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