1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <unistd.h>
20 #include <string.h>
21
22 #define to565(r,g,b) \
23 ((((r) >> 3) << 11) | (((g) >> 2) << 5) | ((b) >> 3))
24
25 #define from565_r(x) ((((x) >> 11) & 0x1f) * 255 / 31)
26 #define from565_g(x) ((((x) >> 5) & 0x3f) * 255 / 63)
27 #define from565_b(x) (((x) & 0x1f) * 255 / 31)
28
to_565_raw(void)29 void to_565_raw(void)
30 {
31 unsigned char in[3];
32 unsigned short out;
33
34 while(read(0, in, 3) == 3) {
35 out = to565(in[0],in[1],in[2]);
36 write(1, &out, 2);
37 }
38 return;
39 }
40
to_565_raw_dither(int width)41 void to_565_raw_dither(int width)
42 {
43 unsigned char in[3];
44 unsigned short out;
45 int i = 0;
46 int e;
47
48 int* error = malloc((width+2) * 3 * sizeof(int));
49 int* next_error = malloc((width+2) * 3 * sizeof(int));
50 memset(error, 0, (width+2) * 3 * sizeof(int));
51 memset(next_error, 0, (width+2) * 3 * sizeof(int));
52 error += 3; // array goes from [-3..((width+1)*3+2)]
53 next_error += 3;
54
55 while(read(0, in, 3) == 3) {
56 int r = in[0] + error[i*3+0];
57 int rb = (r < 0) ? 0 : ((r > 255) ? 255 : r);
58
59 int g = in[1] + error[i*3+1];
60 int gb = (g < 0) ? 0 : ((g > 255) ? 255 : g);
61
62 int b = in[2] + error[i*3+2];
63 int bb = (b < 0) ? 0 : ((b > 255) ? 255 : b);
64
65 out = to565(rb, gb, bb);
66 write(1, &out, 2);
67
68 #define apply_error(ch) { \
69 next_error[(i-1)*3+ch] += e * 3 / 16; \
70 next_error[(i)*3+ch] += e * 5 / 16; \
71 next_error[(i+1)*3+ch] += e * 1 / 16; \
72 error[(i+1)*3+ch] += e - ((e*1/16) + (e*3/16) + (e*5/16)); \
73 }
74
75 e = r - from565_r(out);
76 apply_error(0);
77
78 e = g - from565_g(out);
79 apply_error(1);
80
81 e = b - from565_b(out);
82 apply_error(2);
83
84 #undef apply_error
85
86 ++i;
87 if (i == width) {
88 // error <- next_error; next_error <- 0
89 int* temp = error; error = next_error; next_error = temp;
90 memset(next_error, 0, (width+1) * 3 * sizeof(int));
91 i = 0;
92 }
93 }
94
95 free(error-3);
96 free(next_error-3);
97
98 return;
99 }
100
to_565_rle(void)101 void to_565_rle(void)
102 {
103 unsigned char in[3];
104 unsigned short last, color, count;
105 unsigned total = 0;
106 count = 0;
107
108 while(read(0, in, 3) == 3) {
109 color = to565(in[0],in[1],in[2]);
110 if (count) {
111 if ((color == last) && (count != 65535)) {
112 count++;
113 continue;
114 } else {
115 write(1, &count, 2);
116 write(1, &last, 2);
117 total += count;
118 }
119 }
120 last = color;
121 count = 1;
122 }
123 if (count) {
124 write(1, &count, 2);
125 write(1, &last, 2);
126 total += count;
127 }
128 fprintf(stderr,"%d pixels\n",total);
129 }
130
main(int argc,char ** argv)131 int main(int argc, char **argv)
132 {
133 if ((argc == 2) && (!strcmp(argv[1],"-rle"))) {
134 to_565_rle();
135 } else {
136 if (argc > 2 && (!strcmp(argv[1], "-w"))) {
137 to_565_raw_dither(atoi(argv[2]));
138 } else {
139 to_565_raw();
140 }
141 }
142 return 0;
143 }
144