jdapistd.c
Go to the documentation of this file.
1 /*
2  * jdapistd.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 application interface code for the decompression half
9  * of the JPEG library. These are the "standard" API routines that are
10  * used in the normal full-decompression case. They are not used by a
11  * transcoding-only application. Note that if an application links in
12  * jpeg_start_decompress, it will end up linking in the entire decompressor.
13  * We thus must separate this file from jdapimin.c to avoid linking the
14  * whole decompression library into a transcoder.
15  */
16 
17 #define JPEG_INTERNALS
18 #include "jinclude.h"
19 #include "jpeglib.h"
20 
21 
22 /* Forward declarations */
24 
25 
26 /*
27  * Decompression initialization.
28  * jpeg_read_header must be completed before calling this.
29  *
30  * If a multipass operating mode was selected, this will do all but the
31  * last pass, and thus may take a great deal of time.
32  *
33  * Returns FALSE if suspended. The return value need be inspected only if
34  * a suspending data source is used.
35  */
36 
37 GLOBAL(boolean)
38 jpeg_start_decompress (j_decompress_ptr cinfo)
39 {
40  if (cinfo->global_state == DSTATE_READY) {
41  /* First call: initialize master control, select active modules */
43  if (cinfo->buffered_image) {
44  /* No more work here; expecting jpeg_start_output next */
45  cinfo->global_state = DSTATE_BUFIMAGE;
46  return TRUE;
47  }
48  cinfo->global_state = DSTATE_PRELOAD;
49  }
50  if (cinfo->global_state == DSTATE_PRELOAD) {
51  /* If file has multiple scans, absorb them all into the coef buffer */
52  if (cinfo->inputctl->has_multiple_scans) {
53 #ifdef D_MULTISCAN_FILES_SUPPORTED
54  for (;;) {
55  int retcode;
56  /* Call progress monitor hook if present */
57  if (cinfo->progress != NULL)
58  (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
59  /* Absorb some more input */
60  retcode = (*cinfo->inputctl->consume_input) (cinfo);
61  if (retcode == JPEG_SUSPENDED)
62  return FALSE;
63  if (retcode == JPEG_REACHED_EOI)
64  break;
65  /* Advance progress counter if appropriate */
66  if (cinfo->progress != NULL &&
67  (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
68  if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
69  /* jdmaster underestimated number of scans; ratchet up one scan */
70  cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
71  }
72  }
73  }
74 #else
75  ERREXIT(cinfo, JERR_NOT_COMPILED);
76 #endif /* D_MULTISCAN_FILES_SUPPORTED */
77  }
78  cinfo->output_scan_number = cinfo->input_scan_number;
79  } else if (cinfo->global_state != DSTATE_PRESCAN)
80  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
81  /* Perform any dummy output passes, and set up for the final pass */
82  return output_pass_setup(cinfo);
83 }
84 
85 
86 /*
87  * Set up for an output pass, and perform any dummy pass(es) needed.
88  * Common subroutine for jpeg_start_decompress and jpeg_start_output.
89  * Entry: global_state = DSTATE_PRESCAN only if previously suspended.
90  * Exit: If done, returns TRUE and sets global_state for proper output mode.
91  * If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
92  */
93 
94 LOCAL(boolean)
96 {
97  if (cinfo->global_state != DSTATE_PRESCAN) {
98  /* First call: do pass setup */
99  (*cinfo->master->prepare_for_output_pass) (cinfo);
100  cinfo->output_scanline = 0;
101  cinfo->global_state = DSTATE_PRESCAN;
102  }
103  /* Loop over any required dummy passes */
104  while (cinfo->master->is_dummy_pass) {
105 #ifdef QUANT_2PASS_SUPPORTED
106  /* Crank through the dummy pass */
107  while (cinfo->output_scanline < cinfo->output_height) {
108  JDIMENSION last_scanline;
109  /* Call progress monitor hook if present */
110  if (cinfo->progress != NULL) {
111  cinfo->progress->pass_counter = (long) cinfo->output_scanline;
112  cinfo->progress->pass_limit = (long) cinfo->output_height;
113  (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
114  }
115  /* Process some data */
116  last_scanline = cinfo->output_scanline;
117  (*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL,
118  &cinfo->output_scanline, (JDIMENSION) 0);
119  if (cinfo->output_scanline == last_scanline)
120  return FALSE; /* No progress made, must suspend */
121  }
122  /* Finish up dummy pass, and set up for another one */
123  (*cinfo->master->finish_output_pass) (cinfo);
124  (*cinfo->master->prepare_for_output_pass) (cinfo);
125  cinfo->output_scanline = 0;
126 #else
127  ERREXIT(cinfo, JERR_NOT_COMPILED);
128 #endif /* QUANT_2PASS_SUPPORTED */
129  }
130  /* Ready for application to drive output pass through
131  * jpeg_read_scanlines or jpeg_read_raw_data.
