xref: /reactos/dll/3rdparty/libjpeg/transupp.c (revision 1d574191)
1 /*
2  * transupp.c
3  *
4  * Copyright (C) 1997-2019, Thomas G. Lane, Guido Vollbeding.
5  * This file is part of the Independent JPEG Group's software.
6  * For conditions of distribution and use, see the accompanying README file.
7  *
8  * This file contains image transformation routines and other utility code
9  * used by the jpegtran sample application.  These are NOT part of the core
10  * JPEG library.  But we keep these routines separate from jpegtran.c to
11  * ease the task of maintaining jpegtran-like programs that have other user
12  * interfaces.
13  */
14 
15 /* Although this file really shouldn't have access to the library internals,
16  * it's helpful to let it call jround_up() and jcopy_block_row().
17  * Also, the (switchable) virtual memory adaptation code for
18  * the drop feature has dependencies on library internals.
19  */
20 #define JPEG_INTERNALS
21 
22 #include "jinclude.h"
23 #include "jpeglib.h"
24 #include "transupp.h"		/* My own external interface */
25 #include <ctype.h>		/* to declare isdigit() */
26 
27 
28 #if TRANSFORMS_SUPPORTED
29 
30 /*
31  * Lossless image transformation routines.  These routines work on DCT
32  * coefficient arrays and thus do not require any lossy decompression
33  * or recompression of the image.
34  * Thanks to Guido Vollbeding for the initial design and code of this feature,
35  * and to Ben Jackson for introducing the cropping feature.
36  *
37  * Horizontal flipping is done in-place, using a single top-to-bottom
38  * pass through the virtual source array.  It will thus be much the
39  * fastest option for images larger than main memory.
40  *
41  * The other routines require a set of destination virtual arrays, so they
42  * need twice as much memory as jpegtran normally does.  The destination
43  * arrays are always written in normal scan order (top to bottom) because
44  * the virtual array manager expects this.  The source arrays will be scanned
45  * in the corresponding order, which means multiple passes through the source
46  * arrays for most of the transforms.  That could result in much thrashing
47  * if the image is larger than main memory.
48  *
49  * If cropping or trimming is involved, the destination arrays may be smaller
50  * than the source arrays.  Note it is not possible to do horizontal flip
51  * in-place when a nonzero Y crop offset is specified, since we'd have to move
52  * data from one block row to another but the virtual array manager doesn't
53  * guarantee we can touch more than one row at a time.  So in that case,
54  * we have to use a separate destination array.
55  *
56  * Some notes about the operating environment of the individual transform
57  * routines:
58  * 1. Both the source and destination virtual arrays are allocated from the
59  *    source JPEG object, and therefore should be manipulated by calling the
60  *    source's memory manager.
61  * 2. The destination's component count should be used.  It may be smaller
62  *    than the source's when forcing to grayscale.
63  * 3. Likewise the destination's sampling factors should be used.  When
64  *    forcing to grayscale the destination's sampling factors will be all 1,
65  *    and we may as well take that as the effective iMCU size.
66  * 4. When "trim" is in effect, the destination's dimensions will be the
67  *    trimmed values but the source's will be untrimmed.
68  * 5. When "crop" is in effect, the destination's dimensions will be the
69  *    cropped values but the source's will be uncropped.  Each transform
70  *    routine is responsible for picking up source data starting at the
71  *    correct X and Y offset for the crop region.  (The X and Y offsets
72  *    passed to the transform routines are measured in iMCU blocks of the
73  *    destination.)
74  * 6. All the routines assume that the source and destination buffers are
75  *    padded out to a full iMCU boundary.  This is true, although for the
76  *    source buffer it is an undocumented property of jdcoefct.c.
77  */
78 
79 
80 /* Drop code may be used with or without virtual memory adaptation code.
81  * This code has some dependencies on internal library behavior, so you
82  * may choose to disable it.  For example, it doesn't make a difference
83  * if you only use jmemnobs anyway.
84  */
85 #ifndef DROP_REQUEST_FROM_SRC
86 #define DROP_REQUEST_FROM_SRC 1		/* 0 disables adaptation */
87 #endif
88 
89 
90 #if DROP_REQUEST_FROM_SRC
91 /* Force jpeg_read_coefficients to request
92  * the virtual coefficient arrays from
93  * the source decompression object.
94  */
95 METHODDEF(jvirt_barray_ptr)
drop_request_virt_barray(j_common_ptr cinfo,int pool_id,boolean pre_zero,JDIMENSION blocksperrow,JDIMENSION numrows,JDIMENSION maxaccess)96 drop_request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero,
97 			  JDIMENSION blocksperrow, JDIMENSION numrows,
98 			  JDIMENSION maxaccess)
99 {
100   j_common_ptr srcinfo = (j_common_ptr) cinfo->client_data;
101 
102   return (*srcinfo->mem->request_virt_barray)
103 	  (srcinfo, pool_id, pre_zero,
104 	   blocksperrow, numrows, maxaccess);
105 }
106 
107 
108 /* Force jpeg_read_coefficients to return
109  * after requesting and before accessing
110  * the virtual coefficient arrays.
111  */
112 METHODDEF(int)
drop_consume_input(j_decompress_ptr cinfo)113 drop_consume_input (j_decompress_ptr cinfo)
114 {
115   return JPEG_SUSPENDED;
116 }
117 
118 
119 METHODDEF(void)
drop_start_input_pass(j_decompress_ptr cinfo)120 drop_start_input_pass (j_decompress_ptr cinfo)
121 {
122   cinfo->inputctl->consume_input = drop_consume_input;
123 }
124 
125 
126 LOCAL(void)
drop_request_from_src(j_decompress_ptr dropinfo,j_decompress_ptr srcinfo)127 drop_request_from_src (j_decompress_ptr dropinfo, j_decompress_ptr srcinfo)
128 {
129   void *save_client_data;
130   JMETHOD(jvirt_barray_ptr, save_request_virt_barray,
131 	  (j_common_ptr cinfo, int pool_id, boolean pre_zero,
132 	   JDIMENSION blocksperrow, JDIMENSION numrows, JDIMENSION maxaccess));
133   JMETHOD(void, save_start_input_pass, (j_decompress_ptr cinfo));
134 
135   /* Set custom method pointers, save original pointers */
136   save_client_data = dropinfo->client_data;
137   dropinfo->client_data = (void *) srcinfo;
138   save_request_virt_barray = dropinfo->mem->request_virt_barray;
139   dropinfo->mem->request_virt_barray = drop_request_virt_barray;
140   save_start_input_pass = dropinfo->inputctl->start_input_pass;
141   dropinfo->inputctl->start_input_pass = drop_start_input_pass;
142 
143   /* Execute only initialization part.
144    * Requested coefficient arrays will be realized later by the srcinfo object.
145    * Next call to the same function will then do the actual data reading.
146    * NB: since we request the coefficient arrays from another object,
147    * the inherent realization call is effectively a no-op.
148    */
149   (void) jpeg_read_coefficients(dropinfo);
150 
151   /* Reset method pointers */
152   dropinfo->client_data = save_client_data;
153   dropinfo->mem->request_virt_barray = save_request_virt_barray;
154   dropinfo->inputctl->start_input_pass = save_start_input_pass;
155   /* Do input initialization for first scan now,
156    * which also resets the consume_input method.
157    */
158   (*save_start_input_pass)(dropinfo);
159 }
160 #endif /* DROP_REQUEST_FROM_SRC */
161 
162 
163 LOCAL(void)
dequant_comp(j_decompress_ptr cinfo,jpeg_component_info * compptr,jvirt_barray_ptr coef_array,JQUANT_TBL * qtblptr1)164 dequant_comp (j_decompress_ptr cinfo, jpeg_component_info *compptr,
165 	      jvirt_barray_ptr coef_array, JQUANT_TBL *qtblptr1)
166 {
167   JDIMENSION blk_x, blk_y;
168   int offset_y, k;
169   JQUANT_TBL *qtblptr;
170   JBLOCKARRAY buffer;
171   JBLOCKROW block;
172   JCOEFPTR ptr;
173 
174   qtblptr = compptr->quant_table;
175   for (blk_y = 0; blk_y < compptr->height_in_blocks;
176        blk_y += compptr->v_samp_factor) {
177     buffer = (*cinfo->mem->access_virt_barray)
178       ((j_common_ptr) cinfo, coef_array, blk_y,
179        (JDIMENSION) compptr->v_samp_factor, TRUE);
180     for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
181       block = buffer[offset_y];
182       for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {
183 	ptr = block[blk_x];
184 	for (k = 0; k < DCTSIZE2; k++)
185 	  if (qtblptr->quantval[k] != qtblptr1->quantval[k])
186 	    ptr[k] *= qtblptr->quantval[k] / qtblptr1->quantval[k];
187       }
188     }
189   }
190 }
191 
192 
193 LOCAL(void)
requant_comp(j_decompress_ptr cinfo,jpeg_component_info * compptr,jvirt_barray_ptr coef_array,JQUANT_TBL * qtblptr1)194 requant_comp (j_decompress_ptr cinfo, jpeg_component_info *compptr,
195 	      jvirt_barray_ptr coef_array, JQUANT_TBL *qtblptr1)
196 {
197   JDIMENSION blk_x, blk_y;
198   int offset_y, k;
199   JQUANT_TBL *qtblptr;
200   JBLOCKARRAY buffer;
201   JBLOCKROW block;
202   JCOEFPTR ptr;
203   JCOEF temp, qval;
204 
205   qtblptr = compptr->quant_table;
206   for (blk_y = 0; blk_y < compptr->height_in_blocks;
207        blk_y += compptr->v_samp_factor) {
208     buffer = (*cinfo->mem->access_virt_barray)
209       ((j_common_ptr) cinfo, coef_array, blk_y,
210        (JDIMENSION) compptr->v_samp_factor, TRUE);
211     for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
212       block = buffer[offset_y];
213       for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {
214 	ptr = block[blk_x];
215 	for (k = 0; k < DCTSIZE2; k++) {
216 	  temp = qtblptr->quantval[k];
217 	  qval = qtblptr1->quantval[k];
218 	  if (temp != qval) {
219 	    temp *= ptr[k];
220 	    /* The following quantization code is a copy from jcdctmgr.c */
221 #ifdef FAST_DIVIDE
222 #define DIVIDE_BY(a,b)	a /= b
223 #else
224 #define DIVIDE_BY(a,b)	if (a >= b) a /= b; else a = 0
225 #endif
226 	    if (temp < 0) {
227 	      temp = -temp;
228 	      temp += qval>>1;	/* for rounding */
229 	      DIVIDE_BY(temp, qval);
230 	      temp = -temp;
231 	    } else {
232 	      temp += qval>>1;	/* for rounding */
233 	      DIVIDE_BY(temp, qval);
234 	    }
235 	    ptr[k] = temp;
236 	  }
237 	}
238       }
239     }
240   }
241 }
242 
243 
244 /* Calculate largest common denominator with Euclid's algorithm.
245  */
246 LOCAL(JCOEF)
largest_common_denominator(JCOEF a,JCOEF b)247 largest_common_denominator(JCOEF a, JCOEF b)
248 {
249   JCOEF c;
250 
251   do {
252     c = a % b;
253     a = b;
254     b = c;
255   } while (c);
256 
257   return a;
258 }
259 
260 
261 LOCAL(void)
adjust_quant(j_decompress_ptr srcinfo,jvirt_barray_ptr * src_coef_arrays,j_decompress_ptr dropinfo,jvirt_barray_ptr * drop_coef_arrays,boolean trim,j_compress_ptr dstinfo)262 adjust_quant(j_decompress_ptr srcinfo, jvirt_barray_ptr *src_coef_arrays,
263 	     j_decompress_ptr dropinfo, jvirt_barray_ptr *drop_coef_arrays,
264 	     boolean trim, j_compress_ptr dstinfo)
265 {
266   jpeg_component_info *compptr1, *compptr2;
267   JQUANT_TBL *qtblptr1, *qtblptr2, *qtblptr3;
268   int ci, k;
269 
270   for (ci = 0; ci < dstinfo->num_components &&
271 	       ci < dropinfo->num_components; ci++) {
272     compptr1 = srcinfo->comp_info + ci;
273     compptr2 = dropinfo->comp_info + ci;
274     qtblptr1 = compptr1->quant_table;
275     qtblptr2 = compptr2->quant_table;
276     for (k = 0; k < DCTSIZE2; k++) {
277       if (qtblptr1->quantval[k] != qtblptr2->quantval[k]) {
278 	if (trim)
279 	  requant_comp(dropinfo, compptr2, drop_coef_arrays[ci], qtblptr1);
280 	else {
281 	  qtblptr3 = dstinfo->quant_tbl_ptrs[compptr1->quant_tbl_no];
282 	  for (k = 0; k < DCTSIZE2; k++)
283 	    if (qtblptr1->quantval[k] != qtblptr2->quantval[k])
284 	      qtblptr3->quantval[k] = largest_common_denominator
285 		(qtblptr1->quantval[k], qtblptr2->quantval[k]);
286 	  dequant_comp(srcinfo, compptr1, src_coef_arrays[ci], qtblptr3);
287 	  dequant_comp(dropinfo, compptr2, drop_coef_arrays[ci], qtblptr3);
288 	}
289 	break;
290       }
291     }
292   }
293 }
294 
295 
296 LOCAL(void)
do_drop(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,j_decompress_ptr dropinfo,jvirt_barray_ptr * drop_coef_arrays,JDIMENSION drop_width,JDIMENSION drop_height)297 do_drop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
298 	 JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
299 	 jvirt_barray_ptr *src_coef_arrays,
300 	 j_decompress_ptr dropinfo, jvirt_barray_ptr *drop_coef_arrays,
301 	 JDIMENSION drop_width, JDIMENSION drop_height)
302 /* Drop.  If the dropinfo component number is smaller than the destination's,
303  * we fill in the remaining components with zero.  This provides the feature
304  * of dropping grayscale into (arbitrarily sampled) color images.
