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 
14 #include "./vp8_rtcd.h"
15 
vp8_short_fdct4x4_c(short * input,short * output,int pitch)16 void vp8_short_fdct4x4_c(short *input, short *output, int pitch)
17 {
18     int i;
19     int a1, b1, c1, d1;
20     short *ip = input;
21     short *op = output;
22 
23     for (i = 0; i < 4; i++)
24     {
25         a1 = ((ip[0] + ip[3]) * 8);
26         b1 = ((ip[1] + ip[2]) * 8);
27         c1 = ((ip[1] - ip[2]) * 8);
28         d1 = ((ip[0] - ip[3]) * 8);
29 
30         op[0] = a1 + b1;
31         op[2] = a1 - b1;
32 
33         op[1] = (c1 * 2217 + d1 * 5352 +  14500)>>12;
34         op[3] = (d1 * 2217 - c1 * 5352 +   7500)>>12;
35 
36         ip += pitch / 2;
37         op += 4;
38 
39     }
40     ip = output;
41     op = output;
42     for (i = 0; i < 4; i++)
43     {
44         a1 = ip[0] + ip[12];
45         b1 = ip[4] + ip[8];
46         c1 = ip[4] - ip[8];
47         d1 = ip[0] - ip[12];
48 
49         op[0]  = ( a1 + b1 + 7)>>4;
50         op[8]  = ( a1 - b1 + 7)>>4;
51 
52         op[4]  =((c1 * 2217 + d1 * 5352 +  12000)>>16) + (d1!=0);
53         op[12] = (d1 * 2217 - c1 * 5352 +  51000)>>16;
54 
55         ip++;
56         op++;
57     }
58 }
59 
vp8_short_fdct8x4_c(short * input,short * output,int pitch)60 void vp8_short_fdct8x4_c(short *input, short *output, int pitch)
61 {
62     vp8_short_fdct4x4_c(input,   output,    pitch);
63     vp8_short_fdct4x4_c(input + 4, output + 16, pitch);
64 }
65 
vp8_short_walsh4x4_c(short * input,short * output,int pitch)66 void vp8_short_walsh4x4_c(short *input, short *output, int pitch)
67 {
68     int i;
69     int a1, b1, c1, d1;
70     int a2, b2, c2, d2;
71     short *ip = input;
72     short *op = output;
73 
74 
75     for (i = 0; i < 4; i++)
76     {
77         a1 = ((ip[0] + ip[2]) * 4);
78         d1 = ((ip[1] + ip[3]) * 4);
79         c1 = ((ip[1] - ip[3]) * 4);
80         b1 = ((ip[0] - ip[2]) * 4);
81 
82         op[0] = a1 + d1 + (a1!=0);
83         op[1] = b1 + c1;
84         op[2] = b1 - c1;
85         op[3] = a1 - d1;
86         ip += pitch / 2;
87         op += 4;
88     }
89 
90     ip = output;
91     op = output;
92 
93     for (i = 0; i < 4; i++)
94     {
95         a1 = ip[0] + ip[8];
96         d1 = ip[4] + ip[12];
97         c1 = ip[4] - ip[12];
98         b1 = ip[0] - ip[8];
99 
100         a2 = a1 + d1;
101         b2 = b1 + c1;
102         c2 = b1 - c1;
103         d2 = a1 - d1;
104 
105         a2 += a2<0;
106         b2 += b2<0;
107         c2 += c2<0;
108         d2 += d2<0;
109 
110         op[0] = (a2+3) >> 3;
111         op[4] = (b2+3) >> 3;
112         op[8] = (c2+3) >> 3;
113         op[12]= (d2+3) >> 3;
114 
115         ip++;
116         op++;
117     }
118 }
119