BlueGreycalmElegant

Català-Valencià – Catalan中文 – Chinese (Simplified)中文 – Chinese (Traditional)Česky – CzechDansk – DanishNederlands – DutchEnglish – EnglishSuomi – FinnishFrançais – FrenchDeutsch – Germanעברית – Hebrewहिंदी – HindiMagyar – HungarianBahasa Indonesia – IndonesianItaliano – Italian日本語 – Japanese한국어 – KoreanМакедонски – Macedonianमराठी – MarathiNorsk – NorwegianPolski – PolishPortuguês – PortuguesePortuguês – Portuguese (Brazil)Русский – RussianSlovenčina – SlovakSlovenščina – SlovenianEspañol – SpanishSvenska – SwedishTürkçe – TurkishУкраїнська – UkrainianOëzbekcha – Uzbek

Compare Revisions

• This comparison shows the changes necessary to convert path

  → /contrib/network/netsurf/libnsgif/ @ 4363

  → /contrib/network/netsurf/libnsgif/ @ 4364

  ↔ Reverse comparison

• Compare Path:	Rev

  With Path:	Rev

No changes between revisions

Regard whitespace Rev 4363 → Rev 4364

/contrib/network/netsurf/libnsgif/.gitignore
0,0 → 1,2
build-*

/contrib/network/netsurf/libnsgif/COPYING
0,0 → 1,20
Copyright (C) 2004 Richard Wilson
Copyright (C) 2008 Sean Fox
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
* The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

/contrib/network/netsurf/libnsgif/Makefile
0,0 → 1,35
# Component settings
COMPONENT := nsgif
COMPONENT_VERSION := 0.0.3
# Default to a static library
COMPONENT_TYPE ?= lib-static
# Setup the tooling
PREFIX ?= /opt/netsurf
NSSHARED ?= $(PREFIX)/share/netsurf-buildsystem
include $(NSSHARED)/makefiles/Makefile.tools
# Toolchain flags
WARNFLAGS := -Wall -W -Wundef -Wpointer-arith -Wcast-align \
-Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes \
-Wmissing-declarations -Wnested-externs -pedantic
# BeOS/Haiku standard library headers create warnings
ifneq ($(TARGET),beos)
WARNFLAGS := $(WARNFLAGS) -Werror
endif
CFLAGS := -D_BSD_SOURCE -I$(CURDIR)/include/ \
-I$(CURDIR)/src $(WARNFLAGS) $(CFLAGS)
ifneq ($(GCCVER),2)
CFLAGS := $(CFLAGS) -std=c99
else
# __inline__ is a GCCism
CFLAGS := $(CFLAGS) -Dinline="__inline__"
endif
include $(NSBUILD)/Makefile.top
# Extra installation rules
I := /include
INSTALL_ITEMS := $(INSTALL_ITEMS) $(I):include/libnsgif.h
INSTALL_ITEMS := $(INSTALL_ITEMS) /lib/pkgconfig:lib$(COMPONENT).pc.in
INSTALL_ITEMS := $(INSTALL_ITEMS) /lib:$(OUTPUT)

/contrib/network/netsurf/libnsgif/examples/decode_gif.c
0,0 → 1,211
/*
* Copyright 2008 Sean Fox <dyntryx@gmail.com>
* Copyright 2008 James Bursa <james@netsurf-browser.org>
*
* This file is part of NetSurf's libnsgif, http://www.netsurf-browser.org/
* Licenced under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
*/
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include "../libnsgif.h"
unsigned char *load_file(const char *path, size_t *data_size);
void warning(const char *context, int code);
void *bitmap_create(int width, int height);
void bitmap_set_opaque(void *bitmap, bool opaque);
bool bitmap_test_opaque(void *bitmap);
unsigned char *bitmap_get_buffer(void *bitmap);
void bitmap_destroy(void *bitmap);
void bitmap_modified(void *bitmap);
int main(int argc, char *argv[])
{
gif_bitmap_callback_vt bitmap_callbacks = {
bitmap_create,
bitmap_destroy,
bitmap_get_buffer,
bitmap_set_opaque,
bitmap_test_opaque,
bitmap_modified
};
gif_animation gif;
size_t size;
gif_result code;
unsigned int i;
if (argc != 2) {
fprintf(stderr, "Usage: %s image.gif\n", argv[0]);
return 1;
}
/* create our gif animation */
gif_create(&gif, &bitmap_callbacks);
/* load file into memory */
unsigned char *data = load_file(argv[1], &size);
/* begin decoding */
do {
code = gif_initialise(&gif, size, data);
if (code != GIF_OK && code != GIF_WORKING) {
warning("gif_initialise", code);
exit(1);
}
} while (code != GIF_OK);
printf("P3\n");
printf("# %s\n", argv[1]);
printf("# width %u \n", gif.width);
printf("# height %u \n", gif.height);
printf("# frame_count %u \n", gif.frame_count);
printf("# frame_count_partial %u \n", gif.frame_count_partial);
printf("# loop_count %u \n", gif.loop_count);
printf("%u %u 256\n", gif.width, gif.height * gif.frame_count);
/* decode the frames */
for (i = 0; i != gif.frame_count; i++) {
unsigned int row, col;
unsigned char *image;
code = gif_decode_frame(&gif, i);
if (code != GIF_OK)
warning("gif_decode_frame", code);
printf("# frame %u:\n", i);
image = (unsigned char *) gif.frame_image;
for (row = 0; row != gif.height; row++) {
for (col = 0; col != gif.width; col++) {
size_t z = (row * gif.width + col) * 4;
printf("%u %u %u ",
(unsigned char) image[z],
(unsigned char) image[z + 1],
(unsigned char) image[z + 2]);
}
printf("\n");
}
}
/* clean up */
gif_finalise(&gif);
free(data);
return 0;
}
unsigned char *load_file(const char *path, size_t *data_size)
{
FILE *fd;
struct stat sb;
unsigned char *buffer;
size_t size;
size_t n;
fd = fopen(path, "rb");
if (!fd) {
perror(path);
exit(EXIT_FAILURE);
}
if (stat(path, &sb)) {
perror(path);
exit(EXIT_FAILURE);
}
size = sb.st_size;
buffer = malloc(size);
if (!buffer) {
fprintf(stderr, "Unable to allocate %lld bytes\n",
(long long) size);
exit(EXIT_FAILURE);
}
n = fread(buffer, 1, size, fd);
if (n != size) {
perror(path);
exit(EXIT_FAILURE);
}
fclose(fd);
*data_size = size;
return buffer;
}
void warning(const char *context, gif_result code)
{
fprintf(stderr, "%s failed: ", context);
switch (code)
{
case GIF_INSUFFICIENT_FRAME_DATA:
fprintf(stderr, "GIF_INSUFFICIENT_FRAME_DATA");
break;
case GIF_FRAME_DATA_ERROR:
fprintf(stderr, "GIF_FRAME_DATA_ERROR");
break;
case GIF_INSUFFICIENT_DATA:
fprintf(stderr, "GIF_INSUFFICIENT_DATA");
break;
case GIF_DATA_ERROR:
fprintf(stderr, "GIF_DATA_ERROR");
break;
case GIF_INSUFFICIENT_MEMORY:
fprintf(stderr, "GIF_INSUFFICIENT_MEMORY");
break;
default:
fprintf(stderr, "unknown code %i", code);
break;
}
fprintf(stderr, "\n");
}
void *bitmap_create(int width, int height)
{
return calloc(width * height, 4);
}
void bitmap_set_opaque(void *bitmap, bool opaque)
{
(void) opaque; /* unused */
assert(bitmap);
}
bool bitmap_test_opaque(void *bitmap)
{
assert(bitmap);
return false;
}
unsigned char *bitmap_get_buffer(void *bitmap)
{
assert(bitmap);
return bitmap;
}
void bitmap_destroy(void *bitmap)
{
assert(bitmap);
free(bitmap);
}
void bitmap_modified(void *bitmap)
{
assert(bitmap);
return;
}