305  */
306 {
307   JDIMENSION comp_width, comp_height;
308   JDIMENSION blk_y, x_drop_blocks, y_drop_blocks;
309   int ci, offset_y;
310   JBLOCKARRAY src_buffer, dst_buffer;
311   jpeg_component_info *compptr;
312 
313   for (ci = 0; ci < dstinfo->num_components; ci++) {
314     compptr = dstinfo->comp_info + ci;
315     comp_width = drop_width * compptr->h_samp_factor;
316     comp_height = drop_height * compptr->v_samp_factor;
317     x_drop_blocks = x_crop_offset * compptr->h_samp_factor;
318     y_drop_blocks = y_crop_offset * compptr->v_samp_factor;
319     for (blk_y = 0; blk_y < comp_height; blk_y += compptr->v_samp_factor) {
320       dst_buffer = (*srcinfo->mem->access_virt_barray)
321 	((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y + y_drop_blocks,
322 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
323       if (ci < dropinfo->num_components) {
324 #if DROP_REQUEST_FROM_SRC
325 	src_buffer = (*srcinfo->mem->access_virt_barray)
326 	  ((j_common_ptr) srcinfo, drop_coef_arrays[ci], blk_y,
327 #else
328 	src_buffer = (*dropinfo->mem->access_virt_barray)
329 	  ((j_common_ptr) dropinfo, drop_coef_arrays[ci], blk_y,
330 #endif
331 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
332 	for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
333 	  jcopy_block_row(src_buffer[offset_y],
334 			  dst_buffer[offset_y] + x_drop_blocks,
335 			  comp_width);
336 	}
337       } else {
338 	for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
339 	  FMEMZERO(dst_buffer[offset_y] + x_drop_blocks,
340 		   comp_width * SIZEOF(JBLOCK));
341 	}
342       }
343     }
344   }
345 }
346 
347 
348 LOCAL(void)
do_crop(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)349 do_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
350 	 JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
351 	 jvirt_barray_ptr *src_coef_arrays,
352 	 jvirt_barray_ptr *dst_coef_arrays)
353 /* Crop.  This is only used when no rotate/flip is requested with the crop. */
354 {
355   JDIMENSION dst_blk_y, x_crop_blocks, y_crop_blocks;
356   int ci, offset_y;
357   JBLOCKARRAY src_buffer, dst_buffer;
358   jpeg_component_info *compptr;
359 
360   /* We simply have to copy the right amount of data (the destination's
361    * image size) starting at the given X and Y offsets in the source.
362    */
363   for (ci = 0; ci < dstinfo->num_components; ci++) {
364     compptr = dstinfo->comp_info + ci;
365     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
366     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
367     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
368 	 dst_blk_y += compptr->v_samp_factor) {
369       dst_buffer = (*srcinfo->mem->access_virt_barray)
370 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
371 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
372       src_buffer = (*srcinfo->mem->access_virt_barray)
373 	((j_common_ptr) srcinfo, src_coef_arrays[ci],
374 	 dst_blk_y + y_crop_blocks,
375 	 (JDIMENSION) compptr->v_samp_factor, FALSE);
376       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
377 	jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
378 			dst_buffer[offset_y],
379 			compptr->width_in_blocks);
380       }
381     }
382   }
383 }
384 
385 
386 LOCAL(void)
do_crop_ext_zero(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)387 do_crop_ext_zero (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
388 		  JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
389 		  jvirt_barray_ptr *src_coef_arrays,
390 		  jvirt_barray_ptr *dst_coef_arrays)
391 /* Crop.  This is only used when no rotate/flip is requested with the crop.
392  * Extension: If the destination size is larger than the source, we fill in
393  * the extra area with zero (neutral gray).  Note we also have to zero partial
394  * iMCUs at the right and bottom edge of the source image area in this case.
395  */
396 {
397   JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height;
398   JDIMENSION dst_blk_y, x_crop_blocks, y_crop_blocks;
399   int ci, offset_y;
400   JBLOCKARRAY src_buffer, dst_buffer;
401   jpeg_component_info *compptr;
402 
403   MCU_cols = srcinfo->output_width /
404     (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
405   MCU_rows = srcinfo->output_height /
406     (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
407 
408   for (ci = 0; ci < dstinfo->num_components; ci++) {
409     compptr = dstinfo->comp_info + ci;
410     comp_width = MCU_cols * compptr->h_samp_factor;
411     comp_height = MCU_rows * compptr->v_samp_factor;
412     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
413     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
414     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
415 	 dst_blk_y += compptr->v_samp_factor) {
416       dst_buffer = (*srcinfo->mem->access_virt_barray)
417 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
418 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
419       if (dstinfo->jpeg_height > srcinfo->output_height) {
420 	if (dst_blk_y < y_crop_blocks ||
421 	    dst_blk_y >= y_crop_blocks + comp_height) {
422 	  for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
423 	    FMEMZERO(dst_buffer[offset_y],
424 		     compptr->width_in_blocks * SIZEOF(JBLOCK));
425 	  }
426 	  continue;
427 	}
428 	src_buffer = (*srcinfo->mem->access_virt_barray)
429 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
430 	   dst_blk_y - y_crop_blocks,
431 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
432       } else {
433 	src_buffer = (*srcinfo->mem->access_virt_barray)
434 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
435 	   dst_blk_y + y_crop_blocks,
436 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
437       }
438       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
439 	if (dstinfo->jpeg_width > srcinfo->output_width) {
440 	  if (x_crop_blocks > 0) {
441 	    FMEMZERO(dst_buffer[offset_y],
442 		     x_crop_blocks * SIZEOF(JBLOCK));
443 	  }
444 	  jcopy_block_row(src_buffer[offset_y],
445 			  dst_buffer[offset_y] + x_crop_blocks,
446 			  comp_width);
447 	  if (compptr->width_in_blocks > x_crop_blocks + comp_width) {
448 	    FMEMZERO(dst_buffer[offset_y] +
449 		       x_crop_blocks + comp_width,
450 		     (compptr->width_in_blocks -
451 		       x_crop_blocks - comp_width) * SIZEOF(JBLOCK));
452 	  }
453 	} else {
454 	  jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
455 			  dst_buffer[offset_y],
456 			  compptr->width_in_blocks);
457 	}
458       }
459     }
460   }
461 }
462 
463 
464 LOCAL(void)
do_crop_ext_flat(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)465 do_crop_ext_flat (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
466 		  JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
467 		  jvirt_barray_ptr *src_coef_arrays,
468 		  jvirt_barray_ptr *dst_coef_arrays)
469 /* Crop.  This is only used when no rotate/flip is requested with the crop.
470  * Extension: The destination width is larger than the source and we fill in
471  * the extra area with the DC of the adjacent block.  Note we also have to
472  * fill partial iMCUs at the right and bottom edge of the source image area
473  * in this case.
474  */
475 {
476   JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height;
477   JDIMENSION dst_blk_x, dst_blk_y, x_crop_blocks, y_crop_blocks;
478   int ci, offset_y;
479   JCOEF dc;
480   JBLOCKARRAY src_buffer, dst_buffer;
481   jpeg_component_info *compptr;
482 
483   MCU_cols = srcinfo->output_width /
484     (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
485   MCU_rows = srcinfo->output_height /
486     (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
487 
488   for (ci = 0; ci < dstinfo->num_components; ci++) {
489     compptr = dstinfo->comp_info + ci;
490     comp_width = MCU_cols * compptr->h_samp_factor;
491     comp_height = MCU_rows * compptr->v_samp_factor;
492     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
493     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
494     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
495 	 dst_blk_y += compptr->v_samp_factor) {
496       dst_buffer = (*srcinfo->mem->access_virt_barray)
497 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
498 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
499       if (dstinfo->jpeg_height > srcinfo->output_height) {
500 	if (dst_blk_y < y_crop_blocks ||
501 	    dst_blk_y >= y_crop_blocks + comp_height) {
502 	  for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
503 	    FMEMZERO(dst_buffer[offset_y],
504 		     compptr->width_in_blocks * SIZEOF(JBLOCK));
505 	  }
506 	  continue;
507 	}
508 	src_buffer = (*srcinfo->mem->access_virt_barray)
509 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
510 	   dst_blk_y - y_crop_blocks,
511 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
512       } else {
513 	src_buffer = (*srcinfo->mem->access_virt_barray)
514 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
515 	   dst_blk_y + y_crop_blocks,
516 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
517       }
518       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
519 	if (x_crop_blocks > 0) {
520 	  FMEMZERO(dst_buffer[offset_y],
521 		   x_crop_blocks * SIZEOF(JBLOCK));
522 	  dc = src_buffer[offset_y][0][0];
523 	  for (dst_blk_x = 0; dst_blk_x < x_crop_blocks; dst_blk_x++) {
524 	    dst_buffer[offset_y][dst_blk_x][0] = dc;
525 	  }
526 	}
527 	jcopy_block_row(src_buffer[offset_y],
528 			dst_buffer[offset_y] + x_crop_blocks,
529 			comp_width);
530 	if (compptr->width_in_blocks > x_crop_blocks + comp_width) {
531 	  FMEMZERO(dst_buffer[offset_y] +
532 		     x_crop_blocks + comp_width,
533 		   (compptr->width_in_blocks -
534 		     x_crop_blocks - comp_width) * SIZEOF(JBLOCK));
535 	  dc = src_buffer[offset_y][comp_width - 1][0];
536 	  for (dst_blk_x = x_crop_blocks + comp_width;
537 	       dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
538 	    dst_buffer[offset_y][dst_blk_x][0] = dc;
539 	  }
540 	}
541       }
542     }
543   }
544 }
545 
546 
547 LOCAL(void)
do_crop_ext_reflect(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)548 do_crop_ext_reflect (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
549 		     JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
550 		     jvirt_barray_ptr *src_coef_arrays,
551 		     jvirt_barray_ptr *dst_coef_arrays)
552 /* Crop.  This is only used when no rotate/flip is requested with the crop.
553  * Extension: The destination width is larger than the source and we fill in
554  * the extra area with repeated reflections of the source region.  Note we
555  * also have to fill partial iMCUs at the right and bottom edge of the source
556  * image area in this case.
