Visualization Library 2.0.0-b5

A lightweight C++ OpenGL middleware for 2D/3D graphics

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jcmainct.c
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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 */
33  boolean suspended; /* remember if we suspended output */
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  */
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 */
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 {
71  my_main_ptr main = (my_main_ptr) cinfo->main;
72 
73  /* Do nothing in raw-data mode. */
74  if (cinfo->raw_data_in)
75  return;
76 
77  main->cur_iMCU_row = 0; /* initialize counters */
78  main->rowgroup_ctr = 0;
79  main->suspended = FALSE;
80  main->pass_mode = pass_mode; /* save mode for use by process_data */
81 
82  switch (pass_mode) {
83  case JBUF_PASS_THRU:
84 #ifdef FULL_MAIN_BUFFER_SUPPORTED
85  if (main->whole_image[0] != NULL)
86  ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
87 #endif
88  main->pub.process_data = process_data_simple_main;
89  break;
90 #ifdef FULL_MAIN_BUFFER_SUPPORTED
91  case JBUF_SAVE_SOURCE:
92  case JBUF_CRANK_DEST:
93  case JBUF_SAVE_AND_PASS:
94  if (main->whole_image[0] == NULL)
95  ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
96  main->pub.process_data = process_data_buffer_main;
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)
114  JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
115  JDIMENSION in_rows_avail)
116 {
117  my_main_ptr main = (my_main_ptr) cinfo->main;
118 
119  while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
120  /* Read input data if we haven't filled the main buffer yet */
121  if (main->rowgroup_ctr < DCTSIZE)
122  (*cinfo->prep->pre_process_data) (cinfo,
123  input_buf, in_row_ctr, in_rows_avail,
124  main->buffer, &main->rowgroup_ctr,
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  */
131  if (main->rowgroup_ctr != DCTSIZE)
132  return;
133 
134  /* Send the completed row to the compressor */
135  if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
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  */
142  if (! main->suspended) {
143  (*in_row_ctr)--;
144  main->suspended = TRUE;
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  */
151  if (main->suspended) {
152  (*in_row_ctr)++;
153  main->suspended = FALSE;
154  }
155  main->rowgroup_ctr = 0;
156  main->cur_iMCU_row++;
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 {
173  my_main_ptr main = (my_main_ptr) cinfo->main;
174  int ci;
176  boolean writing = (main->pass_mode != JBUF_CRANK_DEST);
177 
178  while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
179  /* Realign the virtual buffers if at the start of an iMCU row. */
180  if (main->rowgroup_ctr == 0) {
181  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
182  ci++, compptr++) {
183  main->buffer[ci] = (*cinfo->mem->access_virt_sarray)
184  ((j_common_ptr) cinfo, main->whole_image[ci],
185  main->cur_iMCU_row * (compptr->v_samp_factor * DCTSIZE),
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;
191  main->rowgroup_ctr = DCTSIZE;
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,
200  main->buffer, &main->rowgroup_ctr,
201  (JDIMENSION) DCTSIZE);
202  /* Return to application if we need more data to fill the iMCU row. */
203  if (main->rowgroup_ctr < DCTSIZE)
204  return;
205  }
206 
207  /* Emit data, unless this is a sink-only pass. */
208  if (main->pass_mode != JBUF_SAVE_SOURCE) {
209  if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
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  */
216  if (! main->suspended) {
217  (*in_row_ctr)--;
218  main->suspended = TRUE;
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  */
225  if (main->suspended) {
226  (*in_row_ctr)++;
227  main->suspended = FALSE;
228  }
229  }
230 
231  /* If get here, we are done with this iMCU row. Mark buffer empty. */
232  main->rowgroup_ctr = 0;
233  main->cur_iMCU_row++;
234  }
235 }
236 
237 #endif /* FULL_MAIN_BUFFER_SUPPORTED */
238 
239 
240 /*
241  * Initialize main buffer controller.
242  */
243 
244 GLOBAL(void)
246 {
248  int ci;
250 
251  main = (my_main_ptr)
252  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
253  SIZEOF(my_main_controller));
254  cinfo->main = (struct jpeg_c_main_controller *) main;
255  main->pub.start_pass = start_pass_main;
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++) {
270  main->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
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
282  main->whole_image[0] = NULL; /* flag for no virtual arrays */
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++) {
287  main->buffer[ci] = (*cinfo->mem->alloc_sarray)
288  ((j_common_ptr) cinfo, JPOOL_IMAGE,
289  compptr->width_in_blocks * DCTSIZE,
290  (JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
291  }
292  }
293 }
struct jpeg_c_prep_controller * prep
Definition: jpeglib.h:397
jinit_c_main_controller(j_compress_ptr cinfo, boolean need_full_buffer)
Definition: jcmainct.c:245
#define NULL
Definition: ftobjs.h:61
struct jpeg_common_struct * j_common_ptr
Definition: jpeglib.h:261
process_data_simple_main(j_compress_ptr cinfo, JSAMPARRAY input_buf, JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail)
Definition: jcmainct.c:113
#define MAX_COMPONENTS
Definition: jmorecfg.h:35
#define ERREXIT(cinfo, code)
Definition: jerror.h:205
#define SIZEOF(object)
Definition: jinclude.h:80
boolean need_full_buffer
Definition: jpegint.h:338
start_pass_main(j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
Definition: jdmainct.c:307
jpeg_component_info * compptr
Definition: jdct.h:102
JDIMENSION width_in_blocks
Definition: jpeglib.h:139
#define JPOOL_IMAGE
Definition: jpeglib.h:749
jround_up(long a, long b)
Definition: jutils.c:81
JDIMENSION height_in_blocks
Definition: jpeglib.h:140
struct jpeg_c_coef_controller * coef
Definition: jpeglib.h:398
JDIMENSION total_iMCU_rows
Definition: jpeglib.h:367
typedef long(ZCALLBACK *tell_file_func) OF((voidpf opaque
GLuint buffer
struct jpeg_c_main_controller * main
Definition: jpeglib.h:396
#define JPP(arglist)
Definition: jpeglib.h:818
#define FALSE
Definition: ftobjs.h:57
JSAMPROW * JSAMPARRAY
Definition: jpeglib.h:67
if(!abbox) return FT_THROW(Invalid_Argument)
#define GLOBAL(type)
Definition: jmorecfg.h:191
J_BUF_MODE
Definition: jpegint.h:16
#define DCTSIZE
Definition: jpeglib.h:41
METHODDEF(void)
Definition: jcmainct.c:54
unsigned int JDIMENSION
Definition: jmorecfg.h:174
int main(void)
Definition: gxvfgen.c:443
boolean raw_data_in
Definition: jpeglib.h:320
#define TRUE
Definition: ftobjs.h:53
struct jvirt_sarray_control * jvirt_sarray_ptr
Definition: jpeglib.h:752
jpeg_component_info * comp_info
Definition: jpeglib.h:299
my_main_controller * my_main_ptr
Definition: jcmainct.c:50