/contrib/network/netsurf/libnsgif/examples/disassemble_gif.pl
0,0 → 1,109
#!/usr/bin/perl
#
# Disassemble a GIF file and display the sections and chunks within.
#
# Warning: only part of the specification is implemented.
#
use strict;
use warnings;
die "Usage: $0 IMAGE\n" unless @ARGV == 1;
my ($image) = @ARGV;
open IMAGE, '<', $image or die "$0: open $image: $!\n";
undef $/;
my $gif = <IMAGE>;
close IMAGE;
print "$image: ", length $gif, " bytes\n\n";
my @gif = unpack 'C*', $gif;
my $z = 0;
output_chunk('Header', 6);
output_chunk('Logical Screen Descriptor', 7);
my $global_colors = $gif[10] & 0x80;
my $color_table_size = 2 << ($gif[10] & 0x07);
if ($global_colors) {
output_chunk('Global Color Table', $color_table_size * 3);
}
while (1) {
while ($gif[$z] == 0x21) {
if ($gif[$z + 1] == 0xf9) {
output_chunk('Graphic Control Extension', 5 + 2);
} elsif ($gif[$z + 1] == 0xfe) {
output_chunk('Comment Extension', 2);
} elsif ($gif[$z + 1] == 0x01) {
output_chunk('Plain Text Extension', 13 + 2);
} elsif ($gif[$z + 1] == 0xff) {
output_chunk('Application Extension', 12 + 2);
} else {
output_chunk((sprintf 'Unknown Extension 0x%.2x',
$gif[$z + 1]), $gif[$z + 2] + 3);
}
while ($gif[$z] != 0) {
output_chunk('Data Sub-block', $gif[$z] + 1);
}
output_chunk('Block Terminator', 1);
}
if ($gif[$z] == 0x3b) {
output_chunk('Trailer', 1);
last;
}
if ($gif[$z] != 0x2c) {
last;
}
output_chunk('Image Descriptor', 10);
output_chunk('Table Based Image Data', 1);
while ($gif[$z] != 0) {
output_chunk('Data Sub-block', $gif[$z] + 1);
}
output_chunk('Block Terminator', 1);
}
if ($z != @gif) {
output_chunk('*** Junk on End ***', @gif - $z);
}
#
# Output a chunk of data as hex and characters.
#
sub output_chunk
{
my ($description, $length) = @_;
print "$description";
for (my $i = 0; $i != $length; $i++) {
if ($i % 8 == 0) {
print "\n";
printf "%8i: ", $z + $i;
}
if ($z + $i == @gif) {
print "EOF\n\n";
print "Unexpected end of file\n";
exit;
}
my $c = $gif[$z + $i];
printf "%.2x ", $c;
if (32 <= $c and $c <= 126) {
printf "'%c'", $c;
} else {
print " ";
}
print " ";
}
print "\n\n";
$z += $length;
}
Property changes:
Added: svn:executable
+*
\ No newline at end of property

/contrib/network/netsurf/libnsgif/examples/waves.gif
Cannot display: file marked as a binary type.
svn:mime-type = application/octet-stream
Property changes:
Added: svn:mime-type
+application/octet-stream
\ No newline at end of property

/contrib/network/netsurf/libnsgif/gif_display
0,0 → 1,3
set -e
make
bin/decode_gif $1 | display
Property changes:
Added: svn:executable
+*
\ No newline at end of property

/contrib/network/netsurf/libnsgif/include/libnsgif.h
0,0 → 1,108
/*
* Copyright 2004 Richard Wilson <richard.wilson@netsurf-browser.org>
* Copyright 2008 Sean Fox <dyntryx@gmail.com>
*
* This file is part of NetSurf's libnsgif, http://www.netsurf-browser.org/
* Licenced under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
*/
/** \file
* Progressive animated GIF file decoding (interface).
*/
#ifndef _LIBNSGIF_H_
#define _LIBNSGIF_H_
#include <stdbool.h>
#include <inttypes.h>
/* Error return values
*/
typedef enum {
GIF_WORKING = 1,
GIF_OK = 0,
GIF_INSUFFICIENT_FRAME_DATA = -1,
GIF_FRAME_DATA_ERROR = -2,
GIF_INSUFFICIENT_DATA = -3,
GIF_DATA_ERROR = -4,
GIF_INSUFFICIENT_MEMORY = -5,
GIF_FRAME_NO_DISPLAY = -6,
GIF_END_OF_FRAME = -7
} gif_result;
/* The GIF frame data
*/
typedef struct gif_frame {
bool display; /**< whether the frame should be displayed/animated */
unsigned int frame_delay; /**< delay (in cs) before animating the frame */
/** Internal members are listed below
*/
unsigned int frame_pointer; /**< offset (in bytes) to the GIF frame data */
bool virgin; /**< whether the frame has previously been used */
bool opaque; /**< whether the frame is totally opaque */
bool redraw_required; /**< whether a forcable screen redraw is required */
unsigned char disposal_method; /**< how the previous frame should be disposed; affects plotting */
bool transparency; /**< whether we acknoledge transparency */
unsigned char transparency_index; /**< the index designating a transparent pixel */
unsigned int redraw_x; /**< x co-ordinate of redraw rectangle */
unsigned int redraw_y; /**< y co-ordinate of redraw rectangle */
unsigned int redraw_width; /**< width of redraw rectangle */
unsigned int redraw_height; /**< height of redraw rectangle */
} gif_frame;
/* API for Bitmap callbacks
*/
typedef void* (*gif_bitmap_cb_create)(int width, int height);
typedef void (*gif_bitmap_cb_destroy)(void *bitmap);
typedef unsigned char* (*gif_bitmap_cb_get_buffer)(void *bitmap);
typedef void (*gif_bitmap_cb_set_opaque)(void *bitmap, bool opaque);
typedef bool (*gif_bitmap_cb_test_opaque)(void *bitmap);
typedef void (*gif_bitmap_cb_modified)(void *bitmap);
/* The Bitmap callbacks function table
*/
typedef struct gif_bitmap_callback_vt {
gif_bitmap_cb_create bitmap_create; /**< Create a bitmap. */
gif_bitmap_cb_destroy bitmap_destroy; /**< Free a bitmap. */
gif_bitmap_cb_get_buffer bitmap_get_buffer; /**< Return a pointer to the pixel data in a bitmap. */
/** Members below are optional
*/
gif_bitmap_cb_set_opaque bitmap_set_opaque; /**< Sets whether a bitmap should be plotted opaque. */
gif_bitmap_cb_test_opaque bitmap_test_opaque; /**< Tests whether a bitmap has an opaque alpha channel. */
gif_bitmap_cb_modified bitmap_modified; /**< The bitmap image has changed, so flush any persistant cache. */
} gif_bitmap_callback_vt;
/* The GIF animation data
*/
typedef struct gif_animation {
gif_bitmap_callback_vt bitmap_callbacks; /**< callbacks for bitmap functions */
unsigned char *gif_data; /**< pointer to GIF data */
unsigned int width; /**< width of GIF (may increase during decoding) */
unsigned int height; /**< heigth of GIF (may increase during decoding) */
unsigned int frame_count; /**< number of frames decoded */
unsigned int frame_count_partial; /**< number of frames partially decoded */
gif_frame *frames; /**< decoded frames */
int decoded_frame; /**< current frame decoded to bitmap */
void *frame_image; /**< currently decoded image; stored as bitmap from bitmap_create callback */
int loop_count; /**< number of times to loop animation */
gif_result current_error; /**< current error type, or 0 for none*/
/** Internal members are listed below
*/
unsigned int buffer_position; /**< current index into GIF data */
unsigned int buffer_size; /**< total number of bytes of GIF data available */
unsigned int frame_holders; /**< current number of frame holders */
unsigned int background_index; /**< index in the colour table for the background colour */
unsigned int aspect_ratio; /**< image aspect ratio (ignored) */
unsigned int colour_table_size; /**< size of colour table (in entries) */
bool global_colours; /**< whether the GIF has a global colour table */
unsigned int *global_colour_table; /**< global colour table */
unsigned int *local_colour_table; /**< local colour table */
} gif_animation;
void gif_create(gif_animation *gif, gif_bitmap_callback_vt *bitmap_callbacks);
gif_result gif_initialise(gif_animation *gif, size_t size, unsigned char *data);
gif_result gif_decode_frame(gif_animation *gif, unsigned int frame);
void gif_finalise(gif_animation *gif);
#endif