557  */
558 {
559   JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, src_blk_x;
560   JDIMENSION dst_blk_x, dst_blk_y, x_crop_blocks, y_crop_blocks;
561   int ci, k, offset_y;
562   JBLOCKARRAY src_buffer, dst_buffer;
563   JBLOCKROW src_row_ptr, dst_row_ptr;
564   JCOEFPTR src_ptr, dst_ptr;
565   jpeg_component_info *compptr;
566 
567   MCU_cols = srcinfo->output_width /
568     (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
569   MCU_rows = srcinfo->output_height /
570     (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
571 
572   for (ci = 0; ci < dstinfo->num_components; ci++) {
573     compptr = dstinfo->comp_info + ci;
574     comp_width = MCU_cols * compptr->h_samp_factor;
575     comp_height = MCU_rows * compptr->v_samp_factor;
576     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
577     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
578     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
579 	 dst_blk_y += compptr->v_samp_factor) {
580       dst_buffer = (*srcinfo->mem->access_virt_barray)
581 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
582 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
583       if (dstinfo->jpeg_height > srcinfo->output_height) {
584 	if (dst_blk_y < y_crop_blocks ||
585 	    dst_blk_y >= y_crop_blocks + comp_height) {
586 	  for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
587 	    FMEMZERO(dst_buffer[offset_y],
588 		     compptr->width_in_blocks * SIZEOF(JBLOCK));
589 	  }
590 	  continue;
591 	}
592 	src_buffer = (*srcinfo->mem->access_virt_barray)
593 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
594 	   dst_blk_y - y_crop_blocks,
595 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
596       } else {
597 	src_buffer = (*srcinfo->mem->access_virt_barray)
598 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
599 	   dst_blk_y + y_crop_blocks,
600 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
601       }
602       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
603 	/* Copy source region */
604 	jcopy_block_row(src_buffer[offset_y],
605 			dst_buffer[offset_y] + x_crop_blocks,
606 			comp_width);
607 	if (x_crop_blocks > 0) {
608 	  /* Reflect to left */
609 	  dst_row_ptr = dst_buffer[offset_y] + x_crop_blocks;
610 	  for (dst_blk_x = x_crop_blocks; dst_blk_x > 0;) {
611 	    src_row_ptr = dst_row_ptr;	   /* (re)set axis of reflection */
612 	    for (src_blk_x = comp_width; src_blk_x > 0 && dst_blk_x > 0;
613 		 src_blk_x--, dst_blk_x--) {
614 	      dst_ptr = *--dst_row_ptr;	   /* destination goes left */
615 	      src_ptr = *src_row_ptr++;	   /* source goes right */
616 	      /* this unrolled loop doesn't need to know which row it's on... */
617 	      for (k = 0; k < DCTSIZE2; k += 2) {
618 		*dst_ptr++ = *src_ptr++;   /* copy even column */
619 		*dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */
620 	      }
621 	    }
622 	  }
623 	}
624 	if (compptr->width_in_blocks > x_crop_blocks + comp_width) {
625 	  /* Reflect to right */
626 	  dst_row_ptr = dst_buffer[offset_y] + x_crop_blocks + comp_width;
627 	  for (dst_blk_x = compptr->width_in_blocks - x_crop_blocks - comp_width;
628 	       dst_blk_x > 0;) {
629 	    src_row_ptr = dst_row_ptr;	   /* (re)set axis of reflection */
630 	    for (src_blk_x = comp_width; src_blk_x > 0 && dst_blk_x > 0;
631 		 src_blk_x--, dst_blk_x--) {
632 	      dst_ptr = *dst_row_ptr++;	   /* destination goes right */
633 	      src_ptr = *--src_row_ptr;	   /* source goes left */
634 	      /* this unrolled loop doesn't need to know which row it's on... */
635 	      for (k = 0; k < DCTSIZE2; k += 2) {
636 		*dst_ptr++ = *src_ptr++;   /* copy even column */
637 		*dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */
638 	      }
639 	    }
640 	  }
641 	}
642       }
643     }
644   }
645 }
646 
647 
648 LOCAL(void)
do_wipe(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,JDIMENSION drop_width,JDIMENSION drop_height)649 do_wipe (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
650 	 JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
651 	 jvirt_barray_ptr *src_coef_arrays,
652 	 JDIMENSION drop_width, JDIMENSION drop_height)
653 /* Wipe - drop content of specified area, fill with zero (neutral gray) */
654 {
655   JDIMENSION x_wipe_blocks, wipe_width;
656   JDIMENSION y_wipe_blocks, wipe_bottom;
657   int ci, offset_y;
658   JBLOCKARRAY buffer;
659   jpeg_component_info *compptr;
660 
661   for (ci = 0; ci < dstinfo->num_components; ci++) {
662     compptr = dstinfo->comp_info + ci;
663     x_wipe_blocks = x_crop_offset * compptr->h_samp_factor;
664     wipe_width = drop_width * compptr->h_samp_factor;
665     y_wipe_blocks = y_crop_offset * compptr->v_samp_factor;
666     wipe_bottom = drop_height * compptr->v_samp_factor + y_wipe_blocks;
667     for (; y_wipe_blocks < wipe_bottom;
668 	 y_wipe_blocks += compptr->v_samp_factor) {
669       buffer = (*srcinfo->mem->access_virt_barray)
670 	((j_common_ptr) srcinfo, src_coef_arrays[ci], y_wipe_blocks,
671 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
672       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
673 	FMEMZERO(buffer[offset_y] + x_wipe_blocks,
674 		 wipe_width * SIZEOF(JBLOCK));
675       }
676     }
677   }
678 }
679 
680 
681 LOCAL(void)
do_flatten(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,JDIMENSION drop_width,JDIMENSION drop_height)682 do_flatten (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
683 	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
684 	    jvirt_barray_ptr *src_coef_arrays,
685 	    JDIMENSION drop_width, JDIMENSION drop_height)
686 /* Flatten - drop content of specified area, similar to wipe,
687  * but fill with average of adjacent blocks, instead of zero.
688  */
689 {
690   JDIMENSION x_wipe_blocks, wipe_width, wipe_right;
691   JDIMENSION y_wipe_blocks, wipe_bottom, blk_x;
692   int ci, offset_y, dc_left_value, dc_right_value, average;
693   JBLOCKARRAY buffer;
694   jpeg_component_info *compptr;
695 
696   for (ci = 0; ci < dstinfo->num_components; ci++) {
697     compptr = dstinfo->comp_info + ci;
698     x_wipe_blocks = x_crop_offset * compptr->h_samp_factor;
699     wipe_width = drop_width * compptr->h_samp_factor;
700     wipe_right = wipe_width + x_wipe_blocks;
701     y_wipe_blocks = y_crop_offset * compptr->v_samp_factor;
702     wipe_bottom = drop_height * compptr->v_samp_factor + y_wipe_blocks;
703     for (; y_wipe_blocks < wipe_bottom;
704 	 y_wipe_blocks += compptr->v_samp_factor) {
705       buffer = (*srcinfo->mem->access_virt_barray)
706 	((j_common_ptr) srcinfo, src_coef_arrays[ci], y_wipe_blocks,
707 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
708       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
709 	FMEMZERO(buffer[offset_y] + x_wipe_blocks,
710 		 wipe_width * SIZEOF(JBLOCK));
711 	if (x_wipe_blocks > 0) {
712 	  dc_left_value = buffer[offset_y][x_wipe_blocks - 1][0];
713 	  if (wipe_right < compptr->width_in_blocks) {
714 	    dc_right_value = buffer[offset_y][wipe_right][0];
715 	    average = (dc_left_value + dc_right_value) >> 1;
716 	  } else {
717 	    average = dc_left_value;
718 	  }
719 	} else if (wipe_right < compptr->width_in_blocks) {
720 	  average = buffer[offset_y][wipe_right][0];
721 	} else continue;
722 	for (blk_x = x_wipe_blocks; blk_x < wipe_right; blk_x++) {
723 	  buffer[offset_y][blk_x][0] = (JCOEF) average;
724 	}
725       }
726     }
727   }
728 }
729 
730 
731 LOCAL(void)
do_reflect(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,jvirt_barray_ptr * src_coef_arrays,JDIMENSION drop_width,JDIMENSION drop_height)732 do_reflect (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
733 	    JDIMENSION x_crop_offset,
734 	    jvirt_barray_ptr *src_coef_arrays,
735 	    JDIMENSION drop_width, JDIMENSION drop_height)
736 /* Reflect - drop content of specified area, similar to wipe, but
737  * fill with repeated reflections of the outside area, instead of zero.
738  * NB: y_crop_offset is assumed to be zero.
739  */
740 {
741   JDIMENSION x_wipe_blocks, wipe_width;
742   JDIMENSION y_wipe_blocks, wipe_bottom;
743   JDIMENSION src_blk_x, dst_blk_x;
744   int ci, k, offset_y;
745   JBLOCKARRAY buffer;
746   JBLOCKROW src_row_ptr, dst_row_ptr;
747   JCOEFPTR src_ptr, dst_ptr;
748   jpeg_component_info *compptr;
749 
750   for (ci = 0; ci < dstinfo->num_components; ci++) {
751     compptr = dstinfo->comp_info + ci;
752     x_wipe_blocks = x_crop_offset * compptr->h_samp_factor;
753     wipe_width = drop_width * compptr->h_samp_factor;
754     wipe_bottom = drop_height * compptr->v_samp_factor;
755     for (y_wipe_blocks = 0; y_wipe_blocks < wipe_bottom;
756 	 y_wipe_blocks += compptr->v_samp_factor) {
757       buffer = (*srcinfo->mem->access_virt_barray)
758 	((j_common_ptr) srcinfo, src_coef_arrays[ci], y_wipe_blocks,
759 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
760       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
761 	if (x_wipe_blocks > 0) {
762 	  /* Reflect from left */
763 	  dst_row_ptr = buffer[offset_y] + x_wipe_blocks;
764 	  for (dst_blk_x = wipe_width; dst_blk_x > 0;) {
765 	    src_row_ptr = dst_row_ptr;	   /* (re)set axis of reflection */
766 	    for (src_blk_x = x_wipe_blocks;
767 		 src_blk_x > 0 && dst_blk_x > 0; src_blk_x--, dst_blk_x--) {
768 	      dst_ptr = *dst_row_ptr++;	   /* destination goes right */
769 	      src_ptr = *--src_row_ptr;	   /* source goes left */
770 	      /* this unrolled loop doesn't need to know which row it's on... */
771 	      for (k = 0; k < DCTSIZE2; k += 2) {
772 		*dst_ptr++ = *src_ptr++;   /* copy even column */
773 		*dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */
774 	      }
775 	    }
776 	  }
777 	} else if (compptr->width_in_blocks > x_wipe_blocks + wipe_width) {
778 	  /* Reflect from right */
779 	  dst_row_ptr = buffer[offset_y] + x_wipe_blocks + wipe_width;
780 	  for (dst_blk_x = wipe_width; dst_blk_x > 0;) {
781 	    src_row_ptr = dst_row_ptr;	   /* (re)set axis of reflection */
782 	    src_blk_x = compptr->width_in_blocks - x_wipe_blocks - wipe_width;
783 	    for (; src_blk_x > 0 && dst_blk_x > 0; src_blk_x--, dst_blk_x--) {
784 	      dst_ptr = *--dst_row_ptr;	   /* destination goes left */
785 	      src_ptr = *src_row_ptr++;	   /* source goes right */
786 	      /* this unrolled loop doesn't need to know which row it's on... */
787 	      for (k = 0; k < DCTSIZE2; k += 2) {
788 		*dst_ptr++ = *src_ptr++;   /* copy even column */
789 		*dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */
790 	      }
791 	    }
792 	  }
793 	} else {
794 	  FMEMZERO(buffer[offset_y] + x_wipe_blocks,
795 		   wipe_width * SIZEOF(JBLOCK));
796 	}
797       }
798     }
799   }
800 }
801 
802 
803 LOCAL(void)
do_flip_h_no_crop(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,jvirt_barray_ptr * src_coef_arrays)804 do_flip_h_no_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
805 		   JDIMENSION x_crop_offset,
806 		   jvirt_barray_ptr *src_coef_arrays)
807 /* Horizontal flip; done in-place, so no separate dest array is required.
808  * NB: this only works when y_crop_offset is zero.
809  */
810 {
811   JDIMENSION MCU_cols, comp_width, blk_x, blk_y, x_crop_blocks;
812   int ci, k, offset_y;
813   JBLOCKARRAY buffer;
814   JCOEFPTR ptr1, ptr2;
815   JCOEF temp1, temp2;
816   jpeg_component_info *compptr;
817 
818   /* Horizontal mirroring of DCT blocks is accomplished by swapping
819    * pairs of blocks in-place.  Within a DCT block, we perform horizontal
820    * mirroring by changing the signs of odd-numbered columns.
821    * Partial iMCUs at the right edge are left untouched.
822    */
823   MCU_cols = srcinfo->output_width /
824     (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
825 
826   for (ci = 0; ci < dstinfo->num_components; ci++) {
827     compptr = dstinfo->comp_info + ci;
828     comp_width = MCU_cols * compptr->h_samp_factor;
829     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
830     for (blk_y = 0; blk_y < compptr->height_in_blocks;
831 	 blk_y += compptr->v_samp_factor) {
832       buffer = (*srcinfo->mem->access_virt_barray)
833 	((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,
834 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
835       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
836 	/* Do the mirroring */
837 	for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {
838 	  ptr1 = buffer[offset_y][blk_x];
839 	  ptr2 = buffer[offset_y][comp_width - blk_x - 1];
840 	  /* this unrolled loop doesn't need to know which row it's on... */
841 	  for (k = 0; k < DCTSIZE2; k += 2) {
842 	    temp1 = *ptr1;	/* swap even column */
843 	    temp2 = *ptr2;
844 	    *ptr1++ = temp2;
845 	    *ptr2++ = temp1;
846 	    temp1 = *ptr1;	/* swap odd column with sign change */
847 	    temp2 = *ptr2;
848 	    *ptr1++ = -temp2;
849 	    *ptr2++ = -temp1;
850 	  }
851 	}
852 	if (x_crop_blocks > 0) {
853 	  /* Now left-justify the portion of the data to be kept.
854 	   * We can't use a single jcopy_block_row() call because that routine
855 	   * depends on memcpy(), whose behavior is unspecified for overlapping
856 	   * source and destination areas.  Sigh.
857 	   */
858 	  for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {
859 	    jcopy_block_row(buffer[offset_y] + blk_x + x_crop_blocks,
860 			    buffer[offset_y] + blk_x,
861 			    (JDIMENSION) 1);
862 	  }
863 	}
864       }
865     }
866   }
867 }
868 
869 
870 LOCAL(void)
do_flip_h(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)871 do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
872 	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
873 	   jvirt_barray_ptr *src_coef_arrays,
874 	   jvirt_barray_ptr *dst_coef_arrays)
875 /* Horizontal flip in general cropping case */
876 {
877   JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
878   JDIMENSION x_crop_blocks, y_crop_blocks;
879   int ci, k, offset_y;
880   JBLOCKARRAY src_buffer, dst_buffer;
881   JBLOCKROW src_row_ptr, dst_row_ptr;
882   JCOEFPTR src_ptr, dst_ptr;
883   jpeg_component_info *compptr;
884 
885   /* Here we must output into a separate array because we can't touch
886    * different rows of a single virtual array simultaneously.  Otherwise,
887    * this is essentially the same as the routine above.
