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e1929140 RR |
1 | /* |
2 | * jcmainct.c | |
3 | * | |
4 | * Copyright (C) 1994-1996, 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 the main buffer controller for compression. | |
9 | * The main buffer lies between the pre-processor and the JPEG | |
10 | * compressor proper; it holds downsampled data in the JPEG colorspace. | |
11 | */ | |
12 | ||
13 | #define JPEG_INTERNALS | |
14 | #include "jinclude.h" | |
15 | #include "jpeglib.h" | |
16 | ||
17 | ||
18 | /* Note: currently, there is no operating mode in which a full-image buffer | |
19 | * is needed at this step. If there were, that mode could not be used with | |
20 | * "raw data" input, since this module is bypassed in that case. However, | |
21 | * we've left the code here for possible use in special applications. | |
22 | */ | |
23 | #undef FULL_MAIN_BUFFER_SUPPORTED | |
24 | ||
25 | ||
26 | /* Private buffer controller object */ | |
27 | ||
28 | typedef struct { | |
29 | struct jpeg_c_main_controller pub; /* public fields */ | |
30 | ||
31 | JDIMENSION cur_iMCU_row; /* number of current iMCU row */ | |
32 | JDIMENSION rowgroup_ctr; /* counts row groups received in iMCU row */ | |
e604ac79 | 33 | wxjpeg_boolean suspended; /* remember if we suspended output */ |
e1929140 RR |
34 | J_BUF_MODE pass_mode; /* current operating mode */ |
35 | ||
36 | /* If using just a strip buffer, this points to the entire set of buffers | |
37 | * (we allocate one for each component). In the full-image case, this | |
38 | * points to the currently accessible strips of the virtual arrays. | |
39 | */ | |
40 | JSAMPARRAY buffer[MAX_COMPONENTS]; | |
41 | ||
42 | #ifdef FULL_MAIN_BUFFER_SUPPORTED | |
43 | /* If using full-image storage, this array holds pointers to virtual-array | |
44 | * control blocks for each component. Unused if not full-image storage. | |
45 | */ | |
46 | jvirt_sarray_ptr whole_image[MAX_COMPONENTS]; | |
47 | #endif | |
48 | } my_main_controller; | |
49 | ||
50 | typedef my_main_controller * my_main_ptr; | |
51 | ||
52 | ||
53 | /* Forward declarations */ | |
54 | METHODDEF(void) process_data_simple_main | |
55 | JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf, | |
56 | JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail)); | |
57 | #ifdef FULL_MAIN_BUFFER_SUPPORTED | |
58 | METHODDEF(void) process_data_buffer_main | |
59 | JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf, | |
60 | JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail)); | |
61 | #endif | |
62 | ||
63 | ||
64 | /* | |
65 | * Initialize for a processing pass. | |
66 | */ | |
67 | ||
68 | METHODDEF(void) | |
69 | start_pass_main (j_compress_ptr cinfo, J_BUF_MODE pass_mode) | |
70 | { | |
5f4bffab | 71 | my_main_ptr mymain = (my_main_ptr) cinfo->main; |
e1929140 RR |
72 | |
73 | /* Do nothing in raw-data mode. */ | |
74 | if (cinfo->raw_data_in) | |
75 | return; | |
76 | ||
5f4bffab VZ |
77 | mymain->cur_iMCU_row = 0; /* initialize counters */ |
78 | mymain->rowgroup_ctr = 0; | |
79 | mymain->suspended = FALSE; | |
80 | mymain->pass_mode = pass_mode; /* save mode for use by process_data */ | |
e1929140 RR |
81 | |
82 | switch (pass_mode) { | |
83 | case JBUF_PASS_THRU: | |
84 | #ifdef FULL_MAIN_BUFFER_SUPPORTED | |
5f4bffab | 85 | if (mymain->whole_image[0] != NULL) |
e1929140 RR |
86 | ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); |
87 | #endif | |
5f4bffab | 88 | mymain->pub.process_data = process_data_simple_main; |
e1929140 RR |
89 | break; |
90 | #ifdef FULL_MAIN_BUFFER_SUPPORTED | |
91 | case JBUF_SAVE_SOURCE: | |
92 | case JBUF_CRANK_DEST: | |
93 | case JBUF_SAVE_AND_PASS: | |
5f4bffab | 94 | if (mymain->whole_image[0] == NULL) |
e1929140 | 95 | ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); |
5f4bffab | 96 | mymain->pub.process_data = process_data_buffer_main; |
e1929140 RR |
97 | break; |
98 | #endif | |
99 | default: | |
100 | ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
101 | break; | |
102 | } | |
103 | } | |
104 | ||
105 | ||
