source: trunk/libjpeg/transupp.c @ 15

Last change on this file since 15 was 15, checked in by Eugene Romanenko, 16 years ago

needed libs update

File size: 32.8 KB
Line 
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
65LOCAL(void)
66do_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
114LOCAL(void)
115do_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
185LOCAL(void)
186do_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
229LOCAL(void)
230do_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
293LOCAL(void)
294do_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
357LOCAL(void)
358do_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
458LOCAL(void)
459do_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
567GLOBAL(void)
568jtransform_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
639LOCAL(void)
640transpose_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
679LOCAL(void)
680trim_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
699LOCAL(void)
700trim_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
731GLOBAL(jvirt_barray_ptr *)
732jtransform_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
818GLOBAL(void)
819jtransform_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
860GLOBAL(void)
861jcopy_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
885GLOBAL(void)
886jcopy_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}
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