888    */
889   MCU_cols = srcinfo->output_width /
890     (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
891 
892   for (ci = 0; ci < dstinfo->num_components; ci++) {
893     compptr = dstinfo->comp_info + ci;
894     comp_width = MCU_cols * compptr->h_samp_factor;
895     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
896     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
897     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
898 	 dst_blk_y += compptr->v_samp_factor) {
899       dst_buffer = (*srcinfo->mem->access_virt_barray)
900 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
901 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
902       src_buffer = (*srcinfo->mem->access_virt_barray)
903 	((j_common_ptr) srcinfo, src_coef_arrays[ci],
904 	 dst_blk_y + y_crop_blocks,
905 	 (JDIMENSION) compptr->v_samp_factor, FALSE);
906       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
907 	dst_row_ptr = dst_buffer[offset_y];
908 	src_row_ptr = src_buffer[offset_y];
909 	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
910 	  if (x_crop_blocks + dst_blk_x < comp_width) {
911 	    /* Do the mirrorable blocks */
912 	    dst_ptr = dst_row_ptr[dst_blk_x];
913 	    src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
914 	    /* this unrolled loop doesn't need to know which row it's on... */
915 	    for (k = 0; k < DCTSIZE2; k += 2) {
916 	      *dst_ptr++ = *src_ptr++;	 /* copy even column */
917 	      *dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */
918 	    }
919 	  } else {
920 	    /* Copy last partial block(s) verbatim */
921 	    jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
922 			    dst_row_ptr + dst_blk_x,
923 			    (JDIMENSION) 1);
924 	  }
925 	}
926       }
927     }
928   }
929 }
930 
931 
932 LOCAL(void)
do_flip_v(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)933 do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
934 	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
935 	   jvirt_barray_ptr *src_coef_arrays,
936 	   jvirt_barray_ptr *dst_coef_arrays)
937 /* Vertical flip */
938 {
939   JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
940   JDIMENSION x_crop_blocks, y_crop_blocks;
941   int ci, i, j, offset_y;
942   JBLOCKARRAY src_buffer, dst_buffer;
943   JBLOCKROW src_row_ptr, dst_row_ptr;
944   JCOEFPTR src_ptr, dst_ptr;
945   jpeg_component_info *compptr;
946 
947   /* We output into a separate array because we can't touch different
948    * rows of the source virtual array simultaneously.  Otherwise, this
949    * is a pretty straightforward analog of horizontal flip.
950    * Within a DCT block, vertical mirroring is done by changing the signs
951    * of odd-numbered rows.
952    * Partial iMCUs at the bottom edge are copied verbatim.
953    */
954   MCU_rows = srcinfo->output_height /
955     (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
956 
957   for (ci = 0; ci < dstinfo->num_components; ci++) {
958     compptr = dstinfo->comp_info + ci;
959     comp_height = MCU_rows * compptr->v_samp_factor;
960     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
961     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
962     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
963 	 dst_blk_y += compptr->v_samp_factor) {
964       dst_buffer = (*srcinfo->mem->access_virt_barray)
965 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
966 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
967       if (y_crop_blocks + dst_blk_y < comp_height) {
968 	/* Row is within the mirrorable area. */
969 	src_buffer = (*srcinfo->mem->access_virt_barray)
970 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
971 	   comp_height - y_crop_blocks - dst_blk_y -
972 	   (JDIMENSION) compptr->v_samp_factor,
973 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
974       } else {
975 	/* Bottom-edge blocks will be copied verbatim. */
976 	src_buffer = (*srcinfo->mem->access_virt_barray)
977 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
978 	   dst_blk_y + y_crop_blocks,
979 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
980       }
981       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
982 	if (y_crop_blocks + dst_blk_y < comp_height) {
983 	  /* Row is within the mirrorable area. */
984 	  dst_row_ptr = dst_buffer[offset_y];
985 	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
986 	  src_row_ptr += x_crop_blocks;
987 	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
988 	       dst_blk_x++) {
989 	    dst_ptr = dst_row_ptr[dst_blk_x];
990 	    src_ptr = src_row_ptr[dst_blk_x];
991 	    for (i = 0; i < DCTSIZE; i += 2) {
992 	      /* copy even row */
993 	      for (j = 0; j < DCTSIZE; j++)
994 		*dst_ptr++ = *src_ptr++;
995 	      /* copy odd row with sign change */
996 	      for (j = 0; j < DCTSIZE; j++)
997 		*dst_ptr++ = - *src_ptr++;
998 	    }
999 	  }
1000 	} else {
1001 	  /* Just copy row verbatim. */
1002 	  jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
1003 			  dst_buffer[offset_y],
1004 			  compptr->width_in_blocks);
1005 	}
1006       }
1007     }
1008   }
1009 }
1010 
1011 
1012 LOCAL(void)
do_transpose(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)1013 do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
1014 	      JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
1015 	      jvirt_barray_ptr *src_coef_arrays,
1016 	      jvirt_barray_ptr *dst_coef_arrays)
1017 /* Transpose source into destination */
1018 {
1019   JDIMENSION dst_blk_x, dst_blk_y, x_crop_blocks, y_crop_blocks;
1020   int ci, i, j, offset_x, offset_y;
1021   JBLOCKARRAY src_buffer, dst_buffer;
1022   JCOEFPTR src_ptr, dst_ptr;
1023   jpeg_component_info *compptr;
1024 
1025   /* Transposing pixels within a block just requires transposing the
1026    * DCT coefficients.
1027    * Partial iMCUs at the edges require no special treatment; we simply
1028    * process all the available DCT blocks for every component.
1029    */
1030   for (ci = 0; ci < dstinfo->num_components; ci++) {
1031     compptr = dstinfo->comp_info + ci;
1032     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
1033     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
1034     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
1035 	 dst_blk_y += compptr->v_samp_factor) {
1036       dst_buffer = (*srcinfo->mem->access_virt_barray)
1037 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
1038 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
1039       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
1040 	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
1041 	     dst_blk_x += compptr->h_samp_factor) {
1042 	  src_buffer = (*srcinfo->mem->access_virt_barray)
1043 	    ((j_common_ptr) srcinfo, src_coef_arrays[ci],
1044 	     dst_blk_x + x_crop_blocks,
1045 	     (JDIMENSION) compptr->h_samp_factor, FALSE);
1046 	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
1047 	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
1048 	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y + y_crop_blocks];
1049 	    for (i = 0; i < DCTSIZE; i++)
1050 	      for (j = 0; j < DCTSIZE; j++)
1051 		dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1052 	  }
1053 	}
1054       }
1055     }
1056   }
1057 }
1058 
1059 
1060 LOCAL(void)
do_rot_90(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)1061 do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
1062 	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
1063 	   jvirt_barray_ptr *src_coef_arrays,
1064 	   jvirt_barray_ptr *dst_coef_arrays)
1065 /* 90 degree rotation is equivalent to
1066  *   1. Transposing the image;
1067  *   2. Horizontal mirroring.
1068  * These two steps are merged into a single processing routine.
1069  */
1070 {
1071   JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
1072   JDIMENSION x_crop_blocks, y_crop_blocks;
1073   int ci, i, j, offset_x, offset_y;
1074   JBLOCKARRAY src_buffer, dst_buffer;
1075   JCOEFPTR src_ptr, dst_ptr;
1076   jpeg_component_info *compptr;
1077 
1078   /* Because of the horizontal mirror step, we can't process partial iMCUs
1079    * at the (output) right edge properly.  They just get transposed and
1080    * not mirrored.
1081    */
1082   MCU_cols = srcinfo->output_height /
1083     (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
1084 
1085   for (ci = 0; ci < dstinfo->num_components; ci++) {
1086     compptr = dstinfo->comp_info + ci;
1087     comp_width = MCU_cols * compptr->h_samp_factor;
1088     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
1089     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
1090     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
1091 	 dst_blk_y += compptr->v_samp_factor) {
1092       dst_buffer = (*srcinfo->mem->access_virt_barray)
1093 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
1094 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
1095       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
1096 	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
1097 	     dst_blk_x += compptr->h_samp_factor) {
1098 	  if (x_crop_blocks + dst_blk_x < comp_width) {
1099 	    /* Block is within the mirrorable area. */
1100 	    src_buffer = (*srcinfo->mem->access_virt_barray)
1101 	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
1102 	       comp_width - x_crop_blocks - dst_blk_x -
1103 	       (JDIMENSION) compptr->h_samp_factor,
1104 	       (JDIMENSION) compptr->h_samp_factor, FALSE);
1105 	  } else {
1106 	    /* Edge blocks are transposed but not mirrored. */
1107 	    src_buffer = (*srcinfo->mem->access_virt_barray)
1108 	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
1109 	       dst_blk_x + x_crop_blocks,
1110 	       (JDIMENSION) compptr->h_samp_factor, FALSE);
1111 	  }
1112 	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
1113 	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
1114 	    if (x_crop_blocks + dst_blk_x < comp_width) {
1115 	      /* Block is within the mirrorable area. */
1116 	      src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
1117 		[dst_blk_y + offset_y + y_crop_blocks];
1118 	      for (i = 0; i < DCTSIZE; i++) {
1119 		for (j = 0; j < DCTSIZE; j++)
1120 		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1121 		i++;
1122 		for (j = 0; j < DCTSIZE; j++)
1123 		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
1124 	      }
1125 	    } else {
1126 	      /* Edge blocks are transposed but not mirrored. */
1127 	      src_ptr = src_buffer[offset_x]
1128 		[dst_blk_y + offset_y + y_crop_blocks];
1129 	      for (i = 0; i < DCTSIZE; i++)
1130 		for (j = 0; j < DCTSIZE; j++)
1131 		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1132 	    }
1133 	  }
1134 	}
1135       }
1136     }
1137   }
1138 }
1139 
1140 
1141 LOCAL(void)
do_rot_270(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)1142 do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
1143 	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
1144 	    jvirt_barray_ptr *src_coef_arrays,
1145 	    jvirt_barray_ptr *dst_coef_arrays)
1146 /* 270 degree rotation is equivalent to
1147  *   1. Horizontal mirroring;
1148  *   2. Transposing the image.
1149  * These two steps are merged into a single processing routine.
1150  */
1151 {
1152   JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
1153   JDIMENSION x_crop_blocks, y_crop_blocks;
1154   int ci, i, j, offset_x, offset_y;
1155   JBLOCKARRAY src_buffer, dst_buffer;
1156   JCOEFPTR src_ptr, dst_ptr;
1157   jpeg_component_info *compptr;
1158 
1159   /* Because of the horizontal mirror step, we can't process partial iMCUs
1160    * at the (output) bottom edge properly.  They just get transposed and
1161    * not mirrored.
1162    */
1163   MCU_rows = srcinfo->output_width /
1164     (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
1165 
1166   for (ci = 0; ci < dstinfo->num_components; ci++) {
1167     compptr = dstinfo->comp_info + ci;
1168     comp_height = MCU_rows * compptr->v_samp_factor;
1169     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
1170     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
1171     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
1172 	 dst_blk_y += compptr->v_samp_factor) {
1173       dst_buffer = (*srcinfo->mem->access_virt_barray)
1174 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
1175 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
1176       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
1177 	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
1178 	     dst_blk_x += compptr->h_samp_factor) {
1179 	  src_buffer = (*srcinfo->mem->access_virt_barray)
1180 	    ((j_common_ptr) srcinfo, src_coef_arrays[ci],
1181 	     dst_blk_x + x_crop_blocks,
1182 	     (JDIMENSION) compptr->h_samp_factor, FALSE);
1183 	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
1184 	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
1185 	    if (y_crop_blocks + dst_blk_y < comp_height) {
1186 	      /* Block is within the mirrorable area. */
1187 	      src_ptr = src_buffer[offset_x]
1188 		[comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
1189 	      for (i = 0; i < DCTSIZE; i++) {
1190 		for (j = 0; j < DCTSIZE; j++) {
1191 		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1192 		  j++;
1193 		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
1194 		}
1195 	      }
1196 	    } else {
1197 	      /* Edge blocks are transposed but not mirrored. */
1198 	      src_ptr = src_buffer[offset_x]
1199 		[dst_blk_y + offset_y + y_crop_blocks];
1200 	      for (i = 0; i < DCTSIZE; i++)
1201 		for (j = 0; j < DCTSIZE; j++)
1202 		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1203 	    }
1204 	  }
1205 	}
1206       }
1207     }
1208   }
1209 }
1210 
1211 
1212 LOCAL(void)
do_rot_180(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)1213 do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
1214 	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
1215 	    jvirt_barray_ptr *src_coef_arrays,
1216 	    jvirt_barray_ptr *dst_coef_arrays)
1217 /* 180 degree rotation is equivalent to
1218  *   1. Vertical mirroring;
1219  *   2. Horizontal mirroring.
1220  * These two steps are merged into a single processing routine.
