1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
|
/*
* jcmainct.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains the main buffer controller for compression.
* The main buffer lies between the pre-processor and the JPEG
* compressor proper; it holds downsampled data in the JPEG colorspace.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/* Note: currently, there is no operating mode in which a full-image buffer
* is needed at this step. If there were, that mode could not be used with
* "raw data" input, since this module is bypassed in that case. However,
* we've left the code here for possible use in special applications.
*/
#undef FULL_MAIN_BUFFER_SUPPORTED
/* Private buffer controller object */
typedef struct {
struct jpeg_c_main_controller pub; /* public fields */
JDIMENSION cur_iMCU_row; /* number of current iMCU row */
JDIMENSION rowgroup_ctr; /* counts row groups received in iMCU row */
boolean suspended; /* remember if we suspended output */
J_BUF_MODE pass_mode; /* current operating mode */
/* If using just a strip buffer, this points to the entire set of buffers
* (we allocate one for each component). In the full-image case, this
* points to the currently accessible strips of the virtual arrays.
*/
JSAMPARRAY buffer[MAX_COMPONENTS];
#ifdef FULL_MAIN_BUFFER_SUPPORTED
/* If using full-image storage, this array holds pointers to virtual-array
* control blocks for each component. Unused if not full-image storage.
*/
jvirt_sarray_ptr whole_image[MAX_COMPONENTS];
#endif
} my_main_controller;
typedef my_main_controller * my_main_ptr;
/* Forward declarations */
METHODDEF(void) process_data_simple_main
JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf,
JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail));
#ifdef FULL_MAIN_BUFFER_SUPPORTED
METHODDEF(void) process_data_buffer_main
JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf,
JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail));
#endif
/*
* Initialize for a processing pass.
*/
METHODDEF(void)
start_pass_main (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
{
my_main_ptr main = (my_main_ptr) cinfo->main;
/* Do nothing in raw-data mode. */
if (cinfo->raw_data_in)
return;
main->cur_iMCU_row = 0; /* initialize counters */
main->rowgroup_ctr = 0;
main->suspended = FALSE;
main->pass_mode = pass_mode; /* save mode for use by process_data */
switch (pass_mode) {
case JBUF_PASS_THRU:
#ifdef FULL_MAIN_BUFFER_SUPPORTED
if (main->whole_image[0] != NULL)
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
#endif
main->pub.process_data = process_data_simple_main;
break;
#ifdef FULL_MAIN_BUFFER_SUPPORTED
case JBUF_SAVE_SOURCE:
case JBUF_CRANK_DEST:
case JBUF_SAVE_AND_PASS:
if (main->whole_image[0] == NULL)
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
main->pub.process_data = process_data_buffer_main;
break;
#endif
default:
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
break;
}
}
/*
* Process some data.
* This routine handles the simple pass-through mode,
* where we have only a strip buffer.
*/
METHODDEF(void)
process_data_simple_main (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
JDIMENSION in_rows_avail)
{
my_main_ptr main = (my_main_ptr) cinfo->main;
while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
/* Read input data if we haven't filled the main buffer yet */
if (main->rowgroup_ctr < (JDIMENSION) cinfo->min_DCT_v_scaled_size)
(*cinfo->prep->pre_process_data) (cinfo,
input_buf, in_row_ctr, in_rows_avail,
main->buffer, &main->rowgroup_ctr,
(JDIMENSION) cinfo->min_DCT_v_scaled_size);
/* If we don't have a full iMCU row buffered, return to application for
* more data. Note that preprocessor will always pad to fill the iMCU row
* at the bottom of the image.
*/
if (main->rowgroup_ctr != (JDIMENSION) cinfo->min_DCT_v_scaled_size)
return;
/* Send the completed row to the compressor */
if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
/* If compressor did not consume the whole row, then we must need to
* suspend processing and return to the application. In this situation
* we pretend we didn't yet consume the last input row; otherwise, if
* it happened to be the last row of the image, the application would
* think we were done.
*/
if (! main->suspended) {
(*in_row_ctr)--;
main->suspended = TRUE;
}
return;
}
/* We did finish the row. Undo our little suspension hack if a previous
* call suspended; then mark the main buffer empty.
