3rdparty/libjpeg/jdapistd.c

/*
 * jdapistd.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 application interface code for the decompression half
 * of the JPEG library.  These are the "standard" API routines that are
 * used in the normal full-decompression case.  They are not used by a
 * transcoding-only application.  Note that if an application links in
 * jpeg_start_decompress, it will end up linking in the entire decompressor.
 * We thus must separate this file from jdapimin.c to avoid linking the
 * whole decompression library into a transcoder.
 */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"


/* Forward declarations */
LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo));


/*
 * Decompression initialization.
 * jpeg_read_header must be completed before calling this.
 *
 * If a multipass operating mode was selected, this will do all but the
 * last pass, and thus may take a great deal of time.
 *
 * Returns FALSE if suspended.  The return value need be inspected only if
 * a suspending data source is used.
 */

GLOBAL(boolean)
jpeg_start_decompress (j_decompress_ptr cinfo)
{
  if (cinfo->global_state == DSTATE_READY) {
    /* First call: initialize master control, select active modules */
    jinit_master_decompress(cinfo);
    if (cinfo->buffered_image) {
      /* No more work here; expecting jpeg_start_output next */
      cinfo->global_state = DSTATE_BUFIMAGE;
      return TRUE;
    }
    cinfo->global_state = DSTATE_PRELOAD;
  }
  if (cinfo->global_state == DSTATE_PRELOAD) {
    /* If file has multiple scans, absorb them all into the coef buffer */
    if (cinfo->inputctl->has_multiple_scans) {
#ifdef D_MULTISCAN_FILES_SUPPORTED
      for (;;) {
        int retcode;
        /* Call progress monitor hook if present */
        if (cinfo->progress != NULL)
          (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
        /* Absorb some more input */
        retcode = (*cinfo->inputctl->consume_input) (cinfo);
        if (retcode == JPEG_SUSPENDED)
          return FALSE;
        if (retcode == JPEG_REACHED_EOI)
          break;
        /* Advance progress counter if appropriate */
        if (cinfo->progress != NULL &&
            (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
          if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
            /* jdmaster underestimated number of scans; ratchet up one scan */
            cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
          }
        }
      }
#else
      ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif /* D_MULTISCAN_FILES_SUPPORTED */
    }
    cinfo->output_scan_number = cinfo->input_scan_number;
  } else if (cinfo->global_state != DSTATE_PRESCAN)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  /* Perform any dummy output passes, and set up for the final pass */
  return output_pass_setup(cinfo);
}


/*
 * Set up for an output pass, and perform any dummy pass(es) needed.
 * Common subroutine for jpeg_start_decompress and jpeg_start_output.
 * Entry: global_state = DSTATE_PRESCAN only if previously suspended.
 * Exit: If done, returns TRUE and sets global_state for proper output mode.
 *       If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
 */

LOCAL(boolean)
output_pass_setup (j_decompress_ptr cinfo)
{
  if (cinfo->global_state != DSTATE_PRESCAN) {
    /* First call: do pass setup */
    (*cinfo->master->prepare_for_output_pass) (cinfo);
    cinfo->output_scanline = 0;
    cinfo->global_state = DSTATE_PRESCAN;
  }
  /* Loop over any required dummy passes */
  while (cinfo->master->is_dummy_pass) {
#ifdef QUANT_2PASS_SUPPORTED
    /* Crank through the dummy pass */
    while (cinfo->output_scanline < cinfo->output_height) {
      JDIMENSION last_scanline;
      /* Call progress monitor hook if present */
      if (cinfo->progress != NULL) {
        cinfo->progress->pass_counter = (long) cinfo->output_scanline;
        cinfo->progress->pass_limit = (long) cinfo->output_height;
        (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
      }
      /* Process some data */
      last_scanline = cinfo->output_scanline;
      (*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL,
                                    &cinfo->output_scanline, (JDIMENSION) 0);
      if (cinfo->output_scanline == last_scanline)
        return FALSE;           /* No progress made, must suspend */
    }
    /* Finish up dummy pass, and set up for another one */
    (*cinfo->master->finish_output_pass) (cinfo);
    (*cinfo->master->prepare_for_output_pass) (cinfo);
    cinfo->output_scanline = 0;
#else
    ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif /* QUANT_2PASS_SUPPORTED */
  }
  /* Ready for application to drive output pass through
   * jpeg_read_scanlines or jpeg_read_raw_data.
   */
  cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
  return TRUE;
}


