1 |
/***************************************************************************** |
/************************************************************************** |
2 |
* |
* |
3 |
* XVID MPEG-4 VIDEO CODEC |
* XVID MPEG-4 VIDEO CODEC |
4 |
* - Mpeg4 quantization/dequantization functions - |
* mpeg-4 quantization/dequantization |
5 |
* |
* |
6 |
* Copyright(C) 2002 Peter Ross <pross@xvid.org> |
* 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 |
8 |
|
* to use this software module in hardware or software products are |
9 |
|
* advised that its use may infringe existing patents or copyrights, and |
10 |
|
* any such use would be at such party's own risk. The original |
11 |
|
* developer of this software module and his/her company, and subsequent |
12 |
|
* editors and their companies, will have no liability for use of this |
13 |
|
* software or modifications or derivatives thereof. |
14 |
* |
* |
15 |
* This file is part of XviD, a free MPEG-4 video encoder/decoder |
* This program is free software; you can redistribute it and/or modify |
16 |
* |
* it under the terms of the GNU General Public License as published by |
|
* XviD is free software; you can redistribute it and/or modify it |
|
|
* under the terms of the GNU General Public License as published by |
|
17 |
* the Free Software Foundation; either version 2 of the License, or |
* the Free Software Foundation; either version 2 of the License, or |
18 |
* (at your option) any later version. |
* (at your option) any later version. |
19 |
* |
* |
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. |
|
* |
|
|
* Under section 8 of the GNU General Public License, the copyright |
|
|
* holders of XVID explicitly forbid distribution in the following |
|
|
* countries: |
|
|
* |
|
|
* - Japan |
|
|
* - United States of America |
|
28 |
* |
* |
29 |
* Linking XviD statically or dynamically with other modules is making a |
*************************************************************************/ |
30 |
* combined work based on XviD. Thus, the terms and conditions of the |
|
31 |
* GNU General Public License cover the whole combination. |
/************************************************************************** |
|
* |
|
|
* As a special exception, the copyright holders of XviD give you |
|
|
* permission to link XviD with independent modules that communicate with |
|
|
* XviD solely through the VFW1.1 and DShow interfaces, regardless of the |
|
|
* license terms of these independent modules, and to copy and distribute |
|
|
* the resulting combined work under terms of your choice, provided that |
|
|
* every copy of the combined work is accompanied by a complete copy of |
|
|
* the source code of XviD (the version of XviD used to produce the |
|
|
* combined work), being distributed under the terms of the GNU General |
|
|
* Public License plus this exception. An independent module is a module |
|
|
* which is not derived from or based on XviD. |
|
32 |
* |
* |
33 |
* Note that people who make modified versions of XviD are not obligated |
* History: |
|
* to grant this special exception for their modified versions; it is |
|
|
* their choice whether to do so. The GNU General Public License gives |
|
|
* permission to release a modified version without this exception; this |
|
|
* exception also makes it possible to release a modified version which |
|
|
* carries forward this exception. |
|
34 |
* |
* |
35 |
* $Id$ |
* 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) |
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); |