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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
commit | 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch) | |
tree | a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /image/decoders/GIF2.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.tar.xz firefox-esr-0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d.zip |
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'image/decoders/GIF2.h')
-rw-r--r-- | image/decoders/GIF2.h | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/image/decoders/GIF2.h b/image/decoders/GIF2.h new file mode 100644 index 0000000000..c0c6bf0fde --- /dev/null +++ b/image/decoders/GIF2.h @@ -0,0 +1,67 @@ +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef mozilla_image_decoders_GIF2_H +#define mozilla_image_decoders_GIF2_H + +#define MAX_LZW_BITS 12 +#define MAX_BITS 4097 // 2^MAX_LZW_BITS+1 +#define MAX_COLORS 256 +#define MIN_HOLD_SIZE 256 + +enum { GIF_TRAILER = 0x3B }; // ';' +enum { GIF_IMAGE_SEPARATOR = 0x2C }; // ',' +enum { GIF_EXTENSION_INTRODUCER = 0x21 }; // '!' +enum { GIF_GRAPHIC_CONTROL_LABEL = 0xF9 }; +enum { GIF_APPLICATION_EXTENSION_LABEL = 0xFF }; + +// A GIF decoder's state +typedef struct gif_struct { + // LZW decoder state machine + uint8_t* stackp; // Current stack pointer + int datasize; + int codesize; + int codemask; + int avail; // Index of next available slot in dictionary + int oldcode; + uint8_t firstchar; + int bits; // Number of unread bits in "datum" + int32_t datum; // 32-bit input buffer + + // Output state machine + int64_t pixels_remaining; // Pixels remaining to be output. + + // Parameters for image frame currently being decoded + int tpixel; // Index of transparent pixel + int32_t disposal_method; // Restore to background, leave in place, etc. + uint32_t* local_colormap; // Per-image colormap + uint32_t local_colormap_buffer_size; // Size of the buffer containing the + // local colormap. + int local_colormap_size; // Size of local colormap array. + uint32_t delay_time; // Display time, in milliseconds, + // for this image in a multi-image GIF + + // Global (multi-image) state + int version; // Either 89 for GIF89 or 87 for GIF87 + int32_t screen_width; // Logical screen width & height + int32_t screen_height; + uint8_t global_colormap_depth; // Depth of global colormap array + uint16_t global_colormap_count; // Number of colors in global colormap + int images_decoded; // Counts images for multi-part GIFs + int loop_count; // Netscape specific extension block to control + // the number of animation loops a GIF + // renders. + + bool is_transparent; // TRUE, if tpixel is valid + + uint16_t prefix[MAX_BITS]; // LZW decoding tables + uint32_t global_colormap[MAX_COLORS]; // Default colormap if local not + // supplied + uint8_t suffix[MAX_BITS]; // LZW decoding tables + uint8_t stack[MAX_BITS]; // Base of LZW decoder stack + +} gif_struct; + +#endif // mozilla_image_decoders_GIF2_H |