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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
|
#include "mupdf/fitz.h"
#include <zlib.h>
#ifndef PATH_MAX
#define PATH_MAX (1024)
#endif
static inline void big32(unsigned char *buf, unsigned int v)
{
buf[0] = (v >> 24) & 0xff;
buf[1] = (v >> 16) & 0xff;
buf[2] = (v >> 8) & 0xff;
buf[3] = (v) & 0xff;
}
static void putchunk(fz_context *ctx, fz_output *out, char *tag, unsigned char *data, int size)
{
unsigned int sum;
fz_write_int32_be(ctx, out, size);
fz_write(ctx, out, tag, 4);
fz_write(ctx, out, data, size);
sum = crc32(0, NULL, 0);
sum = crc32(sum, (unsigned char*)tag, 4);
sum = crc32(sum, data, size);
fz_write_int32_be(ctx, out, sum);
}
void
fz_save_pixmap_as_png(fz_context *ctx, fz_pixmap *pixmap, const char *filename)
{
fz_output *out = fz_new_output_with_path(ctx, filename, 0);
fz_png_output_context *poc = NULL;
fz_var(poc);
fz_try(ctx)
{
poc = fz_write_png_header(ctx, out, pixmap->w, pixmap->h, pixmap->n, pixmap->alpha);
fz_write_png_band(ctx, out, poc, pixmap->stride, 0, pixmap->h, pixmap->samples);
}
fz_always(ctx)
{
fz_write_png_trailer(ctx, out, poc);
fz_drop_output(ctx, out);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
}
void
fz_write_pixmap_as_png(fz_context *ctx, fz_output *out, const fz_pixmap *pixmap)
{
fz_png_output_context *poc;
if (!out)
return;
poc = fz_write_png_header(ctx, out, pixmap->w, pixmap->h, pixmap->n, pixmap->alpha);
fz_try(ctx)
{
fz_write_png_band(ctx, out, poc, pixmap->stride, 0, pixmap->h, pixmap->samples);
}
fz_always(ctx)
{
fz_write_png_trailer(ctx, out, poc);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
}
struct fz_png_output_context_s
{
unsigned char *udata;
unsigned char *cdata;
uLong usize, csize;
z_stream stream;
int w;
int h;
int n;
int alpha;
};
fz_png_output_context *
fz_write_png_header(fz_context *ctx, fz_output *out, int w, int h, int n, int alpha)
{
static const unsigned char pngsig[8] = { 137, 80, 78, 71, 13, 10, 26, 10 };
unsigned char head[13];
int color;
fz_png_output_context *poc;
if (!out)
return NULL;
/* Treat alpha only as greyscale */
if (n == 1 && alpha)
alpha = 0;
switch (n - alpha)
{
case 1: color = (alpha ? 4 : 0); break; /* 0 = Greyscale, 4 = Greyscale + Alpha */
case 3: color = (alpha ? 6 : 2); break; /* 2 = RGB, 6 = RGBA */
default:
fz_throw(ctx, FZ_ERROR_GENERIC, "pixmap must be grayscale or rgb to write as png");
}
poc = fz_malloc_struct(ctx, fz_png_output_context);
poc->w = w;
poc->h = h;
poc->n = n;
poc->alpha = alpha;
big32(head+0, w);
big32(head+4, h);
head[8] = 8; /* depth */
head[9] = color;
head[10] = 0; /* compression */
head[11] = 0; /* filter */
head[12] = 0; /* interlace */
fz_write(ctx, out, pngsig, 8);
putchunk(ctx, out, "IHDR", head, 13);
return poc;
}
void
fz_write_png_band(fz_context *ctx, fz_output *out, fz_png_output_context *poc, int stride, int band, int bandheight, unsigned char *sp)
{
unsigned char *dp;
int y, x, k, err, finalband;
int w, h, n, alpha;
if (!out || !sp || !poc)
return;
w = poc->w;
h = poc->h;
n = poc->n;
alpha = poc->alpha;
band *= bandheight;
finalband = (band+bandheight >= h);
if (finalband)
bandheight = h - band;
if (poc->udata == NULL)
{
poc->usize = (w * n + 1) * bandheight;
/* Sadly the bound returned by compressBound is just for a
* single usize chunk; if you compress a sequence of them
* the buffering can result in you suddenly getting a block
* larger than compressBound outputted in one go, even if you
* take all the data out each time. */
poc->csize = compressBound(poc->usize);
fz_try(ctx)
{
poc->udata = fz_malloc(ctx, poc->usize);
poc->cdata = fz_malloc(ctx, poc->csize);
}
fz_catch(ctx)
{
fz_free(ctx, poc->udata);
poc->udata = NULL;
poc->cdata = NULL;
fz_rethrow(ctx);
}
err = deflateInit(&poc->stream, Z_DEFAULT_COMPRESSION);
if (err != Z_OK)
fz_throw(ctx, FZ_ERROR_GENERIC, "compression error %d", err);
}
dp = poc->udata;
stride -= w*n;
for (y = 0; y < bandheight; y++)
{
