/src/freeimage-svn/FreeImage/trunk/Source/LibJPEG/jcinit.c

Source
/*
 * jcinit.c
 *
 * Copyright (C) 1991-1997, Thomas G. Lane.
 * Modified 2003-2017 by Guido Vollbeding.
 * 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 initialization logic for the JPEG compressor.
 * This routine is in charge of selecting the modules to be executed and
 * making an initialization call to each one.
 *
 * Logically, this code belongs in jcmaster.c.  It's split out because
 * linking this routine implies linking the entire compression library.
 * For a transcoding-only application, we want to be able to use jcmaster.c
 * without linking in the whole library.
 */

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


/*
 * Compute JPEG image dimensions and related values.
 * NOTE: this is exported for possible use by application.
 * Hence it mustn't do anything that can't be done twice.
 */

GLOBAL(void)
jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo)
/* Do computations that are needed before master selection phase */
{
  /* Sanity check on input image dimensions to prevent overflow in
   * following calculations.
   * We do check jpeg_width and jpeg_height in initial_setup in jcmaster.c,
   * but image_width and image_height can come from arbitrary data,
   * and we need some space for multiplication by block_size.
   */
  if (((long) cinfo->image_width >> 24) || ((long) cinfo->image_height >> 24))
    ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);

#ifdef DCT_SCALING_SUPPORTED

  /* Compute actual JPEG image dimensions and DCT scaling choices. */
  if (cinfo->scale_num >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/1 scaling */
    cinfo->jpeg_width = cinfo->image_width * cinfo->block_size;
    cinfo->jpeg_height = cinfo->image_height * cinfo->block_size;
    cinfo->min_DCT_h_scaled_size = 1;
    cinfo->min_DCT_v_scaled_size = 1;
  } else if (cinfo->scale_num * 2 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/2 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 2L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 2L);
    cinfo->min_DCT_h_scaled_size = 2;
    cinfo->min_DCT_v_scaled_size = 2;
  } else if (cinfo->scale_num * 3 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/3 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 3L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 3L);
    cinfo->min_DCT_h_scaled_size = 3;
    cinfo->min_DCT_v_scaled_size = 3;
  } else if (cinfo->scale_num * 4 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/4 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 4L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 4L);
    cinfo->min_DCT_h_scaled_size = 4;
    cinfo->min_DCT_v_scaled_size = 4;
  } else if (cinfo->scale_num * 5 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/5 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 5L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 5L);
    cinfo->min_DCT_h_scaled_size = 5;
    cinfo->min_DCT_v_scaled_size = 5;
  } else if (cinfo->scale_num * 6 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/6 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 6L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 6L);
    cinfo->min_DCT_h_scaled_size = 6;
    cinfo->min_DCT_v_scaled_size = 6;
  } else if (cinfo->scale_num * 7 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/7 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 7L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 7L);
    cinfo->min_DCT_h_scaled_size = 7;
    cinfo->min_DCT_v_scaled_size = 7;
  } else if (cinfo->scale_num * 8 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/8 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 8L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 8L);
    cinfo->min_DCT_h_scaled_size = 8;
    cinfo->min_DCT_v_scaled_size = 8;
  } else if (cinfo->scale_num * 9 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/9 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 9L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 9L);
    cinfo->min_DCT_h_scaled_size = 9;
    cinfo->min_DCT_v_scaled_size = 9;
  } else if (cinfo->scale_num * 10 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/10 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 10L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 10L);
    cinfo->min_DCT_h_scaled_size = 10;
    cinfo->min_DCT_v_scaled_size = 10;
  } else if (cinfo->scale_num * 11 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/11 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 11L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 11L);
    cinfo->min_DCT_h_scaled_size = 11;
    cinfo->min_DCT_v_scaled_size = 11;
  } else if (cinfo->scale_num * 12 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/12 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 12L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 12L);
    cinfo->min_DCT_h_scaled_size = 12;
    cinfo->min_DCT_v_scaled_size = 12;
  } else if (cinfo->scale_num * 13 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/13 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 13L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 13L);
    cinfo->min_DCT_h_scaled_size = 13;
    cinfo->min_DCT_v_scaled_size = 13;
  } else if (cinfo->scale_num * 14 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/14 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 14L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 14L);
    cinfo->min_DCT_h_scaled_size = 14;
    cinfo->min_DCT_v_scaled_size = 14;
  } else if (cinfo->scale_num * 15 >= cinfo->scale_denom * cinfo->block_size) {
    /* Provide block_size/15 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 15L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 15L);
    cinfo->min_DCT_h_scaled_size = 15;
    cinfo->min_DCT_v_scaled_size = 15;
  } else {
    /* Provide block_size/16 scaling */
    cinfo->jpeg_width = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 16L);
    cinfo->jpeg_height = (JDIMENSION)
      jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 16L);
    cinfo->min_DCT_h_scaled_size = 16;
    cinfo->min_DCT_v_scaled_size = 16;
  }