1221  */
1222 {
1223   JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
1224   JDIMENSION x_crop_blocks, y_crop_blocks;
1225   int ci, i, j, offset_y;
1226   JBLOCKARRAY src_buffer, dst_buffer;
1227   JBLOCKROW src_row_ptr, dst_row_ptr;
1228   JCOEFPTR src_ptr, dst_ptr;
1229   jpeg_component_info *compptr;
1230 
1231   MCU_cols = srcinfo->output_width /
1232     (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
1233   MCU_rows = srcinfo->output_height /
1234     (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
1235 
1236   for (ci = 0; ci < dstinfo->num_components; ci++) {
1237     compptr = dstinfo->comp_info + ci;
1238     comp_width = MCU_cols * compptr->h_samp_factor;
1239     comp_height = MCU_rows * compptr->v_samp_factor;
1240     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
1241     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
1242     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
1243 	 dst_blk_y += compptr->v_samp_factor) {
1244       dst_buffer = (*srcinfo->mem->access_virt_barray)
1245 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
1246 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
1247       if (y_crop_blocks + dst_blk_y < comp_height) {
1248 	/* Row is within the vertically mirrorable area. */
1249 	src_buffer = (*srcinfo->mem->access_virt_barray)
1250 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
1251 	   comp_height - y_crop_blocks - dst_blk_y -
1252 	   (JDIMENSION) compptr->v_samp_factor,
1253 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
1254       } else {
1255 	/* Bottom-edge rows are only mirrored horizontally. */
1256 	src_buffer = (*srcinfo->mem->access_virt_barray)
1257 	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],
1258 	   dst_blk_y + y_crop_blocks,
1259 	   (JDIMENSION) compptr->v_samp_factor, FALSE);
1260       }
1261       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
1262 	dst_row_ptr = dst_buffer[offset_y];
1263 	if (y_crop_blocks + dst_blk_y < comp_height) {
1264 	  /* Row is within the mirrorable area. */
1265 	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
1266 	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
1267 	    dst_ptr = dst_row_ptr[dst_blk_x];
1268 	    if (x_crop_blocks + dst_blk_x < comp_width) {
1269 	      /* Process the blocks that can be mirrored both ways. */
1270 	      src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
1271 	      for (i = 0; i < DCTSIZE; i += 2) {
1272 		/* For even row, negate every odd column. */
1273 		for (j = 0; j < DCTSIZE; j += 2) {
1274 		  *dst_ptr++ = *src_ptr++;
1275 		  *dst_ptr++ = - *src_ptr++;
1276 		}
1277 		/* For odd row, negate every even column. */
1278 		for (j = 0; j < DCTSIZE; j += 2) {
1279 		  *dst_ptr++ = - *src_ptr++;
1280 		  *dst_ptr++ = *src_ptr++;
1281 		}
1282 	      }
1283 	    } else {
1284 	      /* Any remaining right-edge blocks are only mirrored vertically. */
1285 	      src_ptr = src_row_ptr[x_crop_blocks + dst_blk_x];
1286 	      for (i = 0; i < DCTSIZE; i += 2) {
1287 		for (j = 0; j < DCTSIZE; j++)
1288 		  *dst_ptr++ = *src_ptr++;
1289 		for (j = 0; j < DCTSIZE; j++)
1290 		  *dst_ptr++ = - *src_ptr++;
1291 	      }
1292 	    }
1293 	  }
1294 	} else {
1295 	  /* Remaining rows are just mirrored horizontally. */
1296 	  src_row_ptr = src_buffer[offset_y];
1297 	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
1298 	    if (x_crop_blocks + dst_blk_x < comp_width) {
1299 	      /* Process the blocks that can be mirrored. */
1300 	      dst_ptr = dst_row_ptr[dst_blk_x];
1301 	      src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
1302 	      for (i = 0; i < DCTSIZE2; i += 2) {
1303 		*dst_ptr++ = *src_ptr++;
1304 		*dst_ptr++ = - *src_ptr++;
1305 	      }
1306 	    } else {
1307 	      /* Any remaining right-edge blocks are only copied. */
1308 	      jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
1309 			      dst_row_ptr + dst_blk_x,
1310 			      (JDIMENSION) 1);
1311 	    }
1312 	  }
1313 	}
1314       }
1315     }
1316   }
1317 }
1318 
1319 
1320 LOCAL(void)
do_transverse(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JDIMENSION x_crop_offset,JDIMENSION y_crop_offset,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)1321 do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
1322 	       JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
1323 	       jvirt_barray_ptr *src_coef_arrays,
1324 	       jvirt_barray_ptr *dst_coef_arrays)
1325 /* Transverse transpose is equivalent to
1326  *   1. 180 degree rotation;
1327  *   2. Transposition;
1328  * or
1329  *   1. Horizontal mirroring;
1330  *   2. Transposition;
1331  *   3. Horizontal mirroring.
1332  * These steps are merged into a single processing routine.
1333  */
1334 {
1335   JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
1336   JDIMENSION x_crop_blocks, y_crop_blocks;
1337   int ci, i, j, offset_x, offset_y;
1338   JBLOCKARRAY src_buffer, dst_buffer;
1339   JCOEFPTR src_ptr, dst_ptr;
1340   jpeg_component_info *compptr;
1341 
1342   MCU_cols = srcinfo->output_height /
1343     (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
1344   MCU_rows = srcinfo->output_width /
1345     (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
1346 
1347   for (ci = 0; ci < dstinfo->num_components; ci++) {
1348     compptr = dstinfo->comp_info + ci;
1349     comp_width = MCU_cols * compptr->h_samp_factor;
1350     comp_height = MCU_rows * compptr->v_samp_factor;
1351     x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
1352     y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
1353     for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
1354 	 dst_blk_y += compptr->v_samp_factor) {
1355       dst_buffer = (*srcinfo->mem->access_virt_barray)
1356 	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
1357 	 (JDIMENSION) compptr->v_samp_factor, TRUE);
1358       for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
1359 	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
1360 	     dst_blk_x += compptr->h_samp_factor) {
1361 	  if (x_crop_blocks + dst_blk_x < comp_width) {
1362 	    /* Block is within the mirrorable area. */
1363 	    src_buffer = (*srcinfo->mem->access_virt_barray)
1364 	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
1365 	       comp_width - x_crop_blocks - dst_blk_x -
1366 	       (JDIMENSION) compptr->h_samp_factor,
1367 	       (JDIMENSION) compptr->h_samp_factor, FALSE);
1368 	  } else {
1369 	    src_buffer = (*srcinfo->mem->access_virt_barray)
1370 	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],
1371 	       dst_blk_x + x_crop_blocks,
1372 	       (JDIMENSION) compptr->h_samp_factor, FALSE);
1373 	  }
1374 	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
1375 	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
1376 	    if (y_crop_blocks + dst_blk_y < comp_height) {
1377 	      if (x_crop_blocks + dst_blk_x < comp_width) {
1378 		/* Block is within the mirrorable area. */
1379 		src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
1380 		  [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
1381 		for (i = 0; i < DCTSIZE; i++) {
1382 		  for (j = 0; j < DCTSIZE; j++) {
1383 		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1384 		    j++;
1385 		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
1386 		  }
1387 		  i++;
1388 		  for (j = 0; j < DCTSIZE; j++) {
1389 		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
1390 		    j++;
1391 		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1392 		  }
1393 		}
1394 	      } else {
1395 		/* Right-edge blocks are mirrored in y only */
1396 		src_ptr = src_buffer[offset_x]
1397 		  [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
1398 		for (i = 0; i < DCTSIZE; i++) {
1399 		  for (j = 0; j < DCTSIZE; j++) {
1400 		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1401 		    j++;
1402 		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
1403 		  }
1404 		}
1405 	      }
1406 	    } else {
1407 	      if (x_crop_blocks + dst_blk_x < comp_width) {
1408 		/* Bottom-edge blocks are mirrored in x only */
1409 		src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
1410 		  [dst_blk_y + offset_y + y_crop_blocks];
1411 		for (i = 0; i < DCTSIZE; i++) {
1412 		  for (j = 0; j < DCTSIZE; j++)
1413 		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1414 		  i++;
1415 		  for (j = 0; j < DCTSIZE; j++)
1416 		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
1417 		}
1418 	      } else {
1419 		/* At lower right corner, just transpose, no mirroring */
1420 		src_ptr = src_buffer[offset_x]
1421 		  [dst_blk_y + offset_y + y_crop_blocks];
1422 		for (i = 0; i < DCTSIZE; i++)
1423 		  for (j = 0; j < DCTSIZE; j++)
1424 		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
1425 	      }
1426 	    }
1427 	  }
1428 	}
1429       }
1430     }
1431   }
1432 }
1433 
1434 
1435 /* Parse an unsigned integer: subroutine for jtransform_parse_crop_spec.
1436  * Returns TRUE if valid integer found, FALSE if not.
1437  * *strptr is advanced over the digit string, and *result is set to its value.
1438  */
1439 
1440 LOCAL(boolean)
jt_read_integer(const char ** strptr,JDIMENSION * result)1441 jt_read_integer (const char ** strptr, JDIMENSION * result)
1442 {
1443   const char * ptr = *strptr;
1444   JDIMENSION val = 0;
1445 
1446   for (; isdigit(*ptr); ptr++) {
1447     val = val * 10 + (JDIMENSION) (*ptr - '0');
1448   }
1449   *result = val;
1450   if (ptr == *strptr)
1451     return FALSE;		/* oops, no digits */
1452   *strptr = ptr;
1453   return TRUE;
1454 }
1455 
1456 
1457 /* Parse a crop specification (written in X11 geometry style).
1458  * The routine returns TRUE if the spec string is valid, FALSE if not.
1459  *
1460  * The crop spec string should have the format
1461  *	<width>[{fr}]x<height>[{fr}]{+-}<xoffset>{+-}<yoffset>
1462  * where width, height, xoffset, and yoffset are unsigned integers.
1463  * Each of the elements can be omitted to indicate a default value.
1464  * (A weakness of this style is that it is not possible to omit xoffset
1465  * while specifying yoffset, since they look alike.)
1466  *
1467  * This code is loosely based on XParseGeometry from the X11 distribution.
1468  */
1469 
1470 GLOBAL(boolean)
jtransform_parse_crop_spec(jpeg_transform_info * info,const char * spec)1471 jtransform_parse_crop_spec (jpeg_transform_info *info, const char *spec)
1472 {
1473   info->crop = FALSE;
1474   info->crop_width_set = JCROP_UNSET;
1475   info->crop_height_set = JCROP_UNSET;
1476   info->crop_xoffset_set = JCROP_UNSET;
1477   info->crop_yoffset_set = JCROP_UNSET;
1478 
1479   if (isdigit(*spec)) {
1480     /* fetch width */
1481     if (! jt_read_integer(&spec, &info->crop_width))
1482       return FALSE;
1483     if (*spec == 'f' || *spec == 'F') {
1484       spec++;
1485       info->crop_width_set = JCROP_FORCE;
1486     } else if (*spec == 'r' || *spec == 'R') {
1487       spec++;
1488       info->crop_width_set = JCROP_REFLECT;
1489     } else
1490       info->crop_width_set = JCROP_POS;
1491   }
1492   if (*spec == 'x' || *spec == 'X') {
1493     /* fetch height */
1494     spec++;
1495     if (! jt_read_integer(&spec, &info->crop_height))
1496       return FALSE;
1497     if (*spec == 'f' || *spec == 'F') {
1498       spec++;
1499       info->crop_height_set = JCROP_FORCE;
1500     } else if (*spec == 'r' || *spec == 'R') {
1501       spec++;
1502       info->crop_height_set = JCROP_REFLECT;
1503     } else
1504       info->crop_height_set = JCROP_POS;
1505   }
1506   if (*spec == '+' || *spec == '-') {
1507     /* fetch xoffset */
1508     info->crop_xoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
1509     spec++;
1510     if (! jt_read_integer(&spec, &info->crop_xoffset))
1511       return FALSE;
1512   }
1513   if (*spec == '+' || *spec == '-') {
1514     /* fetch yoffset */
1515     info->crop_yoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
1516     spec++;
1517     if (! jt_read_integer(&spec, &info->crop_yoffset))
1518       return FALSE;
1519   }
1520   /* We had better have gotten to the end of the string. */
1521   if (*spec != '\0')
1522     return FALSE;
1523   info->crop = TRUE;
1524   return TRUE;
1525 }
1526 
1527 
1528 /* Trim off any partial iMCUs on the indicated destination edge */
1529 
1530 LOCAL(void)
trim_right_edge(jpeg_transform_info * info,JDIMENSION full_width)1531 trim_right_edge (jpeg_transform_info *info, JDIMENSION full_width)
1532 {
1533   JDIMENSION MCU_cols;
1534 
1535   MCU_cols = info->output_width / info->iMCU_sample_width;
1536   if (MCU_cols > 0 && info->x_crop_offset + MCU_cols ==
1537       full_width / info->iMCU_sample_width)
1538     info->output_width = MCU_cols * info->iMCU_sample_width;
1539 }
1540 
1541 LOCAL(void)
trim_bottom_edge(jpeg_transform_info * info,JDIMENSION full_height)1542 trim_bottom_edge (jpeg_transform_info *info, JDIMENSION full_height)
1543 {
1544   JDIMENSION MCU_rows;
1545 
1546   MCU_rows = info->output_height / info->iMCU_sample_height;
1547   if (MCU_rows > 0 && info->y_crop_offset + MCU_rows ==
1548       full_height / info->iMCU_sample_height)
1549     info->output_height = MCU_rows * info->iMCU_sample_height;
1550 }
1551 
1552 
1553 /* Request any required workspace.
1554  *
1555  * This routine figures out the size that the output image will be
1556  * (which implies that all the transform parameters must be set before
1557  * it is called).
