1 /*
2 * Copyright (c) 1995, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * This file was based upon the example.c stub file included in the
28 * release 6 of the Independent JPEG Group's free JPEG software.
29 * It has been updated to conform to release 6b.
30 */
31
32 /* First, if system header files define "boolean" map it to "system_boolean" */
33 #define boolean system_boolean
34
35 #include <stdio.h>
36 #include <setjmp.h>
37 #include <string.h>
38 #include <stdlib.h>
39 #include <assert.h>
40
41 #include "jni.h"
42 #include "jni_util.h"
43
44 /* undo "system_boolean" hack and undef FAR since we don't use it anyway */
45 #undef boolean
46 #undef FAR
47 #include <jpeglib.h>
48 #include "jerror.h"
49
50 /* The method IDs we cache. Note that the last two belongs to the
51 * java.io.InputStream class.
52 */
53 static jmethodID sendHeaderInfoID;
54 static jmethodID sendPixelsByteID;
55 static jmethodID sendPixelsIntID;
56 static jmethodID InputStream_readID;
57 static jmethodID InputStream_availableID;
58
59 /* Initialize the Java VM instance variable when the library is
60 first loaded */
61 JavaVM *jvm;
62
63 JNIEXPORT jint JNICALL
64 JNI_OnLoad(JavaVM *vm, void *reserved)
65 {
66 jvm = vm;
67 return JNI_VERSION_1_2;
68 }
69
70 /*
71 * ERROR HANDLING:
72 *
73 * The JPEG library's standard error handler (jerror.c) is divided into
74 * several "methods" which you can override individually. This lets you
75 * adjust the behavior without duplicating a lot of code, which you might
76 * have to update with each future release.
77 *
78 * Our example here shows how to override the "error_exit" method so that
79 * control is returned to the library's caller when a fatal error occurs,
80 * rather than calling exit() as the standard error_exit method does.
81 *
82 * We use C's setjmp/longjmp facility to return control. This means that the
83 * routine which calls the JPEG library must first execute a setjmp() call to
84 * establish the return point. We want the replacement error_exit to do a
85 * longjmp(). But we need to make the setjmp buffer accessible to the
86 * error_exit routine. To do this, we make a private extension of the
87 * standard JPEG error handler object. (If we were using C++, we'd say we
88 * were making a subclass of the regular error handler.)
89 *
90 * Here's the extended error handler struct:
91 */
92
93 struct sun_jpeg_error_mgr {
94 struct jpeg_error_mgr pub; /* "public" fields */
95
96 jmp_buf setjmp_buffer; /* for return to caller */
97 };
98
99 typedef struct sun_jpeg_error_mgr * sun_jpeg_error_ptr;
100
101 /*
102 * Here's the routine that will replace the standard error_exit method:
103 */
104
105 METHODDEF(void)
106 sun_jpeg_error_exit (j_common_ptr cinfo)
107 {
108 /* cinfo->err really points to a sun_jpeg_error_mgr struct */
109 sun_jpeg_error_ptr myerr = (sun_jpeg_error_ptr) cinfo->err;
110
111 /* Always display the message. */
112 /* We could postpone this until after returning, if we chose. */
113 /* (*cinfo->err->output_message) (cinfo); */
114 /* For Java, we will format the message and put it in the error we throw. */
115
116 /* Return control to the setjmp point */
117 longjmp(myerr->setjmp_buffer, 1);
118 }
119
120 /*
121 * Error Message handling
122 *
123 * This overrides the output_message method to send JPEG messages
124 *
125 */
126
127 METHODDEF(void)
128 sun_jpeg_output_message (j_common_ptr cinfo)
129 {
130 char buffer[JMSG_LENGTH_MAX];
131
132 /* Create the message */
133 (*cinfo->err->format_message) (cinfo, buffer);
134
135 /* Send it to stderr, adding a newline */
136 fprintf(stderr, "%s\n", buffer);
137 }
138
139
140
141
142 /*
143 * INPUT HANDLING:
144 *
145 * The JPEG library's input management is defined by the jpeg_source_mgr
146 * structure which contains two fields to convey the information in the
147 * buffer and 5 methods which perform all buffer management. The library
148 * defines a standard input manager that uses stdio for obtaining compressed
149 * jpeg data, but here we need to use Java to get our data.