#else /* !DCT_SCALING_SUPPORTED */

  /* Hardwire it to "no scaling" */
  cinfo->jpeg_width = cinfo->image_width;
  cinfo->jpeg_height = cinfo->image_height;
  cinfo->min_DCT_h_scaled_size = DCTSIZE;
  cinfo->min_DCT_v_scaled_size = DCTSIZE;

#endif /* DCT_SCALING_SUPPORTED */
}


/*
 * Master selection of compression modules.
 * This is done once at the start of processing an image.  We determine
 * which modules will be used and give them appropriate initialization calls.
 */

GLOBAL(void)
jinit_compress_master (j_compress_ptr cinfo)
{
  long samplesperrow;
  JDIMENSION jd_samplesperrow;

  /* For now, precision must match compiled-in value... */
  if (cinfo->data_precision != BITS_IN_JSAMPLE)
    ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);

  /* Sanity check on input image dimensions */
  if (cinfo->image_height <= 0 || cinfo->image_width <= 0 ||
      cinfo->input_components <= 0)
    ERREXIT(cinfo, JERR_EMPTY_IMAGE);

  /* Width of an input scanline must be representable as JDIMENSION. */
  samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
  jd_samplesperrow = (JDIMENSION) samplesperrow;
  if ((long) jd_samplesperrow != samplesperrow)
    ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);

  /* Compute JPEG image dimensions and related values. */
  jpeg_calc_jpeg_dimensions(cinfo);

  /* Initialize master control (includes parameter checking/processing) */
  jinit_c_master_control(cinfo, FALSE /* full compression */);

  /* Preprocessing */
  if (! cinfo->raw_data_in) {
    jinit_color_converter(cinfo);
    jinit_downsampler(cinfo);
    jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
  }
  /* Forward DCT */
  jinit_forward_dct(cinfo);
  /* Entropy encoding: either Huffman or arithmetic coding. */
  if (cinfo->arith_code)
    jinit_arith_encoder(cinfo);
  else {
    jinit_huff_encoder(cinfo);
  }

  /* Need a full-image coefficient buffer in any multi-pass mode. */
  jinit_c_coef_controller(cinfo,
    (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
  jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);

  jinit_marker_writer(cinfo);

  /* We can now tell the memory manager to allocate virtual arrays. */
  (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);

  /* Write the datastream header (SOI) immediately.
   * Frame and scan headers are postponed till later.
   * This lets application insert special markers after the SOI.
   */
  (*cinfo->marker->write_file_header) (cinfo);
}