1558  *
1559  * We allocate the workspace virtual arrays from the source decompression
1560  * object, so that all the arrays (both the original data and the workspace)
1561  * will be taken into account while making memory management decisions.
1562  * Hence, this routine must be called after jpeg_read_header (which reads
1563  * the image dimensions) and before jpeg_read_coefficients (which realizes
1564  * the source's virtual arrays).
1565  *
1566  * This function returns FALSE right away if -perfect is given
1567  * and transformation is not perfect.  Otherwise returns TRUE.
1568  */
1569 
1570 GLOBAL(boolean)
jtransform_request_workspace(j_decompress_ptr srcinfo,jpeg_transform_info * info)1571 jtransform_request_workspace (j_decompress_ptr srcinfo,
1572 			      jpeg_transform_info *info)
1573 {
1574   jvirt_barray_ptr *coef_arrays;
1575   boolean need_workspace, transpose_it;
1576   jpeg_component_info *compptr;
1577   JDIMENSION xoffset, yoffset, dtemp;
1578   JDIMENSION width_in_iMCUs, height_in_iMCUs;
1579   JDIMENSION width_in_blocks, height_in_blocks;
1580   int itemp, ci, h_samp_factor, v_samp_factor;
1581 
1582   /* Determine number of components in output image */
1583   if (info->force_grayscale &&
1584       (srcinfo->jpeg_color_space == JCS_YCbCr ||
1585        srcinfo->jpeg_color_space == JCS_BG_YCC) &&
1586       srcinfo->num_components == 3)
1587     /* We'll only process the first component */
1588     info->num_components = 1;
1589   else
1590     /* Process all the components */
1591     info->num_components = srcinfo->num_components;
1592 
1593   /* Compute output image dimensions and related values. */
1594   jpeg_core_output_dimensions(srcinfo);
1595 
1596   /* Return right away if -perfect is given and transformation is not perfect.
1597    */
1598   if (info->perfect) {
1599     if (info->num_components == 1) {
1600       if (!jtransform_perfect_transform(srcinfo->output_width,
1601 	  srcinfo->output_height,
1602 	  srcinfo->min_DCT_h_scaled_size,
1603 	  srcinfo->min_DCT_v_scaled_size,
1604 	  info->transform))
1605 	return FALSE;
1606     } else {
1607       if (!jtransform_perfect_transform(srcinfo->output_width,
1608 	  srcinfo->output_height,
1609 	  srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size,
1610 	  srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size,
1611 	  info->transform))
1612 	return FALSE;
1613     }
1614   }
1615 
1616   /* If there is only one output component, force the iMCU size to be 1;
1617    * else use the source iMCU size.  (This allows us to do the right thing
1618    * when reducing color to grayscale, and also provides a handy way of
1619    * cleaning up "funny" grayscale images whose sampling factors are not 1x1.)
1620    */
1621   switch (info->transform) {
1622   case JXFORM_TRANSPOSE:
1623   case JXFORM_TRANSVERSE:
1624   case JXFORM_ROT_90:
1625   case JXFORM_ROT_270:
1626     info->output_width = srcinfo->output_height;
1627     info->output_height = srcinfo->output_width;
1628     if (info->num_components == 1) {
1629       info->iMCU_sample_width = srcinfo->min_DCT_v_scaled_size;
1630       info->iMCU_sample_height = srcinfo->min_DCT_h_scaled_size;
1631     } else {
1632       info->iMCU_sample_width =
1633 	srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;
1634       info->iMCU_sample_height =
1635 	srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;
1636     }
1637     break;
1638   default:
1639     info->output_width = srcinfo->output_width;
1640     info->output_height = srcinfo->output_height;
1641     if (info->num_components == 1) {
1642       info->iMCU_sample_width = srcinfo->min_DCT_h_scaled_size;
1643       info->iMCU_sample_height = srcinfo->min_DCT_v_scaled_size;
1644     } else {
1645       info->iMCU_sample_width =
1646 	srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;
1647       info->iMCU_sample_height =
1648 	srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;
1649     }
1650   }
1651 
1652   /* If cropping has been requested, compute the crop area's position and
1653    * dimensions, ensuring that its upper left corner falls at an iMCU boundary.
1654    */
1655   if (info->crop) {
1656     /* Insert default values for unset crop parameters */
1657     if (info->crop_xoffset_set == JCROP_UNSET)
1658       info->crop_xoffset = 0;	/* default to +0 */
1659     if (info->crop_yoffset_set == JCROP_UNSET)
1660       info->crop_yoffset = 0;	/* default to +0 */
1661     if (info->crop_width_set == JCROP_UNSET) {
1662       if (info->crop_xoffset >= info->output_width)
1663 	ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
1664       info->crop_width = info->output_width - info->crop_xoffset;
1665     } else {
1666       /* Check for crop extension */
1667       if (info->crop_width > info->output_width) {
1668 	/* Crop extension does not work when transforming! */
1669 	if (info->transform != JXFORM_NONE ||
1670 	    info->crop_xoffset >= info->crop_width ||
1671 	    info->crop_xoffset > info->crop_width - info->output_width)
1672 	  ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
1673       } else {
1674 	if (info->crop_xoffset >= info->output_width ||
1675 	    info->crop_width <= 0 ||
1676 	    info->crop_xoffset > info->output_width - info->crop_width)
1677 	  ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
1678       }
1679     }
1680     if (info->crop_height_set == JCROP_UNSET) {
1681       if (info->crop_yoffset >= info->output_height)
1682 	ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
1683       info->crop_height = info->output_height - info->crop_yoffset;
1684     } else {
1685       /* Check for crop extension */
1686       if (info->crop_height > info->output_height) {
1687 	/* Crop extension does not work when transforming! */
1688 	if (info->transform != JXFORM_NONE ||
1689 	    info->crop_yoffset >= info->crop_height ||
1690 	    info->crop_yoffset > info->crop_height - info->output_height)
1691 	  ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
1692       } else {
1693 	if (info->crop_yoffset >= info->output_height ||
1694 	    info->crop_height <= 0 ||
1695 	    info->crop_yoffset > info->output_height - info->crop_height)
1696 	  ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
1697       }
1698     }
1699     /* Convert negative crop offsets into regular offsets */
1700     if (info->crop_xoffset_set != JCROP_NEG)
1701       xoffset = info->crop_xoffset;
1702     else if (info->crop_width > info->output_width) /* crop extension */
1703       xoffset = info->crop_width - info->output_width - info->crop_xoffset;
1704     else
1705       xoffset = info->output_width - info->crop_width - info->crop_xoffset;
1706     if (info->crop_yoffset_set != JCROP_NEG)
1707       yoffset = info->crop_yoffset;
1708     else if (info->crop_height > info->output_height) /* crop extension */
1709       yoffset = info->crop_height - info->output_height - info->crop_yoffset;
1710     else
1711       yoffset = info->output_height - info->crop_height - info->crop_yoffset;
1712     /* Now adjust so that upper left corner falls at an iMCU boundary */
1713     switch (info->transform) {
1714     case JXFORM_DROP:
1715       /* Ensure the effective drop region will not exceed the requested */
1716       itemp = info->iMCU_sample_width;
1717       dtemp = itemp - 1 - ((xoffset + itemp - 1) % itemp);
1718       xoffset += dtemp;
1719       if (info->crop_width <= dtemp)
1720 	info->drop_width = 0;
1721       else if (xoffset + info->crop_width - dtemp == info->output_width)
1722 	/* Matching right edge: include partial iMCU */
1723 	info->drop_width = (info->crop_width - dtemp + itemp - 1) / itemp;
1724       else
1725 	info->drop_width = (info->crop_width - dtemp) / itemp;
1726       itemp = info->iMCU_sample_height;
1727       dtemp = itemp - 1 - ((yoffset + itemp - 1) % itemp);
1728       yoffset += dtemp;
1729       if (info->crop_height <= dtemp)
1730 	info->drop_height = 0;
1731       else if (yoffset + info->crop_height - dtemp == info->output_height)
1732 	/* Matching bottom edge: include partial iMCU */
1733 	info->drop_height = (info->crop_height - dtemp + itemp - 1) / itemp;
1734       else
1735 	info->drop_height = (info->crop_height - dtemp) / itemp;
1736       /* Check if sampling factors match for dropping */
1737       if (info->drop_width != 0 && info->drop_height != 0)
1738 	for (ci = 0; ci < info->num_components &&
1739 		     ci < info->drop_ptr->num_components; ci++) {
1740 	  if (info->drop_ptr->comp_info[ci].h_samp_factor *
1741 	      srcinfo->max_h_samp_factor !=
1742 	      srcinfo->comp_info[ci].h_samp_factor *
1743 	      info->drop_ptr->max_h_samp_factor)
1744 	    ERREXIT6(srcinfo, JERR_BAD_DROP_SAMPLING, ci,
1745 	      info->drop_ptr->comp_info[ci].h_samp_factor,
1746 	      info->drop_ptr->max_h_samp_factor,
1747 	      srcinfo->comp_info[ci].h_samp_factor,
1748 	      srcinfo->max_h_samp_factor, 'h');
1749 	  if (info->drop_ptr->comp_info[ci].v_samp_factor *
1750 	      srcinfo->max_v_samp_factor !=
1751 	      srcinfo->comp_info[ci].v_samp_factor *
1752 	      info->drop_ptr->max_v_samp_factor)
1753 	    ERREXIT6(srcinfo, JERR_BAD_DROP_SAMPLING, ci,
1754 	      info->drop_ptr->comp_info[ci].v_samp_factor,
1755 	      info->drop_ptr->max_v_samp_factor,
1756 	      srcinfo->comp_info[ci].v_samp_factor,
1757 	      srcinfo->max_v_samp_factor, 'v');
1758 	}
1759       break;
1760     case JXFORM_WIPE:
1761       /* Ensure the effective wipe region will cover the requested */
1762       info->drop_width = (JDIMENSION) jdiv_round_up
1763 	((long) (info->crop_width + (xoffset % info->iMCU_sample_width)),
1764 	 (long) info->iMCU_sample_width);
1765       info->drop_height = (JDIMENSION) jdiv_round_up
1766 	((long) (info->crop_height + (yoffset % info->iMCU_sample_height)),
1767 	 (long) info->iMCU_sample_height);
1768       break;
1769     default:
1770       /* Ensure the effective crop region will cover the requested */
1771       if (info->crop_width_set == JCROP_FORCE ||
1772 	  info->crop_width > info->output_width)
1773 	info->output_width = info->crop_width;
1774       else
1775 	info->output_width =
1776 	  info->crop_width + (xoffset % info->iMCU_sample_width);
1777       if (info->crop_height_set == JCROP_FORCE ||
1778 	  info->crop_height > info->output_height)
1779 	info->output_height = info->crop_height;
1780       else
1781 	info->output_height =
1782 	  info->crop_height + (yoffset % info->iMCU_sample_height);
1783     }
1784     /* Save x/y offsets measured in iMCUs */
1785     info->x_crop_offset = xoffset / info->iMCU_sample_width;
1786     info->y_crop_offset = yoffset / info->iMCU_sample_height;
1787   } else {
1788     info->x_crop_offset = 0;
1789     info->y_crop_offset = 0;
1790   }
1791 
1792   /* Figure out whether we need workspace arrays,
1793    * and if so whether they are transposed relative to the source.
1794    */
1795   need_workspace = FALSE;
1796   transpose_it = FALSE;
1797   switch (info->transform) {
1798   case JXFORM_NONE:
1799     if (info->x_crop_offset != 0 || info->y_crop_offset != 0 ||
1800 	info->output_width > srcinfo->output_width ||
1801 	info->output_height > srcinfo->output_height)
1802       need_workspace = TRUE;
1803     /* No workspace needed if neither cropping nor transforming */
1804     break;
1805   case JXFORM_FLIP_H:
1806     if (info->trim)
1807       trim_right_edge(info, srcinfo->output_width);
1808     if (info->y_crop_offset != 0)
1809       need_workspace = TRUE;
1810     /* do_flip_h_no_crop doesn't need a workspace array */
1811     break;
1812   case JXFORM_FLIP_V:
1813     if (info->trim)
1814       trim_bottom_edge(info, srcinfo->output_height);
1815     /* Need workspace arrays having same dimensions as source image. */
1816     need_workspace = TRUE;
1817     break;
1818   case JXFORM_TRANSPOSE:
1819     /* transpose does NOT have to trim anything */
1820     /* Need workspace arrays having transposed dimensions. */
1821     need_workspace = TRUE;
1822     transpose_it = TRUE;
1823     break;
1824   case JXFORM_TRANSVERSE:
1825     if (info->trim) {
1826       trim_right_edge(info, srcinfo->output_height);
1827       trim_bottom_edge(info, srcinfo->output_width);
1828     }
1829     /* Need workspace arrays having transposed dimensions. */
1830     need_workspace = TRUE;
1831     transpose_it = TRUE;
1832     break;
1833   case JXFORM_ROT_90:
1834     if (info->trim)
1835       trim_right_edge(info, srcinfo->output_height);
1836     /* Need workspace arrays having transposed dimensions. */
1837     need_workspace = TRUE;
1838     transpose_it = TRUE;
1839     break;
1840   case JXFORM_ROT_180:
1841     if (info->trim) {
1842       trim_right_edge(info, srcinfo->output_width);
1843       trim_bottom_edge(info, srcinfo->output_height);
1844     }
1845     /* Need workspace arrays having same dimensions as source image. */
1846     need_workspace = TRUE;
1847     break;
1848   case JXFORM_ROT_270:
1849     if (info->trim)
1850       trim_bottom_edge(info, srcinfo->output_width);
1851     /* Need workspace arrays having transposed dimensions. */
1852     need_workspace = TRUE;
1853     transpose_it = TRUE;
1854     break;
1855   case JXFORM_WIPE:
1856     break;
1857   case JXFORM_DROP:
1858 #if DROP_REQUEST_FROM_SRC
1859     drop_request_from_src(info->drop_ptr, srcinfo);
1860 #endif
1861     break;
1862   }
1863 
1864   /* Allocate workspace if needed.
