608 lines
19 KiB
C
608 lines
19 KiB
C
#include "fitz-imp.h"
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#include <string.h>
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#include <limits.h>
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struct info
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{
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int gif89a;
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unsigned int width, height;
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unsigned char aspect;
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unsigned int xres, yres;
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unsigned int image_left, image_top;
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unsigned int image_width, image_height;
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unsigned int image_interlaced;
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int has_gct;
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int gct_entries;
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unsigned char *gct;
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unsigned int gct_background;
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int has_lct;
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int lct_entries;
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unsigned char *lct;
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int has_transparency;
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unsigned int transparent;
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unsigned char *mask;
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fz_pixmap *pix;
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};
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/* default color table, where the first two entries are black and white */
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static const unsigned char dct[256 * 3] = {
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0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02,
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0x03, 0x03, 0x03, 0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x06, 0x06, 0x06,
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0x07, 0x07, 0x07, 0x08, 0x08, 0x08, 0x09, 0x09, 0x09, 0x0a, 0x0a, 0x0a,
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0x0b, 0x0b, 0x0b, 0x0c, 0x0c, 0x0c, 0x0d, 0x0d, 0x0d, 0x0e, 0x0e, 0x0e,
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0x0f, 0x0f, 0x0f, 0x10, 0x10, 0x10, 0x11, 0x11, 0x11, 0x12, 0x12, 0x12,
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0x13, 0x13, 0x13, 0x14, 0x14, 0x14, 0x15, 0x15, 0x15, 0x16, 0x16, 0x16,
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0x17, 0x17, 0x17, 0x18, 0x18, 0x18, 0x19, 0x19, 0x19, 0x1a, 0x1a, 0x1a,
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0x1b, 0x1b, 0x1b, 0x1c, 0x1c, 0x1c, 0x1d, 0x1d, 0x1d, 0x1e, 0x1e, 0x1e,
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0x1f, 0x1f, 0x1f, 0x20, 0x20, 0x20, 0x21, 0x21, 0x21, 0x22, 0x22, 0x22,
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0x23, 0x23, 0x23, 0x24, 0x24, 0x24, 0x25, 0x25, 0x25, 0x26, 0x26, 0x26,
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0x27, 0x27, 0x27, 0x28, 0x28, 0x28, 0x29, 0x29, 0x29, 0x2a, 0x2a, 0x2a,
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0x2b, 0x2b, 0x2b, 0x2c, 0x2c, 0x2c, 0x2d, 0x2d, 0x2d, 0x2e, 0x2e, 0x2e,
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0x2f, 0x2f, 0x2f, 0x30, 0x30, 0x30, 0x31, 0x31, 0x31, 0x32, 0x32, 0x32,
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0x33, 0x33, 0x33, 0x34, 0x34, 0x34, 0x35, 0x35, 0x35, 0x36, 0x36, 0x36,
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0x37, 0x37, 0x37, 0x38, 0x38, 0x38, 0x39, 0x39, 0x39, 0x3a, 0x3a, 0x3a,
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0x3b, 0x3b, 0x3b, 0x3c, 0x3c, 0x3c, 0x3d, 0x3d, 0x3d, 0x3e, 0x3e, 0x3e,
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0x3f, 0x3f, 0x3f, 0x40, 0x40, 0x40, 0x41, 0x41, 0x41, 0x42, 0x42, 0x42,
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0x43, 0x43, 0x43, 0x44, 0x44, 0x44, 0x45, 0x45, 0x45, 0x46, 0x46, 0x46,
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0x47, 0x47, 0x47, 0x48, 0x48, 0x48, 0x49, 0x49, 0x49, 0x4a, 0x4a, 0x4a,
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0x4b, 0x4b, 0x4b, 0x4c, 0x4c, 0x4c, 0x4d, 0x4d, 0x4d, 0x4e, 0x4e, 0x4e,
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0x4f, 0x4f, 0x4f, 0x50, 0x50, 0x50, 0x51, 0x51, 0x51, 0x52, 0x52, 0x52,
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0x53, 0x53, 0x53, 0x54, 0x54, 0x54, 0x55, 0x55, 0x55, 0x56, 0x56, 0x56,
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0x57, 0x57, 0x57, 0x58, 0x58, 0x58, 0x59, 0x59, 0x59, 0x5a, 0x5a, 0x5a,
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0x5b, 0x5b, 0x5b, 0x5c, 0x5c, 0x5c, 0x5d, 0x5d, 0x5d, 0x5e, 0x5e, 0x5e,
