1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
#include "backend.h"
#include "bitmap.h"
#include "image.h"
#include "log.h"
#include "source.h"
#include "source_private.h"
#include <stdlib.h>
#include <png.h>
struct private {
FILE *file;
png_structp png;
png_infop info;
};
static void free_private(void *raw_private)
{
if (!raw_private) {
return;
}
struct private *private = raw_private;
png_destroy_read_struct(&private->png, &private->info, NULL);
if (private->file) {
fclose(private->file);
}
free(private);
}
static void load_image(void *raw_private, struct imv_image **image, int *frametime)
{
*image = NULL;
*frametime = 0;
struct private *private = raw_private;
if (setjmp(png_jmpbuf(private->png))) {
return;
}
const int width = png_get_image_width(private->png, private->info);
const int height = png_get_image_height(private->png, private->info);
png_bytep *rows = malloc(sizeof(png_bytep) * height);
size_t row_len = png_get_rowbytes(private->png, private->info);
rows[0] = malloc(height * row_len);
for (int y = 1; y < height; ++y) {
rows[y] = rows[0] + row_len * y;
}
if (setjmp(png_jmpbuf(private->png))) {
return;
}
png_read_image(private->png, rows);
void *raw_bmp = rows[0];
free(rows);
fclose(private->file);
private->file = NULL;
struct imv_bitmap *bmp = malloc(sizeof *bmp);
bmp->width = width;
bmp->height = height;
bmp->format = IMV_ABGR;
bmp->data = raw_bmp;
*image = imv_image_create_from_bitmap(bmp);
}
static const struct imv_source_vtable vtable = {
.load_first_frame = load_image,
.free = free_private
};
static enum backend_result open_path(const char *path, struct imv_source **src)
{
unsigned char header[8];
FILE *f = fopen(path, "rb");
if (!f) {
return BACKEND_BAD_PATH;
}
fread(header, 1, sizeof header, f);
if (png_sig_cmp(header, 0, sizeof header)) {
fclose(f);
return BACKEND_UNSUPPORTED;
}
struct private *private = calloc(1, sizeof *private);
private->file = f;
private->png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!private->png) {
fclose(private->file);
free(private);
return BACKEND_UNSUPPORTED;
}
/* set max PNG chunk size to 50MB, instead of 8MB default */
png_set_chunk_malloc_max(private->png, 1024 * 1024 * 50);
private->info = png_create_info_struct(private->png);
if (!private->info) {
png_destroy_read_struct(&private->png, NULL, NULL);
fclose(private->file);
free(private);
return BACKEND_UNSUPPORTED;
}
if (setjmp(png_jmpbuf(private->png))) {
png_destroy_read_struct(&private->png, &private->info, NULL);
fclose(private->file);
free(private);
return BACKEND_UNSUPPORTED;
}
png_init_io(private->png, private->file);
png_set_sig_bytes(private->png, sizeof header);
png_read_info(private->png, private->info);
/* Tell libpng to give us a consistent output format */
png_set_gray_to_rgb(private->png);
png_set_filler(private->png, 0xff, PNG_FILLER_AFTER);
png_set_strip_16(private->png);
png_set_expand(private->png);
png_set_packing(private->png);
png_read_update_info(private->png, private->info);
imv_log(IMV_DEBUG, "libpng: info width=%d height=%d bit_depth=%d color_type=%d\n",
png_get_image_width(private->png, private->info),
png_get_image_height(private->png, private->info),
png_get_bit_depth(private->png, private->info),
png_get_color_type(private->png, private->info));
if (setjmp(png_jmpbuf(private->png))) {
png_destroy_read_struct(&private->png, &private->info, NULL);
fclose(private->file);
free(private);
return BACKEND_UNSUPPORTED;
}
*src = imv_source_create(&vtable, private);
return BACKEND_SUCCESS;
}
const struct imv_backend imv_backend_libpng = {
.name = "libpng",
.description = "The official PNG reference implementation",
.website = "http://www.libpng.org/pub/png/libpng.html",
.license = "The libpng license",
.open_path = &open_path,
};
|