/contrib/network/netsurf/libnsgif/libnsgif.pc.in
0,0 → 1,10
prefix=PREFIX
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir=${prefix}/include
Name: libnsgif
Description: Provides gif loading and conversion
Version: VERSION
Libs: -L${libdir} -lnsgif
Cflags: -I${includedir}

/contrib/network/netsurf/libnsgif/src/Makefile
0,0 → 1,6
OBJS := libnsgif.o
OUTFILE = libo.o
CFLAGS += -I ../../include/ -I ../../ -I ../ -I ./ -I /home/sourcerer/kos_src/newenginek/kolibri/include
include $(MENUETDEV)/makefiles/Makefile_for_o_lib

/contrib/network/netsurf/libnsgif/src/libnsgif.c
0,0 → 1,1285
/*
* Copyright 2004 Richard Wilson <richard.wilson@netsurf-browser.org>
* Copyright 2008 Sean Fox <dyntryx@gmail.com>
*
* This file is part of NetSurf's libnsgif, http://www.netsurf-browser.org/
* Licenced under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
*/
#include <stdbool.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include "libnsgif.h"
#include "utils/log.h"
/* READING GIF FILES
=================
The functions provided by this file allow for efficient progressive GIF
decoding. Whilst the initialisation does not ensure that there is
sufficient image data to complete the entire frame, it does ensure that
the information provided is valid. Any subsequent attempts to decode an
initialised GIF are guaranteed to succeed, and any bytes of the image
not present are assumed to be totally transparent.
To begin decoding a GIF, the 'gif' structure must be initialised with
the 'gif_data' and 'buffer_size' set to their initial values. The
'buffer_position' should initially be 0, and will be internally updated
as the decoding commences. The caller should then repeatedly call
gif_initialise() with the structure until the function returns 1, or
no more data is avaliable.
Once the initialisation has begun, the decoder completes the variables
'frame_count' and 'frame_count_partial'. The former being the total
number of frames that have been successfully initialised, and the
latter being the number of frames that a partial amount of data is
available for. This assists the caller in managing the animation whilst
decoding is continuing.
To decode a frame, the caller must use gif_decode_frame() which updates
the current 'frame_image' to reflect the desired frame. The required
'disposal_method' is also updated to reflect how the frame should be
plotted. The caller must not assume that the current 'frame_image' will
be valid between calls if initialisation is still occuring, and should
either always request that the frame is decoded (no processing will
occur if the 'decoded_frame' has not been invalidated by initialisation)
or perform the check itself.
It should be noted that gif_finalise() should always be called, even if
no frames were initialised. Additionally, it is the responsibility of
the caller to free 'gif_data'.
[rjw] - Fri 2nd April 2004
*/
/* TO-DO LIST
=================
+ Plain text and comment extensions could be implemented if there is any
interest in doing so.
*/
/* Maximum colour table size
*/
#define GIF_MAX_COLOURS 256
/* Internal flag that the colour table needs to be processed
*/
#define GIF_PROCESS_COLOURS 0xaa000000
/* Internal flag that a frame is invalid/unprocessed
*/
#define GIF_INVALID_FRAME -1
/* Maximum LZW bits available
*/
#define GIF_MAX_LZW 12
/* Transparent colour
*/
#define GIF_TRANSPARENT_COLOUR 0x00
/* GIF Flags
*/
#define GIF_FRAME_COMBINE 1
#define GIF_FRAME_CLEAR 2
#define GIF_FRAME_RESTORE 3
#define GIF_FRAME_QUIRKS_RESTORE 4
#define GIF_IMAGE_SEPARATOR 0x2c
#define GIF_INTERLACE_MASK 0x40
#define GIF_COLOUR_TABLE_MASK 0x80
#define GIF_COLOUR_TABLE_SIZE_MASK 0x07
#define GIF_EXTENSION_INTRODUCER 0x21
#define GIF_EXTENSION_GRAPHIC_CONTROL 0xf9
#define GIF_DISPOSAL_MASK 0x1c
#define GIF_TRANSPARENCY_MASK 0x01
#define GIF_EXTENSION_COMMENT 0xfe
#define GIF_EXTENSION_PLAIN_TEXT 0x01
#define GIF_EXTENSION_APPLICATION 0xff
#define GIF_BLOCK_TERMINATOR 0x00
#define GIF_TRAILER 0x3b
/* Internal GIF routines
*/
static gif_result gif_initialise_sprite(gif_animation *gif, unsigned int width, unsigned int height);
static gif_result gif_initialise_frame(gif_animation *gif);
static gif_result gif_initialise_frame_extensions(gif_animation *gif, const int frame);
static gif_result gif_skip_frame_extensions(gif_animation *gif);
static unsigned int gif_interlaced_line(int height, int y);
/* Internal LZW routines
*/
static void gif_init_LZW(gif_animation *gif);
static bool gif_next_LZW(gif_animation *gif);
static int gif_next_code(gif_animation *gif, int code_size);
/* General LZW values. They are shared for all GIFs being decoded, and
thus we can't handle progressive decoding efficiently without having
the data for each image which would use an extra 10Kb or so per GIF.
*/
static unsigned char buf[4];
static unsigned char *direct;
static int maskTbl[16] = {0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f,
0x00ff, 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff};
static int table[2][(1 << GIF_MAX_LZW)];
static unsigned char stack[(1 << GIF_MAX_LZW) * 2];
static unsigned char *stack_pointer;
static int code_size, set_code_size;
static int max_code, max_code_size;
static int clear_code, end_code;
static int curbit, lastbit, last_byte;
static int firstcode, oldcode;
static bool zero_data_block = false;
static bool get_done;
/* Whether to clear the decoded image rather than plot
*/
static bool clear_image = false;
/** Initialises necessary gif_animation members.
*/
void gif_create(gif_animation *gif, gif_bitmap_callback_vt *bitmap_callbacks) {
memset(gif, 0, sizeof(gif_animation));
gif->bitmap_callbacks = *bitmap_callbacks;
gif->decoded_frame = GIF_INVALID_FRAME;
}
/** Initialises any workspace held by the animation and attempts to decode
any information that hasn't already been decoded.
If an error occurs, all previously decoded frames are retained.
@return GIF_FRAME_DATA_ERROR for GIF frame data error
GIF_INSUFFICIENT_FRAME_DATA for insufficient data to process
any more frames
GIF_INSUFFICIENT_MEMORY for memory error
GIF_DATA_ERROR for GIF error
GIF_INSUFFICIENT_DATA for insufficient data to do anything
GIF_OK for successful decoding
GIF_WORKING for successful decoding if more frames are expected
*/
gif_result gif_initialise(gif_animation *gif, size_t size, unsigned char *data) {