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0x5f, 0x5f, 0x5f, 0x60, 0x60, 0x60, 0x61, 0x61, 0x61, 0x62, 0x62, 0x62,
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0x63, 0x63, 0x63, 0x64, 0x64, 0x64, 0x65, 0x65, 0x65, 0x66, 0x66, 0x66,
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0x67, 0x67, 0x67, 0x68, 0x68, 0x68, 0x69, 0x69, 0x69, 0x6a, 0x6a, 0x6a,
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0x6b, 0x6b, 0x6b, 0x6c, 0x6c, 0x6c, 0x6d, 0x6d, 0x6d, 0x6e, 0x6e, 0x6e,
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0x6f, 0x6f, 0x6f, 0x70, 0x70, 0x70, 0x71, 0x71, 0x71, 0x72, 0x72, 0x72,
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0x73, 0x73, 0x73, 0x74, 0x74, 0x74, 0x75, 0x75, 0x75, 0x76, 0x76, 0x76,
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0x77, 0x77, 0x77, 0x78, 0x78, 0x78, 0x79, 0x79, 0x79, 0x7a, 0x7a, 0x7a,
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0x7b, 0x7b, 0x7b, 0x7c, 0x7c, 0x7c, 0x7d, 0x7d, 0x7d, 0x7e, 0x7e, 0x7e,
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0x7f, 0x7f, 0x7f, 0x80, 0x80, 0x80, 0x81, 0x81, 0x81, 0x82, 0x82, 0x82,
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0x83, 0x83, 0x83, 0x84, 0x84, 0x84, 0x85, 0x85, 0x85, 0x86, 0x86, 0x86,
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0x87, 0x87, 0x87, 0x88, 0x88, 0x88, 0x89, 0x89, 0x89, 0x8a, 0x8a, 0x8a,
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0x8b, 0x8b, 0x8b, 0x8c, 0x8c, 0x8c, 0x8d, 0x8d, 0x8d, 0x8e, 0x8e, 0x8e,
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0x8f, 0x8f, 0x8f, 0x90, 0x90, 0x90, 0x91, 0x91, 0x91, 0x92, 0x92, 0x92,
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0x93, 0x93, 0x93, 0x94, 0x94, 0x94, 0x95, 0x95, 0x95, 0x96, 0x96, 0x96,
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0x97, 0x97, 0x97, 0x98, 0x98, 0x98, 0x99, 0x99, 0x99, 0x9a, 0x9a, 0x9a,
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0x9b, 0x9b, 0x9b, 0x9c, 0x9c, 0x9c, 0x9d, 0x9d, 0x9d, 0x9e, 0x9e, 0x9e,
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0x9f, 0x9f, 0x9f, 0xa0, 0xa0, 0xa0, 0xa1, 0xa1, 0xa1, 0xa2, 0xa2, 0xa2,
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0xa3, 0xa3, 0xa3, 0xa4, 0xa4, 0xa4, 0xa5, 0xa5, 0xa5, 0xa6, 0xa6, 0xa6,
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0xa7, 0xa7, 0xa7, 0xa8, 0xa8, 0xa8, 0xa9, 0xa9, 0xa9, 0xaa, 0xaa, 0xaa,
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0xab, 0xab, 0xab, 0xac, 0xac, 0xac, 0xad, 0xad, 0xad, 0xae, 0xae, 0xae,
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0xaf, 0xaf, 0xaf, 0xb0, 0xb0, 0xb0, 0xb1, 0xb1, 0xb1, 0xb2, 0xb2, 0xb2,
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0xb3, 0xb3, 0xb3, 0xb4, 0xb4, 0xb4, 0xb5, 0xb5, 0xb5, 0xb6, 0xb6, 0xb6,
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0xb7, 0xb7, 0xb7, 0xb8, 0xb8, 0xb8, 0xb9, 0xb9, 0xb9, 0xba, 0xba, 0xba,
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0xbb, 0xbb, 0xbb, 0xbc, 0xbc, 0xbc, 0xbd, 0xbd, 0xbd, 0xbe, 0xbe, 0xbe,
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0xbf, 0xbf, 0xbf, 0xc0, 0xc0, 0xc0, 0xc1, 0xc1, 0xc1, 0xc2, 0xc2, 0xc2,
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0xc3, 0xc3, 0xc3, 0xc4, 0xc4, 0xc4, 0xc5, 0xc5, 0xc5, 0xc6, 0xc6, 0xc6,
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0xc7, 0xc7, 0xc7, 0xc8, 0xc8, 0xc8, 0xc9, 0xc9, 0xc9, 0xca, 0xca, 0xca,
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0xcb, 0xcb, 0xcb, 0xcc, 0xcc, 0xcc, 0xcd, 0xcd, 0xcd, 0xce, 0xce, 0xce,
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0xcf, 0xcf, 0xcf, 0xd0, 0xd0, 0xd0, 0xd1, 0xd1, 0xd1, 0xd2, 0xd2, 0xd2,
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0xd3, 0xd3, 0xd3, 0xd4, 0xd4, 0xd4, 0xd5, 0xd5, 0xd5, 0xd6, 0xd6, 0xd6,
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0xd7, 0xd7, 0xd7, 0xd8, 0xd8, 0xd8, 0xd9, 0xd9, 0xd9, 0xda, 0xda, 0xda,
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0xdb, 0xdb, 0xdb, 0xdc, 0xdc, 0xdc, 0xdd, 0xdd, 0xdd, 0xde, 0xde, 0xde,
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0xdf, 0xdf, 0xdf, 0xe0, 0xe0, 0xe0, 0xe1, 0xe1, 0xe1, 0xe2, 0xe2, 0xe2,
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0xe3, 0xe3, 0xe3, 0xe4, 0xe4, 0xe4, 0xe5, 0xe5, 0xe5, 0xe6, 0xe6, 0xe6,
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0xe7, 0xe7, 0xe7, 0xe8, 0xe8, 0xe8, 0xe9, 0xe9, 0xe9, 0xea, 0xea, 0xea,
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0xeb, 0xeb, 0xeb, 0xec, 0xec, 0xec, 0xed, 0xed, 0xed, 0xee, 0xee, 0xee,
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0xef, 0xef, 0xef, 0xf0, 0xf0, 0xf0, 0xf1, 0xf1, 0xf1, 0xf2, 0xf2, 0xf2,
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0xf3, 0xf3, 0xf3, 0xf4, 0xf4, 0xf4, 0xf5, 0xf5, 0xf5, 0xf6, 0xf6, 0xf6,
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0xf7, 0xf7, 0xf7, 0xf8, 0xf8, 0xf8, 0xf9, 0xf9, 0xf9, 0xfa, 0xfa, 0xfa,