150 *
151 * We need to make the Java class information accessible to the source_mgr
152 * input routines. We also need to store a pointer to the start of the
153 * Java array being used as an input buffer so that it is not moved or
154 * garbage collected while the JPEG library is using it. To store these
155 * things, we make a private extension of the standard JPEG jpeg_source_mgr
156 * object.
157 *
158 * Here's the extended source manager struct:
159 */
160
161 struct sun_jpeg_source_mgr {
162 struct jpeg_source_mgr pub; /* "public" fields */
163
164 jobject hInputStream;
165 int suspendable;
166 unsigned long remaining_skip;
167
168 JOCTET *inbuf;
169 jbyteArray hInputBuffer;
170 size_t inbufoffset;
171
172 /* More stuff */
173 union pixptr {
174 int *ip;
175 unsigned char *bp;
176 } outbuf;
177 jobject hOutputBuffer;
178 };
179
180 typedef struct sun_jpeg_source_mgr * sun_jpeg_source_ptr;
181
182 /* We use Get/ReleasePrimitiveArrayCritical functions to avoid
183 * the need to copy buffer elements.
184 *
185 * MAKE SURE TO:
186 *
187 * - carefully insert pairs of RELEASE_ARRAYS and GET_ARRAYS around
188 * callbacks to Java.
189 * - call RELEASE_ARRAYS before returning to Java.
190 *
191 * Otherwise things will go horribly wrong. There may be memory leaks,
192 * excessive pinning, or even VM crashes!
193 *
194 * Note that GetPrimitiveArrayCritical may fail!
195 */
196 static void RELEASE_ARRAYS(JNIEnv *env, sun_jpeg_source_ptr src)
197 {
198 if (src->inbuf) {
199 if (src->pub.next_input_byte == 0) {
200 src->inbufoffset = -1;
201 } else {
202 src->inbufoffset = src->pub.next_input_byte - src->inbuf;
203 }
204 (*env)->ReleasePrimitiveArrayCritical(env, src->hInputBuffer,
205 src->inbuf, 0);
206 src->inbuf = 0;
207 }
208 if (src->outbuf.ip) {
209 (*env)->ReleasePrimitiveArrayCritical(env, src->hOutputBuffer,
210 src->outbuf.ip, 0);
211 src->outbuf.ip = 0;
212 }
213 }
214
215 static int GET_ARRAYS(JNIEnv *env, sun_jpeg_source_ptr src)
216 {
217 if (src->hInputBuffer) {
218 assert(src->inbuf == 0);
219 src->inbuf = (JOCTET *)(*env)->GetPrimitiveArrayCritical
220 (env, src->hInputBuffer, 0);
221 if (src->inbuf == 0) {
222 return 0;
223 }
224 if ((int)(src->inbufoffset) >= 0) {
225 src->pub.next_input_byte = src->inbuf + src->inbufoffset;
226 }
227 }
228 if (src->hOutputBuffer) {
229 assert(src->outbuf.ip == 0);
230 src->outbuf.ip = (int *)(*env)->GetPrimitiveArrayCritical
231 (env, src->hOutputBuffer, 0);
232 if (src->outbuf.ip == 0) {
233 RELEASE_ARRAYS(env, src);
234 return 0;
235 }
236 }
237 return 1;
238 }
239
240 /*
241 * Initialize source. This is called by jpeg_read_header() before any
242 * data is actually read. Unlike init_destination(), it may leave
243 * bytes_in_buffer set to 0 (in which case a fill_input_buffer() call
244 * will occur immediately).
245 */
246
247 GLOBAL(void)
248 sun_jpeg_init_source(j_decompress_ptr cinfo)
249 {
250 sun_jpeg_source_ptr src = (sun_jpeg_source_ptr) cinfo->src;
251 src->pub.next_input_byte = 0;
252 src->pub.bytes_in_buffer = 0;
253 }
254
255 /*
256 * This is called whenever bytes_in_buffer has reached zero and more
257 * data is wanted. In typical applications, it should read fresh data
258 * into the buffer (ignoring the current state of next_input_byte and
259 * bytes_in_buffer), reset the pointer & count to the start of the
260 * buffer, and return TRUE indicating that the buffer has been reloaded.
