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1/*
2 * Fast C2P (Chunky-to-Planar) Conversion
3 *
4 * Copyright (C) 2003-2008 Geert Uytterhoeven
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive
8 * for more details.
9 */
10
11#include <linux/export.h>
12#include <linux/module.h>
13#include <linux/string.h>
14
15#include <linux/unaligned.h>
16
17#include "c2p.h"
18#include "c2p_core.h"
19
20
21 /*
22 * Perform a full C2P step on 32 8-bit pixels, stored in 8 32-bit words
23 * containing
24 * - 32 8-bit chunky pixels on input
25 * - permutated planar data (1 plane per 32-bit word) on output
26 */
27
28static void c2p_32x8(u32 d[8])
29{
30 transp8(d, 16, 4);
31 transp8(d, 8, 2);
32 transp8(d, 4, 1);
33 transp8(d, 2, 4);
34 transp8(d, 1, 2);
35}
36
37
38 /*
39 * Array containing the permutation indices of the planar data after c2p
40 */
41
42static const int perm_c2p_32x8[8] = { 7, 5, 3, 1, 6, 4, 2, 0 };
43
44
45 /*
46 * Store a full block of planar data after c2p conversion
47 */
48
49static inline void store_planar(void *dst, u32 dst_inc, u32 bpp, u32 d[8])
50{
51 int i;
52
53 for (i = 0; i < bpp; i++, dst += dst_inc)
54 put_unaligned_be32(d[perm_c2p_32x8[i]], dst);
55}
56
57
58 /*
59 * Store a partial block of planar data after c2p conversion
60 */
61
62static inline void store_planar_masked(void *dst, u32 dst_inc, u32 bpp,
63 u32 d[8], u32 mask)
64{
65 int i;
66
67 for (i = 0; i < bpp; i++, dst += dst_inc)
68 put_unaligned_be32(comp(d[perm_c2p_32x8[i]],
69 get_unaligned_be32(dst), mask),
70 dst);
71}
72
73
74 /*
75 * c2p_planar - Copy 8-bit chunky image data to a planar frame buffer
76 * @dst: Starting address of the planar frame buffer
77 * @dx: Horizontal destination offset (in pixels)
78 * @dy: Vertical destination offset (in pixels)
79 * @width: Image width (in pixels)
80 * @height: Image height (in pixels)
81 * @dst_nextline: Frame buffer offset to the next line (in bytes)
82 * @dst_nextplane: Frame buffer offset to the next plane (in bytes)
83 * @src_nextline: Image offset to the next line (in bytes)
84 * @bpp: Bits per pixel of the planar frame buffer (1-8)
85 */
86
87void c2p_planar(void *dst, const void *src, u32 dx, u32 dy, u32 width,
88 u32 height, u32 dst_nextline, u32 dst_nextplane,
89 u32 src_nextline, u32 bpp)
90{
91 union {
92 u8 pixels[32];
93 u32 words[8];
94 } d;
95 u32 dst_idx, first, last, w;
96 const u8 *c;
97 void *p;
98
99 dst += dy*dst_nextline+(dx & ~31);
100 dst_idx = dx % 32;
101 first = 0xffffffffU >> dst_idx;
102 last = ~(0xffffffffU >> ((dst_idx+width) % 32));
103 while (height--) {
104 c = src;
105 p = dst;
106 w = width;
107 if (dst_idx+width <= 32) {
108 /* Single destination word */
109 first &= last;
110 memset(d.pixels, 0, sizeof(d));
111 memcpy(d.pixels+dst_idx, c, width);
112 c += width;
113 c2p_32x8(d.words);
114 store_planar_masked(p, dst_nextplane, bpp, d.words,
115 first);
116 p += 4;
117 } else {
118 /* Multiple destination words */
119 w = width;
120 /* Leading bits */
121 if (dst_idx) {
122 w = 32 - dst_idx;
123 memset(d.pixels, 0, dst_idx);
124 memcpy(d.pixels+dst_idx, c, w);
125 c += w;
126 c2p_32x8(d.words);
127 store_planar_masked(p, dst_nextplane, bpp,
128 d.words, first);
129 p += 4;
130 w = width-w;
131 }
132 /* Main chunk */
133 while (w >= 32) {
134 memcpy(d.pixels, c, 32);
135 c += 32;
136 c2p_32x8(d.words);
137 store_planar(p, dst_nextplane, bpp, d.words);
138 p += 4;
139 w -= 32;
140 }
141 /* Trailing bits */
142 w %= 32;
143 if (w > 0) {
144 memcpy(d.pixels, c, w);
145 memset(d.pixels+w, 0, 32-w);
146 c2p_32x8(d.words);
147 store_planar_masked(p, dst_nextplane, bpp,
148 d.words, last);
149 }
150 }
151 src += src_nextline;
152 dst += dst_nextline;
153 }
154}
155EXPORT_SYMBOL_GPL(c2p_planar);
156
157MODULE_DESCRIPTION("Fast C2P (Chunky-to-Planar) Conversion");
158MODULE_LICENSE("GPL");