3rdparty/libjpeg/jcapistd.c

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

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


/*
 * Compression initialization.
 * Before calling this, all parameters and a data destination must be set up.
 *
 * We require a write_all_tables parameter as a failsafe check when writing
 * multiple datastreams from the same compression object.  Since prior runs
 * will have left all the tables marked sent_table=TRUE, a subsequent run
 * would emit an abbreviated stream (no tables) by default.  This may be what
 * is wanted, but for safety's sake it should not be the default behavior:
 * programmers should have to make a deliberate choice to emit abbreviated
 * images.  Therefore the documentation and examples should encourage people
 * to pass write_all_tables=TRUE; then it will take active thought to do the
 * wrong thing.
 */

GLOBAL(void)
jpeg_start_compress (j_compress_ptr cinfo, boolean write_all_tables)
{
  if (cinfo->global_state != CSTATE_START)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);

  if (write_all_tables)
    jpeg_suppress_tables(cinfo, FALSE); /* mark all tables to be written */

  /* (Re)initialize error mgr and destination modules */
  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
  (*cinfo->dest->init_destination) (cinfo);
  /* Perform master selection of active modules */
  jinit_compress_master(cinfo);
  /* Set up for the first pass */
  (*cinfo->master->prepare_for_pass) (cinfo);
  /* Ready for application to drive first pass through jpeg_write_scanlines
   * or jpeg_write_raw_data.
   */
  cinfo->next_scanline = 0;
  cinfo->global_state = (cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING);
}


/*
 * Write some scanlines of data to the JPEG compressor.
 *
 * The return value will be the number of lines actually written.
 * This should be less than the supplied num_lines only in case that
 * the data destination module has requested suspension of the compressor,
 * or if more than image_height scanlines are passed in.
 *
 * Note: we warn about excess calls to jpeg_write_scanlines() since
 * this likely signals an application programmer error.  However,
 * excess scanlines passed in the last valid call are *silently* ignored,
 * so that the application need not adjust num_lines for end-of-image
 * when using a multiple-scanline buffer.
 */

GLOBAL(JDIMENSION)
jpeg_write_scanlines (j_compress_ptr cinfo, JSAMPARRAY scanlines,
                      JDIMENSION num_lines)
{
  JDIMENSION row_ctr, rows_left;

  if (cinfo->global_state != CSTATE_SCANNING)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->next_scanline >= cinfo->image_height)
    WARNMS(cinfo, JWRN_TOO_MUCH_DATA);

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

  /* Give master control module another chance if this is first call to
   * jpeg_write_scanlines.  This lets output of the frame/scan headers be
   * delayed so that application can write COM, etc, markers between
   * jpeg_start_compress and jpeg_write_scanlines.
   */
  if (cinfo->master->call_pass_startup)
    (*cinfo->master->pass_startup) (cinfo);

  /* Ignore any extra scanlines at bottom of image. */
  rows_left = cinfo->image_height - cinfo->next_scanline;
  if (num_lines > rows_left)
    num_lines = rows_left;

  row_ctr = 0;
  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, num_lines);
  cinfo->next_scanline += row_ctr;
  return row_ctr;
}


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

GLOBAL(JDIMENSION)
jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data,
                     JDIMENSION num_lines)
{
  JDIMENSION lines_per_iMCU_row;

  if (cinfo->global_state != CSTATE_RAW_OK)
    ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
  if (cinfo->next_scanline >= cinfo->image_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->next_scanline;
    cinfo->progress->pass_limit = (long) cinfo->image_height;
    (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
  }

  /* Give master control module another chance if this is first call to
   * jpeg_write_raw_data.  This lets output of the frame/scan headers be
   * delayed so that application can write COM, etc, markers between
   * jpeg_start_compress and jpeg_write_raw_data.
   */
  if (cinfo->master->call_pass_startup)
    (*cinfo->master->pass_startup) (cinfo);

  /* Verify that at least one iMCU row has been passed. */
  lines_per_iMCU_row = cinfo->max_v_samp_factor * DCTSIZE;
  if (num_lines < lines_per_iMCU_row)
    ERREXIT(cinfo, JERR_BUFFER_SIZE);

  /* Directly compress the row. */
  if (! (*cinfo->coef->compress_data) (cinfo, data)) {
    /* If compressor did not consume the whole row, suspend processing. */
    return 0;
  }

