1 /*
2 * transupp.c
3 *
4 * Copyright (C) 1997, Thomas G. Lane.
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 */
18 #define JPEG_INTERNALS
19
20 #include "jinclude.h"
21 #include "jpeglib.h"
22 #include "transupp.h" /* My own external interface */
23
24
25 #if TRANSFORMS_SUPPORTED
26
27 /*
28 * Lossless image transformation routines. These routines work on DCT
29 * coefficient arrays and thus do not require any lossy decompression
30 * or recompression of the image.
31 * Thanks to Guido Vollbeding for the initial design and code of this feature.
32 *
33 * Horizontal flipping is done in-place, using a single top-to-bottom
34 * pass through the virtual source array. It will thus be much the
35 * fastest option for images larger than main memory.
36 *
37 * The other routines require a set of destination virtual arrays, so they
38 * need twice as much memory as jpegtran normally does. The destination
39 * arrays are always written in normal scan order (top to bottom) because
40 * the virtual array manager expects this. The source arrays will be scanned
41 * in the corresponding order, which means multiple passes through the source
42 * arrays for most of the transforms. That could result in much thrashing
43 * if the image is larger than main memory.
44 *
45 * Some notes about the operating environment of the individual transform
46 * routines:
47 * 1. Both the source and destination virtual arrays are allocated from the
48 * source JPEG object, and therefore should be manipulated by calling the
49 * source's memory manager.
50 * 2. The destination's component count should be used. It may be smaller
51 * than the source's when forcing to grayscale.
52 * 3. Likewise the destination's sampling factors should be used. When
53 * forcing to grayscale the destination's sampling factors will be all 1,
54 * and we may as well take that as the effective iMCU size.
55 * 4. When "trim" is in effect, the destination's dimensions will be the
56 * trimmed values but the source's will be untrimmed.
57 * 5. All the routines assume that the source and destination buffers are
58 * padded out to a full iMCU boundary. This is true, although for the
59 * source buffer it is an undocumented property of jdcoefct.c.
60 * Notes 2,3,4 boil down to this: generally we should use the destination's
61 * dimensions and ignore the source's.
62 */
63
64
65 LOCAL(void)
do_flip_h(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays)66 do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
67 jvirt_barray_ptr *src_coef_arrays)
68 /* Horizontal flip; done in-place, so no separate dest array is required */
69 {
70 JDIMENSION MCU_cols, comp_width, blk_x, blk_y;
71 int ci, k, offset_y;
72 JBLOCKARRAY buffer;
73 JCOEFPTR ptr1, ptr2;
74 JCOEF temp1, temp2;
75 jpeg_component_info *compptr;
76
77 /* Horizontal mirroring of DCT blocks is accomplished by swapping
78 * pairs of blocks in-place. Within a DCT block, we perform horizontal
79 * mirroring by changing the signs of odd-numbered columns.
80 * Partial iMCUs at the right edge are left untouched.
81 */
82 MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
83
84 for (ci = 0; ci < dstinfo->num_components; ci++) {
85 compptr = dstinfo->comp_info + ci;
86 comp_width = MCU_cols * compptr->h_samp_factor;
87 for (blk_y = 0; blk_y < compptr->height_in_blocks;
88 blk_y += compptr->v_samp_factor) {
89 buffer = (*srcinfo->mem->access_virt_barray)
90 ((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,
91 (JDIMENSION) compptr->v_samp_factor, TRUE);
92 for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
93 for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {
94 ptr1 = buffer[offset_y][blk_x];
95 ptr2 = buffer[offset_y][comp_width - blk_x - 1];
96 /* this unrolled loop doesn't need to know which row it's on... */
97 for (k = 0; k < DCTSIZE2; k += 2) {
98 temp1 = *ptr1; /* swap even column */
99 temp2 = *ptr2;
100 *ptr1++ = temp2;
101 *ptr2++ = temp1;
102 temp1 = *ptr1; /* swap odd column with sign change */
103 temp2 = *ptr2;
104 *ptr1++ = -temp2;
105 *ptr2++ = -temp1;
106 }
107 }
108 }
109 }
110 }
111 }
112
113
114 LOCAL(void)
do_flip_v(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)115 do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
116 jvirt_barray_ptr *src_coef_arrays,
117 jvirt_barray_ptr *dst_coef_arrays)
118 /* Vertical flip */
119 {
120 JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
121 int ci, i, j, offset_y;
122 JBLOCKARRAY src_buffer, dst_buffer;
123 JBLOCKROW src_row_ptr, dst_row_ptr;
124 JCOEFPTR src_ptr, dst_ptr;
125 jpeg_component_info *compptr;
126
127 /* We output into a separate array because we can't touch different
128 * rows of the source virtual array simultaneously. Otherwise, this
129 * is a pretty straightforward analog of horizontal flip.