Coverage Report

Created: 2025-10-28 06:24

Line	Count	Source
1		/*
2		* jcinit.c
3		*
4		* Copyright (C) 1991-1997, Thomas G. Lane.
5		* Modified 2003-2017 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 initialization logic for the JPEG compressor.
10		* This routine is in charge of selecting the modules to be executed and
11		* making an initialization call to each one.
12		*
13		* Logically, this code belongs in jcmaster.c. It's split out because
14		* linking this routine implies linking the entire compression library.
15		* For a transcoding-only application, we want to be able to use jcmaster.c
16		* without linking in the whole library.
17		*/
18
19		#define JPEG_INTERNALS
20		#include "jinclude.h"
21		#include "jpeglib.h"
22
23
24		/*
25		* Compute JPEG image dimensions and related values.
26		* NOTE: this is exported for possible use by application.
27		* Hence it mustn't do anything that can't be done twice.
28		*/
29
30		GLOBAL(void)
31		jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo)
32		/* Do computations that are needed before master selection phase */
33	0	{
34		/* Sanity check on input image dimensions to prevent overflow in
35		* following calculations.
36		* We do check jpeg_width and jpeg_height in initial_setup in jcmaster.c,
37		* but image_width and image_height can come from arbitrary data,
38		* and we need some space for multiplication by block_size.
39		*/
40	0	if (((long) cinfo->image_width >> 24) \|\| ((long) cinfo->image_height >> 24))
41	0	ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
42
43	0	#ifdef DCT_SCALING_SUPPORTED
44
45		/* Compute actual JPEG image dimensions and DCT scaling choices. */
46	0	if (cinfo->scale_num >= cinfo->scale_denom * cinfo->block_size) {
47		/* Provide block_size/1 scaling */
48	0	cinfo->jpeg_width = cinfo->image_width * cinfo->block_size;
49	0	cinfo->jpeg_height = cinfo->image_height * cinfo->block_size;
50	0	cinfo->min_DCT_h_scaled_size = 1;
51	0	cinfo->min_DCT_v_scaled_size = 1;
52	0	} else if (cinfo->scale_num * 2 >= cinfo->scale_denom * cinfo->block_size) {
53		/* Provide block_size/2 scaling */
54	0	cinfo->jpeg_width = (JDIMENSION)
55	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 2L);
56	0	cinfo->jpeg_height = (JDIMENSION)
57	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 2L);
58	0	cinfo->min_DCT_h_scaled_size = 2;
59	0	cinfo->min_DCT_v_scaled_size = 2;
60	0	} else if (cinfo->scale_num * 3 >= cinfo->scale_denom * cinfo->block_size) {
61		/* Provide block_size/3 scaling */
62	0	cinfo->jpeg_width = (JDIMENSION)
63	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 3L);
64	0	cinfo->jpeg_height = (JDIMENSION)
65	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 3L);
66	0	cinfo->min_DCT_h_scaled_size = 3;
67	0	cinfo->min_DCT_v_scaled_size = 3;
68	0	} else if (cinfo->scale_num * 4 >= cinfo->scale_denom * cinfo->block_size) {
69		/* Provide block_size/4 scaling */
70	0	cinfo->jpeg_width = (JDIMENSION)
71	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 4L);
72	0	cinfo->jpeg_height = (JDIMENSION)
73	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 4L);
74	0	cinfo->min_DCT_h_scaled_size = 4;
75	0	cinfo->min_DCT_v_scaled_size = 4;
76	0	} else if (cinfo->scale_num * 5 >= cinfo->scale_denom * cinfo->block_size) {
77		/* Provide block_size/5 scaling */
78	0	cinfo->jpeg_width = (JDIMENSION)
79	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 5L);
80	0	cinfo->jpeg_height = (JDIMENSION)
81	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 5L);
82	0	cinfo->min_DCT_h_scaled_size = 5;
83	0	cinfo->min_DCT_v_scaled_size = 5;
