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 28 static 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 42 static 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 49 static 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 62 static 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 87 void 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 } 155 EXPORT_SYMBOL_GPL(c2p_planar); 156 157 MODULE_DESCRIPTION("Fast C2P (Chunky-to-Planar) Conversion"); 158 MODULE_LICENSE("GPL"); 159