106 | /* | |
107 | * Process some data. | |
108 | * This routine handles the simple pass-through mode, | |
109 | * where we have only a strip buffer. | |
110 | */ | |
111 | ||
112 | METHODDEF(void) | |
113 | process_data_simple_main (j_compress_ptr cinfo, | |
114 | JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, | |
115 | JDIMENSION in_rows_avail) | |
116 | { | |
5f4bffab | 117 | my_main_ptr mymain = (my_main_ptr) cinfo->main; |
e1929140 | 118 | |
5f4bffab | 119 | while (mymain->cur_iMCU_row < cinfo->total_iMCU_rows) { |
e1929140 | 120 | /* Read input data if we haven't filled the main buffer yet */ |
5f4bffab | 121 | if (mymain->rowgroup_ctr < DCTSIZE) |
e1929140 RR |
122 | (*cinfo->prep->pre_process_data) (cinfo, |
123 | input_buf, in_row_ctr, in_rows_avail, | |
5f4bffab | 124 | mymain->buffer, &mymain->rowgroup_ctr, |
e1929140 RR |
125 | (JDIMENSION) DCTSIZE); |
126 | ||
127 | /* If we don't have a full iMCU row buffered, return to application for | |
128 | * more data. Note that preprocessor will always pad to fill the iMCU row | |
129 | * at the bottom of the image. | |
130 | */ | |
5f4bffab | 131 | if (mymain->rowgroup_ctr != DCTSIZE) |
e1929140 RR |
132 | return; |
133 | ||
134 | /* Send the completed row to the compressor */ | |
5f4bffab | 135 | if (! (*cinfo->coef->compress_data) (cinfo, mymain->buffer)) { |
e1929140 RR |
136 | /* If compressor did not consume the whole row, then we must need to |
137 | * suspend processing and return to the application. In this situation | |
138 | * we pretend we didn't yet consume the last input row; otherwise, if | |
139 | * it happened to be the last row of the image, the application would | |
140 | * think we were done. | |
141 | */ | |
5f4bffab | 142 | if (! mymain->suspended) { |
e1929140 | 143 | (*in_row_ctr)--; |
5f4bffab | 144 | mymain->suspended = TRUE; |
e1929140 RR |
145 | } |
146 | return; | |
147 | } | |
148 | /* We did finish the row. Undo our little suspension hack if a previous | |
149 | * call suspended; then mark the main buffer empty. | |
150 | */ | |
5f4bffab | 151 | if (mymain->suspended) { |
e1929140 | 152 | (*in_row_ctr)++; |
5f4bffab | 153 | mymain->suspended = FALSE; |
e1929140 | 154 | } |
5f4bffab VZ |
155 | mymain->rowgroup_ctr = 0; |
156 | mymain->cur_iMCU_row++; | |
e1929140 RR |
157 | } |
158 | } | |
159 | ||
160 | ||
161 | #ifdef FULL_MAIN_BUFFER_SUPPORTED | |
162 | ||
163 | /* | |
164 | * Process some data. | |
165 | * This routine handles all of the modes that use a full-size buffer. | |
166 | */ | |
167 | ||
168 | METHODDEF(void) | |
169 | process_data_buffer_main (j_compress_ptr cinfo, | |
170 | JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, | |
171 | JDIMENSION in_rows_avail) | |
172 | { | |
5f4bffab | 173 | my_main_ptr mymain = (my_main_ptr) cinfo->main; |
e1929140 RR |
174 | int ci; |
175 | jpeg_component_info *compptr; | |
e604ac79 | 176 | wxjpeg_boolean writing = (mymain->pass_mode != JBUF_CRANK_DEST); |
e1929140 | 177 | |
5f4bffab | 178 | while (mymain->cur_iMCU_row < cinfo->total_iMCU_rows) { |
e1929140 | 179 | /* Realign the virtual buffers if at the start of an iMCU row. */ |
5f4bffab | 180 | if (mymain->rowgroup_ctr == 0) { |
e1929140 RR |
181 | for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
182 | ci++, compptr++) { | |
5f4bffab VZ |
183 | mymain->buffer[ci] = (*cinfo->mem->access_virt_sarray) |
184 | ((j_common_ptr) cinfo, mymain->whole_image[ci], | |
185 | mymain->cur_iMCU_row * (compptr->v_samp_factor * DCTSIZE), | |
e1929140 RR |
186 | (JDIMENSION) (compptr->v_samp_factor * DCTSIZE), writing); |
187 | } | |
188 | /* In a read pass, pretend we just read some source data. */ | |
189 | if (! writing) { | |
190 | *in_row_ctr += cinfo->max_v_samp_factor * DCTSIZE; | |
5f4bffab | 191 | mymain->rowgroup_ctr = DCTSIZE; |
e1929140 RR |
192 | } |
193 | } | |
194 | ||
195 | /* If a write pass, read input data until the current iMCU row is full. */ | |
196 | /* Note: preprocessor will pad if necessary to fill the last iMCU row. */ | |
197 | if (writing) { | |