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0xfb, 0xfb, 0xfb, 0xfc, 0xfc, 0xfc, 0xfd, 0xfd, 0xfd, 0xfe, 0xfe, 0xfe,
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};
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static const unsigned char *
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gif_read_subblocks(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end, fz_buffer *buf)
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{
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int len;
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do
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{
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if (end - p < 1)
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fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in data subblocks in gif image");
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len = *p;
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p += 1;
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if (len > 0)
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{
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if (end - p < len)
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fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in data subblock in gif image");
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if (buf)
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fz_append_data(ctx, buf, p, len);
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p += len;
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}
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} while (len > 0);
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return p;
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}
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static const unsigned char *
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gif_read_header(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
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{
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if (end - p < 6)
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fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in header in gif image");
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if (memcmp(&p[0], "GIF", 3))
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fz_throw(ctx, FZ_ERROR_GENERIC, "invalid signature in gif image");
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if (memcmp(&p[3], "87a", 3) && memcmp(&p[3], "89a", 3))
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fz_throw(ctx, FZ_ERROR_GENERIC, "unsupported version in gif image");
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info->gif89a = !memcmp(p, "GIF89a", 6);
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return p + 6;
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}
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static const unsigned char *
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gif_read_lsd(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
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{
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if (end - p < 7)
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fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in logical screen descriptor in gif image");
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info->width = p[1] << 8 | p[0];
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info->height = p[3] << 8 | p[2];
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if (info->width <= 0)
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fz_throw(ctx, FZ_ERROR_GENERIC, "image width must be > 0");
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if (info->height <= 0)
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fz_throw(ctx, FZ_ERROR_GENERIC, "image height must be > 0");
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if (info->height > UINT_MAX / info->width / 3 /* components */)
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fz_throw(ctx, FZ_ERROR_GENERIC, "image dimensions might overflow");
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info->has_gct = (p[4] >> 7) & 0x1;
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if (info->has_gct)
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{
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info->gct_entries = 1 << ((p[4] & 0x7) + 1);
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info->gct_background = fz_clampi(p[5], 0, info->gct_entries - 1);
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}
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info->aspect = p[6];
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info->xres = 96;
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info->yres= 96;
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if (info->aspect > 0)