130 * Within a DCT block, vertical mirroring is done by changing the signs
131 * of odd-numbered rows.
132 * Partial iMCUs at the bottom edge are copied verbatim.
133 */
134 MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
135
136 for (ci = 0; ci < dstinfo->num_components; ci++) {
137 compptr = dstinfo->comp_info + ci;
138 comp_height = MCU_rows * compptr->v_samp_factor;
139 for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
140 dst_blk_y += compptr->v_samp_factor) {
141 dst_buffer = (*srcinfo->mem->access_virt_barray)
142 ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
143 (JDIMENSION) compptr->v_samp_factor, TRUE);
144 if (dst_blk_y < comp_height) {
145 /* Row is within the mirrorable area. */
146 src_buffer = (*srcinfo->mem->access_virt_barray)
147 ((j_common_ptr) srcinfo, src_coef_arrays[ci],
148 comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
149 (JDIMENSION) compptr->v_samp_factor, FALSE);
150 } else {
151 /* Bottom-edge blocks will be copied verbatim. */
152 src_buffer = (*srcinfo->mem->access_virt_barray)
153 ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
154 (JDIMENSION) compptr->v_samp_factor, FALSE);
155 }
156 for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
157 if (dst_blk_y < comp_height) {
158 /* Row is within the mirrorable area. */
159 dst_row_ptr = dst_buffer[offset_y];
160 src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
161 for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
162 dst_blk_x++) {
163 dst_ptr = dst_row_ptr[dst_blk_x];
164 src_ptr = src_row_ptr[dst_blk_x];
165 for (i = 0; i < DCTSIZE; i += 2) {
166 /* copy even row */
167 for (j = 0; j < DCTSIZE; j++)
168 *dst_ptr++ = *src_ptr++;
169 /* copy odd row with sign change */
170 for (j = 0; j < DCTSIZE; j++)
171 *dst_ptr++ = - *src_ptr++;
172 }
173 }
174 } else {
175 /* Just copy row verbatim. */
176 jcopy_block_row(src_buffer[offset_y], dst_buffer[offset_y],
177 compptr->width_in_blocks);
178 }
179 }
180 }
181 }
182 }
183
184
185 LOCAL(void)
do_transpose(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)186 do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
187 jvirt_barray_ptr *src_coef_arrays,
188 jvirt_barray_ptr *dst_coef_arrays)
189 /* Transpose source into destination */
190 {
191 JDIMENSION dst_blk_x, dst_blk_y;
192 int ci, i, j, offset_x, offset_y;
193 JBLOCKARRAY src_buffer, dst_buffer;
194 JCOEFPTR src_ptr, dst_ptr;
195 jpeg_component_info *compptr;
196
197 /* Transposing pixels within a block just requires transposing the
198 * DCT coefficients.
199 * Partial iMCUs at the edges require no special treatment; we simply
200 * process all the available DCT blocks for every component.
201 */
202 for (ci = 0; ci < dstinfo->num_components; ci++) {
203 compptr = dstinfo->comp_info + ci;
204 for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
205 dst_blk_y += compptr->v_samp_factor) {
206 dst_buffer = (*srcinfo->mem->access_virt_barray)
207 ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
208 (JDIMENSION) compptr->v_samp_factor, TRUE);
209 for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
210 for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
211 dst_blk_x += compptr->h_samp_factor) {
212 src_buffer = (*srcinfo->mem->access_virt_barray)
213 ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
214 (JDIMENSION) compptr->h_samp_factor, FALSE);
215 for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
216 src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
217 dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
218 for (i = 0; i < DCTSIZE; i++)
219 for (j = 0; j < DCTSIZE; j++)
220 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
221 }
222 }
223 }
224 }
225 }
226 }
227
228
229 LOCAL(void)
do_rot_90(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)230 do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
231 jvirt_barray_ptr *src_coef_arrays,
232 jvirt_barray_ptr *dst_coef_arrays)
233 /* 90 degree rotation is equivalent to
234 * 1. Transposing the image;
235 * 2. Horizontal mirroring.
