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