[svn] / branches / dev-api-4 / xvidcore / src / quant / quant_mpeg4.c Repository:
ViewVC logotype

Diff of /branches/dev-api-4/xvidcore/src/quant/quant_mpeg4.c

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 442, Sat Sep 7 11:21:10 2002 UTC revision 851, Sat Feb 15 15:22:19 2003 UTC
# Line 1  Line 1 
1  /*****************************************************************************  /**************************************************************************
2   *   *
3   *  XVID MPEG-4 VIDEO CODEC   *  XVID MPEG-4 VIDEO CODEC
4   *  - Mpeg4 quantization/dequantization functions -   *    mpeg-4 quantization/dequantization
  *  
  *  Copyright(C) 2002 Peter Ross  
5   *   *
6   *  This program is an implementation of a part of one or more MPEG-4   *  This program is an implementation of a part of one or more MPEG-4
7   *  Video tools as specified in ISO/IEC 14496-2 standard.  Those intending   *  Video tools as specified in ISO/IEC 14496-2 standard.  Those intending
# Line 26  Line 24 
24   *   *
25   *  You should have received a copy of the GNU General Public License   *  You should have received a copy of the GNU General Public License
26   *  along with this program ; if not, write to the Free Software   *  along with this program ; if not, write to the Free Software
27   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA   *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28     *
29     *************************************************************************/
30    
31    /**************************************************************************
32     *
33     *    History:
34   *   *
35   *  $Id: quant_mpeg4.c,v 1.4 2002-09-07 11:21:10 edgomez Exp $   *      26.01.2002    fixed  quant4_intra dcscalar signed/unsigned error
36     *  20.01.2002    increased accuracy of >> divide
37     *  26.12.2001    divide-by-multiplication optimization
38     *  22.12.2001    [-127,127] clamping removed; minor tweaks
39     *      19.11.2001    inital version <pross@cs.rmit.edu.au>
40   *   *
41   ****************************************************************************/   *************************************************************************/
42    
43    #include "../global.h"
44  #include "quant_mpeg4.h"  #include "quant_mpeg4.h"
45  #include "quant_matrix.h"  #include "quant_matrix.h"
46    
47  /*****************************************************************************  // function pointers
  * Function pointers  
  ****************************************************************************/  
   
48  quant_intraFuncPtr quant4_intra;  quant_intraFuncPtr quant4_intra;
49  quant_intraFuncPtr dequant4_intra;  quant_intraFuncPtr dequant4_intra;
50  dequant_interFuncPtr dequant4_inter;  dequant_interFuncPtr dequant4_inter;
51  quant_interFuncPtr quant4_inter;  quant_interFuncPtr quant4_inter;
52    
53    
 /*****************************************************************************  
  * Local data  
  ****************************************************************************/  
   
 #define DIV_DIV(A,B)    ( (A) > 0 ? ((A)+((B)>>1))/(B) : ((A)-((B)>>1))/(B) )  
 #define SIGN(A)  ((A)>0?1:-1)  
54  #define VM18P    3  #define VM18P    3
55  #define VM18Q    4  #define VM18Q    4
56    
57    
58  /*  // divide-by-multiply table
59   * divide-by-multiply table  // need 17 bit shift (16 causes slight errors when q > 19)
  * need 17 bit shift (16 causes slight errors when q > 19)  
  */  
60    
61  #define SCALEBITS    17  #define SCALEBITS    17
62  #define FIX(X)        ((1UL << SCALEBITS) / (X) + 1)  #define FIX(X)        ((1UL << SCALEBITS) / (X) + 1)
# Line 74  Line 72 
72          FIX(56), FIX(58), FIX(60), FIX(62)          FIX(56), FIX(58), FIX(60), FIX(62)
73  };  };
74    
 /*****************************************************************************  
  * Functions  
  ****************************************************************************/  
   
75  /*    quantize intra-block  /*    quantize intra-block
76    
77      // const int32_t quantd = DIV_DIV(VM18P*quant, VM18Q);      // const int32_t quantd = DIV_DIV(VM18P*quant, VM18Q);
Legend:
Removed from v.442  
changed lines
  Added in v.851
No admin address has been configured
 ViewVC Help
Powered by ViewVC 1.0.4