From 876aea3dbe0e56984f7336e55698c06c9346c8e8 Mon Sep 17 00:00:00 2001 From: Sean Barrett Date: Sun, 8 Nov 2015 01:22:30 -0800 Subject: [PATCH] refactor bmp header parser for sharing with stbi_info --- stb_image.h | 136 ++++++++++++++++++++++++++++----------------- tests/image_test.c | 4 +- 2 files changed, 87 insertions(+), 53 deletions(-) diff --git a/stb_image.h b/stb_image.h index 354807b..df78c2f 100644 --- a/stb_image.h +++ b/stb_image.h @@ -4598,19 +4598,22 @@ static int stbi__shiftsigned(int v, int shift, int bits) return result; } -static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req_comp) +typedef struct { - stbi_uc *out; - unsigned int mr=0,mg=0,mb=0,ma=0, all_a=255; - stbi_uc pal[256][4]; - int psize=0,i,j,compress=0,width; - int bpp, flip_vertically, pad, target, offset, hsz; + int bpp, offset, hsz; + unsigned int mr,mg,mb,ma, all_a; +} stbi__bmp_data; + +static void *stbi__bmp_parse_header(stbi__context *s, stbi__bmp_data *info) +{ + int hsz; if (stbi__get8(s) != 'B' || stbi__get8(s) != 'M') return stbi__errpuc("not BMP", "Corrupt BMP"); stbi__get32le(s); // discard filesize stbi__get16le(s); // discard reserved stbi__get16le(s); // discard reserved - offset = stbi__get32le(s); - hsz = stbi__get32le(s); + info->offset = stbi__get32le(s); + info->hsz = hsz = stbi__get32le(s); + if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108 && hsz != 124) return stbi__errpuc("unknown BMP", "BMP type not supported: unknown"); if (hsz == 12) { s->img_x = stbi__get16le(s); @@ -4620,15 +4623,10 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int s->img_y = stbi__get32le(s); } if (stbi__get16le(s) != 1) return stbi__errpuc("bad BMP", "bad BMP"); - bpp = stbi__get16le(s); - if (bpp == 1) return stbi__errpuc("monochrome", "BMP type not supported: 1-bit"); - flip_vertically = ((int) s->img_y) > 0; - s->img_y = abs((int) s->img_y); - if (hsz == 12) { - if (bpp < 24) - psize = (offset - 14 - 24) / 3; - } else { - compress = stbi__get32le(s); + info->bpp = stbi__get16le(s); + if (info->bpp == 1) return stbi__errpuc("monochrome", "BMP type not supported: 1-bit"); + if (hsz != 12) { + int compress = stbi__get32le(s); if (compress == 1 || compress == 2) return stbi__errpuc("BMP RLE", "BMP type not supported: RLE"); stbi__get32le(s); // discard sizeof stbi__get32le(s); // discard hres @@ -4642,26 +4640,26 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int stbi__get32le(s); stbi__get32le(s); } - if (bpp == 16 || bpp == 32) { - mr = mg = mb = 0; + if (info->bpp == 16 || info->bpp == 32) { + info->mr = info->mg = info->mb = 0; if (compress == 0) { - if (bpp == 32) { - mr = 0xffu << 16; - mg = 0xffu << 8; - mb = 0xffu << 0; - ma = 0xffu << 24; - all_a = 0; // if all_a is 0 at end, then we loaded alpha channel but it was all 0 + if (info->bpp == 32) { + info->mr = 0xffu << 16; + info->mg = 0xffu << 8; + info->mb = 0xffu << 0; + info->ma = 0xffu << 24; + info->all_a = 0; // if all_a is 0 at end, then we loaded alpha channel but it was all 0 } else { - mr = 31u << 10; - mg = 31u << 5; - mb = 31u << 0; + info->mr = 31u << 10; + info->mg = 31u << 5; + info->mb = 31u << 0; } } else if (compress == 3) { - mr = stbi__get32le(s); - mg = stbi__get32le(s); - mb = stbi__get32le(s); + info->mr = stbi__get32le(s); + info->mg = stbi__get32le(s); + info->mb = stbi__get32le(s); // not documented, but generated by photoshop and handled by mspaint - if (mr == mg && mg == mb) { + if (info->mr == info->mg && info->mg == info->mb) { // ?!?!? return stbi__errpuc("bad BMP", "bad BMP"); } @@ -4669,11 +4667,13 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int return stbi__errpuc("bad BMP", "bad BMP"); } } else { - STBI_ASSERT(hsz == 108 || hsz == 124); - mr = stbi__get32le(s); - mg = stbi__get32le(s); - mb = stbi__get32le(s); - ma = stbi__get32le(s); + int i; + if (hsz != 108 && hsz != 124) + return stbi__errpuc("bad BMP", "bad BMP"); + info->mr = stbi__get32le(s); + info->mg = stbi__get32le(s); + info->mb = stbi__get32le(s); + info->ma = stbi__get32le(s); stbi__get32le(s); // discard color space for (i=0; i < 12; ++i) stbi__get32le(s); // discard color space parameters @@ -4684,35 +4684,68 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int stbi__get32le(s); // discard reserved } } - if (bpp < 16) - psize = (offset - 14 - hsz) >> 2; } + return (void *) 1; +} + + +static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int req_comp) +{ + stbi_uc *out; + unsigned int mr=0,mg=0,mb=0,ma=0, all_a; + stbi_uc pal[256][4]; + int psize=0,i,j,width; + int flip_vertically, pad, target; + stbi__bmp_data info; + + info.all_a = 255; + if (stbi__bmp_parse_header(s, &info) == NULL) + return NULL; // error code already set + + flip_vertically = ((int) s->img_y) > 0; + s->img_y = abs((int) s->img_y); + + mr = info.mr; + mg = info.mg; + mb = info.mb; + ma = info.ma; + all_a = info.all_a; + + if (info.hsz == 12) { + if (info.bpp < 24) + psize = (info.offset - 14 - 24) / 3; + } else { + if (info.bpp < 16) + psize = (info.offset - 14 - info.hsz) >> 2; + } + s->img_n = ma ? 4 : 3; if (req_comp && req_comp >= 3) // we can directly decode 3 or 4 target = req_comp; else target = s->img_n; // if they want monochrome, we'll post-convert + out = (stbi_uc *) stbi__malloc(target * s->img_x * s->img_y); if (!out) return stbi__errpuc("outofmem", "Out of memory"); - if (bpp < 16) { + if (info.bpp < 16) { int z=0; if (psize == 0 || psize > 256) { STBI_FREE(out); return stbi__errpuc("invalid", "Corrupt BMP"); } for (i=0; i < psize; ++i) { pal[i][2] = stbi__get8(s); pal[i][1] = stbi__get8(s); pal[i][0] = stbi__get8(s); - if (hsz != 12) stbi__get8(s); + if (info.hsz != 12) stbi__get8(s); pal[i][3] = 255; } - stbi__skip(s, offset - 14 - hsz - psize * (hsz == 12 ? 3 : 4)); - if (bpp == 4) width = (s->img_x + 1) >> 1; - else if (bpp == 8) width = s->img_x; + stbi__skip(s, info.offset - 14 - info.hsz - psize * (info.hsz == 12 ? 3 : 4)); + if (info.bpp == 4) width = (s->img_x + 1) >> 1; + else if (info.bpp == 8) width = s->img_x; else { STBI_FREE(out); return stbi__errpuc("bad bpp", "Corrupt BMP"); } pad = (-width)&3; for (j=0; j < (int) s->img_y; ++j) { for (i=0; i < (int) s->img_x; i += 2) { int v=stbi__get8(s),v2=0; - if (bpp == 4) { + if (info.bpp == 4) { v2 = v & 15; v >>= 4; } @@ -4721,7 +4754,7 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int out[z++] = pal[v][2]; if (target == 4) out[z++] = 255; if (i+1 == (int) s->img_x) break; - v = (bpp == 8) ? stbi__get8(s) : v2; + v = (info.bpp == 8) ? stbi__get8(s) : v2; out[z++] = pal[v][0]; out[z++] = pal[v][1]; out[z++] = pal[v][2]; @@ -4733,14 +4766,14 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int int rshift=0,gshift=0,bshift=0,ashift=0,rcount=0,gcount=0,bcount=0,acount=0; int z = 0; int easy=0; - stbi__skip(s, offset - 14 - hsz); - if (bpp == 24) width = 3 * s->img_x; - else if (bpp == 16) width = 2*s->img_x; + stbi__skip(s, info.offset - 14 - info.hsz); + if (info.bpp == 24) width = 3 * s->img_x; + else if (info.bpp == 16) width = 2*s->img_x; else /* bpp = 32 and pad = 0 */ width=0; pad = (-width) & 3; - if (bpp == 24) { + if (info.bpp == 24) { easy = 1; - } else if (bpp == 32) { + } else if (info.bpp == 32) { if (mb == 0xff && mg == 0xff00 && mr == 0x00ff0000 && ma == 0xff000000) easy = 2; } @@ -4765,6 +4798,7 @@ static stbi_uc *stbi__bmp_load(stbi__context *s, int *x, int *y, int *comp, int if (target == 4) out[z++] = a; } } else { + int bpp = info.bpp; for (i=0; i < (int) s->img_x; ++i) { stbi__uint32 v = (bpp == 16 ? (stbi__uint32) stbi__get16le(s) : stbi__get32le(s)); int a; diff --git a/tests/image_test.c b/tests/image_test.c index 9bb1832..86d3b46 100644 --- a/tests/image_test.c +++ b/tests/image_test.c @@ -7,7 +7,7 @@ #define STB_DEFINE #include "stb.h" -#define PNGSUITE_PRIMARY +//#define PNGSUITE_PRIMARY #if 0 void test_ycbcr(void) @@ -65,7 +65,7 @@ int main(int argc, char **argv) int w,h; //test_ycbcr(); - #if 1 + #if 0 // test hdr asserts for (h=0; h < 100; h += 2) for (w=0; w < 200; ++w)