unsigned char *gif_data;
unsigned int index;
gif_result return_value;
/* The GIF format is thoroughly documented; a full description
* can be found at http://www.w3.org/Graphics/GIF/spec-gif89a.txt
*/
/* Initialize values
*/
gif->buffer_size = size;
gif->gif_data = data;
/* Check for sufficient data to be a GIF (6-byte header + 7-byte logical screen descriptor)
*/
if (gif->buffer_size < 13) return GIF_INSUFFICIENT_DATA;
/* Get our current processing position
*/
gif_data = gif->gif_data + gif->buffer_position;
/* See if we should initialise the GIF
*/
if (gif->buffer_position == 0) {
/* We want everything to be NULL before we start so we've no chance
of freeing bad pointers (paranoia)
*/
gif->frame_image = NULL;
gif->frames = NULL;
gif->local_colour_table = NULL;
gif->global_colour_table = NULL;
/* The caller may have been lazy and not reset any values
*/
gif->frame_count = 0;
gif->frame_count_partial = 0;
gif->decoded_frame = GIF_INVALID_FRAME;
/* 6-byte GIF file header is:
*
* +0 3CHARS Signature ('GIF')
* +3 3CHARS Version ('87a' or '89a')
*/
if (strncmp((const char *) gif_data, "GIF", 3) != 0)
return GIF_DATA_ERROR;
gif_data += 3;
/* Ensure GIF reports version 87a or 89a
*/
/* if ((strncmp(gif_data, "87a", 3) != 0) &&
(strncmp(gif_data, "89a", 3) != 0))
LOG(("Unknown GIF format - proceeding anyway"));
*/ gif_data += 3;
/* 7-byte Logical Screen Descriptor is:
*
* +0 SHORT Logical Screen Width
* +2 SHORT Logical Screen Height
* +4 CHAR __Packed Fields__
* 1BIT Global Colour Table Flag
* 3BITS Colour Resolution
* 1BIT Sort Flag
* 3BITS Size of Global Colour Table
* +5 CHAR Background Colour Index
* +6 CHAR Pixel Aspect Ratio
*/
gif->width = gif_data[0] | (gif_data[1] << 8);
gif->height = gif_data[2] | (gif_data[3] << 8);
gif->global_colours = (gif_data[4] & GIF_COLOUR_TABLE_MASK);
gif->colour_table_size = (2 << (gif_data[4] & GIF_COLOUR_TABLE_SIZE_MASK));
gif->background_index = gif_data[5];
gif->aspect_ratio = gif_data[6];
gif->loop_count = 1;
gif_data += 7;
/* Some broken GIFs report the size as the screen size they were created in. As
such, we detect for the common cases and set the sizes as 0 if they are found
which results in the GIF being the maximum size of the frames.
*/
if (((gif->width == 640) && (gif->height == 480)) ||
((gif->width == 640) && (gif->height == 512)) ||
((gif->width == 800) && (gif->height == 600)) ||
((gif->width == 1024) && (gif->height == 768)) ||
((gif->width == 1280) && (gif->height == 1024)) ||
((gif->width == 1600) && (gif->height == 1200)) ||
((gif->width == 0) || (gif->height == 0)) ||
((gif->width > 2048) || (gif->height > 2048))) {
gif->width = 1;
gif->height = 1;
}
/* Allocate some data irrespective of whether we've got any colour tables. We
always get the maximum size in case a GIF is lying to us. It's far better
to give the wrong colours than to trample over some memory somewhere.
*/
gif->global_colour_table = (unsigned int *)calloc(GIF_MAX_COLOURS, sizeof(int));
gif->local_colour_table = (unsigned int *)calloc(GIF_MAX_COLOURS, sizeof(int));
if ((gif->global_colour_table == NULL) || (gif->local_colour_table == NULL)) {
gif_finalise(gif);
return GIF_INSUFFICIENT_MEMORY;
}
/* Set the first colour to a value that will never occur in reality so we
know if we've processed it
*/
gif->global_colour_table[0] = GIF_PROCESS_COLOURS;
/* Check if the GIF has no frame data (13-byte header + 1-byte termination block)
* Although generally useless, the GIF specification does not expressly prohibit this
*/
if (gif->buffer_size == 14) {
if (gif_data[0] == GIF_TRAILER)
return GIF_OK;
else
return GIF_INSUFFICIENT_DATA;
}
/* Initialise enough workspace for 4 frames initially
*/
if ((gif->frames = (gif_frame *)malloc(sizeof(gif_frame))) == NULL) {
gif_finalise(gif);
return GIF_INSUFFICIENT_MEMORY;
}
gif->frame_holders = 1;
/* Initialise the sprite header
*/
assert(gif->bitmap_callbacks.bitmap_create);
if ((gif->frame_image = gif->bitmap_callbacks.bitmap_create(gif->width, gif->height)) == NULL) {
gif_finalise(gif);
return GIF_INSUFFICIENT_MEMORY;
}
/* Remember we've done this now
*/
gif->buffer_position = gif_data - gif->gif_data;
}
/* Do the colour map if we haven't already. As the top byte is always 0xff or 0x00
depending on the transparency we know if it's been filled in.
*/
if (gif->global_colour_table[0] == GIF_PROCESS_COLOURS) {
/* Check for a global colour map signified by bit 7
*/
if (gif->global_colours) {
if (gif->buffer_size < (gif->colour_table_size * 3 + 12)) {
return GIF_INSUFFICIENT_DATA;
}
for (index = 0; index < gif->colour_table_size; index++) {
/* Gif colour map contents are r,g,b.
*
* We want to pack them bytewise into the
* colour table, such that the red component
* is in byte 0 and the alpha component is in
* byte 3.
*/
unsigned char *entry = (unsigned char *) &gif->
global_colour_table[index];
entry[0] = gif_data[0]; /* r */
entry[1] = gif_data[1]; /* g */
entry[2] = gif_data[2]; /* b */
entry[3] = 0xff; /* a */
gif_data += 3;
}
gif->buffer_position = (gif_data - gif->gif_data);
} else {
/* Create a default colour table with the first two colours as black and white
*/
unsigned int *entry = gif->global_colour_table;
entry[0] = 0x00000000;
/* Force Alpha channel to opaque */
((unsigned char *) entry)[3] = 0xff;
entry[1] = 0xffffffff;
}
}
/* Repeatedly try to initialise frames
*/
while ((return_value = gif_initialise_frame(gif)) == GIF_WORKING);
/* If there was a memory error tell the caller
*/
if ((return_value == GIF_INSUFFICIENT_MEMORY) ||
(return_value == GIF_DATA_ERROR))
return return_value;
/* If we didn't have some frames then a GIF_INSUFFICIENT_DATA becomes a
GIF_INSUFFICIENT_FRAME_DATA
*/
if ((return_value == GIF_INSUFFICIENT_DATA) && (gif->frame_count_partial > 0))
return GIF_INSUFFICIENT_FRAME_DATA;
/* Return how many we got
*/
return return_value;
}
/** Updates the sprite memory size
@return GIF_INSUFFICIENT_MEMORY for a memory error
GIF_OK for success
*/
static gif_result gif_initialise_sprite(gif_animation *gif, unsigned int width, unsigned int height) {
unsigned int max_width;
unsigned int max_height;
struct bitmap *buffer;
/* Check if we've changed
*/
if ((width <= gif->width) && (height <= gif->height))
return GIF_OK;
/* Get our maximum values
*/
max_width = (width > gif->width) ? width : gif->width;
max_height = (height > gif->height) ? height : gif->height;
