1/*
2 * jcinit.c
3 *
4 * Copyright (C) 1991-1997, 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.ijg
7 * 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 * Master selection of compression modules.
26 * This is done once at the start of processing an image.  We determine
27 * which modules will be used and give them appropriate initialization calls.
28 */
29
30GLOBAL(void)
31jinit_compress_master (j_compress_ptr cinfo)
32{
33  /* Initialize master control (includes parameter checking/processing) */
34  jinit_c_master_control(cinfo, FALSE /* full compression */);
35
36  /* Preprocessing */
37  if (! cinfo->raw_data_in) {
38    jinit_color_converter(cinfo);
39    jinit_downsampler(cinfo);
40    jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
41  }
42  /* Forward DCT */
43  jinit_forward_dct(cinfo);
44  /* Entropy encoding: either Huffman or arithmetic coding. */
45  if (cinfo->arith_code) {
46#ifdef C_ARITH_CODING_SUPPORTED
47    jinit_arith_encoder(cinfo);
48#else
49    ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
50#endif
51  } else {
52    if (cinfo->progressive_mode) {
53#ifdef C_PROGRESSIVE_SUPPORTED
54      jinit_phuff_encoder(cinfo);
55#else
56      ERREXIT(cinfo, JERR_NOT_COMPILED);
57#endif
58    } else
59      jinit_huff_encoder(cinfo);
60  }
61
62  /* Need a full-image coefficient buffer in any multi-pass mode. */
63  jinit_c_coef_controller(cinfo,
64                (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
65  jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
66
67  jinit_marker_writer(cinfo);
68
69  /* We can now tell the memory manager to allocate virtual arrays. */
70  (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
71
72  /* Write the datastream header (SOI) immediately.
73   * Frame and scan headers are postponed till later.
74   * This lets application insert special markers after the SOI.
75   */
76  (*cinfo->marker->write_file_header) (cinfo);
77}
78