84	0	} else if (cinfo->scale_num * 6 >= cinfo->scale_denom * cinfo->block_size) {
85		/* Provide block_size/6 scaling */
86	0	cinfo->jpeg_width = (JDIMENSION)
87	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 6L);
88	0	cinfo->jpeg_height = (JDIMENSION)
89	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 6L);
90	0	cinfo->min_DCT_h_scaled_size = 6;
91	0	cinfo->min_DCT_v_scaled_size = 6;
92	0	} else if (cinfo->scale_num * 7 >= cinfo->scale_denom * cinfo->block_size) {
93		/* Provide block_size/7 scaling */
94	0	cinfo->jpeg_width = (JDIMENSION)
95	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 7L);
96	0	cinfo->jpeg_height = (JDIMENSION)
97	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 7L);
98	0	cinfo->min_DCT_h_scaled_size = 7;
99	0	cinfo->min_DCT_v_scaled_size = 7;
100	0	} else if (cinfo->scale_num * 8 >= cinfo->scale_denom * cinfo->block_size) {
101		/* Provide block_size/8 scaling */
102	0	cinfo->jpeg_width = (JDIMENSION)
103	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 8L);
104	0	cinfo->jpeg_height = (JDIMENSION)
105	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 8L);
106	0	cinfo->min_DCT_h_scaled_size = 8;
107	0	cinfo->min_DCT_v_scaled_size = 8;
108	0	} else if (cinfo->scale_num * 9 >= cinfo->scale_denom * cinfo->block_size) {
109		/* Provide block_size/9 scaling */
110	0	cinfo->jpeg_width = (JDIMENSION)
111	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 9L);
112	0	cinfo->jpeg_height = (JDIMENSION)
113	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 9L);
114	0	cinfo->min_DCT_h_scaled_size = 9;
115	0	cinfo->min_DCT_v_scaled_size = 9;
116	0	} else if (cinfo->scale_num * 10 >= cinfo->scale_denom * cinfo->block_size) {
117		/* Provide block_size/10 scaling */
118	0	cinfo->jpeg_width = (JDIMENSION)
119	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 10L);
120	0	cinfo->jpeg_height = (JDIMENSION)
121	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 10L);
122	0	cinfo->min_DCT_h_scaled_size = 10;
123	0	cinfo->min_DCT_v_scaled_size = 10;
124	0	} else if (cinfo->scale_num * 11 >= cinfo->scale_denom * cinfo->block_size) {
125		/* Provide block_size/11 scaling */
126	0	cinfo->jpeg_width = (JDIMENSION)
127	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 11L);
128	0	cinfo->jpeg_height = (JDIMENSION)
129	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 11L);
130	0	cinfo->min_DCT_h_scaled_size = 11;
131	0	cinfo->min_DCT_v_scaled_size = 11;
132	0	} else if (cinfo->scale_num * 12 >= cinfo->scale_denom * cinfo->block_size) {
133		/* Provide block_size/12 scaling */
134	0	cinfo->jpeg_width = (JDIMENSION)
135	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 12L);
136	0	cinfo->jpeg_height = (JDIMENSION)
137	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 12L);
138	0	cinfo->min_DCT_h_scaled_size = 12;
139	0	cinfo->min_DCT_v_scaled_size = 12;
140	0	} else if (cinfo->scale_num * 13 >= cinfo->scale_denom * cinfo->block_size) {
141		/* Provide block_size/13 scaling */
142	0	cinfo->jpeg_width = (JDIMENSION)
143	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 13L);
144	0	cinfo->jpeg_height = (JDIMENSION)
145	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 13L);
146	0	cinfo->min_DCT_h_scaled_size = 13;
147	0	cinfo->min_DCT_v_scaled_size = 13;
148	0	} else if (cinfo->scale_num * 14 >= cinfo->scale_denom * cinfo->block_size) {
149		/* Provide block_size/14 scaling */
150	0	cinfo->jpeg_width = (JDIMENSION)
151	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 14L);
152	0	cinfo->jpeg_height = (JDIMENSION)
153	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 14L);
