 
* Commercial implementations of AVS, including shareware, may be 
* subject to royalty fees to patent holders. Information regarding 
* the AVS patent policy for standardization procedure is available at  
* AVS Web site http://www.avs.org.cn. Patent Licensing is outside 
* of AVS Working Group. 
* 
* The Original Code is Reference Software for China National Standard  
* GB/T 20090.2-2006 (short for AVS-P2 or AVS Video) at version RM52J. 
* 
* The Initial Developer of the Original Code is Video subgroup of AVS 
* Workinggroup (Audio and Video coding Standard Working Group of China). 
* Contributors:   Guoping Li,    Siwei Ma,    Jian Lou,    Qiang Wang ,  
*   Jianwen Chen,Haiwu Zhao,  Xiaozhen Zheng, Junhao Zheng, Zhiming Wang 
*  
****************************************************************************** 
*/ 
 
 
/* 
************************************************************************************* 
* File name: golomb_dec.c 
* Function: Description 
* 
************************************************************************************* 
*/ 
 
#include  
#include "golomb_dec.h" 
#include "global.h" 
 
#if TRACE 
/* 
************************************************************************* 
* Function: 
* Input: 
* Output: 
* Return:  
* Attention: 
************************************************************************* 
*/ 
void encode_golomb_word(unsigned int symbol,unsigned int grad0,unsigned int max_levels,unsigned int *res_bits,unsigned int *res_len) 
{ 
  unsigned int level,res,numbits; 
  res=1UL<=res && level=max_levels) 
  { 
    if(symbol>=res) 
      symbol=res-1UL;  //crop if too large. 
  } 
  //set data bits 
  *res_bits=res|symbol; 
  *res_len=numbits; 
} 
 
void encode_multilayer_golomb_word(unsigned int symbol,const unsigned int *grad,const unsigned int *max_levels,unsigned int *res_bits,unsigned int *res_len) 
{ 
  unsigned accbits,acclen,bits,len,tmp; 
  accbits=acclen=0UL; 
  while(1) 
  { 
    encode_golomb_word(symbol,*grad,*max_levels,&bits,&len); 
    accbits=(accbits<>bit)&1UL) ; 
    bit = (bit-1UL) & 7UL ; 
    if(bit==7UL)byte=*(++rd); 
  } 
  *buffer=rd; 
  *bitoff=bit; 
  return (((1UL<frame_bitoffset; 
  buf = (unsigned char*)currStream->streamBuffer; 
  BitstreamLengthInBytes = currStream->bitstream_length; 
   
  bit=7UL-(frame_bitoffset&7); 
  read=buf+(frame_bitoffset>>3); 
   
  if(!( se->golomb_maxlevels&~0xFF )) 
  { 
    se->value1=decode_golomb_word(&read,&bit,se->golomb_grad,se->golomb_maxlevels); 
  } 
  else 
  { 
    for(i=0UL;i<4UL;i++) 
    { 
      grad[i]=(se->golomb_grad>>(i<<3))&0xFFUL; 
      max_lev[i]=(se->golomb_maxlevels>>(i<<3))&0xFFUL; 
    } 
    se->value1=decode_multilayer_golomb_word(&read,&bit,grad,max_lev); 
  } 
   
  se->len=(((read-buf)<<3)+(7-bit))-frame_bitoffset; 
   
#if TRACE 
  if(!( se->golomb_maxlevels&~0xFF ))    //only bits 0-7 used? This means normal Golomb word. 
    encode_golomb_word(se->value1,se->golomb_grad,se->golomb_maxlevels,&(se->value2),&len); 
  else 
  { 
    for(i=0UL;i<4UL;i++) 
    { 
      grad[i]=(se->golomb_grad>>(i<<3))&0xFFUL; 
      max_lev[i]=(se->golomb_maxlevels>>(i<<3))&0xFFUL; 
    } 
    encode_multilayer_golomb_word(se->value1,grad,max_lev,&(se->value2),&len); 
  } 
   
  tracebits3("", se->len, se->value2, se->value1); 
#endif 
 
  se->value2=0; 
  currStream->frame_bitoffset += se->len; 
   
  return 1; 
}