1#if !defined(_FX_JPEG_TURBO_)
2/*
3 * jdapistd.c
4 *
5 * Copyright (C) 1994-1996, Thomas G. Lane.
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 application interface code for the decompression half
10 * of the JPEG library.  These are the "standard" API routines that are
11 * used in the normal full-decompression case.  They are not used by a
12 * transcoding-only application.  Note that if an application links in
13 * jpeg_start_decompress, it will end up linking in the entire decompressor.
14 * We thus must separate this file from jdapimin.c to avoid linking the
15 * whole decompression library into a transcoder.
16 */
17
18#define JPEG_INTERNALS
19#include "jinclude.h"
20#include "jpeglib.h"
21
22
23/* Forward declarations */
24LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo));
25
26
27/*
28 * Decompression initialization.
29 * jpeg_read_header must be completed before calling this.
30 *
31 * If a multipass operating mode was selected, this will do all but the
32 * last pass, and thus may take a great deal of time.
33 *
34 * Returns FALSE if suspended.  The return value need be inspected only if
35 * a suspending data source is used.
36 */
37
38GLOBAL(boolean)
39jpeg_start_decompress (j_decompress_ptr cinfo)
40{
41  if (cinfo->global_state == DSTATE_READY) {
42    /* First call: initialize master control, select active modules */
43    jinit_master_decompress(cinfo);
44    if (cinfo->buffered_image) {
45      /* No more work here; expecting jpeg_start_output next */
46      cinfo->global_state = DSTATE_BUFIMAGE;
47      return TRUE;
48    }
49    cinfo->global_state = DSTATE_PRELOAD;
50  }
51  if (cinfo->global_state == DSTATE_PRELOAD) {
52    /* If file has multiple scans, absorb them all into the coef buffer */
53    if (cinfo->inputctl->has_multiple_scans) {
54#ifdef D_MULTISCAN_FILES_SUPPORTED
55      for (;;) {
56	int retcode;
57	/* Call progress monitor hook if present */
58	if (cinfo->progress != NULL)
59	  (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
60	/* Absorb some more input */
61	retcode = (*cinfo->inputctl->consume_input) (cinfo);
62	if (retcode == JPEG_SUSPENDED)
63	  return FALSE;
64	if (retcode == JPEG_REACHED_EOI)
65	  break;
66	/* Advance progress counter if appropriate */
67	if (cinfo->progress != NULL &&
68	    (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
69	  if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
70	    /* jdmaster underestimated number of scans; ratchet up one scan */
71	    cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
72	  }
73	}
74      }
75#else
76      ERREXIT(cinfo, JERR_NOT_COMPILED);
77#endif /* D_MULTISCAN_FILES_SUPPORTED */
78    }
79    cinfo->output_scan_number = cinfo->input_scan_number;
80  } else if (cinfo->global_state != DSTATE_PRESCAN)
81    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
82  /* Perform any dummy output passes, and set up for the final pass */
83  return output_pass_setup(cinfo);
84}
85
86
87/*
88 * Set up for an output pass, and perform any dummy pass(es) needed.
89 * Common subroutine for jpeg_start_decompress and jpeg_start_output.
90 * Entry: global_state = DSTATE_PRESCAN only if previously suspended.
91 * Exit: If done, returns TRUE and sets global_state for proper output mode.
92 *       If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
93 */
94
95LOCAL(boolean)
96output_pass_setup (j_decompress_ptr cinfo)
97{
98  if (cinfo->global_state != DSTATE_PRESCAN) {
99    /* First call: do pass setup */
100    (*cinfo->master->prepare_for_output_pass) (cinfo);
101    cinfo->output_scanline = 0;
102    cinfo->global_state = DSTATE_PRESCAN;
103  }
104  /* Loop over any required dummy passes */
105  while (cinfo->master->is_dummy_pass) {
106#ifdef QUANT_2PASS_SUPPORTED
107    /* Crank through the dummy pass */
108    while (cinfo->output_scanline < cinfo->output_height) {
109      JDIMENSION last_scanline;
110      /* Call progress monitor hook if present */
111      if (cinfo->progress != NULL) {
112	cinfo->progress->pass_counter = (long) cinfo->output_scanline;
113	cinfo->progress->pass_limit = (long) cinfo->output_height;
114	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
115      }
116      /* Process some data */
117      last_scanline = cinfo->output_scanline;
118      (*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL,
119				    &cinfo->output_scanline, (JDIMENSION) 0);
120      if (cinfo->output_scanline == last_scanline)
121	return FALSE;		/* No progress made, must suspend */
122    }
123    /* Finish up dummy pass, and set up for another one */
124    (*cinfo->master->finish_output_pass) (cinfo);
125    (*cinfo->master->prepare_for_output_pass) (cinfo);
126    cinfo->output_scanline = 0;
127#else
128    ERREXIT(cinfo, JERR_NOT_COMPILED);
129#endif /* QUANT_2PASS_SUPPORTED */
130  }
131  /* Ready for application to drive output pass through
132   * jpeg_read_scanlines or jpeg_read_raw_data.