/* Allocate some more memory
*/
assert(gif->bitmap_callbacks.bitmap_create);
if ((buffer = gif->bitmap_callbacks.bitmap_create(max_width, max_height)) == NULL)
return GIF_INSUFFICIENT_MEMORY;
assert(gif->bitmap_callbacks.bitmap_destroy);
gif->bitmap_callbacks.bitmap_destroy(gif->frame_image);
gif->frame_image = buffer;
gif->width = max_width;
gif->height = max_height;
/* Invalidate our currently decoded image
*/
gif->decoded_frame = GIF_INVALID_FRAME;
return GIF_OK;
}
/** Attempts to initialise the next frame
@return GIF_INSUFFICIENT_DATA for insufficient data to do anything
GIF_FRAME_DATA_ERROR for GIF frame data error
GIF_INSUFFICIENT_MEMORY for insufficient memory to process
GIF_INSUFFICIENT_FRAME_DATA for insufficient data to complete the frame
GIF_DATA_ERROR for GIF error (invalid frame header)
GIF_OK for successful decoding
GIF_WORKING for successful decoding if more frames are expected
*/
static gif_result gif_initialise_frame(gif_animation *gif) {
int frame;
gif_frame *temp_buf;
unsigned char *gif_data, *gif_end;
int gif_bytes;
unsigned int flags = 0;
unsigned int width, height, offset_x, offset_y;
unsigned int block_size, colour_table_size;
bool first_image = true;
gif_result return_value;
/* Get the frame to decode and our data position
*/
frame = gif->frame_count;
/* Get our buffer position etc.
*/
gif_data = (unsigned char *)(gif->gif_data + gif->buffer_position);
gif_end = (unsigned char *)(gif->gif_data + gif->buffer_size);
gif_bytes = (gif_end - gif_data);
/* Check if we've finished
*/
if ((gif_bytes > 0) && (gif_data[0] == GIF_TRAILER)) return GIF_OK;
/* Check if we have enough data
* The shortest block of data is a 4-byte comment extension + 1-byte block terminator + 1-byte gif trailer
*/
if (gif_bytes < 6) return GIF_INSUFFICIENT_DATA;
/* We could theoretically get some junk data that gives us millions of frames, so
we ensure that we don't have a silly number
*/
if (frame > 4096) return GIF_FRAME_DATA_ERROR;
/* Get some memory to store our pointers in etc.
*/
if ((int)gif->frame_holders <= frame) {
/* Allocate more memory
*/
if ((temp_buf = (gif_frame *)realloc(gif->frames,
(frame + 1) * sizeof(gif_frame))) == NULL)
return GIF_INSUFFICIENT_MEMORY;
gif->frames = temp_buf;
gif->frame_holders = frame + 1;
}
/* Store our frame pointer. We would do it when allocating except we
start off with one frame allocated so we can always use realloc.
*/
gif->frames[frame].frame_pointer = gif->buffer_position;
gif->frames[frame].display = false;
gif->frames[frame].virgin = true;
gif->frames[frame].disposal_method = 0;
gif->frames[frame].transparency = false;
gif->frames[frame].frame_delay = 100;
gif->frames[frame].redraw_required = false;
/* Invalidate any previous decoding we have of this frame
*/
if (gif->decoded_frame == frame)
gif->decoded_frame = GIF_INVALID_FRAME;
/* We pretend to initialise the frames, but really we just skip over all
the data contained within. This is all basically a cut down version of
gif_decode_frame that doesn't have any of the LZW bits in it.
*/
/* Initialise any extensions
*/
gif->buffer_position = gif_data - gif->gif_data;
if ((return_value = gif_initialise_frame_extensions(gif, frame)) != GIF_OK)
return return_value;
gif_data = (gif->gif_data + gif->buffer_position);
gif_bytes = (gif_end - gif_data);
/* Check if we've finished
*/
if ((gif_bytes = (gif_end - gif_data)) < 1)
return GIF_INSUFFICIENT_FRAME_DATA;
else if (gif_data[0] == GIF_TRAILER) {
gif->buffer_position = (gif_data - gif->gif_data);
gif->frame_count = frame + 1;
return GIF_OK;
}
/* If we're not done, there should be an image descriptor
*/
if (gif_data[0] != GIF_IMAGE_SEPARATOR) return GIF_FRAME_DATA_ERROR;
/* Do some simple boundary checking
*/
offset_x = gif_data[1] | (gif_data[2] << 8);
offset_y = gif_data[3] | (gif_data[4] << 8);
width = gif_data[5] | (gif_data[6] << 8);
height = gif_data[7] | (gif_data[8] << 8);
/* Set up the redraw characteristics. We have to check for extending the area
due to multi-image frames.
*/
if (!first_image) {
if (gif->frames[frame].redraw_x > offset_x) {
gif->frames[frame].redraw_width += (gif->frames[frame].redraw_x - offset_x);
gif->frames[frame].redraw_x = offset_x;
}
if (gif->frames[frame].redraw_y > offset_y) {
gif->frames[frame].redraw_height += (gif->frames[frame].redraw_y - offset_y);
gif->frames[frame].redraw_y = offset_y;
}
if ((offset_x + width) > (gif->frames[frame].redraw_x + gif->frames[frame].redraw_width))
gif->frames[frame].redraw_width = (offset_x + width) - gif->frames[frame].redraw_x;
if ((offset_y + height) > (gif->frames[frame].redraw_y + gif->frames[frame].redraw_height))
gif->frames[frame].redraw_height = (offset_y + height) - gif->frames[frame].redraw_y;
} else {
first_image = false;
gif->frames[frame].redraw_x = offset_x;
gif->frames[frame].redraw_y = offset_y;
gif->frames[frame].redraw_width = width;
gif->frames[frame].redraw_height = height;
}
/* if we are clearing the background then we need to redraw enough to cover the previous
frame too
*/
gif->frames[frame].redraw_required = ((gif->frames[frame].disposal_method == GIF_FRAME_CLEAR) ||
(gif->frames[frame].disposal_method == GIF_FRAME_RESTORE));
/* Boundary checking - shouldn't ever happen except with junk data
*/
if (gif_initialise_sprite(gif, (offset_x + width), (offset_y + height)))
return GIF_INSUFFICIENT_MEMORY;
/* Decode the flags
*/
flags = gif_data[9];
colour_table_size = 2 << (flags & GIF_COLOUR_TABLE_SIZE_MASK);
/* Move our data onwards and remember we've got a bit of this frame
*/
gif_data += 10;
gif_bytes = (gif_end - gif_data);
gif->frame_count_partial = frame + 1;
/* Skip the local colour table
*/
if (flags & GIF_COLOUR_TABLE_MASK) {
gif_data += 3 * colour_table_size;
if ((gif_bytes = (gif_end - gif_data)) < 0)
return GIF_INSUFFICIENT_FRAME_DATA;
}
/* Ensure we have a correct code size
*/
if (gif_data[0] > GIF_MAX_LZW)
return GIF_DATA_ERROR;
/* Move our pointer to the actual image data
*/
gif_data++;
if (--gif_bytes < 0)
return GIF_INSUFFICIENT_FRAME_DATA;
/* Repeatedly skip blocks until we get a zero block or run out of data
* These blocks of image data are processed later by gif_decode_frame()
*/
block_size = 0;
while (block_size != 1) {
block_size = gif_data[0] + 1;
/* Check if the frame data runs off the end of the file
*/
