1 : /*
2 : * jctrans.c
3 : *
4 : * Copyright (C) 1995-1998, Thomas G. Lane.
5 : * Modified 2000-2009 by Guido Vollbeding.
6 : * This file is part of the Independent JPEG Group's software.
7 : * For conditions of distribution and use, see the accompanying README file.
8 : *
9 : * This file contains library routines for transcoding compression,
10 : * that is, writing raw DCT coefficient arrays to an output JPEG file.
11 : * The routines in jcapimin.c will also be needed by a transcoder.
12 : */
13 :
14 : #define JPEG_INTERNALS
15 : #include "jinclude.h"
16 : #include "jpeglib.h"
17 :
18 :
19 : /* Forward declarations */
20 : LOCAL(void) transencode_master_selection
21 : JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
22 : LOCAL(void) transencode_coef_controller
23 : JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
24 :
25 :
26 : /*
27 : * Compression initialization for writing raw-coefficient data.
28 : * Before calling this, all parameters and a data destination must be set up.
29 : * Call jpeg_finish_compress() to actually write the data.
30 : *
31 : * The number of passed virtual arrays must match cinfo->num_components.
32 : * Note that the virtual arrays need not be filled or even realized at
33 : * the time write_coefficients is called; indeed, if the virtual arrays
34 : * were requested from this compression object's memory manager, they
35 : * typically will be realized during this routine and filled afterwards.
36 : */
37 :
38 : GLOBAL(void)
39 0 : jpeg_write_coefficients (j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)
40 : {
41 0 : if (cinfo->global_state != CSTATE_START)
42 0 : ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
43 : /* Mark all tables to be written */
44 0 : jpeg_suppress_tables(cinfo, FALSE);
45 : /* (Re)initialize error mgr and destination modules */
46 0 : (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
47 0 : (*cinfo->dest->init_destination) (cinfo);
48 : /* Perform master selection of active modules */
49 0 : transencode_master_selection(cinfo, coef_arrays);
50 : /* Wait for jpeg_finish_compress() call */
51 0 : cinfo->next_scanline = 0; /* so jpeg_write_marker works */
52 0 : cinfo->global_state = CSTATE_WRCOEFS;
53 0 : }
54 :
55 :
56 : /*
57 : * Initialize the compression object with default parameters,
58 : * then copy from the source object all parameters needed for lossless
59 : * transcoding. Parameters that can be varied without loss (such as
60 : * scan script and Huffman optimization) are left in their default states.
61 : */
62 :
63 : GLOBAL(void)
64 0 : jpeg_copy_critical_parameters (j_decompress_ptr srcinfo,
65 : j_compress_ptr dstinfo)
66 : {
67 : JQUANT_TBL ** qtblptr;
68 : jpeg_component_info *incomp, *outcomp;
69 : JQUANT_TBL *c_quant, *slot_quant;
70 : int tblno, ci, coefi;
71 :
72 : /* Safety check to ensure start_compress not called yet. */
73 0 : if (dstinfo->global_state != CSTATE_START)
74 0 : ERREXIT1(dstinfo, JERR_BAD_STATE, dstinfo->global_state);
75 : /* Copy fundamental image dimensions */
76 0 : dstinfo->image_width = srcinfo->image_width;
77 0 : dstinfo->image_height = srcinfo->image_height;
78 0 : dstinfo->input_components = srcinfo->num_components;
79 0 : dstinfo->in_color_space = srcinfo->jpeg_color_space;
80 : #if JPEG_LIB_VERSION >= 70
81 : dstinfo->jpeg_width = srcinfo->output_width;
82 : dstinfo->jpeg_height = srcinfo->output_height;
83 : dstinfo->min_DCT_h_scaled_size = srcinfo->min_DCT_h_scaled_size;
84 : dstinfo->min_DCT_v_scaled_size = srcinfo->min_DCT_v_scaled_size;
85 : #endif
86 : /* Initialize all parameters to default values */
87 0 : jpeg_set_defaults(dstinfo);
88 : /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB.
89 : * Fix it to get the right header markers for the image colorspace.