133   */
134  cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
135  return TRUE;
136}
137
138
139/*
140 * Read some scanlines of data from the JPEG decompressor.
141 *
142 * The return value will be the number of lines actually read.
143 * This may be less than the number requested in several cases,
144 * including bottom of image, data source suspension, and operating
145 * modes that emit multiple scanlines at a time.
146 *
147 * Note: we warn about excess calls to jpeg_read_scanlines() since
148 * this likely signals an application programmer error.  However,
149 * an oversize buffer (max_lines > scanlines remaining) is not an error.
150 */
151
152GLOBAL(JDIMENSION)
153jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines,
154		     JDIMENSION max_lines)
155{
156  JDIMENSION row_ctr;
157
158  if (cinfo->global_state != DSTATE_SCANNING)
159	  return 0; /* XYQ 2010-6-27: don't throw exception here */
160/*    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state); */
161  if (cinfo->output_scanline >= cinfo->output_height) {
162    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
163    return 0;
164  }
165
166  /* Call progress monitor hook if present */
167  if (cinfo->progress != NULL) {
168    cinfo->progress->pass_counter = (long) cinfo->output_scanline;
169    cinfo->progress->pass_limit = (long) cinfo->output_height;
170    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
171  }
172
173  /* Process some data */
174  row_ctr = 0;
175  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
176  cinfo->output_scanline += row_ctr;
177  return row_ctr;
178}
179
180
181/*
182 * Alternate entry point to read raw data.
183 * Processes exactly one iMCU row per call, unless suspended.
184 */
185
186GLOBAL(JDIMENSION)
187jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data,
188		    JDIMENSION max_lines)
189{
190  JDIMENSION lines_per_iMCU_row;
191
192  if (cinfo->global_state != DSTATE_RAW_OK)
193    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
194  if (cinfo->output_scanline >= cinfo->output_height) {
195    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
196    return 0;
197  }
198
199  /* Call progress monitor hook if present */
200  if (cinfo->progress != NULL) {
201    cinfo->progress->pass_counter = (long) cinfo->output_scanline;
202    cinfo->progress->pass_limit = (long) cinfo->output_height;
203    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
204  }
205
206  /* Verify that at least one iMCU row can be returned. */
207  lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size;
208  if (max_lines < lines_per_iMCU_row)
209    ERREXIT(cinfo, JERR_BUFFER_SIZE);
210
211  /* Decompress directly into user's buffer. */
212  if (! (*cinfo->coef->decompress_data) (cinfo, data))
213    return 0;			/* suspension forced, can do nothing more */
214
215  /* OK, we processed one iMCU row. */
216  cinfo->output_scanline += lines_per_iMCU_row;
217  return lines_per_iMCU_row;
218}
219
220
221/* Additional entry points for buffered-image mode. */
222
223#ifdef D_MULTISCAN_FILES_SUPPORTED
224
225/*
226 * Initialize for an output pass in buffered-image mode.
227 */
228
229GLOBAL(boolean)
230jpeg_start_output (j_decompress_ptr cinfo, int scan_number)
231{
232  if (cinfo->global_state != DSTATE_BUFIMAGE &&
233      cinfo->global_state != DSTATE_PRESCAN)
234    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
235  /* Limit scan number to valid range */
236  if (scan_number <= 0)
237    scan_number = 1;
238  if (cinfo->inputctl->eoi_reached &&
239      scan_number > cinfo->input_scan_number)
240    scan_number = cinfo->input_scan_number;
241  cinfo->output_scan_number = scan_number;
242  /* Perform any dummy output passes, and set up for the real pass */
243  return output_pass_setup(cinfo);
244}
245
246
247/*
248 * Finish up after an output pass in buffered-image mode.
249 *
250 * Returns FALSE if suspended.  The return value need be inspected only if
251 * a suspending data source is used.
252 */
253
254GLOBAL(boolean)
255jpeg_finish_output (j_decompress_ptr cinfo)
256{
257  if ((cinfo->global_state == DSTATE_SCANNING ||
258       cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) {
259    /* Terminate this pass. */
260    /* We do not require the whole pass to have been completed. */
261    (*cinfo->master->finish_output_pass) (cinfo);
262    cinfo->global_state = DSTATE_BUFPOST;
263  } else if (cinfo->global_state != DSTATE_BUFPOST) {
264    /* BUFPOST = repeat call after a suspension, anything else is error */
265    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
266  }
267  /* Read markers looking for SOS or EOI */
268  while (cinfo->input_scan_number <= cinfo->output_scan_number &&
269	 ! cinfo->inputctl->eoi_reached) {
270    if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
271      return FALSE;		/* Suspend, come back later */
272  }
273  cinfo->global_state = DSTATE_BUFIMAGE;
274  return TRUE;
275}
276
277#endif /* D_MULTISCAN_FILES_SUPPORTED */
278
279#endif //_FX_JPEG_TURBO_
280