236 * These two steps are merged into a single processing routine.
237 */
238 {
239 JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
240 int ci, i, j, offset_x, offset_y;
241 JBLOCKARRAY src_buffer, dst_buffer;
242 JCOEFPTR src_ptr, dst_ptr;
243 jpeg_component_info *compptr;
244
245 /* Because of the horizontal mirror step, we can't process partial iMCUs
246 * at the (output) right edge properly. They just get transposed and
247 * not mirrored.
248 */
249 MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
250
251 for (ci = 0; ci < dstinfo->num_components; ci++) {
252 compptr = dstinfo->comp_info + ci;
253 comp_width = MCU_cols * compptr->h_samp_factor;
254 for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
255 dst_blk_y += compptr->v_samp_factor) {
256 dst_buffer = (*srcinfo->mem->access_virt_barray)
257 ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
258 (JDIMENSION) compptr->v_samp_factor, TRUE);
259 for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
260 for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
261 dst_blk_x += compptr->h_samp_factor) {
262 src_buffer = (*srcinfo->mem->access_virt_barray)
263 ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
264 (JDIMENSION) compptr->h_samp_factor, FALSE);
265 for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
266 src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
267 if (dst_blk_x < comp_width) {
268 /* Block is within the mirrorable area. */
269 dst_ptr = dst_buffer[offset_y]
270 [comp_width - dst_blk_x - offset_x - 1];
271 for (i = 0; i < DCTSIZE; i++) {
272 for (j = 0; j < DCTSIZE; j++)
273 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
274 i++;
275 for (j = 0; j < DCTSIZE; j++)
276 dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
277 }
278 } else {
279 /* Edge blocks are transposed but not mirrored. */
280 dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
281 for (i = 0; i < DCTSIZE; i++)
282 for (j = 0; j < DCTSIZE; j++)
283 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
284 }
285 }
286 }
287 }
288 }
289 }
290 }
291
292
293 LOCAL(void)
do_rot_270(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)294 do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
295 jvirt_barray_ptr *src_coef_arrays,
296 jvirt_barray_ptr *dst_coef_arrays)
297 /* 270 degree rotation is equivalent to
298 * 1. Horizontal mirroring;
299 * 2. Transposing the image.
300 * These two steps are merged into a single processing routine.
301 */
302 {
303 JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
304 int ci, i, j, offset_x, offset_y;
305 JBLOCKARRAY src_buffer, dst_buffer;
306 JCOEFPTR src_ptr, dst_ptr;
307 jpeg_component_info *compptr;
308
309 /* Because of the horizontal mirror step, we can't process partial iMCUs
310 * at the (output) bottom edge properly. They just get transposed and
311 * not mirrored.
312 */
313 MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
314
315 for (ci = 0; ci < dstinfo->num_components; ci++) {
316 compptr = dstinfo->comp_info + ci;
317 comp_height = MCU_rows * compptr->v_samp_factor;
318 for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
319 dst_blk_y += compptr->v_samp_factor) {
320 dst_buffer = (*srcinfo->mem->access_virt_barray)
321 ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
322 (JDIMENSION) compptr->v_samp_factor, TRUE);
323 for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
324 for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
325 dst_blk_x += compptr->h_samp_factor) {
326 src_buffer = (*srcinfo->mem->access_virt_barray)
327 ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
328 (JDIMENSION) compptr->h_samp_factor, FALSE);
329 for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
330 dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
331 if (dst_blk_y < comp_height) {
332 /* Block is within the mirrorable area. */
333 src_ptr = src_buffer[offset_x]
334 [comp_height - dst_blk_y - offset_y - 1];
335 for (i = 0; i < DCTSIZE; i++) {
336 for (j = 0; j < DCTSIZE; j++) {
337 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
338 j++;
339 dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
340 }
341 }
342 } else {
343 /* Edge blocks are transposed but not mirrored. */
344 src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
345 for (i = 0; i < DCTSIZE; i++)
346 for (j = 0; j < DCTSIZE; j++)
347 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
348 }
349 }
350 }
351 }
352 }
353 }
354 }
355
356
357 LOCAL(void)
do_rot_180(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)358 do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
359 jvirt_barray_ptr *src_coef_arrays,
360 jvirt_barray_ptr *dst_coef_arrays)
361 /* 180 degree rotation is equivalent to
362 * 1. Vertical mirroring;
363 * 2. Horizontal mirroring.