90 : */
91 0 : jpeg_set_colorspace(dstinfo, srcinfo->jpeg_color_space);
92 0 : dstinfo->data_precision = srcinfo->data_precision;
93 0 : dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling;
94 : /* Copy the source's quantization tables. */
95 0 : for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
96 0 : if (srcinfo->quant_tbl_ptrs[tblno] != NULL) {
97 0 : qtblptr = & dstinfo->quant_tbl_ptrs[tblno];
98 0 : if (*qtblptr == NULL)
99 0 : *qtblptr = jpeg_alloc_quant_table((j_common_ptr) dstinfo);
100 0 : MEMCOPY((*qtblptr)->quantval,
101 : srcinfo->quant_tbl_ptrs[tblno]->quantval,
102 : SIZEOF((*qtblptr)->quantval));
103 0 : (*qtblptr)->sent_table = FALSE;
104 : }
105 : }
106 : /* Copy the source's per-component info.
107 : * Note we assume jpeg_set_defaults has allocated the dest comp_info array.
108 : */
109 0 : dstinfo->num_components = srcinfo->num_components;
110 0 : if (dstinfo->num_components < 1 || dstinfo->num_components > MAX_COMPONENTS)
111 0 : ERREXIT2(dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components,
112 : MAX_COMPONENTS);
113 0 : for (ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info;
114 0 : ci < dstinfo->num_components; ci++, incomp++, outcomp++) {
115 0 : outcomp->component_id = incomp->component_id;
116 0 : outcomp->h_samp_factor = incomp->h_samp_factor;
117 0 : outcomp->v_samp_factor = incomp->v_samp_factor;
118 0 : outcomp->quant_tbl_no = incomp->quant_tbl_no;
119 : /* Make sure saved quantization table for component matches the qtable
120 : * slot. If not, the input file re-used this qtable slot.
121 : * IJG encoder currently cannot duplicate this.
122 : */
123 0 : tblno = outcomp->quant_tbl_no;
124 0 : if (tblno < 0 || tblno >= NUM_QUANT_TBLS ||
125 0 : srcinfo->quant_tbl_ptrs[tblno] == NULL)
126 0 : ERREXIT1(dstinfo, JERR_NO_QUANT_TABLE, tblno);
127 0 : slot_quant = srcinfo->quant_tbl_ptrs[tblno];
128 0 : c_quant = incomp->quant_table;
129 0 : if (c_quant != NULL) {
130 0 : for (coefi = 0; coefi < DCTSIZE2; coefi++) {
131 0 : if (c_quant->quantval[coefi] != slot_quant->quantval[coefi])
132 0 : ERREXIT1(dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno);
133 : }
134 : }
135 : /* Note: we do not copy the source's Huffman table assignments;
136 : * instead we rely on jpeg_set_colorspace to have made a suitable choice.
137 : */
138 : }
139 : /* Also copy JFIF version and resolution information, if available.
140 : * Strictly speaking this isn't "critical" info, but it's nearly
141 : * always appropriate to copy it if available. In particular,
142 : * if the application chooses to copy JFIF 1.02 extension markers from
143 : * the source file, we need to copy the version to make sure we don't
144 : * emit a file that has 1.02 extensions but a claimed version of 1.01.
145 : * We will *not*, however, copy version info from mislabeled "2.01" files.
146 : */
147 0 : if (srcinfo->saw_JFIF_marker) {
148 0 : if (srcinfo->JFIF_major_version == 1) {
149 0 : dstinfo->JFIF_major_version = srcinfo->JFIF_major_version;
150 0 : dstinfo->JFIF_minor_version = srcinfo->JFIF_minor_version;
151 : }
152 0 : dstinfo->density_unit = srcinfo->density_unit;
153 0 : dstinfo->X_density = srcinfo->X_density;
154 0 : dstinfo->Y_density = srcinfo->Y_density;
155 : }
156 0 : }
157 :
158 :
159 : /*
160 : * Master selection of compression modules for transcoding.
161 : * This substitutes for jcinit.c's initialization of the full compressor.
162 : */
163 :
164 : LOCAL(void)
165 0 : transencode_master_selection (j_compress_ptr cinfo,
166 : jvirt_barray_ptr * coef_arrays)
167 : {
168 : /* Although we don't actually use input_components for transcoding,
169 : * jcmaster.c's initial_setup will complain if input_components is 0.
