ReactOS  0.4.14-dev-376-gaedba84
jcmainct.c
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1 /*
2  * jcmainct.c
3  *
4  * Copyright (C) 1994-1996, Thomas G. Lane.
5  * Modified 2003-2012 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 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  */
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
50 
52 
53 
54 /* Forward declarations */
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)
70 start_pass_main (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
71 {
72  my_main_ptr mainp = (my_main_ptr) cinfo->main;
73 
74  /* Do nothing in raw-data mode. */
75  if (cinfo->raw_data_in)
76  return;
77 
78  mainp->cur_iMCU_row = 0; /* initialize counters */
79  mainp->rowgroup_ctr = 0;
80  mainp->suspended = FALSE;
81  mainp->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 (mainp->whole_image[0] != NULL)
87  ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
88 #endif
89  mainp->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 (mainp->whole_image[0] == NULL)
96  ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
97  mainp->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)
115  JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
116  JDIMENSION in_rows_avail)
117 {
118  my_main_ptr mainp = (my_main_ptr) cinfo->main;
119 
120  while (mainp->cur_iMCU_row < cinfo->total_iMCU_rows) {
121  /* Read input data if we haven't filled the main buffer yet */
122  if (mainp->rowgroup_ctr < (JDIMENSION) cinfo->min_DCT_v_scaled_size)
123  (*cinfo->prep->pre_process_data) (cinfo,
124  input_buf, in_row_ctr, in_rows_avail,
125  mainp->buffer, &mainp->rowgroup_ctr,
126  (JDIMENSION) cinfo->min_DCT_v_scaled_size);
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 (mainp->rowgroup_ctr != (JDIMENSION) cinfo->min_DCT_v_scaled_size)
133  return;
134 
135  /* Send the completed row to the compressor */
136  if (! (*cinfo->coef->compress_data) (cinfo, mainp->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 (! mainp->suspended) {
144  (*in_row_ctr)--;
145  mainp->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 (mainp->suspended) {
153  (*in_row_ctr)++;
154  mainp->suspended = FALSE;
155  }
156  mainp->rowgroup_ctr = 0;
157  mainp->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)
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 mainp = (my_main_ptr) cinfo->main;
175  int ci;
177  boolean writing = (mainp->pass_mode != JBUF_CRANK_DEST);
178 
179  while (mainp->cur_iMCU_row < cinfo->total_iMCU_rows) {
180  /* Realign the virtual buffers if at the start of an iMCU row. */
181  if (mainp->rowgroup_ctr == 0) {
182  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
183  ci++, compptr++) {
184  mainp->buffer[ci] = (*cinfo->mem->access_virt_sarray)
185  ((j_common_ptr) cinfo, mainp->whole_image[ci], mainp->cur_iMCU_row *
188  writing);
189  }
190  /* In a read pass, pretend we just read some source data. */
191  if (! writing) {
192  *in_row_ctr += (JDIMENSION)
193  (cinfo->max_v_samp_factor * cinfo->min_DCT_v_scaled_size);
195  }
196  }
197 
198  /* If a write pass, read input data until the current iMCU row is full. */
199  /* Note: preprocessor will pad if necessary to fill the last iMCU row. */
200  if (writing) {
201  (*cinfo->prep->pre_process_data) (cinfo,
202  input_buf, in_row_ctr, in_rows_avail,
203  mainp->buffer, &mainp->rowgroup_ctr,
205  /* Return to application if we need more data to fill the iMCU row. */
206  if (mainp->rowgroup_ctr < (JDIMENSION) cinfo->min_DCT_v_scaled_size)
207  return;
208  }
209 
210  /* Emit data, unless this is a sink-only pass. */
211  if (mainp->pass_mode != JBUF_SAVE_SOURCE) {
212  if (! (*cinfo->coef->compress_data) (cinfo, mainp->buffer)) {
213  /* If compressor did not consume the whole row, then we must need to
214  * suspend processing and return to the application. In this situation
215  * we pretend we didn't yet consume the last input row; otherwise, if
216  * it happened to be the last row of the image, the application would
217  * think we were done.
218  */
219  if (! mainp->suspended) {
220  (*in_row_ctr)--;
221  mainp->suspended = TRUE;
222  }
223  return;
224  }
225  /* We did finish the row. Undo our little suspension hack if a previous
226  * call suspended; then mark the main buffer empty.