1865    * Note that we allocate arrays padded out to the next iMCU boundary,
1866    * so that transform routines need not worry about missing edge blocks.
1867    */
1868   if (need_workspace) {
1869     coef_arrays = (jvirt_barray_ptr *) (*srcinfo->mem->alloc_small)
1870       ((j_common_ptr) srcinfo, JPOOL_IMAGE,
1871        SIZEOF(jvirt_barray_ptr) * info->num_components);
1872     width_in_iMCUs = (JDIMENSION) jdiv_round_up
1873       ((long) info->output_width, (long) info->iMCU_sample_width);
1874     height_in_iMCUs = (JDIMENSION) jdiv_round_up
1875       ((long) info->output_height, (long) info->iMCU_sample_height);
1876     for (ci = 0; ci < info->num_components; ci++) {
1877       compptr = srcinfo->comp_info + ci;
1878       if (info->num_components == 1) {
1879 	/* we're going to force samp factors to 1x1 in this case */
1880 	h_samp_factor = v_samp_factor = 1;
1881       } else if (transpose_it) {
1882 	h_samp_factor = compptr->v_samp_factor;
1883 	v_samp_factor = compptr->h_samp_factor;
1884       } else {
1885 	h_samp_factor = compptr->h_samp_factor;
1886 	v_samp_factor = compptr->v_samp_factor;
1887       }
1888       width_in_blocks = width_in_iMCUs * h_samp_factor;
1889       height_in_blocks = height_in_iMCUs * v_samp_factor;
1890       coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
1891 	((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
1892 	 width_in_blocks, height_in_blocks, (JDIMENSION) v_samp_factor);
1893     }
1894     info->workspace_coef_arrays = coef_arrays;
1895   } else
1896     info->workspace_coef_arrays = NULL;
1897 
1898   return TRUE;
1899 }
1900 
1901 
1902 /* Transpose destination image parameters */
1903 
1904 LOCAL(void)
transpose_critical_parameters(j_compress_ptr dstinfo)1905 transpose_critical_parameters (j_compress_ptr dstinfo)
1906 {
1907   int tblno, i, j, ci, itemp;
1908   jpeg_component_info *compptr;
1909   JQUANT_TBL *qtblptr;
1910   JDIMENSION jtemp;
1911   UINT16 qtemp;
1912 
1913   /* Transpose image dimensions */
1914   jtemp = dstinfo->image_width;
1915   dstinfo->image_width = dstinfo->image_height;
1916   dstinfo->image_height = jtemp;
1917   itemp = dstinfo->min_DCT_h_scaled_size;
1918   dstinfo->min_DCT_h_scaled_size = dstinfo->min_DCT_v_scaled_size;
1919   dstinfo->min_DCT_v_scaled_size = itemp;
1920 
1921   /* Transpose sampling factors */
1922   for (ci = 0; ci < dstinfo->num_components; ci++) {
1923     compptr = dstinfo->comp_info + ci;
1924     itemp = compptr->h_samp_factor;
1925     compptr->h_samp_factor = compptr->v_samp_factor;
1926     compptr->v_samp_factor = itemp;
1927   }
1928 
1929   /* Transpose quantization tables */
1930   for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
1931     qtblptr = dstinfo->quant_tbl_ptrs[tblno];
1932     if (qtblptr != NULL) {
1933       for (i = 0; i < DCTSIZE; i++) {
1934 	for (j = 0; j < i; j++) {
1935 	  qtemp = qtblptr->quantval[i*DCTSIZE+j];
1936 	  qtblptr->quantval[i*DCTSIZE+j] = qtblptr->quantval[j*DCTSIZE+i];
1937 	  qtblptr->quantval[j*DCTSIZE+i] = qtemp;
1938 	}
1939       }
1940     }
1941   }
1942 }
1943 
1944 
1945 /* Adjust Exif image parameters.
1946  *
1947  * We try to adjust the Tags ExifImageWidth and ExifImageHeight if possible.
1948  */
1949 
1950 LOCAL(void)
adjust_exif_parameters(JOCTET FAR * data,unsigned int length,JDIMENSION new_width,JDIMENSION new_height)1951 adjust_exif_parameters (JOCTET FAR * data, unsigned int length,
1952 			JDIMENSION new_width, JDIMENSION new_height)
1953 {
1954   boolean is_motorola; /* Flag for byte order */
1955   unsigned int number_of_tags, tagnum;
1956   unsigned int firstoffset, offset;
1957   JDIMENSION new_value;
1958 
1959   if (length < 12) return; /* Length of an IFD entry */
1960 
1961   /* Discover byte order */
1962   if (GETJOCTET(data[0]) == 0x49 && GETJOCTET(data[1]) == 0x49)
1963     is_motorola = FALSE;
1964   else if (GETJOCTET(data[0]) == 0x4D && GETJOCTET(data[1]) == 0x4D)
1965     is_motorola = TRUE;
1966   else
1967     return;
1968 
1969   /* Check Tag Mark */
1970   if (is_motorola) {
1971     if (GETJOCTET(data[2]) != 0) return;
1972     if (GETJOCTET(data[3]) != 0x2A) return;
1973   } else {
1974     if (GETJOCTET(data[3]) != 0) return;
1975     if (GETJOCTET(data[2]) != 0x2A) return;
1976   }
1977 
1978   /* Get first IFD offset (offset to IFD0) */
1979   if (is_motorola) {
1980     if (GETJOCTET(data[4]) != 0) return;
1981     if (GETJOCTET(data[5]) != 0) return;
1982     firstoffset = GETJOCTET(data[6]);
1983     firstoffset <<= 8;
1984     firstoffset += GETJOCTET(data[7]);
1985   } else {
1986     if (GETJOCTET(data[7]) != 0) return;
1987     if (GETJOCTET(data[6]) != 0) return;
1988     firstoffset = GETJOCTET(data[5]);
1989     firstoffset <<= 8;
1990     firstoffset += GETJOCTET(data[4]);
1991   }
1992   if (firstoffset > length - 2) return; /* check end of data segment */
1993 
1994   /* Get the number of directory entries contained in this IFD */
1995   if (is_motorola) {
1996     number_of_tags = GETJOCTET(data[firstoffset]);
1997     number_of_tags <<= 8;
1998     number_of_tags += GETJOCTET(data[firstoffset+1]);
1999   } else {
2000     number_of_tags = GETJOCTET(data[firstoffset+1]);
2001     number_of_tags <<= 8;
2002     number_of_tags += GETJOCTET(data[firstoffset]);
2003   }
2004   if (number_of_tags == 0) return;
2005   firstoffset += 2;
2006 
2007   /* Search for ExifSubIFD offset Tag in IFD0 */
2008   for (;;) {
2009     if (firstoffset > length - 12) return; /* check end of data segment */
2010     /* Get Tag number */
2011     if (is_motorola) {
2012       tagnum = GETJOCTET(data[firstoffset]);
2013       tagnum <<= 8;
2014       tagnum += GETJOCTET(data[firstoffset+1]);
2015     } else {
2016       tagnum = GETJOCTET(data[firstoffset+1]);
2017       tagnum <<= 8;
2018       tagnum += GETJOCTET(data[firstoffset]);
2019     }
2020     if (tagnum == 0x8769) break; /* found ExifSubIFD offset Tag */
2021     if (--number_of_tags == 0) return;
2022     firstoffset += 12;
2023   }
2024 
2025   /* Get the ExifSubIFD offset */
2026   if (is_motorola) {
2027     if (GETJOCTET(data[firstoffset+8]) != 0) return;
2028     if (GETJOCTET(data[firstoffset+9]) != 0) return;
2029     offset = GETJOCTET(data[firstoffset+10]);
2030     offset <<= 8;
2031     offset += GETJOCTET(data[firstoffset+11]);
2032   } else {
2033     if (GETJOCTET(data[firstoffset+11]) != 0) return;
2034     if (GETJOCTET(data[firstoffset+10]) != 0) return;
2035     offset = GETJOCTET(data[firstoffset+9]);
2036     offset <<= 8;
2037     offset += GETJOCTET(data[firstoffset+8]);
2038   }
2039   if (offset > length - 2) return; /* check end of data segment */
2040 
2041   /* Get the number of directory entries contained in this SubIFD */
2042   if (is_motorola) {
2043     number_of_tags = GETJOCTET(data[offset]);
2044     number_of_tags <<= 8;
2045     number_of_tags += GETJOCTET(data[offset+1]);
2046   } else {
2047     number_of_tags = GETJOCTET(data[offset+1]);
2048     number_of_tags <<= 8;
2049     number_of_tags += GETJOCTET(data[offset]);
2050   }
2051   if (number_of_tags < 2) return;
2052   offset += 2;
2053 
2054   /* Search for ExifImageWidth and ExifImageHeight Tags in this SubIFD */
2055   do {
2056     if (offset > length - 12) return; /* check end of data segment */
2057     /* Get Tag number */
2058     if (is_motorola) {
2059       tagnum = GETJOCTET(data[offset]);
2060       tagnum <<= 8;
2061       tagnum += GETJOCTET(data[offset+1]);
2062     } else {
2063       tagnum = GETJOCTET(data[offset+1]);
2064       tagnum <<= 8;
2065       tagnum += GETJOCTET(data[offset]);
2066     }
2067     if (tagnum == 0xA002 || tagnum == 0xA003) {
2068       if (tagnum == 0xA002)
2069 	new_value = new_width; /* ExifImageWidth Tag */
2070       else
2071 	new_value = new_height; /* ExifImageHeight Tag */
2072       if (is_motorola) {
2073 	data[offset+2] = 0; /* Format = unsigned long (4 octets) */
2074 	data[offset+3] = 4;
2075 	data[offset+4] = 0; /* Number Of Components = 1 */
2076 	data[offset+5] = 0;
2077 	data[offset+6] = 0;
2078 	data[offset+7] = 1;
2079 	data[offset+8] = 0;
2080 	data[offset+9] = 0;
2081 	data[offset+10] = (JOCTET)((new_value >> 8) & 0xFF);
2082 	data[offset+11] = (JOCTET)(new_value & 0xFF);
2083       } else {
2084 	data[offset+2] = 4; /* Format = unsigned long (4 octets) */
2085 	data[offset+3] = 0;
2086 	data[offset+4] = 1; /* Number Of Components = 1 */
2087 	data[offset+5] = 0;
2088 	data[offset+6] = 0;
2089 	data[offset+7] = 0;
2090 	data[offset+8] = (JOCTET)(new_value & 0xFF);
2091 	data[offset+9] = (JOCTET)((new_value >> 8) & 0xFF);
2092 	data[offset+10] = 0;
2093 	data[offset+11] = 0;
2094       }
2095     }
2096     offset += 12;
2097   } while (--number_of_tags);
2098 }
2099 
2100 
2101 /* Adjust output image parameters as needed.
2102  *
2103  * This must be called after jpeg_copy_critical_parameters()
2104  * and before jpeg_write_coefficients().
2105  *
2106  * The return value is the set of virtual coefficient arrays to be written
2107  * (either the ones allocated by jtransform_request_workspace, or the
2108  * original source data arrays).  The caller will need to pass this value
2109  * to jpeg_write_coefficients().
2110  */
2111 
2112 GLOBAL(jvirt_barray_ptr *)
jtransform_adjust_parameters(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays,jpeg_transform_info * info)2113 jtransform_adjust_parameters (j_decompress_ptr srcinfo,
2114 			      j_compress_ptr dstinfo,
2115 			      jvirt_barray_ptr *src_coef_arrays,
2116 			      jpeg_transform_info *info)
2117 {
2118   /* If force-to-grayscale is requested, adjust destination parameters */
2119   if (info->force_grayscale) {
2120     /* First, ensure we have YCC or grayscale data, and that the source's
2121      * Y channel is full resolution.  (No reasonable person would make Y
2122      * be less than full resolution, so actually coping with that case
2123      * isn't worth extra code space.  But we check it to avoid crashing.)
2124      */
2125     if ((((dstinfo->jpeg_color_space == JCS_YCbCr ||
2126 	   dstinfo->jpeg_color_space == JCS_BG_YCC) &&
2127 	  dstinfo->num_components == 3) ||
2128 	 (dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
2129 	  dstinfo->num_components == 1)) &&
2130 	srcinfo->comp_info[0].h_samp_factor == srcinfo->max_h_samp_factor &&
2131 	srcinfo->comp_info[0].v_samp_factor == srcinfo->max_v_samp_factor) {
2132       /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
2133        * properly.  Among other things, it sets the target h_samp_factor &
2134        * v_samp_factor to 1, which typically won't match the source.