132  */
133  cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
134  return TRUE;
135 }
136 
137 
138 /*
139  * Read some scanlines of data from the JPEG decompressor.
140  *
141  * The return value will be the number of lines actually read.
142  * This may be less than the number requested in several cases,
143  * including bottom of image, data source suspension, and operating
144  * modes that emit multiple scanlines at a time.
145  *
146  * Note: we warn about excess calls to jpeg_read_scanlines() since
147  * this likely signals an application programmer error. However,
148  * an oversize buffer (max_lines > scanlines remaining) is not an error.
149  */
150 
154 {
155  JDIMENSION row_ctr;
156 
157  if (cinfo->global_state != DSTATE_SCANNING)
158  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
159  if (cinfo->output_scanline >= cinfo->output_height) {
160  WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
161  return 0;
162  }
163 
164  /* Call progress monitor hook if present */
165  if (cinfo->progress != NULL) {
166  cinfo->progress->pass_counter = (long) cinfo->output_scanline;
167  cinfo->progress->pass_limit = (long) cinfo->output_height;
168  (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
169  }
170 
171  /* Process some data */
172  row_ctr = 0;
173  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
174  cinfo->output_scanline += row_ctr;
175  return row_ctr;
176 }
177 
178 
179 /*
180  * Alternate entry point to read raw data.
181  * Processes exactly one iMCU row per call, unless suspended.
182  */
183 
187 {
188  JDIMENSION lines_per_iMCU_row;
189 
190  if (cinfo->global_state != DSTATE_RAW_OK)
191  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
192  if (cinfo->output_scanline >= cinfo->output_height) {
193  WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
194  return 0;
195  }
196 
197  /* Call progress monitor hook if present */
198  if (cinfo->progress != NULL) {
199  cinfo->progress->pass_counter = (long) cinfo->output_scanline;
200  cinfo->progress->pass_limit = (long) cinfo->output_height;
201  (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
202  }
203 
204  /* Verify that at least one iMCU row can be returned. */
205  lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size;
206  if (max_lines < lines_per_iMCU_row)
207  ERREXIT(cinfo, JERR_BUFFER_SIZE);
208 
209  /* Decompress directly into user's buffer. */
210  if (! (*cinfo->coef->decompress_data) (cinfo, data))
211  return 0; /* suspension forced, can do nothing more */
212 
213  /* OK, we processed one iMCU row. */
214  cinfo->output_scanline += lines_per_iMCU_row;
215  return lines_per_iMCU_row;
216 }
217 
218 
219 /* Additional entry points for buffered-image mode. */
220 
221 #ifdef D_MULTISCAN_FILES_SUPPORTED
222 
223 /*
224  * Initialize for an output pass in buffered-image mode.
225  */
226 
227 GLOBAL(boolean)
229 {
230  if (cinfo->global_state != DSTATE_BUFIMAGE &&
231  cinfo->global_state != DSTATE_PRESCAN)
232  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
233  /* Limit scan number to valid range */
234  if (scan_number <= 0)
235  scan_number = 1;
236  if (cinfo->inputctl->eoi_reached &&
237  scan_number > cinfo->input_scan_number)
238  scan_number = cinfo->input_scan_number;
239  cinfo->output_scan_number = scan_number;
240  /* Perform any dummy output passes, and set up for the real pass */
241  return output_pass_setup(cinfo);
242 }
243 
244 
245 /*
246  * Finish up after an output pass in buffered-image mode.