227  */
228  if (mainp->suspended) {
229  (*in_row_ctr)++;
230  mainp->suspended = FALSE;
231  }
232  }
233 
234  /* If get here, we are done with this iMCU row. Mark buffer empty. */
235  mainp->rowgroup_ctr = 0;
236  mainp->cur_iMCU_row++;
237  }
238 }
239 
240 #endif /* FULL_MAIN_BUFFER_SUPPORTED */
241 
242 
243 /*
244  * Initialize main buffer controller.
245  */
246 
247 GLOBAL(void)
249 {
250  my_main_ptr mainp;
251  int ci;
253 
254  mainp = (my_main_ptr)
255  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
257  cinfo->main = &mainp->pub;
258  mainp->pub.start_pass = start_pass_main;
259 
260  /* We don't need to create a buffer in raw-data mode. */
261  if (cinfo->raw_data_in)
262  return;
263 
264  /* Create the buffer. It holds downsampled data, so each component
265  * may be of a different size.
266  */
267  if (need_full_buffer) {
268 #ifdef FULL_MAIN_BUFFER_SUPPORTED
269  /* Allocate a full-image virtual array for each component */
270  /* Note we pad the bottom to a multiple of the iMCU height */
271  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
272  ci++, compptr++) {
273  mainp->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
274  ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
277  (long) compptr->v_samp_factor)) *
278  ((JDIMENSION) cinfo->min_DCT_v_scaled_size),
280  }
281 #else
282  ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
283 #endif
284  } else {
285 #ifdef FULL_MAIN_BUFFER_SUPPORTED
286  mainp->whole_image[0] = NULL; /* flag for no virtual arrays */
287 #endif
288  /* Allocate a strip buffer for each component */
289  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
290  ci++, compptr++) {
291  mainp->buffer[ci] = (*cinfo->mem->alloc_sarray)
292  ((j_common_ptr) cinfo, JPOOL_IMAGE,
295  }
296  }
297 }
struct jpeg_c_prep_controller * prep
Definition: jpeglib.h:445
#define TRUE
Definition: types.h:120
struct jpeg_c_main_controller pub
Definition: jcmainct.c:30
#define ERREXIT(msg)
Definition: rdjpgcom.c:72
jinit_c_main_controller(j_compress_ptr cinfo, boolean need_full_buffer)
Definition: jcmainct.c:248
struct jpeg_common_struct * j_common_ptr
Definition: jpeglib.h:284
process_data_simple_main(j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail)
Definition: jcmainct.c:114
#define MAX_COMPONENTS
Definition: jmorecfg.h:45
GLuint buffer
Definition: glext.h:5915
J_BUF_MODE pass_mode
Definition: jcmainct.c:35
boolean need_full_buffer
Definition: jpegint.h:377
JDIMENSION rowgroup_ctr
Definition: jcmainct.c:33
start_pass_main(j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
Definition: jdmainct.c:309
boolean suspended
Definition: jcmainct.c:34
jpeg_component_info * compptr
Definition: jdct.h:238
JDIMENSION width_in_blocks
Definition: jpeglib.h:148
while(1)
Definition: macro.lex.yy.c:740
#define SIZEOF(_ar)
Definition: calc.h:97
#define JPOOL_IMAGE
Definition: jpeglib.h:808
jround_up(long a, long b)
Definition: jutils.c:133
JSAMPARRAY buffer[MAX_COMPONENTS]
Definition: jcmainct.c:41
smooth NULL
Definition: ftsmooth.c:416
JDIMENSION height_in_blocks
Definition: jpeglib.h:149
struct jpeg_c_coef_controller * coef
Definition: jpeglib.h:446
JDIMENSION total_iMCU_rows
Definition: jpeglib.h:411
if(!(yy_init))
Definition: macro.lex.yy.c:714
struct jpeg_c_main_controller * main
Definition: jpeglib.h:444
#define JPP(arglist)
Definition: jpeglib.h:877
JDIMENSION cur_iMCU_row
Definition: jcmainct.c:32
JSAMPROW * JSAMPARRAY
Definition: jpeglib.h:76
#define GLOBAL(type)
Definition: jmorecfg.h:291
#define long
Definition: qsort.c:33
J_BUF_MODE
Definition: jpegint.h:17
METHODDEF(void)
Definition: jcmainct.c:55
unsigned int JDIMENSION
Definition: jmorecfg.h:229
boolean raw_data_in
Definition: jpeglib.h:357
jpeg_component_info * comp_info
Definition: jpeglib.h:333
my_main_controller * my_main_ptr
Definition: jcmainct.c:51