ReactOS  0.4.14-dev-854-gb9426a3
jcapistd.c
Go to the documentation of this file.
1 /*
2  * jcapistd.c
3  *
4  * Copyright (C) 1994-1996, Thomas G. Lane.
5  * Modified 2013 by Guido Vollbeding.
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 compression half
10  * of the JPEG library. These are the "standard" API routines that are
11  * used in the normal full-compression case. They are not used by a
12  * transcoding-only application. Note that if an application links in
13  * jpeg_start_compress, it will end up linking in the entire compressor.
14  * We thus must separate this file from jcapimin.c to avoid linking the
15  * whole compression library into a transcoder.
16  */
17 
18 #define JPEG_INTERNALS
19 #include "jinclude.h"
20 #include "jpeglib.h"
21 
22 
23 /*
24  * Compression initialization.
25  * Before calling this, all parameters and a data destination must be set up.
26  *
27  * We require a write_all_tables parameter as a failsafe check when writing
28  * multiple datastreams from the same compression object. Since prior runs
29  * will have left all the tables marked sent_table=TRUE, a subsequent run
30  * would emit an abbreviated stream (no tables) by default. This may be what
31  * is wanted, but for safety's sake it should not be the default behavior:
32  * programmers should have to make a deliberate choice to emit abbreviated
33  * images. Therefore the documentation and examples should encourage people
34  * to pass write_all_tables=TRUE; then it will take active thought to do the
35  * wrong thing.
36  */
37 
38 GLOBAL(void)
40 {
41  if (cinfo->global_state != CSTATE_START)
42  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
43 
44  if (write_all_tables)
45  jpeg_suppress_tables(cinfo, FALSE); /* mark all tables to be written */
46 
47  /* (Re)initialize error mgr and destination modules */
48  (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
49  (*cinfo->dest->init_destination) (cinfo);
50  /* Perform master selection of active modules */
51  jinit_compress_master(cinfo);
52  /* Set up for the first pass */
53  (*cinfo->master->prepare_for_pass) (cinfo);
54  /* Ready for application to drive first pass through jpeg_write_scanlines
55  * or jpeg_write_raw_data.
56  */
57  cinfo->next_scanline = 0;
58  cinfo->global_state = (cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING);
59 }
60 
61 
62 /*
63  * Write some scanlines of data to the JPEG compressor.
64  *
65  * The return value will be the number of lines actually written.
66  * This should be less than the supplied num_lines only in case that
67  * the data destination module has requested suspension of the compressor,
68  * or if more than image_height scanlines are passed in.
69  *
70  * Note: we warn about excess calls to jpeg_write_scanlines() since
71  * this likely signals an application programmer error. However,
72  * excess scanlines passed in the last valid call are *silently* ignored,
73  * so that the application need not adjust num_lines for end-of-image
74  * when using a multiple-scanline buffer.
75  */
76 
80 {
81  JDIMENSION row_ctr, rows_left;
82 
83  if (cinfo->global_state != CSTATE_SCANNING)
84  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
85  if (cinfo->next_scanline >= cinfo->image_height)
86  WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
87 
88  /* Call progress monitor hook if present */
89  if (cinfo->progress != NULL) {
90  cinfo->progress->pass_counter = (long) cinfo->next_scanline;
91  cinfo->progress->pass_limit = (long) cinfo->image_height;
92  (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
93  }
94 
95  /* Give master control module another chance if this is first call to
96  * jpeg_write_scanlines. This lets output of the frame/scan headers be
97  * delayed so that application can write COM, etc, markers between
98  * jpeg_start_compress and jpeg_write_scanlines.
99  */
100  if (cinfo->master->call_pass_startup)
101  (*cinfo->master->pass_startup) (cinfo);
102 
103  /* Ignore any extra scanlines at bottom of image. */
104  rows_left = cinfo->image_height - cinfo->next_scanline;
105  if (num_lines > rows_left)
106  num_lines = rows_left;
107 
108  row_ctr = 0;
109  (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, num_lines);
110  cinfo->next_scanline += row_ctr;
111  return row_ctr;
112 }
113 
114 
115 /*
116  * Alternate entry point to write raw data.
117  * Processes exactly one iMCU row per call, unless suspended.
118  */
119 
123 {
124  JDIMENSION lines_per_iMCU_row;
125 
126  if (cinfo->global_state != CSTATE_RAW_OK)
127  ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
128  if (cinfo->next_scanline >= cinfo->image_height) {
129  WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
130  return 0;
131  }
132 
133  /* Call progress monitor hook if present */
134  if (cinfo->progress != NULL) {
135  cinfo->progress->pass_counter = (long) cinfo->next_scanline;
136  cinfo->progress->pass_limit = (long) cinfo->image_height;
137  (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
138  }
139 
140  /* Give master control module another chance if this is first call to
141  * jpeg_write_raw_data. This lets output of the frame/scan headers be
142  * delayed so that application can write COM, etc, markers between
143  * jpeg_start_compress and jpeg_write_raw_data.
144  */
145  if (cinfo->master->call_pass_startup)
146  (*cinfo->master->pass_startup) (cinfo);
147 
148  /* Verify that at least one iMCU row has been passed. */
149  lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_v_scaled_size;
150  if (num_lines < lines_per_iMCU_row)
151  ERREXIT(cinfo, JERR_BUFFER_SIZE);
152 
153  /* Directly compress the row. */
154  if (! (*cinfo->coef->compress_data) (cinfo, data)) {
155  /* If compressor did not consume the whole row, suspend processing. */
156  return 0;
157  }
158 
159  /* OK, we processed one iMCU row. */
160  cinfo->next_scanline += lines_per_iMCU_row;
161  return lines_per_iMCU_row;
162 }
jpeg_write_raw_data(j_compress_ptr cinfo, JSAMPIMAGE data, JDIMENSION num_lines)
Definition: jcapistd.c:121
#define CSTATE_START
Definition: jpegint.h:26
#define ERREXIT(msg)
Definition: rdjpgcom.c:72
JSAMPARRAY JDIMENSION num_lines
Definition: jpeglib.h:1013
#define CSTATE_RAW_OK
Definition: jpegint.h:28
#define CSTATE_SCANNING
Definition: jpegint.h:27
jpeg_start_compress(j_compress_ptr cinfo, boolean write_all_tables)
Definition: jcapistd.c:39
jpeg_suppress_tables(j_compress_ptr cinfo, boolean suppress)
Definition: jcapimin.c:127
smooth NULL
Definition: ftsmooth.c:416
jpeg_write_scanlines(j_compress_ptr cinfo, JSAMPARRAY scanlines, JDIMENSION num_lines)
Definition: jcapistd.c:78
#define WARNMS(cinfo, code)
Definition: jerror.h:251
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: gl.h:1950
JSAMPARRAY * JSAMPIMAGE
Definition: jpeglib.h:77
#define ERREXIT1(cinfo, code, p1)
Definition: jerror.h:212
boolean write_all_tables
Definition: jpeglib.h:1011
JSAMPROW * JSAMPARRAY
Definition: jpeglib.h:76
JSAMPARRAY scanlines
Definition: jpeglib.h:1013
#define GLOBAL(type)
Definition: jmorecfg.h:291
#define long
Definition: qsort.c:33
unsigned int JDIMENSION
Definition: jmorecfg.h:229
jinit_compress_master(j_compress_ptr cinfo)
Definition: jcinit.c:193