170 : */
171 0 : cinfo->input_components = 1;
172 : /* Initialize master control (includes parameter checking/processing) */
173 0 : jinit_c_master_control(cinfo, TRUE /* transcode only */);
174 :
175 : /* Entropy encoding: either Huffman or arithmetic coding. */
176 0 : if (cinfo->arith_code) {
177 : #ifdef C_ARITH_CODING_SUPPORTED
178 : jinit_arith_encoder(cinfo);
179 : #else
180 0 : ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
181 : #endif
182 : } else {
183 0 : if (cinfo->progressive_mode) {
184 : #ifdef C_PROGRESSIVE_SUPPORTED
185 0 : jinit_phuff_encoder(cinfo);
186 : #else
187 : ERREXIT(cinfo, JERR_NOT_COMPILED);
188 : #endif
189 : } else
190 0 : jinit_huff_encoder(cinfo);
191 : }
192 :
193 : /* We need a special coefficient buffer controller. */
194 0 : transencode_coef_controller(cinfo, coef_arrays);
195 :
196 0 : jinit_marker_writer(cinfo);
197 :
198 : /* We can now tell the memory manager to allocate virtual arrays. */
199 0 : (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
200 :
201 : /* Write the datastream header (SOI, JFIF) immediately.
202 : * Frame and scan headers are postponed till later.
203 : * This lets application insert special markers after the SOI.
204 : */
205 0 : (*cinfo->marker->write_file_header) (cinfo);
206 0 : }
207 :
208 :
209 : /*
210 : * The rest of this file is a special implementation of the coefficient
211 : * buffer controller. This is similar to jccoefct.c, but it handles only
212 : * output from presupplied virtual arrays. Furthermore, we generate any
213 : * dummy padding blocks on-the-fly rather than expecting them to be present
214 : * in the arrays.
215 : */
216 :
217 : /* Private buffer controller object */
218 :
219 : typedef struct {
220 : struct jpeg_c_coef_controller pub; /* public fields */
221 :
222 : JDIMENSION iMCU_row_num; /* iMCU row # within image */
223 : JDIMENSION mcu_ctr; /* counts MCUs processed in current row */
224 : int MCU_vert_offset; /* counts MCU rows within iMCU row */
225 : int MCU_rows_per_iMCU_row; /* number of such rows needed */
226 :
227 : /* Virtual block array for each component. */
228 : jvirt_barray_ptr * whole_image;
229 :
230 : /* Workspace for constructing dummy blocks at right/bottom edges. */
231 : JBLOCKROW dummy_buffer[C_MAX_BLOCKS_IN_MCU];
232 : } my_coef_controller;
233 :
234 : typedef my_coef_controller * my_coef_ptr;
235 :
236 :
237 : LOCAL(void)
238 0 : start_iMCU_row (j_compress_ptr cinfo)
239 : /* Reset within-iMCU-row counters for a new row */
240 : {
241 0 : my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
242 :
243 : /* In an interleaved scan, an MCU row is the same as an iMCU row.
244 : * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
245 : * But at the bottom of the image, process only what's left.
246 : */
247 0 : if (cinfo->comps_in_scan > 1) {
248 0 : coef->MCU_rows_per_iMCU_row = 1;
249 : } else {
250 0 : if (coef->iMCU_row_num < (cinfo->total_iMCU_rows-1))
251 0 : coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
252 : else
253 0 : coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
254 : }
255 :
256 0 : coef->mcu_ctr = 0;
257 0 : coef->MCU_vert_offset = 0;
258 0 : }
259 :
260 :
261 : /*
262 : * Initialize for a processing pass.
263 : */
264 :
265 : METHODDEF(void)
266 0 : start_pass_coef (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
267 : {
268 0 : my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
269 :
270 0 : if (pass_mode != JBUF_CRANK_DEST)
271 0 : ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
272 :
273 0 : coef->iMCU_row_num = 0;
274 0 : start_iMCU_row(cinfo);
275 0 : }
276 :
277 :
278 : /*
279 : * Process some data.
280 : * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
281 : * per call, ie, v_samp_factor block rows for each component in the scan.
282 : * The data is obtained from the virtual arrays and fed to the entropy coder.
283 : * Returns TRUE if the iMCU row is completed, FALSE if suspended.
284 : *
285 : * NB: input_buf is ignored; it is likely to be a NULL pointer.