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info->yres = (((float) info->aspect + 15) / 64) * 96;
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return p + 7;
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}
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static const unsigned char *
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gif_read_gct(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
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{
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if (end - p < info->gct_entries * 3)
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fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in global color table in gif image");
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info->gct = fz_malloc(ctx, info->gct_entries * 3);
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memmove(info->gct, p, info->gct_entries * 3);
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return p + info->gct_entries * 3;
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}
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static const unsigned char *
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gif_read_id(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
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{
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if (end - p < 10)
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fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in image descriptor in gif image");
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info->image_left = p[2] << 8 | p[1];
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info->image_top = p[4] << 8 | p[3];
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info->image_width = p[6] << 8 | p[5];
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info->image_height = p[8] << 8 | p[7];
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info->has_lct = (p[9] >> 7) & 0x1;
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info->image_interlaced = (p[9] >> 6) & 0x1;
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if (info->has_lct)
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info->lct_entries = 1 << ((p[9] & 0x7) + 1);
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return p + 10;
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}
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static const unsigned char *
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gif_read_lct(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
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{
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if (end - p < info->lct_entries * 3)
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fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in local color table in gif image");
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info->lct = fz_malloc(ctx, info->lct_entries * 3);
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memmove(info->lct, p, info->lct_entries * 3);
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return p + info->lct_entries * 3;
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}
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static void
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gif_read_line(fz_context *ctx, struct info *info, int ct_entries, const unsigned char *ct, unsigned int y, unsigned char *sp)
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{
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unsigned int index = (info->image_top + y) * info->width + info->image_left;
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unsigned char *samples = fz_pixmap_samples(ctx, info->pix);
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unsigned char *dp = &samples[index * 4];
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unsigned char *mp = &info->mask[index];
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unsigned int x, k;
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if (info->image_top + y >= info->height)
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return;
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for (x = 0; x < info->image_width && info->image_left + x < info->width; x++, sp++, mp++, dp += 4)
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if (!info->has_transparency || *sp != info->transparent)
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{
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*mp = 0x02;
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for (k = 0; k < 3; k++)
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dp[k] = ct[fz_clampi(*sp, 0, ct_entries - 1) * 3 + k];
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dp[3] = 255;
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}
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else if (*mp == 0x01)
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*mp = 0x00;