261 * It is not necessary to fill the buffer entirely, only to obtain at
262 * least one more byte. bytes_in_buffer MUST be set to a positive value
263 * if TRUE is returned. A FALSE return should only be used when I/O
264 * suspension is desired (this mode is discussed in the next section).
265 */
266 /*
267 * Note that with I/O suspension turned on, this procedure should not
268 * do any work since the JPEG library has a very simple backtracking
269 * mechanism which relies on the fact that the buffer will be filled
270 * only when it has backed out to the top application level. When
271 * suspendable is turned on, the sun_jpeg_fill_suspended_buffer will
272 * do the actual work of filling the buffer.
273 */
274
275 GLOBAL(boolean)
276 sun_jpeg_fill_input_buffer(j_decompress_ptr cinfo)
277 {
278 sun_jpeg_source_ptr src = (sun_jpeg_source_ptr) cinfo->src;
279 JNIEnv *env = (JNIEnv *)JNU_GetEnv(jvm, JNI_VERSION_1_2);
280 int ret, buflen;
281
282 if (src->suspendable) {
283 return FALSE;
284 }
285 if (src->remaining_skip) {
286 src->pub.skip_input_data(cinfo, 0);
287 }
288 RELEASE_ARRAYS(env, src);
289 buflen = (*env)->GetArrayLength(env, src->hInputBuffer);
290 ret = (*env)->CallIntMethod(env, src->hInputStream, InputStream_readID,
291 src->hInputBuffer, 0, buflen);
292 if ((*env)->ExceptionOccurred(env) || !GET_ARRAYS(env, src)) {
293 cinfo->err->error_exit((struct jpeg_common_struct *) cinfo);
294 }
295 if (ret <= 0) {
296 /* Silently accept truncated JPEG files */
297 WARNMS(cinfo, JWRN_JPEG_EOF);
298 src->inbuf[0] = (JOCTET) 0xFF;
299 src->inbuf[1] = (JOCTET) JPEG_EOI;
300 ret = 2;
301 }
302
303 src->pub.next_input_byte = src->inbuf;
304 src->pub.bytes_in_buffer = ret;
305
306 return TRUE;
307 }
308
309 /*
310 * Note that with I/O suspension turned on, the JPEG library requires
311 * that all buffer filling be done at the top application level. Due
312 * to the way that backtracking works, this procedure should save all
313 * of the data that was left in the buffer when suspension occured and
314 * only read new data at the end.
315 */
316
317 GLOBAL(void)
318 sun_jpeg_fill_suspended_buffer(j_decompress_ptr cinfo)
319 {
320 sun_jpeg_source_ptr src = (sun_jpeg_source_ptr) cinfo->src;
321 JNIEnv *env = (JNIEnv *)JNU_GetEnv(jvm, JNI_VERSION_1_2);
322 size_t offset, buflen;
323 int ret;
324
325 RELEASE_ARRAYS(env, src);
326 ret = (*env)->CallIntMethod(env, src->hInputStream,
327 InputStream_availableID);
328 if ((*env)->ExceptionOccurred(env) || !GET_ARRAYS(env, src)) {
329 cinfo->err->error_exit((struct jpeg_common_struct *) cinfo);
330 }
331 if (ret < 0 || (unsigned int)ret <= src->remaining_skip) {
332 return;
333 }
334 if (src->remaining_skip) {
335 src->pub.skip_input_data(cinfo, 0);
336 }
337 /* Save the data currently in the buffer */
338 offset = src->pub.bytes_in_buffer;
339 if (src->pub.next_input_byte > src->inbuf) {
340 memcpy(src->inbuf, src->pub.next_input_byte, offset);
341 }
342 RELEASE_ARRAYS(env, src);
343 buflen = (*env)->GetArrayLength(env, src->hInputBuffer) - offset;
344 if (buflen <= 0) {
345 if (!GET_ARRAYS(env, src)) {
346 cinfo->err->error_exit((struct jpeg_common_struct *) cinfo);
347 }
348 return;
349 }
350 ret = (*env)->CallIntMethod(env, src->hInputStream, InputStream_readID,
351 src->hInputBuffer, offset, buflen);
352 if ((*env)->ExceptionOccurred(env) || !GET_ARRAYS(env, src)) {
353 cinfo->err->error_exit((struct jpeg_common_struct *) cinfo);
354 }
355 if (ret <= 0) {
356 /* Silently accept truncated JPEG files */
357 WARNMS(cinfo, JWRN_JPEG_EOF);
358 src->inbuf[offset] = (JOCTET) 0xFF;
359 src->inbuf[offset + 1] = (JOCTET) JPEG_EOI;
360 ret = 2;
361 }
362
363 src->pub.next_input_byte = src->inbuf;
364 src->pub.bytes_in_buffer = ret + offset;
365
366 return;
367 }
368
369 /*
370 * Skip num_bytes worth of data. The buffer pointer and count should
371 * be advanced over num_bytes input bytes, refilling the buffer as
372 * needed. This is used to skip over a potentially large amount of
373 * uninteresting data (such as an APPn marker). In some applications
374 * it may be possible to optimize away the reading of the skipped data,
375 * but it's not clear that being smart is worth much trouble; large
376 * skips are uncommon. bytes_in_buffer may be zero on return.