*dp++ = 1; /* sub prediction filter */
for (x = 0; x < w; x++)
{
for (k = 0; k < n; k++)
{
if (x == 0)
dp[k] = sp[k];
else
dp[k] = sp[k] - sp[k-n];
}
sp += n;
dp += n;
}
sp += stride;
}
poc->stream.next_in = (Bytef*)poc->udata;
poc->stream.avail_in = (uInt)(dp - poc->udata);
do
{
poc->stream.next_out = poc->cdata;
poc->stream.avail_out = (uInt)poc->csize;
if (!finalband)
{
err = deflate(&poc->stream, Z_NO_FLUSH);
if (err != Z_OK)
fz_throw(ctx, FZ_ERROR_GENERIC, "compression error %d", err);
}
else
{
err = deflate(&poc->stream, Z_FINISH);
if (err != Z_STREAM_END)
fz_throw(ctx, FZ_ERROR_GENERIC, "compression error %d", err);
}
if (poc->stream.next_out != poc->cdata)
putchunk(ctx, out, "IDAT", poc->cdata, poc->stream.next_out - poc->cdata);
}
while (poc->stream.avail_out == 0);
}
void
fz_write_png_trailer(fz_context *ctx, fz_output *out, fz_png_output_context *poc)
{
unsigned char block[1];
int err;
if (!out || !poc)
return;
err = deflateEnd(&poc->stream);
if (err != Z_OK)
fz_throw(ctx, FZ_ERROR_GENERIC, "compression error %d", err);
fz_free(ctx, poc->cdata);
fz_free(ctx, poc->udata);
fz_free(ctx, poc);
putchunk(ctx, out, "IEND", block, 0);
}
/* We use an auxiliary function to do pixmap_as_png, as it can enable us to
* drop pix early in the case where we have to convert, potentially saving
* us having to have 2 copies of the pixmap and a buffer open at once. */
static fz_buffer *
png_from_pixmap(fz_context *ctx, fz_pixmap *pix, int drop)
{
fz_buffer *buf = NULL;
fz_output *out;
fz_pixmap *pix2 = NULL;
fz_var(buf);
fz_var(out);
fz_var(pix2);
if (pix->w == 0 || pix->h == 0)
return NULL;
fz_try(ctx)
{
if (pix->colorspace && pix->colorspace != fz_device_gray(ctx) && pix->colorspace != fz_device_rgb(ctx))
{
pix2 = fz_new_pixmap(ctx, fz_device_rgb(ctx), pix->w, pix->h, pix->alpha);
fz_convert_pixmap(ctx, pix2, pix);
if (drop)
fz_drop_pixmap(ctx, pix);
pix = pix2;
}
buf = fz_new_buffer(ctx, 1024);
out = fz_new_output_with_buffer(ctx, buf);
fz_write_pixmap_as_png(ctx, out, pix);
}
fz_always(ctx)
{
fz_drop_pixmap(ctx, drop ? pix : pix2);
fz_drop_output(ctx, out);
}
fz_catch(ctx)
{
fz_drop_buffer(ctx, buf);
fz_rethrow(ctx);
}
return buf;
}
fz_buffer *
fz_new_buffer_from_image_as_png(fz_context *ctx, fz_image *image)
{
return png_from_pixmap(ctx, fz_get_pixmap_from_image(ctx, image, NULL, NULL, NULL, NULL), 0);
}
fz_buffer *
fz_new_buffer_from_pixmap_as_png(fz_context *ctx, fz_pixmap *pix)
{
return png_from_pixmap(ctx, pix, 0);
}
/* PNG output writer */
typedef struct fz_png_writer_s fz_png_writer;
struct fz_png_writer_s
{
fz_document_writer super;
fz_draw_options options;
fz_pixmap *pixmap;
int count;
char *path;
};
const char *fz_png_write_options_usage = "";
static fz_device *
png_begin_page(fz_context *ctx, fz_document_writer *wri_, const fz_rect *mediabox, fz_matrix *transform)
{
fz_png_writer *wri = (fz_png_writer*)wri_;
return fz_new_draw_device_with_options(ctx, &wri->options, mediabox, transform, &wri->pixmap);
}
static void
png_end_page(fz_context *ctx, fz_document_writer *wri_, fz_device *dev)
{
fz_png_writer *wri = (fz_png_writer*)wri_;
char path[PATH_MAX];
wri->count += 1;
fz_format_output_path(ctx, path, sizeof path, wri->path, wri->count);
fz_save_pixmap_as_png(ctx, wri->pixmap, path);
fz_drop_pixmap(ctx, wri->pixmap);
wri->pixmap = NULL;
}
static void
png_close(fz_context *ctx, fz_document_writer *wri_)
{
fz_png_writer *wri = (fz_png_writer*)wri_;
fz_drop_pixmap(ctx, wri->pixmap);
fz_free(ctx, wri->path);
}
fz_document_writer *
fz_new_png_writer(fz_context *ctx, const char *path, const char *options)
{
fz_png_writer *wri;
wri = fz_malloc_struct(ctx, fz_png_writer);
wri->super.begin_page = png_begin_page;
wri->super.end_page = png_end_page;
wri->super.close = png_close;
fz_try(ctx)
{
fz_parse_draw_options(ctx, &wri->options, options);
wri->path = fz_strdup(ctx, path ? path : "out-%04d.png");
}
fz_catch(ctx)
{
fz_free(ctx, wri);
fz_rethrow(ctx);
}
return (fz_document_writer*)wri;
}
|