if ((int)(gif_bytes - block_size) < 0) {
/* Try to recover by signaling the end of the gif.
* Once we get garbage data, there is no logical
* way to determine where the next frame is.
* It's probably better to partially load the gif
* than not at all.
*/
if (gif_bytes >= 2) {
gif_data[0] = 0;
gif_data[1] = GIF_TRAILER;
gif_bytes = 1;
++gif_data;
break;
} else
return GIF_INSUFFICIENT_FRAME_DATA;
} else {
gif_bytes -= block_size;
gif_data += block_size;
}
}
/* Add the frame and set the display flag
*/
gif->buffer_position = gif_data - gif->gif_data;
gif->frame_count = frame + 1;
gif->frames[frame].display = true;
/* Check if we've finished
*/
if (gif_bytes < 1)
return GIF_INSUFFICIENT_FRAME_DATA;
else
if (gif_data[0] == GIF_TRAILER) return GIF_OK;
return GIF_WORKING;
}
/** Attempts to initialise the frame's extensions
@return GIF_INSUFFICIENT_FRAME_DATA for insufficient data to complete the frame
GIF_OK for successful initialisation
*/
static gif_result gif_initialise_frame_extensions(gif_animation *gif, const int frame) {
unsigned char *gif_data, *gif_end;
int gif_bytes;
unsigned int block_size;
/* Get our buffer position etc.
*/
gif_data = (unsigned char *)(gif->gif_data + gif->buffer_position);
gif_end = (unsigned char *)(gif->gif_data + gif->buffer_size);
/* Initialise the extensions
*/
while (gif_data[0] == GIF_EXTENSION_INTRODUCER) {
++gif_data;
gif_bytes = (gif_end - gif_data);
/* Switch on extension label
*/
switch(gif_data[0]) {
/* 6-byte Graphic Control Extension is:
*
* +0 CHAR Graphic Control Label
* +1 CHAR Block Size
* +2 CHAR __Packed Fields__
* 3BITS Reserved
* 3BITS Disposal Method
* 1BIT User Input Flag
* 1BIT Transparent Color Flag
* +3 SHORT Delay Time
* +5 CHAR Transparent Color Index
*/
case GIF_EXTENSION_GRAPHIC_CONTROL:
if (gif_bytes < 6) return GIF_INSUFFICIENT_FRAME_DATA;
gif->frames[frame].frame_delay = gif_data[3] | (gif_data[4] << 8);
if (gif_data[2] & GIF_TRANSPARENCY_MASK) {
gif->frames[frame].transparency = true;
gif->frames[frame].transparency_index = gif_data[5];
}
gif->frames[frame].disposal_method = ((gif_data[2] & GIF_DISPOSAL_MASK) >> 2);
/* I have encountered documentation and GIFs in the wild that use
* 0x04 to restore the previous frame, rather than the officially
* documented 0x03. I believe some (older?) software may even actually
* export this way. We handle this as a type of "quirks" mode.
*/
if (gif->frames[frame].disposal_method == GIF_FRAME_QUIRKS_RESTORE)
gif->frames[frame].disposal_method = GIF_FRAME_RESTORE;
gif_data += (2 + gif_data[1]);
break;
/* 14-byte+ Application Extension is:
*
* +0 CHAR Application Extension Label
* +1 CHAR Block Size
* +2 8CHARS Application Identifier
* +10 3CHARS Appl. Authentication Code
* +13 1-256 Application Data (Data sub-blocks)
*/
case GIF_EXTENSION_APPLICATION:
if (gif_bytes < 17) return GIF_INSUFFICIENT_FRAME_DATA;
if ((gif_data[1] == 0x0b) &&
(strncmp((const char *) gif_data + 2,
"NETSCAPE2.0", 11) == 0) &&
(gif_data[13] == 0x03) &&
(gif_data[14] == 0x01)) {
gif->loop_count = gif_data[15] | (gif_data[16] << 8);
}
gif_data += (2 + gif_data[1]);
break;
/* Move the pointer to the first data sub-block
* Skip 1 byte for the extension label
*/
case GIF_EXTENSION_COMMENT:
++gif_data;
break;
/* Move the pointer to the first data sub-block
* Skip 2 bytes for the extension label and size fields
* Skip the extension size itself
*/
default:
gif_data += (2 + gif_data[1]);
}
/* Repeatedly skip blocks until we get a zero block or run out of data
* This data is ignored by this gif decoder
*/
gif_bytes = (gif_end - gif_data);
block_size = 0;
while (gif_data[0] != GIF_BLOCK_TERMINATOR) {
block_size = gif_data[0] + 1;
if ((gif_bytes -= block_size) < 0)
return GIF_INSUFFICIENT_FRAME_DATA;
gif_data += block_size;
}
++gif_data;
}
/* Set buffer position and return
*/
gif->buffer_position = (gif_data - gif->gif_data);
return GIF_OK;
}
/** Decodes a GIF frame.
@return GIF_FRAME_DATA_ERROR for GIF frame data error
GIF_INSUFFICIENT_FRAME_DATA for insufficient data to complete the frame
GIF_DATA_ERROR for GIF error (invalid frame header)
GIF_INSUFFICIENT_DATA for insufficient data to do anything
GIF_INSUFFICIENT_MEMORY for insufficient memory to process
GIF_OK for successful decoding
If a frame does not contain any image data, GIF_OK is returned and
gif->current_error is set to GIF_FRAME_NO_DISPLAY
*/
gif_result gif_decode_frame(gif_animation *gif, unsigned int frame) {
unsigned int index = 0;
unsigned char *gif_data, *gif_end;
int gif_bytes;
unsigned int width, height, offset_x, offset_y;
unsigned int flags, colour_table_size, interlace;
unsigned int *colour_table;
unsigned int *frame_data = 0; // Set to 0 for no warnings
unsigned int *frame_scanline;
unsigned int save_buffer_position;
unsigned int return_value = 0;
unsigned int x, y, decode_y, burst_bytes;
int last_undisposed_frame = (frame - 1);
register unsigned char colour;
/* Ensure this frame is supposed to be decoded
*/
if (gif->frames[frame].display == false) {
gif->current_error = GIF_FRAME_NO_DISPLAY;
return GIF_OK;
}
/* Ensure we have a frame to decode
*/
if (frame > gif->frame_count_partial)
return GIF_INSUFFICIENT_DATA;
if ((!clear_image) && ((int)frame == gif->decoded_frame))
return GIF_OK;
/* Get the start of our frame data and the end of the GIF data
*/
gif_data = gif->gif_data + gif->frames[frame].frame_pointer;
gif_end = gif->gif_data + gif->buffer_size;
gif_bytes = (gif_end - gif_data);
/* Check if we have enough data
* The shortest block of data is a 10-byte image descriptor + 1-byte gif trailer
*/
if (gif_bytes < 12) return GIF_INSUFFICIENT_FRAME_DATA;
/* Save the buffer position
*/
save_buffer_position = gif->buffer_position;
gif->buffer_position = gif_data - gif->gif_data;
/* Skip any extensions because we all ready processed them
*/
if ((return_value = gif_skip_frame_extensions(gif)) != GIF_OK)
goto gif_decode_frame_exit;
gif_data = (gif->gif_data + gif->buffer_position);
gif_bytes = (gif_end - gif_data);
/* Ensure we have enough data for the 10-byte image descriptor + 1-byte gif trailer
*/
if (gif_bytes < 12) {
return_value = GIF_INSUFFICIENT_FRAME_DATA;
goto gif_decode_frame_exit;
}
/* 10-byte Image Descriptor is:
*
* +0 CHAR Image Separator (0x2c)
* +1 SHORT Image Left Position
* +3 SHORT Image Top Position
* +5 SHORT Width
* +7 SHORT Height
* +9 CHAR __Packed Fields__
