1 #if !defined(_FX_JPEG_TURBO_)
2 /*
3 * jcmainct.c
4 *
5 * Copyright (C) 1994-1996, Thomas G. Lane.
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 the main buffer controller for compression.
10 * The main buffer lies between the pre-processor and the JPEG
11 * compressor proper; it holds downsampled data in the JPEG colorspace.
12 */
13
14 #define JPEG_INTERNALS
15 #include "jinclude.h"
16 #include "jpeglib.h"
17
18
19 /* Note: currently, there is no operating mode in which a full-image buffer
20 * is needed at this step. If there were, that mode could not be used with
21 * "raw data" input, since this module is bypassed in that case. However,
22 * we've left the code here for possible use in special applications.
23 */
24 #undef FULL_MAIN_BUFFER_SUPPORTED
25
26
27 /* Private buffer controller object */
28
29 typedef struct {
30 struct jpeg_c_main_controller pub; /* public fields */
31
32 JDIMENSION cur_iMCU_row; /* number of current iMCU row */
33 JDIMENSION rowgroup_ctr; /* counts row groups received in iMCU row */
34 boolean suspended; /* remember if we suspended output */
35 J_BUF_MODE pass_mode; /* current operating mode */
36
37 /* If using just a strip buffer, this points to the entire set of buffers
38 * (we allocate one for each component). In the full-image case, this
39 * points to the currently accessible strips of the virtual arrays.
40 */
41 JSAMPARRAY buffer[MAX_COMPONENTS];
42
43 #ifdef FULL_MAIN_BUFFER_SUPPORTED
44 /* If using full-image storage, this array holds pointers to virtual-array
45 * control blocks for each component. Unused if not full-image storage.
46 */
47 jvirt_sarray_ptr whole_image[MAX_COMPONENTS];
48 #endif
49 } my_main_controller;
50
51 typedef my_main_controller * my_main_ptr;
52
53
54 /* Forward declarations */
55 METHODDEF(void) process_data_simple_main
56 JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf,
57 JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail));
58 #ifdef FULL_MAIN_BUFFER_SUPPORTED
59 METHODDEF(void) process_data_buffer_main
60 JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf,
61 JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail));
62 #endif
63
64
65 /*
66 * Initialize for a processing pass.
67 */
68
69 METHODDEF(void)
start_pass_main(j_compress_ptr cinfo,J_BUF_MODE pass_mode)70 start_pass_main (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
71 {
72 my_main_ptr main = (my_main_ptr) cinfo->main;
73
74 /* Do nothing in raw-data mode. */
75 if (cinfo->raw_data_in)
76 return;
77
78 main->cur_iMCU_row = 0; /* initialize counters */
79 main->rowgroup_ctr = 0;
80 main->suspended = FALSE;
81 main->pass_mode = pass_mode; /* save mode for use by process_data */
82
83 switch (pass_mode) {
84 case JBUF_PASS_THRU:
85 #ifdef FULL_MAIN_BUFFER_SUPPORTED
86 if (main->whole_image[0] != NULL)
87 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
88 #endif
89 main->pub.process_data = process_data_simple_main;
90 break;
91 #ifdef FULL_MAIN_BUFFER_SUPPORTED
92 case JBUF_SAVE_SOURCE:
93 case JBUF_CRANK_DEST:
94 case JBUF_SAVE_AND_PASS:
95 if (main->whole_image[0] == NULL)
96 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
97 main->pub.process_data = process_data_buffer_main;
98 break;
99 #endif
100 default:
101 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
102 break;
103 }
104 }
105
106
107 /*
108 * Process some data.
109 * This routine handles the simple pass-through mode,
110 * where we have only a strip buffer.
111 */
112
113 METHODDEF(void)
process_data_simple_main(j_compress_ptr cinfo,JSAMPARRAY input_buf,JDIMENSION * in_row_ctr,JDIMENSION in_rows_avail)114 process_data_simple_main (j_compress_ptr cinfo,
115 JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
116 JDIMENSION in_rows_avail)
117 {
118 my_main_ptr main = (my_main_ptr) cinfo->main;
119
120 while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
121 /* Read input data if we haven't filled the main buffer yet */
122 if (main->rowgroup_ctr < DCTSIZE)
123 (*cinfo->prep->pre_process_data) (cinfo,
124 input_buf, in_row_ctr, in_rows_avail,
125 main->buffer, &main->rowgroup_ctr,
126 (JDIMENSION) DCTSIZE);
127
128 /* If we don't have a full iMCU row buffered, return to application for
129 * more data. Note that preprocessor will always pad to fill the iMCU row
130 * at the bottom of the image.
131 */
132 if (main->rowgroup_ctr != DCTSIZE)
133 return;
134
135 /* Send the completed row to the compressor */
136 if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
137 /* If compressor did not consume the whole row, then we must need to
138 * suspend processing and return to the application. In this situation
139 * we pretend we didn't yet consume the last input row; otherwise, if
140 * it happened to be the last row of the image, the application would
141 * think we were done.
142 */
143 if (! main->suspended) {
144 (*in_row_ctr)--;
145 main->suspended = TRUE;
146 }
147 return;
148 }
149 /* We did finish the row. Undo our little suspension hack if a previous
150 * call suspended; then mark the main buffer empty.