377 * A zero or negative skip count should be treated as a no-op.
378 */
379 /*
380 * Note that with I/O suspension turned on, this procedure should not
381 * do any I/O since the JPEG library has a very simple backtracking
382 * mechanism which relies on the fact that the buffer will be filled
383 * only when it has backed out to the top application level.
384 */
385
386 GLOBAL(void)
387 sun_jpeg_skip_input_data(j_decompress_ptr cinfo, long num_bytes)
388 {
389 sun_jpeg_source_ptr src = (sun_jpeg_source_ptr) cinfo->src;
390 JNIEnv *env = (JNIEnv *)JNU_GetEnv(jvm, JNI_VERSION_1_2);
391 int ret;
392 int buflen;
393
394
395 if (num_bytes < 0) {
396 return;
397 }
398 num_bytes += src->remaining_skip;
399 src->remaining_skip = 0;
400 ret = (int)src->pub.bytes_in_buffer; /* this conversion is safe, because capacity of the buffer is limited by jnit */
401 if (ret >= num_bytes) {
402 src->pub.next_input_byte += num_bytes;
403 src->pub.bytes_in_buffer -= num_bytes;
404 return;
405 }
406 num_bytes -= ret;
407 if (src->suspendable) {
408 src->remaining_skip = num_bytes;
409 src->pub.bytes_in_buffer = 0;
410 src->pub.next_input_byte = src->inbuf;
411 return;
412 }
413
414 /* Note that the signature for the method indicates that it takes
415 * and returns a long. Casting the int num_bytes to a long on
416 * the input should work well enough, and if we assume that the
417 * return value for this particular method should always be less
418 * than the argument value (or -1), then the return value coerced
419 * to an int should return us the information we need...
420 */
421 RELEASE_ARRAYS(env, src);
422 buflen = (*env)->GetArrayLength(env, src->hInputBuffer);
423 while (num_bytes > 0) {
424 ret = (*env)->CallIntMethod(env, src->hInputStream,
425 InputStream_readID,
426 src->hInputBuffer, 0, buflen);
427 if ((*env)->ExceptionOccurred(env)) {
428 cinfo->err->error_exit((struct jpeg_common_struct *) cinfo);
429 }
430 if (ret < 0) {
431 break;
432 }
433 num_bytes -= ret;
434 }
435 if (!GET_ARRAYS(env, src)) {
436 cinfo->err->error_exit((struct jpeg_common_struct *) cinfo);
437 }
438 if (num_bytes > 0) {
439 /* Silently accept truncated JPEG files */
440 WARNMS(cinfo, JWRN_JPEG_EOF);
441 src->inbuf[0] = (JOCTET) 0xFF;
442 src->inbuf[1] = (JOCTET) JPEG_EOI;
443 src->pub.bytes_in_buffer = 2;
444 src->pub.next_input_byte = src->inbuf;
445 } else {
446 src->pub.bytes_in_buffer = -num_bytes;
447 src->pub.next_input_byte = src->inbuf + ret + num_bytes;
448 }
449 }
450
451 /*
452 * Terminate source --- called by jpeg_finish_decompress() after all
453 * data has been read. Often a no-op.
