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1 | /* |
2 | * Electronic Arts TGQ/TQI/MAD IDCT algorithm | |
3 | * Copyright (c) 2007-2008 Peter Ross <pross@xvid.org> | |
4 | * | |
5 | * This file is part of FFmpeg. | |
6 | * | |
7 | * FFmpeg is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; either | |
10 | * version 2.1 of the License, or (at your option) any later version. | |
11 | * | |
12 | * FFmpeg is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with FFmpeg; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | /** | |
23 | * @file | |
24 | * Electronic Arts TGQ/TQI/MAD IDCT algorithm | |
25 | * @author Peter Ross <pross@xvid.org> | |
26 | */ | |
27 | ||
28 | #include "eaidct.h" | |
29 | #include "libavutil/common.h" | |
30 | ||
31 | #define ASQRT 181 /* (1/sqrt(2))<<8 */ | |
32 | #define A4 669 /* cos(pi/8)*sqrt(2)<<9 */ | |
33 | #define A2 277 /* sin(pi/8)*sqrt(2)<<9 */ | |
34 | #define A5 196 /* sin(pi/8)<<9 */ | |
35 | ||
36 | #define IDCT_TRANSFORM(dest,s0,s1,s2,s3,s4,s5,s6,s7,d0,d1,d2,d3,d4,d5,d6,d7,munge,src) {\ | |
37 | const int a1 = (src)[s1] + (src)[s7]; \ | |
38 | const int a7 = (src)[s1] - (src)[s7]; \ | |
39 | const int a5 = (src)[s5] + (src)[s3]; \ | |
40 | const int a3 = (src)[s5] - (src)[s3]; \ | |
41 | const int a2 = (src)[s2] + (src)[s6]; \ | |
42 | const int a6 = (ASQRT*((src)[s2] - (src)[s6]))>>8; \ | |
43 | const int a0 = (src)[s0] + (src)[s4]; \ | |
44 | const int a4 = (src)[s0] - (src)[s4]; \ | |
45 | const int b0 = (((A4-A5)*a7 - A5*a3)>>9) + a1+a5; \ | |
46 | const int b1 = (((A4-A5)*a7 - A5*a3)>>9) + ((ASQRT*(a1-a5))>>8); \ | |
47 | const int b2 = (((A2+A5)*a3 + A5*a7)>>9) + ((ASQRT*(a1-a5))>>8); \ | |
48 | const int b3 = ((A2+A5)*a3 + A5*a7)>>9; \ | |
49 | (dest)[d0] = munge(a0+a2+a6+b0); \ | |
50 | (dest)[d1] = munge(a4+a6 +b1); \ | |
51 | (dest)[d2] = munge(a4-a6 +b2); \ | |
52 | (dest)[d3] = munge(a0-a2-a6+b3); \ | |
53 | (dest)[d4] = munge(a0-a2-a6-b3); \ | |
54 | (dest)[d5] = munge(a4-a6 -b2); \ | |
55 | (dest)[d6] = munge(a4+a6 -b1); \ | |
56 | (dest)[d7] = munge(a0+a2+a6-b0); \ | |
57 | } | |
58 | /* end IDCT_TRANSFORM macro */ | |
59 | ||
60 | #define MUNGE_NONE(x) (x) | |
61 | #define IDCT_COL(dest,src) IDCT_TRANSFORM(dest,0,8,16,24,32,40,48,56,0,8,16,24,32,40,48,56,MUNGE_NONE,src) | |
62 | ||
63 | #define MUNGE_8BIT(x) av_clip_uint8((x)>>4) | |
64 | #define IDCT_ROW(dest,src) IDCT_TRANSFORM(dest,0,1,2,3,4,5,6,7,0,1,2,3,4,5,6,7,MUNGE_8BIT,src) | |
65 | ||
66 | static inline void ea_idct_col(int16_t *dest, const int16_t *src) { | |
67 | if ((src[8]|src[16]|src[24]|src[32]|src[40]|src[48]|src[56])==0) { | |
68 | dest[0] = | |
69 | dest[8] = | |
70 | dest[16] = | |
71 | dest[24] = | |
72 | dest[32] = | |
73 | dest[40] = | |
74 | dest[48] = | |
75 | dest[56] = src[0]; | |
76 | }else | |
77 | IDCT_COL(dest, src); | |
78 | } | |
79 | ||
80 | void ff_ea_idct_put_c(uint8_t *dest, int linesize, int16_t *block) { | |
81 | int i; | |
82 | int16_t temp[64]; | |
83 | block[0] += 4; | |
84 | for (i=0; i<8; i++) | |
85 | ea_idct_col(&temp[i], &block[i]); | |
86 | for (i=0; i<8; i++) | |
87 | IDCT_ROW( (&dest[i*linesize]), (&temp[8*i]) ); | |
88 | } |