247  *
248  * Returns FALSE if suspended. The return value need be inspected only if
249  * a suspending data source is used.
250  */
251 
252 GLOBAL(boolean)
254 {
255  if ((cinfo->global_state == DSTATE_SCANNING ||
256  cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) {
257  /* Terminate this pass. */
258  /* We do not require the whole pass to have been completed. */
259  (*cinfo->master->finish_output_pass) (cinfo);
260  cinfo->global_state = DSTATE_BUFPOST;
261  } else if (cinfo->global_state != DSTATE_BUFPOST) {
262  /* BUFPOST = repeat call after a suspension, anything else is error */
263  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
264  }
265  /* Read markers looking for SOS or EOI */
266  while (cinfo->input_scan_number <= cinfo->output_scan_number &&
267  ! cinfo->inputctl->eoi_reached) {
268  if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
269  return FALSE; /* Suspend, come back later */
270  }
271  cinfo->global_state = DSTATE_BUFIMAGE;
272  return TRUE;
273 }
274 
275 #endif /* D_MULTISCAN_FILES_SUPPORTED */
boolean has_multiple_scans
Definition: jpegint.h:153
#define DSTATE_RAW_OK
Definition: jpegint.h:35
int scan_number
Definition: jpeglib.h:989
#define FALSE
Definition: OPC_IceHook.h:9
struct jpeg_input_controller * inputctl
Definition: jpeglib.h:623
#define JPEG_REACHED_SOS
Definition: jpeglib.h:996
#define JPEG_REACHED_EOI
Definition: jpeglib.h:997
JSAMPARRAY JDIMENSION max_lines
Definition: jpeglib.h:977
#define DSTATE_BUFIMAGE
Definition: jpegint.h:36
#define ERREXIT(cinfo, code)
Definition: jerror.h:205
#define JPEG_ROW_COMPLETED
Definition: jpeglib.h:998
#define TRUE
Definition: OPC_IceHook.h:13
#define DSTATE_PRELOAD
Definition: jpegint.h:32
LOCAL(boolean)
Definition: jdapistd.c:23
jpeg_read_raw_data(j_decompress_ptr cinfo, JSAMPIMAGE data, JDIMENSION max_lines)
Definition: jdapistd.c:185
jpeg_finish_output(j_decompress_ptr cinfo)
Definition: jdapistd.c:253
#define DSTATE_READY
Definition: jpegint.h:31
#define WARNMS(cinfo, code)
Definition: jerror.h:238
#define DSTATE_SCANNING
Definition: jpegint.h:34
jinit_master_decompress(j_decompress_ptr cinfo)
Definition: jdmaster.c:543
#define JPP(arglist)
Definition: jpeglib.h:818
JSAMPARRAY * JSAMPIMAGE
Definition: jpeglib.h:68
#define ERREXIT1(cinfo, code, p1)
Definition: jerror.h:208
#define DSTATE_BUFPOST
Definition: jpegint.h:37
JSAMPROW * JSAMPARRAY
Definition: jpeglib.h:67
JSAMPARRAY scanlines
Definition: jpeglib.h:939
jpeg_read_scanlines(j_decompress_ptr cinfo, JSAMPARRAY scanlines, JDIMENSION max_lines)
Definition: jdapistd.c:152
#define GLOBAL(type)
Definition: jmorecfg.h:188
#define DSTATE_PRESCAN
Definition: jpegint.h:33
output_pass_setup(j_decompress_ptr cinfo)
Definition: jdapistd.c:95
#define JPEG_SUSPENDED
Definition: jpeglib.h:965
jpeg_start_output(j_decompress_ptr cinfo, int scan_number)
Definition: jdapistd.c:228
JSAMPIMAGE data
Definition: jpeglib.h:945
retcode
unsigned int JDIMENSION
Definition: jmorecfg.h:171
boolean buffered_image
Definition: jpeglib.h:436
JDIMENSION total_iMCU_rows
Definition: jpeglib.h:580


openhrp3
Author(s): AIST, General Robotix Inc., Nakamura Lab of Dept. of Mechano Informatics at University of Tokyo
autogenerated on Thu Sep 8 2022 02:24:04