454 */
455
456 GLOBAL(void)
457 sun_jpeg_term_source(j_decompress_ptr cinfo)
458 {
459 }
460
461 JNIEXPORT void JNICALL
462 Java_sun_awt_image_JPEGImageDecoder_initIDs(JNIEnv *env, jclass cls,
463 jclass InputStreamClass)
464 {
465 sendHeaderInfoID = (*env)->GetMethodID(env, cls, "sendHeaderInfo",
466 "(IIZZZ)Z");
467 sendPixelsByteID = (*env)->GetMethodID(env, cls, "sendPixels", "([BI)Z");
468 sendPixelsIntID = (*env)->GetMethodID(env, cls, "sendPixels", "([II)Z");
469 InputStream_readID = (*env)->GetMethodID(env, InputStreamClass,
470 "read", "([BII)I");
471 InputStream_availableID = (*env)->GetMethodID(env, InputStreamClass,
472 "available", "()I");
473 }
474
475
476 /*
477 * The Windows Itanium Aug 2002 SDK generates bad code
478 * for this routine. Disable optimization for now.
479 */
480 #ifdef _M_IA64
481 #pragma optimize ("", off)
482 #endif
483
484 JNIEXPORT void JNICALL
485 Java_sun_awt_image_JPEGImageDecoder_readImage(JNIEnv *env,
486 jobject this,
487 jobject hInputStream,
488 jbyteArray hInputBuffer)
489 {
490 /* This struct contains the JPEG decompression parameters and pointers to
491 * working space (which is allocated as needed by the JPEG library).
492 */
493 struct jpeg_decompress_struct cinfo;
494 /* We use our private extension JPEG error handler.
495 * Note that this struct must live as long as the main JPEG parameter
496 * struct, to avoid dangling-pointer problems.
497 */
498 struct sun_jpeg_error_mgr jerr;
499 struct sun_jpeg_source_mgr jsrc;
500
501 int ret;
502 unsigned char *bp;
503 int *ip, pixel;
504 int grayscale;
505 int hasalpha;
506 int buffered_mode;
507 int final_pass;
508
509 /* Step 0: verify the inputs. */
510
511 if (hInputBuffer == 0 || hInputStream == 0) {
512 JNU_ThrowNullPointerException(env, 0);
513 return;
514 }
515
516 jsrc.outbuf.ip = 0;
517 jsrc.inbuf = 0;
518
519 /* Step 1: allocate and initialize JPEG decompression object */
520
521 /* We set up the normal JPEG error routines, then override error_exit. */
522 cinfo.err = jpeg_std_error(&jerr.pub);
523 jerr.pub.error_exit = sun_jpeg_error_exit;
524
525 /* We need to setup our own print routines */
526 jerr.pub.output_message = sun_jpeg_output_message;
527
528 /* Establish the setjmp return context for sun_jpeg_error_exit to use. */
529 if (setjmp(jerr.setjmp_buffer)) {
530 /* If we get here, the JPEG code has signaled an error.
531 * We need to clean up the JPEG object, close the input file, and return.
532 */
533 jpeg_destroy_decompress(&cinfo);
534 RELEASE_ARRAYS(env, &jsrc);
535 if (!(*env)->ExceptionOccurred(env)) {
536 char buffer[JMSG_LENGTH_MAX];
537 (*cinfo.err->format_message) ((struct jpeg_common_struct *) &cinfo,
538 buffer);
539 JNU_ThrowByName(env, "sun/awt/image/ImageFormatException", buffer);
540 }
541 return;
542 }
543 /* Now we can initialize the JPEG decompression object. */
544 jpeg_create_decompress(&cinfo);
545
546 /* Step 2: specify data source (eg, a file) */
547
548 cinfo.src = &jsrc.pub;
549 jsrc.hInputStream = hInputStream;
550 jsrc.hInputBuffer = hInputBuffer;
551 jsrc.hOutputBuffer = 0;
552 jsrc.suspendable = FALSE;
553 jsrc.remaining_skip = 0;
554 jsrc.inbufoffset = -1;
555 jsrc.pub.init_source = sun_jpeg_init_source;
556 jsrc.pub.fill_input_buffer = sun_jpeg_fill_input_buffer;
557 jsrc.pub.skip_input_data = sun_jpeg_skip_input_data;
558 jsrc.pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
559 jsrc.pub.term_source = sun_jpeg_term_source;
560 if (!GET_ARRAYS(env, &jsrc)) {
561 jpeg_destroy_decompress(&cinfo);
562 return;
563 }
564 /* Step 3: read file parameters with jpeg_read_header() */
565
566 (void) jpeg_read_header(&cinfo, TRUE);
567 /* select buffered-image mode if it is a progressive JPEG only */
568 buffered_mode = cinfo.buffered_image = jpeg_has_multiple_scans(&cinfo);
569 grayscale = (cinfo.out_color_space == JCS_GRAYSCALE);
570 #ifdef YCCALPHA
571 hasalpha = (cinfo.out_color_space == JCS_RGBA);
572 #else
573 hasalpha = 0;
574 #endif
575 /* We can ignore the return value from jpeg_read_header since
576 * (a) suspension is not possible with the stdio data source, and
577 * (nor with the Java input source)
578 * (b) we passed TRUE to reject a tables-only JPEG file as an error.
