The Tor Browser / file comparison
comparison: image/decoders/GIF2.h
image/decoders/GIF2.h
- branch
- TOR_BUG_9701
- changeset 10
- ac0c01689b40
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| -1:000000000000 | 0:9c1b8224d0a9 |
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| 1 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ | |
| 2 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 3 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 5 #ifndef _GIF_H_ | |
| 6 #define _GIF_H_ | |
| 7 | |
| 8 #define MAX_LZW_BITS 12 | |
| 9 #define MAX_BITS 4097 /* 2^MAX_LZW_BITS+1 */ | |
| 10 #define MAX_COLORS 256 | |
| 11 #define MIN_HOLD_SIZE 256 | |
| 12 | |
| 13 enum { GIF_TRAILER = 0x3B }; //';' | |
| 14 enum { GIF_IMAGE_SEPARATOR = 0x2C }; //',' | |
| 15 enum { GIF_EXTENSION_INTRODUCER = 0x21 }; //'!' | |
| 16 enum { GIF_GRAPHIC_CONTROL_LABEL = 0xF9 }; | |
| 17 enum { GIF_COMMENT_LABEL = 0xFE }; | |
| 18 enum { GIF_PLAIN_TEXT_LABEL = 0x01 }; | |
| 19 enum { GIF_APPLICATION_EXTENSION_LABEL = 0xFF }; | |
| 20 | |
| 21 /* gif2.h | |
| 22 The interface for the GIF87/89a decoder. | |
| 23 */ | |
| 24 // List of possible parsing states | |
| 25 typedef enum { | |
| 26 gif_type, | |
| 27 gif_global_header, | |
| 28 gif_global_colormap, | |
| 29 gif_image_start, | |
| 30 gif_image_header, | |
| 31 gif_image_header_continue, | |
| 32 gif_image_colormap, | |
| 33 gif_image_body, | |
| 34 gif_lzw_start, | |
| 35 gif_lzw, | |
| 36 gif_sub_block, | |
| 37 gif_extension, | |
| 38 gif_control_extension, | |
| 39 gif_consume_block, | |
| 40 gif_skip_block, | |
| 41 gif_done, | |
| 42 gif_error, | |
| 43 gif_comment_extension, | |
| 44 gif_application_extension, | |
| 45 gif_netscape_extension_block, | |
| 46 gif_consume_netscape_extension, | |
| 47 gif_consume_comment | |
| 48 } gstate; | |
| 49 | |
| 50 /* A GIF decoder's state */ | |
| 51 typedef struct gif_struct { | |
| 52 /* Parsing state machine */ | |
| 53 gstate state; /* Curent decoder master state */ | |
| 54 uint32_t bytes_to_consume; /* Number of bytes to accumulate */ | |
| 55 uint32_t bytes_in_hold; /* bytes accumulated so far*/ | |
| 56 | |
| 57 /* LZW decoder state machine */ | |
| 58 uint8_t *stackp; /* Current stack pointer */ | |
| 59 int datasize; | |
| 60 int codesize; | |
| 61 int codemask; | |
| 62 int avail; /* Index of next available slot in dictionary */ | |
| 63 int oldcode; | |
| 64 uint8_t firstchar; | |
| 65 int count; /* Remaining # bytes in sub-block */ | |
| 66 int bits; /* Number of unread bits in "datum" */ | |
| 67 int32_t datum; /* 32-bit input buffer */ | |
| 68 | |
| 69 /* Output state machine */ | |
| 70 int ipass; /* Interlace pass; Ranges 1-4 if interlaced. */ | |
| 71 unsigned rows_remaining; /* Rows remaining to be output */ | |
| 72 unsigned irow; /* Current output row, starting at zero */ | |
| 73 uint8_t *rowp; /* Current output pointer */ | |
| 74 | |
| 75 /* Parameters for image frame currently being decoded*/ | |
| 76 unsigned x_offset, y_offset; /* With respect to "screen" origin */ | |
| 77 unsigned height, width; | |
| 78 int tpixel; /* Index of transparent pixel */ | |
| 79 int32_t disposal_method; /* Restore to background, leave in place, etc.*/ | |
| 80 uint32_t *local_colormap; /* Per-image colormap */ | |
| 81 int local_colormap_size; /* Size of local colormap array. */ | |
| 82 uint32_t delay_time; /* Display time, in milliseconds, | |
| 83 for this image in a multi-image GIF */ | |
| 84 | |
| 85 /* Global (multi-image) state */ | |
| 86 int version; /* Either 89 for GIF89 or 87 for GIF87 */ | |
| 87 unsigned screen_width; /* Logical screen width & height */ | |
| 88 unsigned screen_height; | |
| 89 uint32_t global_colormap_depth; /* Depth of global colormap array. */ | |
| 90 int images_decoded; /* Counts images for multi-part GIFs */ | |
| 91 int loop_count; /* Netscape specific extension block to control | |
| 92 the number of animation loops a GIF renders. */ | |
| 93 | |
| 94 bool progressive_display; /* If TRUE, do Haeberli interlace hack */ | |
| 95 bool interlaced; /* TRUE, if scanlines arrive interlaced order */ | |
| 96 bool is_transparent; /* TRUE, if tpixel is valid */ | |
| 97 | |
| 98 uint16_t prefix[MAX_BITS]; /* LZW decoding tables */ | |
| 99 uint8_t* hold; /* Accumulation buffer */ | |
| 100 uint32_t global_colormap[MAX_COLORS]; /* Default colormap if local not supplied */ | |
| 101 uint8_t suffix[MAX_BITS]; /* LZW decoding tables */ | |
| 102 uint8_t stack[MAX_BITS]; /* Base of LZW decoder stack */ | |
| 103 | |
| 104 } gif_struct; | |
| 105 | |
| 106 #endif | |
| 107 |