151 */
152 if (main->suspended) {
153 (*in_row_ctr)++;
154 main->suspended = FALSE;
155 }
156 main->rowgroup_ctr = 0;
157 main->cur_iMCU_row++;
158 }
159 }
160
161
162 #ifdef FULL_MAIN_BUFFER_SUPPORTED
163
164 /*
165 * Process some data.
166 * This routine handles all of the modes that use a full-size buffer.
167 */
168
169 METHODDEF(void)
process_data_buffer_main(j_compress_ptr cinfo,JSAMPARRAY input_buf,JDIMENSION * in_row_ctr,JDIMENSION in_rows_avail)170 process_data_buffer_main (j_compress_ptr cinfo,
171 JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
172 JDIMENSION in_rows_avail)
173 {
174 my_main_ptr main = (my_main_ptr) cinfo->main;
175 int ci;
176 jpeg_component_info *compptr;
177 boolean writing = (main->pass_mode != JBUF_CRANK_DEST);
178
179 while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
180 /* Realign the virtual buffers if at the start of an iMCU row. */
181 if (main->rowgroup_ctr == 0) {
182 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
183 ci++, compptr++) {
184 main->buffer[ci] = (*cinfo->mem->access_virt_sarray)
185 ((j_common_ptr) cinfo, main->whole_image[ci],
186 main->cur_iMCU_row * (compptr->v_samp_factor * DCTSIZE),
187 (JDIMENSION) (compptr->v_samp_factor * DCTSIZE), writing);
188 }
189 /* In a read pass, pretend we just read some source data. */
190 if (! writing) {
191 *in_row_ctr += cinfo->max_v_samp_factor * DCTSIZE;
192 main->rowgroup_ctr = DCTSIZE;
193 }
194 }
195
196 /* If a write pass, read input data until the current iMCU row is full. */
197 /* Note: preprocessor will pad if necessary to fill the last iMCU row. */
198 if (writing) {
199 (*cinfo->prep->pre_process_data) (cinfo,
200 input_buf, in_row_ctr, in_rows_avail,
201 main->buffer, &main->rowgroup_ctr,
202 (JDIMENSION) DCTSIZE);
203 /* Return to application if we need more data to fill the iMCU row. */
204 if (main->rowgroup_ctr < DCTSIZE)
205 return;
206 }
207
208 /* Emit data, unless this is a sink-only pass. */
209 if (main->pass_mode != JBUF_SAVE_SOURCE) {
210 if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
211 /* If compressor did not consume the whole row, then we must need to
212 * suspend processing and return to the application. In this situation
213 * we pretend we didn't yet consume the last input row; otherwise, if
214 * it happened to be the last row of the image, the application would
215 * think we were done.
216 */
217 if (! main->suspended) {
218 (*in_row_ctr)--;
219 main->suspended = TRUE;
220 }
221 return;
222 }
223 /* We did finish the row. Undo our little suspension hack if a previous
224 * call suspended; then mark the main buffer empty.
225 */
226 if (main->suspended) {
227 (*in_row_ctr)++;
228 main->suspended = FALSE;
229 }
230 }
231
232 /* If get here, we are done with this iMCU row. Mark buffer empty. */
233 main->rowgroup_ctr = 0;
234 main->cur_iMCU_row++;
235 }
236 }
237
238 #endif /* FULL_MAIN_BUFFER_SUPPORTED */
239
240
241 /*
242 * Initialize main buffer controller.
243 */
244
245 GLOBAL(void)
jinit_c_main_controller(j_compress_ptr cinfo,boolean need_full_buffer)246 jinit_c_main_controller (j_compress_ptr cinfo, boolean need_full_buffer)
247 {
248 my_main_ptr main;
249 int ci;
250 jpeg_component_info *compptr;
251
252 main = (my_main_ptr)
253 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
254 SIZEOF(my_main_controller));
255 cinfo->main = (struct jpeg_c_main_controller *) main;
256 main->pub.start_pass = start_pass_main;
257
258 /* We don't need to create a buffer in raw-data mode. */
259 if (cinfo->raw_data_in)
260 return;
261
262 /* Create the buffer. It holds downsampled data, so each component
263 * may be of a different size.
264 */
265 if (need_full_buffer) {
266 #ifdef FULL_MAIN_BUFFER_SUPPORTED
267 /* Allocate a full-image virtual array for each component */
268 /* Note we pad the bottom to a multiple of the iMCU height */
269 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
270 ci++, compptr++) {
271 main->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
272 ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
273 compptr->width_in_blocks * DCTSIZE,
274 (JDIMENSION) jround_up((long) compptr->height_in_blocks,
275 (long) compptr->v_samp_factor) * DCTSIZE,
276 (JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
277 }
278 #else
279 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
280 #endif
281 } else {
282 #ifdef FULL_MAIN_BUFFER_SUPPORTED
283 main->whole_image[0] = NULL; /* flag for no virtual arrays */
284 #endif
285 /* Allocate a strip buffer for each component */
286 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
287 ci++, compptr++) {
288 main->buffer[ci] = (*cinfo->mem->alloc_sarray)
289 ((j_common_ptr) cinfo, JPOOL_IMAGE,
290 compptr->width_in_blocks * DCTSIZE,
291 (JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
292 }
293 }
294 }
295
296 #endif //_FX_JPEG_TURBO_
297