579 * See libjpeg.doc for more info.
580 */
581 RELEASE_ARRAYS(env, &jsrc);
582 ret = (*env)->CallBooleanMethod(env, this, sendHeaderInfoID,
583 cinfo.image_width, cinfo.image_height,
584 grayscale, hasalpha, buffered_mode);
585 if ((*env)->ExceptionOccurred(env) || !ret) {
586 /* No more interest in this image... */
587 jpeg_destroy_decompress(&cinfo);
588 return;
589 }
590 /* Make a one-row-high sample array with enough room to expand to ints */
591 if (grayscale) {
592 jsrc.hOutputBuffer = (*env)->NewByteArray(env, cinfo.image_width);
593 } else {
594 jsrc.hOutputBuffer = (*env)->NewIntArray(env, cinfo.image_width);
595 }
596
597 if (jsrc.hOutputBuffer == 0 || !GET_ARRAYS(env, &jsrc)) {
598 jpeg_destroy_decompress(&cinfo);
599 return;
600 }
601
602 /* Step 4: set parameters for decompression */
603
604 /* In this example, we don't need to change any of the defaults set by
605 * jpeg_read_header(), so we do nothing here.
606 */
607 /* For the first pass for Java, we want to deal with RGB for simplicity */
608 /* Unfortunately, the JPEG code does not automatically convert Grayscale */
609 /* to RGB, so we have to deal with Grayscale explicitly. */
610 if (!grayscale && !hasalpha) {
611 cinfo.out_color_space = JCS_RGB;
612 }
613
614 /* Step 5: Start decompressor */
615
616 jpeg_start_decompress(&cinfo);
617
618 /* We may need to do some setup of our own at this point before reading
619 * the data. After jpeg_start_decompress() we have the correct scaled
620 * output image dimensions available, as well as the output colormap
621 * if we asked for color quantization.
622 */
623
624 /* Step 6: while (scan lines remain to be read) */
625 /* jpeg_read_scanlines(...); */
626
627 /* Here we use the library's state variable cinfo.output_scanline as the
628 * loop counter, so that we don't have to keep track ourselves.