364 * These two steps are merged into a single processing routine.
365 */
366 {
367 JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
368 int ci, i, j, offset_y;
369 JBLOCKARRAY src_buffer, dst_buffer;
370 JBLOCKROW src_row_ptr, dst_row_ptr;
371 JCOEFPTR src_ptr, dst_ptr;
372 jpeg_component_info *compptr;
373
374 MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
375 MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
376
377 for (ci = 0; ci < dstinfo->num_components; ci++) {
378 compptr = dstinfo->comp_info + ci;
379 comp_width = MCU_cols * compptr->h_samp_factor;
380 comp_height = MCU_rows * compptr->v_samp_factor;
381 for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
382 dst_blk_y += compptr->v_samp_factor) {
383 dst_buffer = (*srcinfo->mem->access_virt_barray)
384 ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
385 (JDIMENSION) compptr->v_samp_factor, TRUE);
386 if (dst_blk_y < comp_height) {
387 /* Row is within the vertically mirrorable area. */
388 src_buffer = (*srcinfo->mem->access_virt_barray)
389 ((j_common_ptr) srcinfo, src_coef_arrays[ci],
390 comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
391 (JDIMENSION) compptr->v_samp_factor, FALSE);
392 } else {
393 /* Bottom-edge rows are only mirrored horizontally. */
394 src_buffer = (*srcinfo->mem->access_virt_barray)
395 ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
396 (JDIMENSION) compptr->v_samp_factor, FALSE);
397 }
398 for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
399 if (dst_blk_y < comp_height) {
400 /* Row is within the mirrorable area. */
401 dst_row_ptr = dst_buffer[offset_y];
402 src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
403 /* Process the blocks that can be mirrored both ways. */
404 for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
405 dst_ptr = dst_row_ptr[dst_blk_x];
406 src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
407 for (i = 0; i < DCTSIZE; i += 2) {
408 /* For even row, negate every odd column. */
409 for (j = 0; j < DCTSIZE; j += 2) {
410 *dst_ptr++ = *src_ptr++;
411 *dst_ptr++ = - *src_ptr++;
412 }
413 /* For odd row, negate every even column. */
414 for (j = 0; j < DCTSIZE; j += 2) {
415 *dst_ptr++ = - *src_ptr++;
416 *dst_ptr++ = *src_ptr++;
417 }
418 }
419 }
420 /* Any remaining right-edge blocks are only mirrored vertically. */
421 for (; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
422 dst_ptr = dst_row_ptr[dst_blk_x];
423 src_ptr = src_row_ptr[dst_blk_x];
424 for (i = 0; i < DCTSIZE; i += 2) {
425 for (j = 0; j < DCTSIZE; j++)
426 *dst_ptr++ = *src_ptr++;
427 for (j = 0; j < DCTSIZE; j++)
428 *dst_ptr++ = - *src_ptr++;
429 }
430 }
431 } else {
432 /* Remaining rows are just mirrored horizontally. */
433 dst_row_ptr = dst_buffer[offset_y];
434 src_row_ptr = src_buffer[offset_y];
435 /* Process the blocks that can be mirrored. */
436 for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
437 dst_ptr = dst_row_ptr[dst_blk_x];
438 src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
439 for (i = 0; i < DCTSIZE2; i += 2) {
440 *dst_ptr++ = *src_ptr++;
441 *dst_ptr++ = - *src_ptr++;
442 }
443 }
444 /* Any remaining right-edge blocks are only copied. */
445 for (; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
446 dst_ptr = dst_row_ptr[dst_blk_x];
447 src_ptr = src_row_ptr[dst_blk_x];
448 for (i = 0; i < DCTSIZE2; i++)
449 *dst_ptr++ = *src_ptr++;
450 }
451 }
452 }
453 }
454 }
455 }
456
457
458 LOCAL(void)
do_transverse(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays,jvirt_barray_ptr * dst_coef_arrays)459 do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
460 jvirt_barray_ptr *src_coef_arrays,
461 jvirt_barray_ptr *dst_coef_arrays)
462 /* Transverse transpose is equivalent to
463 * 1. 180 degree rotation;
464 * 2. Transposition;
465 * or
466 * 1. Horizontal mirroring;
467 * 2. Transposition;
468 * 3. Horizontal mirroring.
469 * These steps are merged into a single processing routine.