286 : */
287 :
288 : METHODDEF(boolean)
289 0 : compress_output (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
290 : {
291 0 : my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
292 : JDIMENSION MCU_col_num; /* index of current MCU within row */
293 0 : JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
294 0 : JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
295 : int blkn, ci, xindex, yindex, yoffset, blockcnt;
296 : JDIMENSION start_col;
297 : JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
298 : JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
299 : JBLOCKROW buffer_ptr;
300 : jpeg_component_info *compptr;
301 :
302 : /* Align the virtual buffers for the components used in this scan. */
303 0 : for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
304 0 : compptr = cinfo->cur_comp_info[ci];
305 0 : buffer[ci] = (*cinfo->mem->access_virt_barray)
306 0 : ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
307 0 : coef->iMCU_row_num * compptr->v_samp_factor,
308 0 : (JDIMENSION) compptr->v_samp_factor, FALSE);
309 : }
310 :
311 : /* Loop to process one whole iMCU row */
312 0 : for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
313 0 : yoffset++) {
314 0 : for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
315 0 : MCU_col_num++) {
316 : /* Construct list of pointers to DCT blocks belonging to this MCU */
317 0 : blkn = 0; /* index of current DCT block within MCU */
318 0 : for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
319 0 : compptr = cinfo->cur_comp_info[ci];
320 0 : start_col = MCU_col_num * compptr->MCU_width;
321 0 : blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
322 0 : : compptr->last_col_width;
323 0 : for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
324 0 : if (coef->iMCU_row_num < last_iMCU_row ||
325 0 : yindex+yoffset < compptr->last_row_height) {
326 : /* Fill in pointers to real blocks in this row */
327 0 : buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
328 0 : for (xindex = 0; xindex < blockcnt; xindex++)
329 0 : MCU_buffer[blkn++] = buffer_ptr++;
330 : } else {
331 : /* At bottom of image, need a whole row of dummy blocks */
332 0 : xindex = 0;
333 : }
334 : /* Fill in any dummy blocks needed in this row.
335 : * Dummy blocks are filled in the same way as in jccoefct.c:
336 : * all zeroes in the AC entries, DC entries equal to previous
337 : * block's DC value. The init routine has already zeroed the
338 : * AC entries, so we need only set the DC entries correctly.
339 : */
340 0 : for (; xindex < compptr->MCU_width; xindex++) {
341 0 : MCU_buffer[blkn] = coef->dummy_buffer[blkn];
342 0 : MCU_buffer[blkn][0][0] = MCU_buffer[blkn-1][0][0];
343 0 : blkn++;
344 : }
345 : }
346 : }
347 : /* Try to write the MCU. */
348 0 : if (! (*cinfo->entropy->encode_mcu) (cinfo, MCU_buffer)) {
349 : /* Suspension forced; update state counters and exit */
350 0 : coef->MCU_vert_offset = yoffset;
351 0 : coef->mcu_ctr = MCU_col_num;
352 0 : return FALSE;
353 : }
354 : }
355 : /* Completed an MCU row, but perhaps not an iMCU row */
356 0 : coef->mcu_ctr = 0;
357 : }
358 : /* Completed the iMCU row, advance counters for next one */
359 0 : coef->iMCU_row_num++;
360 0 : start_iMCU_row(cinfo);
361 0 : return TRUE;
362 : }
363 :
364 :
365 : /*
366 : * Initialize coefficient buffer controller.
367 : *
368 : * Each passed coefficient array must be the right size for that
369 : * coefficient: width_in_blocks wide and height_in_blocks high,
370 : * with unitheight at least v_samp_factor.
371 : */
372 :
373 : LOCAL(void)
374 0 : transencode_coef_controller (j_compress_ptr cinfo,
375 : jvirt_barray_ptr * coef_arrays)
376 : {
377 : my_coef_ptr coef;
378 : JBLOCKROW buffer;
379 : int i;
380 :
381 0 : coef = (my_coef_ptr)
382 0 : (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
383 : SIZEOF(my_coef_controller));
384 0 : cinfo->coef = (struct jpeg_c_coef_controller *) coef;
385 0 : coef->pub.start_pass = start_pass_coef;
386 0 : coef->pub.compress_data = compress_output;
387 :
388 : /* Save pointer to virtual arrays */
389 0 : coef->whole_image = coef_arrays;
390 :
391 : /* Allocate and pre-zero space for dummy DCT blocks. */
392 0 : buffer = (JBLOCKROW)
393 0 : (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
394 : C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
395 0 : jzero_far((void FAR *) buffer, C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
396 0 : for (i = 0; i < C_MAX_BLOCKS_IN_MCU; i++) {
397 0 : coef->dummy_buffer[i] = buffer + i;
398 : }
399 0 : }
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