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}
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static const unsigned char *
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gif_read_tbid(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
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{
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fz_stream *stm = NULL, *lzwstm = NULL;
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unsigned int mincodesize, y;
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fz_buffer *compressed = NULL, *uncompressed = NULL;
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const unsigned char *ct;
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unsigned char *sp;
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int ct_entries;
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if (end - p < 1)
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fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in table based image data in gif image");
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mincodesize = *p;
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/* if there is no overlap, avoid pasting image data, just consume it */
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if (info->image_top >= info->height || info->image_left >= info->width)
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{
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p = gif_read_subblocks(ctx, info, p + 1, end, NULL);
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return p;
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}
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fz_var(compressed);
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fz_var(lzwstm);
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fz_var(stm);
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fz_var(uncompressed);
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fz_try(ctx)
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{
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compressed = fz_new_buffer(ctx, 0);
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p = gif_read_subblocks(ctx, info, p + 1, end, compressed);
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stm = fz_open_buffer(ctx, compressed);
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lzwstm = fz_open_lzwd(ctx, stm, 0, mincodesize + 1, 1, 1);
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uncompressed = fz_read_all(ctx, lzwstm, 0);
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if (uncompressed->len < info->image_width * info->image_height)
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fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in compressed table based image data in gif image");
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if (info->has_lct)
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{
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ct = info->lct;
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ct_entries = info->lct_entries;
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}
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else if (info->has_gct)
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{
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ct = info->gct;
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ct_entries = info->gct_entries;
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}
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else
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{
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ct = dct;
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ct_entries = 256;
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}
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sp = uncompressed->data;
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if (info->image_interlaced)
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{
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for (y = 0; y < info->image_height; y += 8, sp += info->image_width)
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gif_read_line(ctx, info, ct_entries, ct, y, sp);
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for (y = 4; y < info->image_height; y += 8, sp += info->image_width)
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gif_read_line(ctx, info, ct_entries, ct, y, sp);
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for (y = 2; y < info->image_height; y += 4, sp += info->image_width)
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gif_read_line(ctx, info, ct_entries, ct, y, sp);
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for (y = 1; y < info->image_height; y += 2, sp += info->image_width)
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gif_read_line(ctx, info, ct_entries, ct, y, sp);