470 */
471 {
472 JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
473 int ci, i, j, offset_x, offset_y;
474 JBLOCKARRAY src_buffer, dst_buffer;
475 JCOEFPTR src_ptr, dst_ptr;
476 jpeg_component_info *compptr;
477
478 MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
479 MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
480
481 for (ci = 0; ci < dstinfo->num_components; ci++) {
482 compptr = dstinfo->comp_info + ci;
483 comp_width = MCU_cols * compptr->h_samp_factor;
484 comp_height = MCU_rows * compptr->v_samp_factor;
485 for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
486 dst_blk_y += compptr->v_samp_factor) {
487 dst_buffer = (*srcinfo->mem->access_virt_barray)
488 ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
489 (JDIMENSION) compptr->v_samp_factor, TRUE);
490 for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
491 for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
492 dst_blk_x += compptr->h_samp_factor) {
493 src_buffer = (*srcinfo->mem->access_virt_barray)
494 ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
495 (JDIMENSION) compptr->h_samp_factor, FALSE);
496 for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
497 if (dst_blk_y < comp_height) {
498 src_ptr = src_buffer[offset_x]
499 [comp_height - dst_blk_y - offset_y - 1];
500 if (dst_blk_x < comp_width) {
501 /* Block is within the mirrorable area. */
502 dst_ptr = dst_buffer[offset_y]
503 [comp_width - dst_blk_x - offset_x - 1];
504 for (i = 0; i < DCTSIZE; i++) {
505 for (j = 0; j < DCTSIZE; j++) {
506 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
507 j++;
508 dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
509 }
510 i++;
511 for (j = 0; j < DCTSIZE; j++) {
512 dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
513 j++;
514 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
515 }
516 }
517 } else {
518 /* Right-edge blocks are mirrored in y only */
519 dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
520 for (i = 0; i < DCTSIZE; i++) {
521 for (j = 0; j < DCTSIZE; j++) {
522 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
523 j++;
524 dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
525 }
526 }
527 }
528 } else {
529 src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
530 if (dst_blk_x < comp_width) {
531 /* Bottom-edge blocks are mirrored in x only */
532 dst_ptr = dst_buffer[offset_y]
533 [comp_width - dst_blk_x - offset_x - 1];
534 for (i = 0; i < DCTSIZE; i++) {
535 for (j = 0; j < DCTSIZE; j++)
536 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
537 i++;
538 for (j = 0; j < DCTSIZE; j++)
539 dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
540 }
541 } else {
542 /* At lower right corner, just transpose, no mirroring */
543 dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
544 for (i = 0; i < DCTSIZE; i++)
545 for (j = 0; j < DCTSIZE; j++)
546 dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
547 }
548 }
549 }
550 }
551 }
552 }
553 }
554 }
555
556
557 /* Request any required workspace.
558 *
559 * We allocate the workspace virtual arrays from the source decompression
560 * object, so that all the arrays (both the original data and the workspace)
561 * will be taken into account while making memory management decisions.
562 * Hence, this routine must be called after jpeg_read_header (which reads
563 * the image dimensions) and before jpeg_read_coefficients (which realizes
564 * the source's virtual arrays).
565 */
566
567 GLOBAL(void)
jtransform_request_workspace(j_decompress_ptr srcinfo,jpeg_transform_info * info)568 jtransform_request_workspace (j_decompress_ptr srcinfo,
569 jpeg_transform_info *info)
570 {
571 jvirt_barray_ptr *coef_arrays = NULL;
572 jpeg_component_info *compptr;
573 int ci;
574
575 if (info->force_grayscale &&
576 srcinfo->jpeg_color_space == JCS_YCbCr &&
577 srcinfo->num_components == 3) {
578 /* We'll only process the first component */
579 info->num_components = 1;
580 } else {
581 /* Process all the components */
582 info->num_components = srcinfo->num_components;
583 }
584
585 switch (info->transform) {
586 case JXFORM_NONE:
587 case JXFORM_FLIP_H:
588 /* Don't need a workspace array */
589 break;
590 case JXFORM_FLIP_V:
591 case JXFORM_ROT_180:
592 /* Need workspace arrays having same dimensions as source image.
593 * Note that we allocate arrays padded out to the next iMCU boundary,
594 * so that transform routines need not worry about missing edge blocks.