  /* OK, we processed one iMCU row. */
  cinfo->next_scanline += lines_per_iMCU_row;
  return lines_per_iMCU_row;
}
1	/*
2	* jcapistd.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 compression half
9	* of the JPEG library. These are the "standard" API routines that are
10	* used in the normal full-compression case. They are not used by a
11	* transcoding-only application. Note that if an application links in
12	* jpeg_start_compress, it will end up linking in the entire compressor.
13	* We thus must separate this file from jcapimin.c to avoid linking the
14	* whole compression library into a transcoder.
15	*/
16
17	#define JPEG_INTERNALS
18	#include "jinclude.h"
19	#include "jpeglib.h"
20
21
22	/*
23	* Compression initialization.
24	* Before calling this, all parameters and a data destination must be set up.
25	*
26	* We require a write_all_tables parameter as a failsafe check when writing
27	* multiple datastreams from the same compression object. Since prior runs
28	* will have left all the tables marked sent_table=TRUE, a subsequent run
29	* would emit an abbreviated stream (no tables) by default. This may be what
30	* is wanted, but for safety's sake it should not be the default behavior:
31	* programmers should have to make a deliberate choice to emit abbreviated
32	* images. Therefore the documentation and examples should encourage people
33	* to pass write_all_tables=TRUE; then it will take active thought to do the
34	* wrong thing.
35	*/
36
37	GLOBAL(void)
38	jpeg_start_compress (j_compress_ptr cinfo, boolean write_all_tables)
39	{
40	if (cinfo->global_state != CSTATE_START)
41	ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
42
43	if (write_all_tables)
44	jpeg_suppress_tables(cinfo, FALSE); /* mark all tables to be written */
45
46	/* (Re)initialize error mgr and destination modules */
47	(*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
48	(*cinfo->dest->init_destination) (cinfo);
49	/* Perform master selection of active modules */
50	jinit_compress_master(cinfo);
51	/* Set up for the first pass */
52	(*cinfo->master->prepare_for_pass) (cinfo);
53	/* Ready for application to drive first pass through jpeg_write_scanlines
54	* or jpeg_write_raw_data.
55	*/
56	cinfo->next_scanline = 0;
57	cinfo->global_state = (cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING);
58	}
59
60
61	/*
62	* Write some scanlines of data to the JPEG compressor.
63	*
64	* The return value will be the number of lines actually written.
65	* This should be less than the supplied num_lines only in case that
66	* the data destination module has requested suspension of the compressor,
67	* or if more than image_height scanlines are passed in.
68	*
69	* Note: we warn about excess calls to jpeg_write_scanlines() since
70	* this likely signals an application programmer error. However,
71	* excess scanlines passed in the last valid call are silently ignored,
72	* so that the application need not adjust num_lines for end-of-image
73	* when using a multiple-scanline buffer.
74	*/
75
76	GLOBAL(JDIMENSION)
77	jpeg_write_scanlines (j_compress_ptr cinfo, JSAMPARRAY scanlines,
78	JDIMENSION num_lines)
79	{
80	JDIMENSION row_ctr, rows_left;
81
82	if (cinfo->global_state != CSTATE_SCANNING)
83	ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
84	if (cinfo->next_scanline >= cinfo->image_height)
85	WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
86
87	/* Call progress monitor hook if present */
88	if (cinfo->progress != NULL) {
89	cinfo->progress->pass_counter = (long) cinfo->next_scanline;
90	cinfo->progress->pass_limit = (long) cinfo->image_height;
91	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
92	}
93
94	/* Give master control module another chance if this is first call to
95	* jpeg_write_scanlines. This lets output of the frame/scan headers be
96	* delayed so that application can write COM, etc, markers between
97	* jpeg_start_compress and jpeg_write_scanlines.
98	*/
99	if (cinfo->master->call_pass_startup)
100	(*cinfo->master->pass_startup) (cinfo);
101
102	/* Ignore any extra scanlines at bottom of image. */
103	rows_left = cinfo->image_height - cinfo->next_scanline;
104	if (num_lines > rows_left)
105	num_lines = rows_left;
106
107	row_ctr = 0;
108	(*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, num_lines);
109	cinfo->next_scanline += row_ctr;
110	return row_ctr;
111	}
112
113
114	/*
115	* Alternate entry point to write raw data.
116	* Processes exactly one iMCU row per call, unless suspended.
117	*/
118
119	GLOBAL(JDIMENSION)
120	jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data,
121	JDIMENSION num_lines)
122	{
123	JDIMENSION lines_per_iMCU_row;
124
125	if (cinfo->global_state != CSTATE_RAW_OK)
126	ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
127	if (cinfo->next_scanline >= cinfo->image_height) {
128	WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
129	return 0;
130	}
131
132	/* Call progress monitor hook if present */
133	if (cinfo->progress != NULL) {
134	cinfo->progress->pass_counter = (long) cinfo->next_scanline;
135	cinfo->progress->pass_limit = (long) cinfo->image_height;
136	(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
137	}
138
139	/* Give master control module another chance if this is first call to
140	* jpeg_write_raw_data. This lets output of the frame/scan headers be
141	* delayed so that application can write COM, etc, markers between
142	* jpeg_start_compress and jpeg_write_raw_data.
143	*/
144	if (cinfo->master->call_pass_startup)
145	(*cinfo->master->pass_startup) (cinfo);
146
147	/* Verify that at least one iMCU row has been passed. */
148	lines_per_iMCU_row = cinfo->max_v_samp_factor * DCTSIZE;
149	if (num_lines < lines_per_iMCU_row)
150	ERREXIT(cinfo, JERR_BUFFER_SIZE);
151
152	/* Directly compress the row. */
153	if (! (*cinfo->coef->compress_data) (cinfo, data)) {
154	/* If compressor did not consume the whole row, suspend processing. */
155	return 0;
156	}
157
158	/* OK, we processed one iMCU row. */
159	cinfo->next_scanline += lines_per_iMCU_row;
160	return lines_per_iMCU_row;
161	}