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}
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else
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for (y = 0; y < info->image_height; y++, sp += info->image_width)
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gif_read_line(ctx, info, ct_entries, ct, y, sp);
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}
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fz_always(ctx)
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{
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fz_drop_buffer(ctx, uncompressed);
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fz_drop_buffer(ctx, compressed);
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fz_drop_stream(ctx, lzwstm);
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fz_drop_stream(ctx, stm);
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}
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fz_catch(ctx)
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{
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fz_rethrow(ctx);
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}
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return p;
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}
|
|
|
|
static const unsigned char *
|
|
gif_read_gce(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
|
|
{
|
|
if (end - p < 8)
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in graphic control extension in gif image");
|
|
if (p[2] != 0x04)
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "out of range graphic control extension block size in gif image");
|
|
|
|
info->has_transparency = p[3] & 0x1;
|
|
if (info->has_transparency)
|
|
info->transparent = p[6];
|
|
|
|
return p + 8;
|
|
}
|
|
|
|
static const unsigned char *
|
|
gif_read_ce(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
|
|
{
|
|
return gif_read_subblocks(ctx, info, p + 2, end, NULL);
|
|
}
|
|
|
|
static const unsigned char*
|
|
gif_read_pte(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
|
|
{
|
|
if (end - p < 15)
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in plain text extension in gif image");
|
|
if (p[2] != 0x0c)
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "out of range plain text extension block size in gif image");
|
|
return gif_read_subblocks(ctx, info, p + 15, end, NULL);
|
|
}
|
|
|
|
static const unsigned char *
|
|
gif_read_icc(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
|
|
{
|
|
#if FZ_ENABLE_ICC
|
|
fz_colorspace *icc = NULL;
|
|
fz_buffer *buf = NULL;
|
|
|
|
fz_var(p);
|
|
|
|
buf = fz_new_buffer(ctx, 0);
|
|
fz_try(ctx)
|
|
{
|
|
p = gif_read_subblocks(ctx, info, p, end, buf);
|
|
icc = fz_new_icc_colorspace(ctx, FZ_COLORSPACE_RGB, 0, NULL, buf);
|
|
fz_drop_colorspace(ctx, info->pix->colorspace);
|
|
info->pix->colorspace = icc;
|
|
}
|
|
fz_always(ctx)
|
|
fz_drop_buffer(ctx, buf);
|
|
fz_catch(ctx)
|
|
fz_warn(ctx, "ignoring embedded ICC profile in GIF");
|
|
|
|
return p;
|
|
#else
|
|
return gif_read_subblocks(ctx, info, p, end, NULL);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
NETSCAPE2.0
|
|
http://odur.let.rug.nl/~kleiweg/gif/netscape.html
|
|
http://www.vurdalakov.net/misc/gif/netscape-looping-application-extension
|
|
http://www.vurdalakov.net/misc/gif/netscape-buffering-application-extension
|
|
https://code.google.com/p/gifdotnet/source/browse/src/GifDotNet/GifApplicationExtensionBlock.cs#95
|
|
http://trac.webkit.org/browser/trunk/Source/WebCore/platform/image-decoders/gif/GIFImageReader.cpp#L617
|
|
|
|
ANIMEXTS1.0
|
|
http://www.vurdalakov.net/misc/gif/animexts-looping-application-extension
|
|
https://code.google.com/p/gifdotnet/source/browse/src/GifDotNet/GifApplicationExtensionBlock.cs#95
|
|
|
|
ICCRGBG1012
|
|
http://www.color.org/icc1V42.pdf
|
|
|
|
XMP DataXMP
|
|
http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/xmp/pdfs/XMPSpecificationPart3.pdf
|
|
|
|
fractint
|
|
http://fractint.net/fractsvn/trunk/fractint/common/loadfile.c
|
|
|
|
ZGATEXTI5 ZGATILEI5 ZGACTRLI5 ZGANPIMGI5
|
|
ZGAVECTI5 ZGAALPHAI5 ZGATITLE4.0 ZGATEXTI4.0
|
|
Zoner GIF animator 4.0 and 5.0
|
|
*/
|
|
static const unsigned char *
|
|
gif_read_ae(fz_context *ctx, struct info *info, const unsigned char *p, const unsigned char *end)
|
|
{
|
|
static char *ignorable[] = {
|
|
"NETSACPE2.0", "ANIMEXTS1.0", "XMP DataXMP",
|
|
"ZGATEXTI5\0\0", "ZGATILEI5\0\0", "ZGANPIMGI5\0", "ZGACTRLI5\0\0",
|
|
"ZGAVECTI5\0\0", "ZGAALPHAI5\0", "ZGATITLE4.0", "ZGATEXTI4.0",
|
|
};
|
|
int i, ignored;
|
|
|
|
if (end - p < 14)
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in application extension in gif image");
|
|
if (p[2] != 0x0b)
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "out of range application extension block size in gif image");
|
|
|
|
ignored = 0;
|
|
for (i = 0; i < (int)nelem(ignorable); i++)
|
|
ignored |= memcmp(&p[3], ignorable[i], 8 + 3);
