mpeg_encode/src/dct.h

/*===========================================================================*
 * dct.h                                                                     *
 *                                                                           *
 *      DCT procedures                                                       *
 *                                                                           *
 *===========================================================================*/

/*
 * Copyright (c) 1995 The Regents of the University of California.
 * All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without written agreement is
 * hereby granted, provided that the above copyright notice and the following
 * two paragraphs appear in all copies of this software.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
 * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
 * CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 */


#ifndef DCT_INCLUDED
#define DCT_INCLUDED


#include "ansi.h"


#define DCTSIZE     8   /* you really don't want to change this */
#define DCTSIZE_SQ 64   /* you really don't want to change this */

#define DCTSIZE2    DCTSIZE*DCTSIZE
typedef short DCTELEM;
typedef DCTELEM DCTBLOCK[DCTSIZE2];
typedef DCTELEM DCTBLOCK_2D[DCTSIZE][DCTSIZE];


/*  
 *  from mfwddct.c:
 */
extern void mp_fwd_dct_block2 _ANSI_ARGS_((DCTBLOCK_2D src, DCTBLOCK_2D dest));

/* jrevdct.c */
extern void init_pre_idct _ANSI_ARGS_((void ));
extern void mpeg_jrevdct _ANSI_ARGS_((DCTBLOCK data ));


/* We assume that right shift corresponds to signed division by 2 with
 * rounding towards minus infinity.  This is correct for typical "arithmetic
 * shift" instructions that shift in copies of the sign bit.  But some
 * C compilers implement >> with an unsigned shift.  For these machines you
 * must define RIGHT_SHIFT_IS_UNSIGNED.
 * RIGHT_SHIFT provides a proper signed right shift of an int32 quantity.
 * It is only applied with constant shift counts.  SHIFT_TEMPS must be
 * included in the variables of any routine using RIGHT_SHIFT.
 */

#ifdef RIGHT_SHIFT_IS_UNSIGNED
#define SHIFT_TEMPS     int32 shift_temp;
#define RIGHT_SHIFT(x,shft)  \
        ((shift_temp = (x)) < 0 ? \
         (shift_temp >> (shft)) | ((~((int32) 0)) << (32-(shft))) : \
         (shift_temp >> (shft)))
#else
#define SHIFT_TEMPS
#define RIGHT_SHIFT(x,shft)     ((x) >> (shft))
#endif


#endif /* DCT_INCLUDED */
Revision:	22
Committed:	Mon Jul 7 22:16:37 2008 UTC (13 years, 10 months ago) by wdelano
File size:	2801 byte(s)
Log Message:	initial checkin of mpeg_encode source
Line	File contents
1	/===========================================================================
2	* dct.h *
3	* *
4	* DCT procedures *
5	* *
6	===========================================================================/
7
8	/*
9	* Copyright (c) 1995 The Regents of the University of California.
10	* All rights reserved.
11	*
12	* Permission to use, copy, modify, and distribute this software and its
13	* documentation for any purpose, without fee, and without written agreement is
14	* hereby granted, provided that the above copyright notice and the following
15	* two paragraphs appear in all copies of this software.
16	*
17	* IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
18	* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
19	* OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
20	* CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
21	*
22	* THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
23	* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
24	* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
25	* ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
26	* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
27	*/
28
29
30	#ifndef DCT_INCLUDED
31	#define DCT_INCLUDED
32
33
34	#include "ansi.h"
35
36
37
38	#define DCTSIZE 8 /* you really don't want to change this */
39	#define DCTSIZE_SQ 64 /* you really don't want to change this */
40
41	#define DCTSIZE2 DCTSIZE*DCTSIZE
42	typedef short DCTELEM;
43	typedef DCTELEM DCTBLOCK[DCTSIZE2];
44	typedef DCTELEM DCTBLOCK_2D[DCTSIZE][DCTSIZE];
45
46
47	/*
48	* from mfwddct.c:
49	*/
50	extern void mp_fwd_dct_block2 _ANSI_ARGS_((DCTBLOCK_2D src, DCTBLOCK_2D dest));
51
52	/* jrevdct.c */
53	extern void init_pre_idct _ANSI_ARGS_((void ));
54	extern void mpeg_jrevdct _ANSI_ARGS_((DCTBLOCK data ));
55
56
57	/* We assume that right shift corresponds to signed division by 2 with
58	* rounding towards minus infinity. This is correct for typical "arithmetic
59	* shift" instructions that shift in copies of the sign bit. But some
60	* C compilers implement >> with an unsigned shift. For these machines you
61	* must define RIGHT_SHIFT_IS_UNSIGNED.
62	* RIGHT_SHIFT provides a proper signed right shift of an int32 quantity.
63	* It is only applied with constant shift counts. SHIFT_TEMPS must be
64	* included in the variables of any routine using RIGHT_SHIFT.
65	*/
66
67	#ifdef RIGHT_SHIFT_IS_UNSIGNED
68	#define SHIFT_TEMPS int32 shift_temp;
69	#define RIGHT_SHIFT(x,shft) \
70	((shift_temp = (x)) < 0 ? \
71	(shift_temp >> (shft)) \| ((~((int32) 0)) << (32-(shft))) : \
72	(shift_temp >> (shft)))
73	#else
74	#define SHIFT_TEMPS
75	#define RIGHT_SHIFT(x,shft) ((x) >> (shft))
76	#endif
77
78
79	#endif /* DCT_INCLUDED */