2135        * We have to preserve the source's quantization table number, however.
2136        */
2137       int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;
2138       jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);
2139       dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;
2140     } else {
2141       /* Sorry, can't do it */
2142       ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);
2143     }
2144   } else if (info->num_components == 1) {
2145     /* For a single-component source, we force the destination sampling factors
2146      * to 1x1, with or without force_grayscale.  This is useful because some
2147      * decoders choke on grayscale images with other sampling factors.
2148      */
2149     dstinfo->comp_info[0].h_samp_factor = 1;
2150     dstinfo->comp_info[0].v_samp_factor = 1;
2151   }
2152 
2153   /* Correct the destination's image dimensions as necessary
2154    * for rotate/flip, resize, and crop operations.
2155    */
2156   dstinfo->jpeg_width = info->output_width;
2157   dstinfo->jpeg_height = info->output_height;
2158 
2159   /* Transpose destination image parameters, adjust quantization */
2160   switch (info->transform) {
2161   case JXFORM_TRANSPOSE:
2162   case JXFORM_TRANSVERSE:
2163   case JXFORM_ROT_90:
2164   case JXFORM_ROT_270:
2165     transpose_critical_parameters(dstinfo);
2166     break;
2167   case JXFORM_DROP:
2168     if (info->drop_width != 0 && info->drop_height != 0)
2169       adjust_quant(srcinfo, src_coef_arrays,
2170 		   info->drop_ptr, info->drop_coef_arrays,
2171 		   info->trim, dstinfo);
2172     break;
2173   default:
2174     break;
2175   }
2176 
2177   /* Adjust Exif properties */
2178   if (srcinfo->marker_list != NULL &&
2179       srcinfo->marker_list->marker == JPEG_APP0+1 &&
2180       srcinfo->marker_list->data_length >= 6 &&
2181       GETJOCTET(srcinfo->marker_list->data[0]) == 0x45 &&
2182       GETJOCTET(srcinfo->marker_list->data[1]) == 0x78 &&
2183       GETJOCTET(srcinfo->marker_list->data[2]) == 0x69 &&
2184       GETJOCTET(srcinfo->marker_list->data[3]) == 0x66 &&
2185       GETJOCTET(srcinfo->marker_list->data[4]) == 0 &&
2186       GETJOCTET(srcinfo->marker_list->data[5]) == 0) {
2187     /* Suppress output of JFIF marker */
2188     dstinfo->write_JFIF_header = FALSE;
2189     /* Adjust Exif image parameters */
2190     if (dstinfo->jpeg_width != srcinfo->image_width ||
2191 	dstinfo->jpeg_height != srcinfo->image_height)
2192       /* Align data segment to start of TIFF structure for parsing */
2193       adjust_exif_parameters(srcinfo->marker_list->data + 6,
2194 	srcinfo->marker_list->data_length - 6,
2195 	dstinfo->jpeg_width, dstinfo->jpeg_height);
2196   }
2197 
2198   /* Return the appropriate output data set */
2199   if (info->workspace_coef_arrays != NULL)
2200     return info->workspace_coef_arrays;
2201   return src_coef_arrays;
2202 }
2203 
2204 
2205 /* Execute the actual transformation, if any.
2206  *
2207  * This must be called *after* jpeg_write_coefficients, because it depends
2208  * on jpeg_write_coefficients to have computed subsidiary values such as
2209  * the per-component width and height fields in the destination object.
2210  *
2211  * Note that some transformations will modify the source data arrays!
2212  */
2213 
2214 GLOBAL(void)
jtransform_execute_transform(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays,jpeg_transform_info * info)2215 jtransform_execute_transform (j_decompress_ptr srcinfo,
2216 			      j_compress_ptr dstinfo,
2217 			      jvirt_barray_ptr *src_coef_arrays,
2218 			      jpeg_transform_info *info)
2219 {
2220   jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;
2221 
2222   /* Note: conditions tested here should match those in switch statement
2223    * in jtransform_request_workspace()
2224    */
2225   switch (info->transform) {
2226   case JXFORM_NONE:
2227     if (info->output_width > srcinfo->output_width ||
2228 	info->output_height > srcinfo->output_height) {
2229       if (info->output_width > srcinfo->output_width &&
2230 	  info->crop_width_set == JCROP_REFLECT)
2231 	do_crop_ext_reflect(srcinfo, dstinfo,
2232 			    info->x_crop_offset, info->y_crop_offset,
2233 			    src_coef_arrays, dst_coef_arrays);
2234       else if (info->output_width > srcinfo->output_width &&
2235 	       info->crop_width_set == JCROP_FORCE)
2236 	do_crop_ext_flat(srcinfo, dstinfo,
2237 			 info->x_crop_offset, info->y_crop_offset,
2238 			 src_coef_arrays, dst_coef_arrays);
2239       else
2240 	do_crop_ext_zero(srcinfo, dstinfo,
2241 			 info->x_crop_offset, info->y_crop_offset,
2242 			 src_coef_arrays, dst_coef_arrays);
2243     } else if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
2244       do_crop(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2245 	      src_coef_arrays, dst_coef_arrays);
2246     break;
2247   case JXFORM_FLIP_H:
2248     if (info->y_crop_offset != 0)
2249       do_flip_h(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2250 		src_coef_arrays, dst_coef_arrays);
2251     else
2252       do_flip_h_no_crop(srcinfo, dstinfo, info->x_crop_offset,
2253 			src_coef_arrays);
2254     break;
2255   case JXFORM_FLIP_V:
2256     do_flip_v(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2257 	      src_coef_arrays, dst_coef_arrays);
2258     break;
2259   case JXFORM_TRANSPOSE:
2260     do_transpose(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2261 		 src_coef_arrays, dst_coef_arrays);
2262     break;
2263   case JXFORM_TRANSVERSE:
2264     do_transverse(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2265 		  src_coef_arrays, dst_coef_arrays);
2266     break;
2267   case JXFORM_ROT_90:
2268     do_rot_90(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2269 	      src_coef_arrays, dst_coef_arrays);
2270     break;
2271   case JXFORM_ROT_180:
2272     do_rot_180(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2273 	       src_coef_arrays, dst_coef_arrays);
2274     break;
2275   case JXFORM_ROT_270:
2276     do_rot_270(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2277 	       src_coef_arrays, dst_coef_arrays);
2278     break;
2279   case JXFORM_WIPE:
2280     if (info->crop_width_set == JCROP_REFLECT &&
2281 	info->y_crop_offset == 0 && info->drop_height ==
2282 	(JDIMENSION) jdiv_round_up
2283 	  ((long) info->output_height, (long) info->iMCU_sample_height) &&
2284 	(info->x_crop_offset == 0 ||
2285 	 info->x_crop_offset + info->drop_width ==
2286 	 (JDIMENSION) jdiv_round_up
2287 	   ((long) info->output_width, (long) info->iMCU_sample_width)))
2288       do_reflect(srcinfo, dstinfo, info->x_crop_offset,
2289 		 src_coef_arrays, info->drop_width, info->drop_height);
2290     else if (info->crop_width_set == JCROP_FORCE)
2291       do_flatten(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2292 		 src_coef_arrays, info->drop_width, info->drop_height);
2293     else
2294       do_wipe(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2295 	      src_coef_arrays, info->drop_width, info->drop_height);
2296     break;
2297   case JXFORM_DROP:
2298     if (info->drop_width != 0 && info->drop_height != 0)
2299       do_drop(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
2300 	      src_coef_arrays, info->drop_ptr, info->drop_coef_arrays,
2301 	      info->drop_width, info->drop_height);
2302     break;
2303   }
2304 }
2305 
2306 /* jtransform_perfect_transform
2307  *
2308  * Determine whether lossless transformation is perfectly
2309  * possible for a specified image and transformation.
2310  *
2311  * Inputs:
2312  *   image_width, image_height: source image dimensions.
2313  *   MCU_width, MCU_height: pixel dimensions of MCU.
2314  *   transform: transformation identifier.
2315  * Parameter sources from initialized jpeg_struct
2316  * (after reading source header):
2317  *   image_width = cinfo.image_width
2318  *   image_height = cinfo.image_height
2319  *   MCU_width = cinfo.max_h_samp_factor * cinfo.block_size
2320  *   MCU_height = cinfo.max_v_samp_factor * cinfo.block_size
2321  * Result:
2322  *   TRUE = perfect transformation possible
2323  *   FALSE = perfect transformation not possible
2324  *           (may use custom action then)
2325  */
2326 
2327 GLOBAL(boolean)
jtransform_perfect_transform(JDIMENSION image_width,JDIMENSION image_height,int MCU_width,int MCU_height,JXFORM_CODE transform)2328 jtransform_perfect_transform(JDIMENSION image_width, JDIMENSION image_height,
2329 			     int MCU_width, int MCU_height,
2330 			     JXFORM_CODE transform)
2331 {
2332   boolean result = TRUE; /* initialize TRUE */
2333 
2334   switch (transform) {
2335   case JXFORM_FLIP_H:
2336   case JXFORM_ROT_270:
2337     if (image_width % (JDIMENSION) MCU_width)
2338       result = FALSE;
2339     break;
2340   case JXFORM_FLIP_V:
2341   case JXFORM_ROT_90:
2342     if (image_height % (JDIMENSION) MCU_height)
2343       result = FALSE;
2344     break;
2345   case JXFORM_TRANSVERSE:
2346   case JXFORM_ROT_180:
2347     if (image_width % (JDIMENSION) MCU_width)
2348       result = FALSE;
2349     if (image_height % (JDIMENSION) MCU_height)
2350       result = FALSE;
2351     break;
2352   default:
2353     break;
2354   }
2355 
2356   return result;
2357 }
2358 
2359 #endif /* TRANSFORMS_SUPPORTED */
2360 
2361 
2362 /* Setup decompression object to save desired markers in memory.
2363  * This must be called before jpeg_read_header() to have the desired effect.
2364  */
2365 
2366 GLOBAL(void)
jcopy_markers_setup(j_decompress_ptr srcinfo,JCOPY_OPTION option)2367 jcopy_markers_setup (j_decompress_ptr srcinfo, JCOPY_OPTION option)
2368 {
2369 #ifdef SAVE_MARKERS_SUPPORTED
2370   int m;
2371 
2372   /* Save comments except under NONE option */
2373   if (option != JCOPYOPT_NONE) {
2374     jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);
2375   }
2376   /* Save all types of APPn markers iff ALL option */
2377   if (option == JCOPYOPT_ALL) {
2378     for (m = 0; m < 16; m++)
2379       jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);
2380   }
2381 #endif /* SAVE_MARKERS_SUPPORTED */
2382 }
2383 
2384 /* Copy markers saved in the given source object to the destination object.
2385  * This should be called just after jpeg_start_compress() or
2386  * jpeg_write_coefficients().
2387  * Note that those routines will have written the SOI, and also the
2388  * JFIF APP0 or Adobe APP14 markers if selected.
2389  */
2390 
2391 GLOBAL(void)
jcopy_markers_execute(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JCOPY_OPTION option)2392 jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
2393 		       JCOPY_OPTION option)
2394 {
2395   jpeg_saved_marker_ptr marker;
2396 
2397   /* In the current implementation, we don't actually need to examine the
2398    * option flag here; we just copy everything that got saved.
2399    * But to avoid confusion, we do not output JFIF and Adobe APP14 markers
2400    * if the encoder library already wrote one.
2401    */
2402   for (marker = srcinfo->marker_list; marker != NULL; marker = marker->next) {
2403     if (dstinfo->write_JFIF_header &&
2404 	marker->marker == JPEG_APP0 &&
2405 	marker->data_length >= 5 &&
2406 	GETJOCTET(marker->data[0]) == 0x4A &&
2407 	GETJOCTET(marker->data[1]) == 0x46 &&
2408 	GETJOCTET(marker->data[2]) == 0x49 &&
2409 	GETJOCTET(marker->data[3]) == 0x46 &&
2410 	GETJOCTET(marker->data[4]) == 0)
2411       continue;			/* reject duplicate JFIF */
2412     if (dstinfo->write_Adobe_marker &&
2413 	marker->marker == JPEG_APP0+14 &&
2414 	marker->data_length >= 5 &&
2415 	GETJOCTET(marker->data[0]) == 0x41 &&
2416 	GETJOCTET(marker->data[1]) == 0x64 &&
2417 	GETJOCTET(marker->data[2]) == 0x6F &&
2418 	GETJOCTET(marker->data[3]) == 0x62 &&
2419 	GETJOCTET(marker->data[4]) == 0x65)
2420       continue;			/* reject duplicate Adobe */
2421 #ifdef NEED_FAR_POINTERS
2422     /* We could use jpeg_write_marker if the data weren't FAR... */
2423     {
2424       unsigned int i;
2425       jpeg_write_m_header(dstinfo, marker->marker, marker->data_length);
2426       for (i = 0; i < marker->data_length; i++)
2427 	jpeg_write_m_byte(dstinfo, marker->data[i]);
2428     }
2429 #else
2430     jpeg_write_marker(dstinfo, marker->marker,
2431 		      marker->data, marker->data_length);
2432 #endif
2433   }
2434 }
2435