*/
if (main->suspended) {
(*in_row_ctr)++;
main->suspended = FALSE;
}
main->rowgroup_ctr = 0;
main->cur_iMCU_row++;
}
}
#ifdef FULL_MAIN_BUFFER_SUPPORTED
/*
* Process some data.
* This routine handles all of the modes that use a full-size buffer.
*/
METHODDEF(void)
process_data_buffer_main (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
JDIMENSION in_rows_avail)
{
my_main_ptr main = (my_main_ptr) cinfo->main;
int ci;
jpeg_component_info *compptr;
boolean writing = (main->pass_mode != JBUF_CRANK_DEST);
while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
/* Realign the virtual buffers if at the start of an iMCU row. */
if (main->rowgroup_ctr == 0) {
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
main->buffer[ci] = (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, main->whole_image[ci],
main->cur_iMCU_row * (compptr->v_samp_factor * DCTSIZE),
(JDIMENSION) (compptr->v_samp_factor * DCTSIZE), writing);
}
/* In a read pass, pretend we just read some source data. */
if (! writing) {
*in_row_ctr += cinfo->max_v_samp_factor * DCTSIZE;
main->rowgroup_ctr = DCTSIZE;
}
}
/* If a write pass, read input data until the current iMCU row is full. */
/* Note: preprocessor will pad if necessary to fill the last iMCU row. */
if (writing) {
(*cinfo->prep->pre_process_data) (cinfo,
input_buf, in_row_ctr, in_rows_avail,
main->buffer, &main->rowgroup_ctr,
(JDIMENSION) DCTSIZE);
/* Return to application if we need more data to fill the iMCU row. */
if (main->rowgroup_ctr < DCTSIZE)
return;
}
/* Emit data, unless this is a sink-only pass. */
if (main->pass_mode != JBUF_SAVE_SOURCE) {
if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
/* If compressor did not consume the whole row, then we must need to
* suspend processing and return to the application. In this situation
* we pretend we didn't yet consume the last input row; otherwise, if
* it happened to be the last row of the image, the application would
* think we were done.
*/
if (! main->suspended) {
(*in_row_ctr)--;
main->suspended = TRUE;
}
return;
}
/* We did finish the row. Undo our little suspension hack if a previous
* call suspended; then mark the main buffer empty.
*/
if (main->suspended) {
(*in_row_ctr)++;
main->suspended = FALSE;
}
}
/* If get here, we are done with this iMCU row. Mark buffer empty. */
main->rowgroup_ctr = 0;
main->cur_iMCU_row++;
}
}
#endif /* FULL_MAIN_BUFFER_SUPPORTED */
/*
* Initialize main buffer controller.
*/
GLOBAL(void)
jinit_c_main_controller (j_compress_ptr cinfo, boolean need_full_buffer)
{
my_main_ptr main;
int ci;
jpeg_component_info *compptr;
main = (my_main_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_main_controller));
cinfo->main = (struct jpeg_c_main_controller *) main;
main->pub.start_pass = start_pass_main;
/* We don't need to create a buffer in raw-data mode. */
if (cinfo->raw_data_in)
return;
/* Create the buffer. It holds downsampled data, so each component
* may be of a different size.
*/
if (need_full_buffer) {
#ifdef FULL_MAIN_BUFFER_SUPPORTED
/* Allocate a full-image virtual array for each component */
/* Note we pad the bottom to a multiple of the iMCU height */
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
main->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
compptr->width_in_blocks * compptr->DCT_h_scaled_size,
(JDIMENSION) jround_up((long) compptr->height_in_blocks,
(long) compptr->v_samp_factor) * DCTSIZE,
(JDIMENSION) (compptr->v_samp_factor * compptr->DCT_v_scaled_size));
}
#else
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
#endif
} else {
#ifdef FULL_MAIN_BUFFER_SUPPORTED
main->whole_image[0] = NULL; /* flag for no virtual arrays */
#endif
/* Allocate a strip buffer for each component */
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
main->buffer[ci] = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
compptr->width_in_blocks * compptr->DCT_h_scaled_size,
(JDIMENSION) (compptr->v_samp_factor * compptr->DCT_v_scaled_size));
}
}
}
|