595 */
596 coef_arrays = (jvirt_barray_ptr *)
597 (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
598 SIZEOF(jvirt_barray_ptr) * info->num_components);
599 for (ci = 0; ci < info->num_components; ci++) {
600 compptr = srcinfo->comp_info + ci;
601 coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
602 ((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
603 (JDIMENSION) jround_up((long) compptr->width_in_blocks,
604 (long) compptr->h_samp_factor),
605 (JDIMENSION) jround_up((long) compptr->height_in_blocks,
606 (long) compptr->v_samp_factor),
607 (JDIMENSION) compptr->v_samp_factor);
608 }
609 break;
610 case JXFORM_TRANSPOSE:
611 case JXFORM_TRANSVERSE:
612 case JXFORM_ROT_90:
613 case JXFORM_ROT_270:
614 /* Need workspace arrays having transposed dimensions.
615 * Note that we allocate arrays padded out to the next iMCU boundary,
616 * so that transform routines need not worry about missing edge blocks.
617 */
618 coef_arrays = (jvirt_barray_ptr *)
619 (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
620 SIZEOF(jvirt_barray_ptr) * info->num_components);
621 for (ci = 0; ci < info->num_components; ci++) {
622 compptr = srcinfo->comp_info + ci;
623 coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
624 ((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
625 (JDIMENSION) jround_up((long) compptr->height_in_blocks,
626 (long) compptr->v_samp_factor),
627 (JDIMENSION) jround_up((long) compptr->width_in_blocks,
628 (long) compptr->h_samp_factor),
629 (JDIMENSION) compptr->h_samp_factor);
630 }
631 break;
632 }
633 info->workspace_coef_arrays = coef_arrays;
634 }
635
636
637 /* Transpose destination image parameters */
638
639 LOCAL(void)
transpose_critical_parameters(j_compress_ptr dstinfo)640 transpose_critical_parameters (j_compress_ptr dstinfo)
641 {
642 int tblno, i, j, ci, itemp;
643 jpeg_component_info *compptr;
644 JQUANT_TBL *qtblptr;
645 JDIMENSION dtemp;
646 UINT16 qtemp;
647
648 /* Transpose basic image dimensions */
649 dtemp = dstinfo->image_width;
650 dstinfo->image_width = dstinfo->image_height;
651 dstinfo->image_height = dtemp;
652
653 /* Transpose sampling factors */
654 for (ci = 0; ci < dstinfo->num_components; ci++) {
655 compptr = dstinfo->comp_info + ci;
656 itemp = compptr->h_samp_factor;
657 compptr->h_samp_factor = compptr->v_samp_factor;
658 compptr->v_samp_factor = itemp;
659 }
660
661 /* Transpose quantization tables */
662 for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
663 qtblptr = dstinfo->quant_tbl_ptrs[tblno];
664 if (qtblptr != NULL) {
665 for (i = 0; i < DCTSIZE; i++) {
666 for (j = 0; j < i; j++) {
667 qtemp = qtblptr->quantval[i*DCTSIZE+j];
668 qtblptr->quantval[i*DCTSIZE+j] = qtblptr->quantval[j*DCTSIZE+i];
669 qtblptr->quantval[j*DCTSIZE+i] = qtemp;
670 }
671 }
672 }
673 }
674 }
675
676
677 /* Trim off any partial iMCUs on the indicated destination edge */
678
679 LOCAL(void)
trim_right_edge(j_compress_ptr dstinfo)680 trim_right_edge (j_compress_ptr dstinfo)
681 {
682 int ci, max_h_samp_factor;
683 JDIMENSION MCU_cols;
684
685 /* We have to compute max_h_samp_factor ourselves,
686 * because it hasn't been set yet in the destination
687 * (and we don't want to use the source's value).
688 */
689 max_h_samp_factor = 1;
690 for (ci = 0; ci < dstinfo->num_components; ci++) {
691 int h_samp_factor = dstinfo->comp_info[ci].h_samp_factor;
692 max_h_samp_factor = MAX(max_h_samp_factor, h_samp_factor);
693 }
694 MCU_cols = dstinfo->image_width / (max_h_samp_factor * DCTSIZE);
695 if (MCU_cols > 0) /* can't trim to 0 pixels */
696 dstinfo->image_width = MCU_cols * (max_h_samp_factor * DCTSIZE);
697 }
698
699 LOCAL(void)
trim_bottom_edge(j_compress_ptr dstinfo)700 trim_bottom_edge (j_compress_ptr dstinfo)
701 {
702 int ci, max_v_samp_factor;
703 JDIMENSION MCU_rows;
704
705 /* We have to compute max_v_samp_factor ourselves,
706 * because it hasn't been set yet in the destination
707 * (and we don't want to use the source's value).
