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Diffstat (limited to 'drivers/video/c2p.c')
| -rw-r--r-- | drivers/video/c2p.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/video/c2p.c b/drivers/video/c2p.c new file mode 100644 index 0000000..5c30bbd --- /dev/null +++ b/drivers/video/c2p.c @@ -0,0 +1,229 @@ +/* + * Fast C2P (Chunky-to-Planar) Conversion + * + * Copyright (C) 2003 Geert Uytterhoeven + * + * NOTES: + * - This code was inspired by Scout's C2P tutorial + * - It assumes to run on a big endian system + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +#include <linux/string.h> +#include "c2p.h" + + + /* + * Basic transpose step + */ + +#define _transp(d, i1, i2, shift, mask) \ + do { \ + u32 t = (d[i1] ^ (d[i2] >> shift)) & mask; \ + d[i1] ^= t; \ + d[i2] ^= t << shift; \ + } while (0) + +static inline u32 get_mask(int n) +{ + switch (n) { + case 1: + return 0x55555555; + break; + + case 2: + return 0x33333333; + break; + + case 4: + return 0x0f0f0f0f; + break; + + case 8: + return 0x00ff00ff; + break; + + case 16: + return 0x0000ffff; + break; + } + return 0; +} + +#define transp_nx1(d, n) \ + do { \ + u32 mask = get_mask(n); \ + /* First block */ \ + _transp(d, 0, 1, n, mask); \ + /* Second block */ \ + _transp(d, 2, 3, n, mask); \ + /* Third block */ \ + _transp(d, 4, 5, n, mask); \ + /* Fourth block */ \ + _transp(d, 6, 7, n, mask); \ + } while (0) + +#define transp_nx2(d, n) \ + do { \ + u32 mask = get_mask(n); \ + /* First block */ \ + _transp(d, 0, 2, n, mask); \ + _transp(d, 1, 3, n, mask); \ + /* Second block */ \ + _transp(d, 4, 6, n, mask); \ + _transp(d, 5, 7, n, mask); \ + } while (0) + +#define transp_nx4(d, n) \ + do { \ + u32 mask = get_mask(n); \ + _transp(d, 0, 4, n, mask); \ + _transp(d, 1, 5, n, mask); \ + _transp(d, 2, 6, n, mask); \ + _transp(d, 3, 7, n, mask); \ + } while (0) + +#define transp(d, n, m) transp_nx ## m(d, n) + + + /* + * Perform a full C2P step on 32 8-bit pixels, stored in 8 32-bit words + * containing + * - 32 8-bit chunky pixels on input + * - permuted planar data on output + */ + +static void c2p_8bpp(u32 d[8]) +{ + transp(d, 16, 4); + transp(d, 8, 2); + transp(d, 4, 1); + transp(d, 2, 4); + transp(d, 1, 2); +} + + + /* + * Array containing the permution indices of the planar data after c2p + */ + +static const int perm_c2p_8bpp[8] = { 7, 5, 3, 1, 6, 4, 2, 0 }; + + + /* + * Compose two values, using a bitmask as decision value + * This is equivalent to (a & mask) | (b & ~mask) + */ + +static inline unsigned long comp(unsigned long a, unsigned long b, + unsigned long mask) +{ + return ((a ^ b) & mask) ^ b; +} + + + /* + * Store a full block of planar data after c2p conversion + */ + +static inline void store_planar(char *dst, u32 dst_inc, u32 bpp, u32 d[8]) +{ + int i; + + for (i = 0; i < bpp; i++, dst += dst_inc) + *(u32 *)dst = d[perm_c2p_8bpp[i]]; +} + + + /* + * Store a partial block of planar data after c2p conversion + */ + +static inline void store_planar_masked(char *dst, u32 dst_inc, u32 bpp, + u32 d[8], u32 mask) +{ + int i; + + for (i = 0; i < bpp; i++, dst += dst_inc) + *(u32 *)dst = comp(d[perm_c2p_8bpp[i]], *(u32 *)dst, mask); +} + + + /* + * c2p - Copy 8-bit chunky image data to a planar frame buffer + * @dst: Starting address of the planar frame buffer + * @dx: Horizontal destination offset (in pixels) + * @dy: Vertical destination offset (in pixels) + * @width: Image width (in pixels) + * @height: Image height (in pixels) + * @dst_nextline: Frame buffer offset to the next line (in bytes) + * @dst_nextplane: Frame buffer offset to the next plane (in bytes) + * @src_nextline: Image offset to the next line (in bytes) + * @bpp: Bits per pixel of the planar frame buffer (1-8) + */ + +void c2p(u8 *dst, const u8 *src, u32 dx, u32 dy, u32 width, u32 height, + u32 dst_nextline, u32 dst_nextplane, u32 src_nextline, u32 bpp) +{ + int dst_idx; + u32 d[8], first, last, w; + const u8 *c; + u8 *p; + + dst += dy*dst_nextline+(dx & ~31); + dst_idx = dx % 32; + first = ~0UL >> dst_idx; + last = ~(~0UL >> ((dst_idx+width) % 32)); + while (height--) { + c = src; + p = dst; + w = width; + if (dst_idx+width <= 32) { + /* Single destination word */ + first &= last; + memset(d, 0, sizeof(d)); + memcpy((u8 *)d+dst_idx, c, width); + c += width; + c2p_8bpp(d); + store_planar_masked(p, dst_nextplane, bpp, d, first); + p += 4; + } else { + /* Multiple destination words */ + w = width; + /* Leading bits */ + if (dst_idx) { + w = 32 - dst_idx; + memset(d, 0, dst_idx); + memcpy((u8 *)d+dst_idx, c, w); + c += w; + c2p_8bpp(d); + store_planar_masked(p, dst_nextplane, bpp, d, first); + p += 4; + w = width-w; + } + /* Main chunk */ + while (w >= 32) { + memcpy(d, c, 32); + c += 32; + c2p_8bpp(d); + store_planar(p, dst_nextplane, bpp, d); + p += 4; + w -= 32; + } + /* Trailing bits */ + w %= 32; + if (w > 0) { + memcpy(d, c, w); + memset((u8 *)d+w, 0, 32-w); + c2p_8bpp(d); + store_planar_masked(p, dst_nextplane, bpp, d, last); + } + } + src += src_nextline; + dst += dst_nextline; + } +} + |