|
|
if (!ignored)
|
|
{
|
|
char extension[9];
|
|
memmove(extension, &p[3], 8);
|
|
extension[8] = '\0';
|
|
fz_warn(ctx, "ignoring unsupported application extension '%s' in gif image", extension);
|
|
}
|
|
|
|
if (!memcmp(&p[3], "ICCRGBG1012", 11))
|
|
return gif_read_icc(ctx, info, p + 14, end);
|
|
|
|
return gif_read_subblocks(ctx, info, p + 14, end, NULL);
|
|
}
|
|
|
|
static void
|
|
gif_mask_transparency(fz_context *ctx, struct info *info)
|
|
{
|
|
unsigned char *mp = info->mask;
|
|
unsigned char *dp = fz_pixmap_samples(ctx, info->pix);
|
|
unsigned int x, y;
|
|
|
|
for (y = 0; y < info->height; y++)
|
|
for (x = 0; x < info->width; x++, mp++, dp += 4)
|
|
if (*mp == 0x00)
|
|
dp[3] = 0;
|
|
}
|
|
|
|
static fz_pixmap *
|
|
gif_read_image(fz_context *ctx, struct info *info, const unsigned char *p, size_t total, int only_metadata)
|
|
{
|
|
const unsigned char *end = p + total;
|
|
|
|
memset(info, 0x00, sizeof (*info));
|
|
|
|
/* Read header */
|
|
p = gif_read_header(ctx, info, p, end);
|
|
|
|
/* Read logical screen descriptor */
|
|
p = gif_read_lsd(ctx, info, p, end);
|
|
|
|
if (only_metadata)
|
|
return NULL;
|
|
|
|
info->pix = fz_new_pixmap(ctx, fz_device_rgb(ctx), info->width, info->height, NULL, 1);
|
|
|
|
fz_try(ctx)
|
|
{
|
|
info->mask = fz_calloc(ctx, info->width * info->height, 1);
|
|
|
|
/* Read optional global color table */
|
|
if (info->has_gct)
|
|
{
|
|
unsigned char *bp, *dp = fz_pixmap_samples(ctx, info->pix);
|
|
unsigned int x, y, k;
|
|
|
|
p = gif_read_gct(ctx, info, p, end);
|
|
bp = &info->gct[info->gct_background * 3];
|
|
|
|
memset(info->mask, 0x01, info->width * info->height);
|
|
|
|
for (y = 0; y < info->height; y++)
|
|
for (x = 0; x < info->width; x++, dp += 4)
|
|
{
|
|
for (k = 0; k < 3; k++)
|
|
dp[k] = bp[k];
|
|
dp[3] = 255;
|
|
}
|
|
}
|
|
|
|
while (1)
|
|
{
|
|
/* Read block indicator */
|
|
if (end - p < 1)
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "premature end of block indicator in gif image");
|
|
|
|
/* Read trailer */
|
|
if (p[0] == 0x3b)
|
|
{
|
|
break;
|
|
}
|
|
/* Read extension */
|
|
else if (p[0] == 0x21)
|
|
{
|
|
/* Read extension label */
|
|
if (end - p < 2)
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "premature end in extension label in gif image");
|
|
|
|
if (p[1] == 0x01 && info->gif89a)
|
|
{
|
|
/* Read plain text extension */
|
|
p = gif_read_pte(ctx, info, p, end);
|
|
|
|
/* Graphic control extension applies only to the graphic rendering block following it */
|
|
info->transparent = 0;
|
|
info->has_transparency = 0;
|
|
}
|
|
else if (p[1] == 0xf9 && info->gif89a)
|
|
/* Read graphic control extension */
|
|
p = gif_read_gce(ctx, info, p, end);
|
|
else if (p[1] == 0xfe && info->gif89a)
|
|
/* Read comment extension */
|
|
p = gif_read_ce(ctx, info, p, end);
|
|
else if (p[1] == 0xff && info->gif89a)
|
|
/* Read application extension */
|
|
p = gif_read_ae(ctx, info, p, end);
|
|
else
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "unsupported extension label %02x in gif image", p[1]);
|
|
}
|
|
/* Read image descriptor */
|
|
else if (p[0] == 0x2c)
|
|
{
|
|
p = gif_read_id(ctx, info, p, end);
|
|
|
|
if (info->has_lct)
|
|
/* Read local color table */
|
|
p = gif_read_lct(ctx, info, p, end);
|
|
|
|
/* Read table based image data */
|
|
p = gif_read_tbid(ctx, info, p, end);
|
|
|
|
/* Graphic control extension applies only to the graphic rendering block following it */
|
|
info->transparent = 0;
|
|
info->has_transparency = 0;
|
|
|
|
/* Image descriptor applies only to the table based image data following it */
|
|
info->image_left = info->image_top = 0;
|
|
info->image_width = info->width;
|
|
info->image_height = info->height;
|
|
info->image_interlaced = 0;
|
|
fz_free(ctx, info->lct);
|
|
info->lct = NULL;
|
|
info->has_lct = 0;
|
|
}
|
|
else
|
|
fz_throw(ctx, FZ_ERROR_GENERIC, "unsupported block indicator %02x in gif image", p[0]);
|
|
}
|
|
|
|
gif_mask_transparency(ctx, info);
|
|
fz_premultiply_pixmap(ctx, info->pix);
|
|
}
|
|
fz_always(ctx)
|
|
{
|
|
fz_free(ctx, info->mask);
|
|
fz_free(ctx, info->lct);
|
|
fz_free(ctx, info->gct);
|
|
}
|
|
fz_catch(ctx)
|
|
{
|
|
fz_drop_pixmap(ctx, info->pix);
|
|
fz_rethrow(ctx);
|
|
}
|
|
|
|
return info->pix;
|
|
}
|
|
|
|
fz_pixmap *
|
|
fz_load_gif(fz_context *ctx, const unsigned char *p, size_t total)
|
|
{
|
|
fz_pixmap *image;
|
|
struct info gif;
|
|
|
|
image = gif_read_image(ctx, &gif, p, total, 0);
|
|
image->xres = gif.xres;
|
|
image->yres = gif.yres;
|
|
|
|
return image;
|
|
}
|
|
|
|
void
|
|
fz_load_gif_info(fz_context *ctx, const unsigned char *p, size_t total, int *wp, int *hp, int *xresp, int *yresp, fz_colorspace **cspacep)
|
|
{
|
|
struct info gif;
|
|
|
|
gif_read_image(ctx, &gif, p, total, 1);
|
|
*cspacep = fz_keep_colorspace(ctx, fz_device_rgb(ctx));
|
|
*wp = gif.width;
|
|
*hp = gif.height;
|
|
*xresp = gif.xres;
|
|
*yresp = gif.yres;
|
|
}
|