154	0	cinfo->min_DCT_h_scaled_size = 14;
155	0	cinfo->min_DCT_v_scaled_size = 14;
156	0	} else if (cinfo->scale_num * 15 >= cinfo->scale_denom * cinfo->block_size) {
157		/* Provide block_size/15 scaling */
158	0	cinfo->jpeg_width = (JDIMENSION)
159	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 15L);
160	0	cinfo->jpeg_height = (JDIMENSION)
161	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 15L);
162	0	cinfo->min_DCT_h_scaled_size = 15;
163	0	cinfo->min_DCT_v_scaled_size = 15;
164	0	} else {
165		/* Provide block_size/16 scaling */
166	0	cinfo->jpeg_width = (JDIMENSION)
167	0	jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 16L);
168	0	cinfo->jpeg_height = (JDIMENSION)
169	0	jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 16L);
170	0	cinfo->min_DCT_h_scaled_size = 16;
171	0	cinfo->min_DCT_v_scaled_size = 16;
172	0	}
173
174		#else /* !DCT_SCALING_SUPPORTED */
175
176		/* Hardwire it to "no scaling" */
177		cinfo->jpeg_width = cinfo->image_width;
178		cinfo->jpeg_height = cinfo->image_height;
179		cinfo->min_DCT_h_scaled_size = DCTSIZE;
180		cinfo->min_DCT_v_scaled_size = DCTSIZE;
181
182		#endif /* DCT_SCALING_SUPPORTED */
183	0	}
184
185
186		/*
187		* Master selection of compression modules.
188		* This is done once at the start of processing an image. We determine
189		* which modules will be used and give them appropriate initialization calls.
190		*/
191
192		GLOBAL(void)
193		jinit_compress_master (j_compress_ptr cinfo)
194	0	{
195	0	long samplesperrow;
196	0	JDIMENSION jd_samplesperrow;
197
198		/* For now, precision must match compiled-in value... */
199	0	if (cinfo->data_precision != BITS_IN_JSAMPLE)
200	0	ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
201
202		/* Sanity check on input image dimensions */
203	0	if (cinfo->image_height <= 0 \|\| cinfo->image_width <= 0 \|\|
204	0	cinfo->input_components <= 0)
205	0	ERREXIT(cinfo, JERR_EMPTY_IMAGE);
206
207		/* Width of an input scanline must be representable as JDIMENSION. */
208	0	samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
209	0	jd_samplesperrow = (JDIMENSION) samplesperrow;
210	0	if ((long) jd_samplesperrow != samplesperrow)
211	0	ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
212
213		/* Compute JPEG image dimensions and related values. */
214	0	jpeg_calc_jpeg_dimensions(cinfo);
215
216		/* Initialize master control (includes parameter checking/processing) */
217	0	jinit_c_master_control(cinfo, FALSE /* full compression */);
218
219		/* Preprocessing */
220	0	if (! cinfo->raw_data_in) {
221	0	jinit_color_converter(cinfo);
222	0	jinit_downsampler(cinfo);
223	0	jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
224	0	}
225		/* Forward DCT */
226	0	jinit_forward_dct(cinfo);
227		/* Entropy encoding: either Huffman or arithmetic coding. */
228	0	if (cinfo->arith_code)
229	0	jinit_arith_encoder(cinfo);
230	0	else {
231	0	jinit_huff_encoder(cinfo);
232	0	}
233
234		/* Need a full-image coefficient buffer in any multi-pass mode. */
235	0	jinit_c_coef_controller(cinfo,
236	0	(boolean) (cinfo->num_scans > 1 \|\| cinfo->optimize_coding));
237	0	jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
238
239	0	jinit_marker_writer(cinfo);
240
241		/* We can now tell the memory manager to allocate virtual arrays. */
242	0	(*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
243
244		/* Write the datastream header (SOI) immediately.
245		* Frame and scan headers are postponed till later.
246		* This lets application insert special markers after the SOI.
247		*/
248	0	(*cinfo->marker->write_file_header) (cinfo);
249	0	}