629 */
630 if (buffered_mode) {
631 final_pass = FALSE;
632 cinfo.dct_method = JDCT_IFAST;
633 } else {
634 final_pass = TRUE;
635 }
636 do {
637 if (buffered_mode) {
638 do {
639 sun_jpeg_fill_suspended_buffer(&cinfo);
640 jsrc.suspendable = TRUE;
641 ret = jpeg_consume_input(&cinfo);
642 jsrc.suspendable = FALSE;
643 } while (ret != JPEG_SUSPENDED && ret != JPEG_REACHED_EOI);
644 if (ret == JPEG_REACHED_EOI) {
645 final_pass = TRUE;
646 cinfo.dct_method = JDCT_ISLOW;
647 }
648 jpeg_start_output(&cinfo, cinfo.input_scan_number);
649 }
650 while (cinfo.output_scanline < cinfo.output_height) {
651 if (! final_pass) {
652 do {
653 sun_jpeg_fill_suspended_buffer(&cinfo);
654 jsrc.suspendable = TRUE;
655 ret = jpeg_consume_input(&cinfo);
656 jsrc.suspendable = FALSE;
657 } while (ret != JPEG_SUSPENDED && ret != JPEG_REACHED_EOI);
658 if (ret == JPEG_REACHED_EOI) {
659 break;
660 }
661 }
662 (void) jpeg_read_scanlines(&cinfo, (JSAMPARRAY) &(jsrc.outbuf), 1);
663
664 if (grayscale) {
665 RELEASE_ARRAYS(env, &jsrc);
666 ret = (*env)->CallBooleanMethod(env, this, sendPixelsByteID,
667 jsrc.hOutputBuffer,
668 cinfo.output_scanline - 1);
669 } else {
670 if (hasalpha) {
671 ip = jsrc.outbuf.ip + cinfo.image_width;
672 bp = jsrc.outbuf.bp + cinfo.image_width * 4;
673 while (ip > jsrc.outbuf.ip) {
674 pixel = (*--bp) << 24;
675 pixel |= (*--bp);
676 pixel |= (*--bp) << 8;
677 pixel |= (*--bp) << 16;
678 *--ip = pixel;
679 }
680 } else {
681 ip = jsrc.outbuf.ip + cinfo.image_width;
682 bp = jsrc.outbuf.bp + cinfo.image_width * 3;
683 while (ip > jsrc.outbuf.ip) {
684 pixel = (*--bp);
685 pixel |= (*--bp) << 8;
686 pixel |= (*--bp) << 16;
687 *--ip = pixel;
688 }
689 }
690 RELEASE_ARRAYS(env, &jsrc);
691 ret = (*env)->CallBooleanMethod(env, this, sendPixelsIntID,
692 jsrc.hOutputBuffer,
693 cinfo.output_scanline - 1);
694 }
695 if ((*env)->ExceptionOccurred(env) || !ret ||
696 !GET_ARRAYS(env, &jsrc)) {
697 /* No more interest in this image... */
698 jpeg_destroy_decompress(&cinfo);
699 return;
700 }
701 }
702 if (buffered_mode) {
703 jpeg_finish_output(&cinfo);
704 }
705 } while (! final_pass);
706
707 /* Step 7: Finish decompression */
708
709 (void) jpeg_finish_decompress(&cinfo);
710 /* We can ignore the return value since suspension is not possible
711 * with the stdio data source.
712 * (nor with the Java data source)
713 */
714
715 /* Step 8: Release JPEG decompression object */
716
717 /* This is an important step since it will release a good deal of memory. */
718 jpeg_destroy_decompress(&cinfo);
719
720 /* After finish_decompress, we can close the input file.
721 * Here we postpone it until after no more JPEG errors are possible,
722 * so as to simplify the setjmp error logic above. (Actually, I don't
723 * think that jpeg_destroy can do an error exit, but why assume anything...)
724 */
725 /* Not needed for Java - the Java code will close the file */
726 /* fclose(infile); */
727
728 /* At this point you may want to check to see whether any corrupt-data
729 * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
730 */
731
732 /* And we're done! */
733
734 RELEASE_ARRAYS(env, &jsrc);
735 return;
736 }
737 #ifdef _M_IA64
738 #pragma optimize ("", on)
739 #endif
740
741
742 /*
743 * SOME FINE POINTS:
744 *
745 * In the above code, we ignored the return value of jpeg_read_scanlines,
746 * which is the number of scanlines actually read. We could get away with
747 * this because we asked for only one line at a time and we weren't using
748 * a suspending data source. See libjpeg.doc for more info.
749 *
750 * We cheated a bit by calling alloc_sarray() after jpeg_start_decompress();
751 * we should have done it beforehand to ensure that the space would be
752 * counted against the JPEG max_memory setting. In some systems the above
753 * code would risk an out-of-memory error. However, in general we don't
754 * know the output image dimensions before jpeg_start_decompress(), unless we
755 * call jpeg_calc_output_dimensions(). See libjpeg.doc for more about this.
756 *
757 * Scanlines are returned in the same order as they appear in the JPEG file,
758 * which is standardly top-to-bottom. If you must emit data bottom-to-top,
759 * you can use one of the virtual arrays provided by the JPEG memory manager
760 * to invert the data. See wrbmp.c for an example.
761 *
762 * As with compression, some operating modes may require temporary files.
763 * On some systems you may need to set up a signal handler to ensure that
764 * temporary files are deleted if the program is interrupted. See libjpeg.doc.
765 */