708 */
709 max_v_samp_factor = 1;
710 for (ci = 0; ci < dstinfo->num_components; ci++) {
711 int v_samp_factor = dstinfo->comp_info[ci].v_samp_factor;
712 max_v_samp_factor = MAX(max_v_samp_factor, v_samp_factor);
713 }
714 MCU_rows = dstinfo->image_height / (max_v_samp_factor * DCTSIZE);
715 if (MCU_rows > 0) /* can't trim to 0 pixels */
716 dstinfo->image_height = MCU_rows * (max_v_samp_factor * DCTSIZE);
717 }
718
719
720 /* Adjust output image parameters as needed.
721 *
722 * This must be called after jpeg_copy_critical_parameters()
723 * and before jpeg_write_coefficients().
724 *
725 * The return value is the set of virtual coefficient arrays to be written
726 * (either the ones allocated by jtransform_request_workspace, or the
727 * original source data arrays). The caller will need to pass this value
728 * to jpeg_write_coefficients().
729 */
730
731 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)732 jtransform_adjust_parameters (j_decompress_ptr srcinfo,
733 j_compress_ptr dstinfo,
734 jvirt_barray_ptr *src_coef_arrays,
735 jpeg_transform_info *info)
736 {
737 /* If force-to-grayscale is requested, adjust destination parameters */
738 if (info->force_grayscale) {
739 /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
740 * properly. Among other things, the target h_samp_factor & v_samp_factor
741 * will get set to 1, which typically won't match the source.
742 * In fact we do this even if the source is already grayscale; that
743 * provides an easy way of coercing a grayscale JPEG with funny sampling
744 * factors to the customary 1,1. (Some decoders fail on other factors.)
745 */
746 if ((dstinfo->jpeg_color_space == JCS_YCbCr &&
747 dstinfo->num_components == 3) ||
748 (dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
749 dstinfo->num_components == 1)) {
750 /* We have to preserve the source's quantization table number. */
751 int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;
752 jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);
753 dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;
754 } else {
755 /* Sorry, can't do it */
756 ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);
757 }
758 }
759
760 /* Correct the destination's image dimensions etc if necessary */
761 switch (info->transform) {
762 case JXFORM_NONE:
763 /* Nothing to do */
764 break;
765 case JXFORM_FLIP_H:
766 if (info->trim)
767 trim_right_edge(dstinfo);
768 break;
769 case JXFORM_FLIP_V:
770 if (info->trim)
771 trim_bottom_edge(dstinfo);
772 break;
773 case JXFORM_TRANSPOSE:
774 transpose_critical_parameters(dstinfo);
775 /* transpose does NOT have to trim anything */
776 break;
777 case JXFORM_TRANSVERSE:
778 transpose_critical_parameters(dstinfo);
779 if (info->trim) {
780 trim_right_edge(dstinfo);
781 trim_bottom_edge(dstinfo);
782 }
783 break;
784 case JXFORM_ROT_90:
785 transpose_critical_parameters(dstinfo);
786 if (info->trim)
787 trim_right_edge(dstinfo);
788 break;
789 case JXFORM_ROT_180:
790 if (info->trim) {
791 trim_right_edge(dstinfo);
792 trim_bottom_edge(dstinfo);
793 }
794 break;
795 case JXFORM_ROT_270:
796 transpose_critical_parameters(dstinfo);
797 if (info->trim)
798 trim_bottom_edge(dstinfo);
799 break;
800 }
801
802 /* Return the appropriate output data set */
803 if (info->workspace_coef_arrays != NULL)
804 return info->workspace_coef_arrays;
805 return src_coef_arrays;
806 }
807
808
809 /* Execute the actual transformation, if any.
810 *
811 * This must be called *after* jpeg_write_coefficients, because it depends
812 * on jpeg_write_coefficients to have computed subsidiary values such as
813 * the per-component width and height fields in the destination object.
814 *
815 * Note that some transformations will modify the source data arrays!