* 1BIT Local Colour Table Flag
* 1BIT Interlace Flag
* 1BIT Sort Flag
* 2BITS Reserved
* 3BITS Size of Local Colour Table
*/
if (gif_data[0] != GIF_IMAGE_SEPARATOR) {
return_value = GIF_DATA_ERROR;
goto gif_decode_frame_exit;
}
offset_x = gif_data[1] | (gif_data[2] << 8);
offset_y = gif_data[3] | (gif_data[4] << 8);
width = gif_data[5] | (gif_data[6] << 8);
height = gif_data[7] | (gif_data[8] << 8);
/* Boundary checking - shouldn't ever happen except unless the data has been
modified since initialisation.
*/
if ((offset_x + width > gif->width) || (offset_y + height > gif->height)) {
return_value = GIF_DATA_ERROR;
goto gif_decode_frame_exit;
}
/* Decode the flags
*/
flags = gif_data[9];
colour_table_size = 2 << (flags & GIF_COLOUR_TABLE_SIZE_MASK);
interlace = flags & GIF_INTERLACE_MASK;
/* Move our pointer to the colour table or image data (if no colour table is given)
*/
gif_data += 10;
gif_bytes = (gif_end - gif_data);
/* Set up the colour table
*/
if (flags & GIF_COLOUR_TABLE_MASK) {
if (gif_bytes < (int)(3 * colour_table_size)) {
return_value = GIF_INSUFFICIENT_FRAME_DATA;
goto gif_decode_frame_exit;
}
colour_table = gif->local_colour_table;
if (!clear_image) {
for (index = 0; index < colour_table_size; index++) {
/* Gif colour map contents are r,g,b.
*
* We want to pack them bytewise into the
* colour table, such that the red component
* is in byte 0 and the alpha component is in
* byte 3.
*/
unsigned char *entry =
(unsigned char *) &colour_table[index];
entry[0] = gif_data[0]; /* r */
entry[1] = gif_data[1]; /* g */
entry[2] = gif_data[2]; /* b */
entry[3] = 0xff; /* a */
gif_data += 3;
}
} else {
gif_data += 3 * colour_table_size;
}
gif_bytes = (gif_end - gif_data);
} else {
colour_table = gif->global_colour_table;
}
/* Check if we've finished
*/
if (gif_bytes < 1) {
return_value = GIF_INSUFFICIENT_FRAME_DATA;
goto gif_decode_frame_exit;
} else if (gif_data[0] == GIF_TRAILER) {
return_value = GIF_OK;
goto gif_decode_frame_exit;
}
/* Get the frame data
*/
assert(gif->bitmap_callbacks.bitmap_get_buffer);
frame_data = (void *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image);
if (!frame_data)
return GIF_INSUFFICIENT_MEMORY;
/* If we are clearing the image we just clear, if not decode
*/
if (!clear_image) {
/* Ensure we have enough data for a 1-byte LZW code size + 1-byte gif trailer
*/
if (gif_bytes < 2) {
return_value = GIF_INSUFFICIENT_FRAME_DATA;
goto gif_decode_frame_exit;
/* If we only have a 1-byte LZW code size + 1-byte gif trailer, we're finished
*/
} else if ((gif_bytes == 2) && (gif_data[1] == GIF_TRAILER)) {
return_value = GIF_OK;
goto gif_decode_frame_exit;
}
/* If the previous frame's disposal method requires we restore the background
* colour or this is the first frame, clear the frame data
*/
if ((frame == 0) || (gif->decoded_frame == GIF_INVALID_FRAME)) {
memset((char*)frame_data, GIF_TRANSPARENT_COLOUR, gif->width * gif->height * sizeof(int));
gif->decoded_frame = frame;
/* The line below would fill the image with its background color, but because GIFs support
* transparency we likely wouldn't want to do that. */
/* memset((char*)frame_data, colour_table[gif->background_index], gif->width * gif->height * sizeof(int)); */
} else if ((frame != 0) && (gif->frames[frame - 1].disposal_method == GIF_FRAME_CLEAR)) {
clear_image = true;
if ((return_value = gif_decode_frame(gif, (frame - 1))) != GIF_OK)
goto gif_decode_frame_exit;
clear_image = false;
/* If the previous frame's disposal method requires we restore the previous
* image, find the last image set to "do not dispose" and get that frame data
*/
} else if ((frame != 0) && (gif->frames[frame - 1].disposal_method == GIF_FRAME_RESTORE)) {
while ((last_undisposed_frame != -1) && (gif->frames[--last_undisposed_frame].disposal_method == GIF_FRAME_RESTORE));
/* If we don't find one, clear the frame data
*/
if (last_undisposed_frame == -1) {
/* see notes above on transparency vs. background color */
memset((char*)frame_data, GIF_TRANSPARENT_COLOUR, gif->width * gif->height * sizeof(int));
} else {
if ((return_value = gif_decode_frame(gif, last_undisposed_frame)) != GIF_OK)
goto gif_decode_frame_exit;
/* Get this frame's data
*/
assert(gif->bitmap_callbacks.bitmap_get_buffer);
frame_data = (void *)gif->bitmap_callbacks.bitmap_get_buffer(gif->frame_image);
if (!frame_data)
return GIF_INSUFFICIENT_MEMORY;
}
}
gif->decoded_frame = frame;
/* Initialise the LZW decoding
*/
set_code_size = gif_data[0];
gif->buffer_position = (gif_data - gif->gif_data) + 1;
/* Set our code variables
*/
code_size = set_code_size + 1;
clear_code = (1 << set_code_size);
end_code = clear_code + 1;
max_code_size = clear_code << 1;
max_code = clear_code + 2;
curbit = lastbit = 0;
last_byte = 2;
get_done = false;
direct = buf;
gif_init_LZW(gif);
/* Decompress the data
*/
for (y = 0; y < height; y++) {
if (interlace)
decode_y = gif_interlaced_line(height, y) + offset_y;
else
decode_y = y + offset_y;
frame_scanline = frame_data + offset_x + (decode_y * gif->width);
/* Rather than decoding pixel by pixel, we try to burst out streams
of data to remove the need for end-of data checks every pixel.
*/
x = width;
while (x > 0) {
burst_bytes = (stack_pointer - stack);
if (burst_bytes > 0) {
if (burst_bytes > x)
burst_bytes = x;
x -= burst_bytes;
while (burst_bytes-- > 0) {
colour = *--stack_pointer;
if (((gif->frames[frame].transparency) &&
(colour != gif->frames[frame].transparency_index)) ||
(!gif->frames[frame].transparency))
*frame_scanline = colour_table[colour];
frame_scanline++;
}
} else {
if (!gif_next_LZW(gif)) {
/* Unexpected end of frame, try to recover
*/
if (gif->current_error == GIF_END_OF_FRAME)
return_value = GIF_OK;
else
return_value = gif->current_error;
goto gif_decode_frame_exit;
}
}
}
}
} else {
/* Clear our frame
*/
if (gif->frames[frame].disposal_method == GIF_FRAME_CLEAR) {
for (y = 0; y < height; y++) {
frame_scanline = frame_data + offset_x + ((offset_y + y) * gif->width);
if (gif->frames[frame].transparency)
memset(frame_scanline, GIF_TRANSPARENT_COLOUR, width * 4);
else
memset(frame_scanline, colour_table[gif->background_index], width * 4);
}
}
}
gif_decode_frame_exit:
/* Check if we should test for optimisation
*/
if (gif->frames[frame].virgin) {
if (gif->bitmap_callbacks.bitmap_test_opaque)
gif->frames[frame].opaque = gif->bitmap_callbacks.bitmap_test_opaque(gif->frame_image);