198 | (*cinfo->prep->pre_process_data) (cinfo, | |
199 | input_buf, in_row_ctr, in_rows_avail, | |
5f4bffab | 200 | mymain->buffer, &mymain->rowgroup_ctr, |
e1929140 RR |
201 | (JDIMENSION) DCTSIZE); |
202 | /* Return to application if we need more data to fill the iMCU row. */ | |
5f4bffab | 203 | if (mymain->rowgroup_ctr < DCTSIZE) |
e1929140 RR |
204 | return; |
205 | } | |
206 | ||
207 | /* Emit data, unless this is a sink-only pass. */ | |
5f4bffab VZ |
208 | if (mymain->pass_mode != JBUF_SAVE_SOURCE) { |
209 | if (! (*cinfo->coef->compress_data) (cinfo, mymain->buffer)) { | |
e1929140 RR |
210 | /* If compressor did not consume the whole row, then we must need to |
211 | * suspend processing and return to the application. In this situation | |
212 | * we pretend we didn't yet consume the last input row; otherwise, if | |
213 | * it happened to be the last row of the image, the application would | |
214 | * think we were done. | |
215 | */ | |
5f4bffab | 216 | if (! mymain->suspended) { |
e1929140 | 217 | (*in_row_ctr)--; |
5f4bffab | 218 | mymain->suspended = TRUE; |
e1929140 RR |
219 | } |
220 | return; | |
221 | } | |
222 | /* We did finish the row. Undo our little suspension hack if a previous | |
223 | * call suspended; then mark the main buffer empty. | |
224 | */ | |
5f4bffab | 225 | if (mymain->suspended) { |
e1929140 | 226 | (*in_row_ctr)++; |
5f4bffab | 227 | mymain->suspended = FALSE; |
e1929140 RR |
228 | } |
229 | } | |
230 | ||
231 | /* If get here, we are done with this iMCU row. Mark buffer empty. */ | |
5f4bffab VZ |
232 | mymain->rowgroup_ctr = 0; |
233 | mymain->cur_iMCU_row++; | |
e1929140 RR |
234 | } |
235 | } | |
236 | ||
237 | #endif /* FULL_MAIN_BUFFER_SUPPORTED */ | |
238 | ||
239 | ||
240 | /* | |
241 | * Initialize main buffer controller. | |
242 | */ | |
243 | ||
244 | GLOBAL(void) | |
e604ac79 | 245 | jinit_c_main_controller (j_compress_ptr cinfo, wxjpeg_boolean need_full_buffer) |
e1929140 | 246 | { |
5f4bffab | 247 | my_main_ptr mymain; |
e1929140 RR |
248 | int ci; |
249 | jpeg_component_info *compptr; | |
250 | ||
5f4bffab | 251 | mymain = (my_main_ptr) |
e1929140 RR |
252 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
253 | SIZEOF(my_main_controller)); | |
5f4bffab VZ |
254 | cinfo->main = (struct jpeg_c_main_controller *) mymain; |
255 | mymain->pub.start_pass = start_pass_main; | |
e1929140 RR |
256 | |
257 | /* We don't need to create a buffer in raw-data mode. */ | |
258 | if (cinfo->raw_data_in) | |
259 | return; | |
260 | ||
261 | /* Create the buffer. It holds downsampled data, so each component | |
262 | * may be of a different size. | |
263 | */ | |
264 | if (need_full_buffer) { | |
265 | #ifdef FULL_MAIN_BUFFER_SUPPORTED | |
266 | /* Allocate a full-image virtual array for each component */ | |
267 | /* Note we pad the bottom to a multiple of the iMCU height */ | |
268 | for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
269 | ci++, compptr++) { | |
5f4bffab | 270 | mymain->whole_image[ci] = (*cinfo->mem->request_virt_sarray) |
e1929140 RR |
271 | ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE, |
272 | compptr->width_in_blocks * DCTSIZE, | |
273 | (JDIMENSION) jround_up((long) compptr->height_in_blocks, | |
274 | (long) compptr->v_samp_factor) * DCTSIZE, | |
275 | (JDIMENSION) (compptr->v_samp_factor * DCTSIZE)); | |
276 | } | |
277 | #else | |
278 | ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); | |
279 | #endif | |
280 | } else { | |
281 | #ifdef FULL_MAIN_BUFFER_SUPPORTED | |
5f4bffab | 282 | mymain->whole_image[0] = NULL; /* flag for no virtual arrays */ |
e1929140 RR |
283 | #endif |
284 | /* Allocate a strip buffer for each component */ | |
285 | for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
286 | ci++, compptr++) { | |
5f4bffab | 287 | mymain->buffer[ci] = (*cinfo->mem->alloc_sarray) |
e1929140 RR |
288 | ((j_common_ptr) cinfo, JPOOL_IMAGE, |
289 | compptr->width_in_blocks * DCTSIZE, | |
290 | (JDIMENSION) (compptr->v_samp_factor * DCTSIZE)); | |
291 | } | |
292 | } | |
293 | } |