/*
 * Read some scanlines of data from the JPEG decompressor.
 *
 * The return value will be the number of lines actually read.
 * This may be less than the number requested in several cases,
 * including bottom of image, data source suspension, and operating
 * modes that emit multiple scanlines at a time.
 *
 * Note: we warn about excess calls to jpeg_read_scanlines() since
 * this likely signals an application programmer error.  However,
 * an oversize buffer (max_lines > scanlines remaining) is not an error.
 */

GLOBAL(JDIMENSION)
jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines,
                     JDIMENSION max_lines)
{
  JDIMENSION row_ctr;

  if (cinfo->global_state != DSTATE_SCANNING)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->output_scanline >= cinfo->output_height) {
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
    return 0;
  }

  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->output_scanline;
    cinfo->progress->pass_limit = (long) cinfo->output_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Process some data */
  row_ctr = 0;
  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
  cinfo->output_scanline += row_ctr;
  return row_ctr;
}


/*
 * Alternate entry point to read raw data.
 * Processes exactly one iMCU row per call, unless suspended.
 */

GLOBAL(JDIMENSION)
jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data,
                    JDIMENSION max_lines)
{
  JDIMENSION lines_per_iMCU_row;

  if (cinfo->global_state != DSTATE_RAW_OK)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->output_scanline >= cinfo->output_height) {
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
    return 0;
  }

  /* Call progress monitor hook if present */
  if (cinfo->progress != NULL) {
    cinfo->progress->pass_counter = (long) cinfo->output_scanline;
    cinfo->progress->pass_limit = (long) cinfo->output_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Verify that at least one iMCU row can be returned. */
  lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_v_scaled_size;
  if (max_lines < lines_per_iMCU_row)
    ERREXIT(cinfo, JERR_BUFFER_SIZE);

  /* Decompress directly into user's buffer. */
  if (! (*cinfo->coef->decompress_data) (cinfo, data))
    return 0;                   /* suspension forced, can do nothing more */

  /* OK, we processed one iMCU row. */
  cinfo->output_scanline += lines_per_iMCU_row;
  return lines_per_iMCU_row;
}


/* Additional entry points for buffered-image mode. */

#ifdef D_MULTISCAN_FILES_SUPPORTED

/*
 * Initialize for an output pass in buffered-image mode.
 */

GLOBAL(boolean)
jpeg_start_output (j_decompress_ptr cinfo, int scan_number)
{
  if (cinfo->global_state != DSTATE_BUFIMAGE &&
      cinfo->global_state != DSTATE_PRESCAN)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  /* Limit scan number to valid range */
  if (scan_number <= 0)
    scan_number = 1;
  if (cinfo->inputctl->eoi_reached &&
      scan_number > cinfo->input_scan_number)
    scan_number = cinfo->input_scan_number;
  cinfo->output_scan_number = scan_number;
  /* Perform any dummy output passes, and set up for the real pass */
  return output_pass_setup(cinfo);
}


/*
 * Finish up after an output pass in buffered-image mode.
 *
 * Returns FALSE if suspended.  The return value need be inspected only if
 * a suspending data source is used.
 */

GLOBAL(boolean)
jpeg_finish_output (j_decompress_ptr cinfo)
{
  if ((cinfo->global_state == DSTATE_SCANNING ||
       cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) {
    /* Terminate this pass. */
    /* We do not require the whole pass to have been completed. */
    (*cinfo->master->finish_output_pass) (cinfo);
    cinfo->global_state = DSTATE_BUFPOST;
  } else if (cinfo->global_state != DSTATE_BUFPOST) {
    /* BUFPOST = repeat call after a suspension, anything else is error */
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  }
  /* Read markers looking for SOS or EOI */
  while (cinfo->input_scan_number <= cinfo->output_scan_number &&
         ! cinfo->inputctl->eoi_reached) {
    if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
      return FALSE;             /* Suspend, come back later */
  }
  cinfo->global_state = DSTATE_BUFIMAGE;
  return TRUE;
}

#endif /* D_MULTISCAN_FILES_SUPPORTED */
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 */
23	LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo));
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 */
42	jinit_master_decompress(cinfo);
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)
95	output_pass_setup (j_decompress_ptr cinfo)
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
151	GLOBAL(JDIMENSION)
152	jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines,
153	JDIMENSION max_lines)
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
184	GLOBAL(JDIMENSION)
185	jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data,
186	JDIMENSION max_lines)
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_v_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)
228	jpeg_start_output (j_decompress_ptr cinfo, int scan_number)
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)
253	jpeg_finish_output (j_decompress_ptr cinfo)
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 */