1/*
2 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11
12#include <math.h>
13
14void vp8_short_fdct4x4_c(short *input, short *output, int pitch)
15{
16    int i;
17    int a1, b1, c1, d1;
18    short *ip = input;
19    short *op = output;
20
21    for (i = 0; i < 4; i++)
22    {
23        a1 = ((ip[0] + ip[3]) * 8);
24        b1 = ((ip[1] + ip[2]) * 8);
25        c1 = ((ip[1] - ip[2]) * 8);
26        d1 = ((ip[0] - ip[3]) * 8);
27
28        op[0] = a1 + b1;
29        op[2] = a1 - b1;
30
31        op[1] = (c1 * 2217 + d1 * 5352 +  14500)>>12;
32        op[3] = (d1 * 2217 - c1 * 5352 +   7500)>>12;
33
34        ip += pitch / 2;
35        op += 4;
36
37    }
38    ip = output;
39    op = output;
40    for (i = 0; i < 4; i++)
41    {
42        a1 = ip[0] + ip[12];
43        b1 = ip[4] + ip[8];
44        c1 = ip[4] - ip[8];
45        d1 = ip[0] - ip[12];
46
47        op[0]  = ( a1 + b1 + 7)>>4;
48        op[8]  = ( a1 - b1 + 7)>>4;
49
50        op[4]  =((c1 * 2217 + d1 * 5352 +  12000)>>16) + (d1!=0);
51        op[12] = (d1 * 2217 - c1 * 5352 +  51000)>>16;
52
53        ip++;
54        op++;
55    }
56}
57
58void vp8_short_fdct8x4_c(short *input, short *output, int pitch)
59{
60    vp8_short_fdct4x4_c(input,   output,    pitch);
61    vp8_short_fdct4x4_c(input + 4, output + 16, pitch);
62}
63
64void vp8_short_walsh4x4_c(short *input, short *output, int pitch)
65{
66    int i;
67    int a1, b1, c1, d1;
68    int a2, b2, c2, d2;
69    short *ip = input;
70    short *op = output;
71
72
73    for (i = 0; i < 4; i++)
74    {
75        a1 = ((ip[0] + ip[2]) * 4);
76        d1 = ((ip[1] + ip[3]) * 4);
77        c1 = ((ip[1] - ip[3]) * 4);
78        b1 = ((ip[0] - ip[2]) * 4);
79
80        op[0] = a1 + d1 + (a1!=0);
81        op[1] = b1 + c1;
82        op[2] = b1 - c1;
83        op[3] = a1 - d1;
84        ip += pitch / 2;
85        op += 4;
86    }
87
88    ip = output;
89    op = output;
90
91    for (i = 0; i < 4; i++)
92    {
93        a1 = ip[0] + ip[8];
94        d1 = ip[4] + ip[12];
95        c1 = ip[4] - ip[12];
96        b1 = ip[0] - ip[8];
97
98        a2 = a1 + d1;
99        b2 = b1 + c1;
100        c2 = b1 - c1;
101        d2 = a1 - d1;
102
103        a2 += a2<0;
104        b2 += b2<0;
105        c2 += c2<0;
106        d2 += d2<0;
107
108        op[0] = (a2+3) >> 3;
109        op[4] = (b2+3) >> 3;
110        op[8] = (c2+3) >> 3;
111        op[12]= (d2+3) >> 3;
112
113        ip++;
114        op++;
115    }
116}
117