else
gif->frames[frame].opaque = false;
gif->frames[frame].virgin = false;
}
if (gif->bitmap_callbacks.bitmap_set_opaque)
gif->bitmap_callbacks.bitmap_set_opaque(gif->frame_image, gif->frames[frame].opaque);
if (gif->bitmap_callbacks.bitmap_modified)
gif->bitmap_callbacks.bitmap_modified(gif->frame_image);
/* Restore the buffer position
*/
gif->buffer_position = save_buffer_position;
/* Success!
*/
return return_value;
}
/** Skips the frame's extensions (which have been previously initialised)
@return GIF_INSUFFICIENT_FRAME_DATA for insufficient data to complete the frame
GIF_OK for successful decoding
*/
static gif_result gif_skip_frame_extensions(gif_animation *gif) {
unsigned char *gif_data, *gif_end;
int gif_bytes;
unsigned int block_size;
/* Get our buffer position etc.
*/
gif_data = (unsigned char *)(gif->gif_data + gif->buffer_position);
gif_end = (unsigned char *)(gif->gif_data + gif->buffer_size);
gif_bytes = (gif_end - gif_data);
/* Skip the extensions
*/
while (gif_data[0] == GIF_EXTENSION_INTRODUCER) {
++gif_data;
/* Switch on extension label
*/
switch(gif_data[0]) {
/* Move the pointer to the first data sub-block
* 1 byte for the extension label
*/
case GIF_EXTENSION_COMMENT:
++gif_data;
break;
/* Move the pointer to the first data sub-block
* 2 bytes for the extension label and size fields
* Skip the extension size itself
*/
default:
gif_data += (2 + gif_data[1]);
}
/* Repeatedly skip blocks until we get a zero block or run out of data
* This data is ignored by this gif decoder
*/
gif_bytes = (gif_end - gif_data);
block_size = 0;
while (gif_data[0] != GIF_BLOCK_TERMINATOR) {
block_size = gif_data[0] + 1;
if ((gif_bytes -= block_size) < 0)
return GIF_INSUFFICIENT_FRAME_DATA;
gif_data += block_size;
}
++gif_data;
}
/* Set buffer position and return
*/
gif->buffer_position = (gif_data - gif->gif_data);
return GIF_OK;
}
static unsigned int gif_interlaced_line(int height, int y) {
if ((y << 3) < height) return (y << 3);
y -= ((height + 7) >> 3);
if ((y << 3) < (height - 4)) return (y << 3) + 4;
y -= ((height + 3) >> 3);
if ((y << 2) < (height - 2)) return (y << 2) + 2;
y -= ((height + 1) >> 2);
return (y << 1) + 1;
}
/* Releases any workspace held by the animation
*/
void gif_finalise(gif_animation *gif) {
/* Release all our memory blocks
*/
if (gif->frame_image) {
assert(gif->bitmap_callbacks.bitmap_destroy);
gif->bitmap_callbacks.bitmap_destroy(gif->frame_image);
}
gif->frame_image = NULL;
free(gif->frames);
gif->frames = NULL;
free(gif->local_colour_table);
gif->local_colour_table = NULL;
free(gif->global_colour_table);
gif->global_colour_table = NULL;
}
/**
* Initialise LZW decoding
*/
void gif_init_LZW(gif_animation *gif) {
int i;
gif->current_error = 0;
if (clear_code >= (1 << GIF_MAX_LZW)) {
stack_pointer = stack;
gif->current_error = GIF_FRAME_DATA_ERROR;
return;
}
/* initialise our table */
memset(table, 0x00, (1 << GIF_MAX_LZW) * 8);
for (i = 0; i < clear_code; ++i)
table[1][i] = i;
/* update our LZW parameters */
code_size = set_code_size + 1;
max_code_size = clear_code << 1;
max_code = clear_code + 2;
stack_pointer = stack;
do {
firstcode = oldcode = gif_next_code(gif, code_size);
} while (firstcode == clear_code);
*stack_pointer++ =firstcode;
}
static bool gif_next_LZW(gif_animation *gif) {
int code, incode;
int block_size;
int new_code;
code = gif_next_code(gif, code_size);
if (code < 0) {
gif->current_error = code;
return false;
} else if (code == clear_code) {
gif_init_LZW(gif);
return true;
} else if (code == end_code) {
/* skip to the end of our data so multi-image GIFs work */
if (zero_data_block) {
gif->current_error = GIF_FRAME_DATA_ERROR;
return false;
}
block_size = 0;
while (block_size != 1) {
block_size = gif->gif_data[gif->buffer_position] + 1;
gif->buffer_position += block_size;
}
gif->current_error = GIF_FRAME_DATA_ERROR;
return false;
}
incode = code;
if (code >= max_code) {
*stack_pointer++ = firstcode;
code = oldcode;
}
/* The following loop is the most important in the GIF decoding cycle as every
* single pixel passes through it.
*
* Note: our stack is always big enough to hold a complete decompressed chunk. */
while (code >= clear_code) {
*stack_pointer++ = table[1][code];
new_code = table[0][code];
if (new_code < clear_code) {
code = new_code;
break;
}
*stack_pointer++ = table[1][new_code];
code = table[0][new_code];
if (code == new_code) {
gif->current_error = GIF_FRAME_DATA_ERROR;
return false;
}
}
*stack_pointer++ = firstcode = table[1][code];
if ((code = max_code) < (1 << GIF_MAX_LZW)) {
table[0][code] = oldcode;
table[1][code] = firstcode;
++max_code;
if ((max_code >= max_code_size) && (max_code_size < (1 << GIF_MAX_LZW))) {
max_code_size = max_code_size << 1;
++code_size;
}
}
oldcode = incode;
return true;
}
static int gif_next_code(gif_animation *gif, int code_size) {
int i, j, end, count, ret;
unsigned char *b;
end = curbit + code_size;
if (end >= lastbit) {
if (get_done)
return GIF_END_OF_FRAME;
buf[0] = direct[last_byte - 2];
buf[1] = direct[last_byte - 1];
/* get the next block */
direct = gif->gif_data + gif->buffer_position;
zero_data_block = ((count = direct[0]) == 0);
if ((gif->buffer_position + count) >= gif->buffer_size)
return GIF_INSUFFICIENT_FRAME_DATA;
if (count == 0)
get_done = true;
else {
direct -= 1;
buf[2] = direct[2];
buf[3] = direct[3];
}
gif->buffer_position += count + 1;
/* update our variables */
last_byte = 2 + count;
curbit = (curbit - lastbit) + 16;
lastbit = (2 + count) << 3;
end = curbit + code_size;
}
i = curbit >> 3;
if (i < 2)
b = buf;
else
b = direct;
ret = b[i];
j = (end >> 3) - 1;
if (i <= j) {
ret |= (b[i + 1] << 8);
if (i < j)
ret |= (b[i + 2] << 16);
}
ret = (ret >> (curbit % 8)) & maskTbl[code_size];
curbit += code_size;
return ret;
}

/contrib/network/netsurf/libnsgif/src/utils/log.h
0,0 → 1,21
/*
* Copyright 2003 James Bursa <bursa@users.sourceforge.net>
* Copyright 2004 John Tytgat <John.Tytgat@aaug.net>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
* Licenced under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
*/
#include <stdio.h>
#ifndef _LIBNSGIF_LOG_H_
#define _LIBNSGIF_LOG_H_
#ifdef NDEBUG
# define LOG(x) ((void) 0)
#else
# define LOG(x) do { fprintf(stderr, x), fputc('\n', stderr); } while (0)
#endif /* NDEBUG */
#endif /* _LIBNSGIF_LOG_H_ */