816 */
817
818 GLOBAL(void)
jtransform_execute_transformation(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,jvirt_barray_ptr * src_coef_arrays,jpeg_transform_info * info)819 jtransform_execute_transformation (j_decompress_ptr srcinfo,
820 j_compress_ptr dstinfo,
821 jvirt_barray_ptr *src_coef_arrays,
822 jpeg_transform_info *info)
823 {
824 jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;
825
826 switch (info->transform) {
827 case JXFORM_NONE:
828 break;
829 case JXFORM_FLIP_H:
830 do_flip_h(srcinfo, dstinfo, src_coef_arrays);
831 break;
832 case JXFORM_FLIP_V:
833 do_flip_v(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
834 break;
835 case JXFORM_TRANSPOSE:
836 do_transpose(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
837 break;
838 case JXFORM_TRANSVERSE:
839 do_transverse(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
840 break;
841 case JXFORM_ROT_90:
842 do_rot_90(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
843 break;
844 case JXFORM_ROT_180:
845 do_rot_180(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
846 break;
847 case JXFORM_ROT_270:
848 do_rot_270(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
849 break;
850 }
851 }
852
853 #endif /* TRANSFORMS_SUPPORTED */
854
855
856 /* Setup decompression object to save desired markers in memory.
857 * This must be called before jpeg_read_header() to have the desired effect.
858 */
859
860 GLOBAL(void)
jcopy_markers_setup(j_decompress_ptr srcinfo,JCOPY_OPTION option)861 jcopy_markers_setup (j_decompress_ptr srcinfo, JCOPY_OPTION option)
862 {
863 #ifdef SAVE_MARKERS_SUPPORTED
864 int m;
865
866 /* Save comments except under NONE option */
867 if (option != JCOPYOPT_NONE) {
868 jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);
869 }
870 /* Save all types of APPn markers iff ALL option */
871 if (option == JCOPYOPT_ALL) {
872 for (m = 0; m < 16; m++)
873 jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);
874 }
875 #endif /* SAVE_MARKERS_SUPPORTED */
876 }
877
878 /* Copy markers saved in the given source object to the destination object.
879 * This should be called just after jpeg_start_compress() or
880 * jpeg_write_coefficients().
881 * Note that those routines will have written the SOI, and also the
882 * JFIF APP0 or Adobe APP14 markers if selected.
883 */
884
885 GLOBAL(void)
jcopy_markers_execute(j_decompress_ptr srcinfo,j_compress_ptr dstinfo,JCOPY_OPTION option)886 jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
887 JCOPY_OPTION option)
888 {
889 jpeg_saved_marker_ptr marker;
890
891 /* In the current implementation, we don't actually need to examine the
892 * option flag here; we just copy everything that got saved.
893 * But to avoid confusion, we do not output JFIF and Adobe APP14 markers
894 * if the encoder library already wrote one.
895 */
896 for (marker = srcinfo->marker_list; marker != NULL; marker = marker->next) {
897 if (dstinfo->write_JFIF_header &&
898 marker->marker == JPEG_APP0 &&
899 marker->data_length >= 5 &&
900 GETJOCTET(marker->data[0]) == 0x4A &&
901 GETJOCTET(marker->data[1]) == 0x46 &&
902 GETJOCTET(marker->data[2]) == 0x49 &&
903 GETJOCTET(marker->data[3]) == 0x46 &&
904 GETJOCTET(marker->data[4]) == 0)
905 continue; /* reject duplicate JFIF */
906 if (dstinfo->write_Adobe_marker &&
907 marker->marker == JPEG_APP0+14 &&
908 marker->data_length >= 5 &&
909 GETJOCTET(marker->data[0]) == 0x41 &&
910 GETJOCTET(marker->data[1]) == 0x64 &&
911 GETJOCTET(marker->data[2]) == 0x6F &&
912 GETJOCTET(marker->data[3]) == 0x62 &&
913 GETJOCTET(marker->data[4]) == 0x65)
914 continue; /* reject duplicate Adobe */
915 #ifdef NEED_FAR_POINTERS
916 /* We could use jpeg_write_marker if the data weren't FAR... */
917 {
918 unsigned int i;
919 jpeg_write_m_header(dstinfo, marker->marker, marker->data_length);
920 for (i = 0; i < marker->data_length; i++)
921 jpeg_write_m_byte(dstinfo, marker->data[i]);
922 }
923 #else
924 jpeg_write_marker(dstinfo, marker->marker,
925 marker->data, marker->data_length);
926 #endif
927 }
928 }
929