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 file.
7 *
8 * This file contains initialization logic for the JPEG compressor.
9 * This routine is in charge of selecting the modules to be executed and
10 * making an initialization call to each one.
11 *
12 * Logically, this code belongs in jcmaster.c.  It's split out because
13 * linking this routine implies linking the entire compression library.
14 * For a transcoding-only application, we want to be able to use jcmaster.c
15 * without linking in the whole library.
16 */
17
18#define JPEG_INTERNALS
19#include "jinclude.h"
20#include "jpeglib.h"
21
22
23/*
24 * Master selection of compression modules.
25 * This is done once at the start of processing an image.  We determine
26 * which modules will be used and give them appropriate initialization calls.
27 */
28
29GLOBAL(void)
30jinit_compress_master (j_compress_ptr cinfo)
31{
32  /* Initialize master control (includes parameter checking/processing) */
33  jinit_c_master_control(cinfo, FALSE /* full compression */);
34
35  /* Preprocessing */
36  if (! cinfo->raw_data_in) {
37    jinit_color_converter(cinfo);
38    jinit_downsampler(cinfo);
39    jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
40  }
41  /* Forward DCT */
42  jinit_forward_dct(cinfo);
43  /* Entropy encoding: either Huffman or arithmetic coding. */
44  if (cinfo->arith_code) {
45#ifdef C_ARITH_CODING_SUPPORTED
46    jinit_arith_encoder(cinfo);
47#else
48    ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
49#endif
50  } else {
51    if (cinfo->progressive_mode) {
52#ifdef C_PROGRESSIVE_SUPPORTED
53      jinit_phuff_encoder(cinfo);
54#else
55      ERREXIT(cinfo, JERR_NOT_COMPILED);
56#endif
57    } else
58      jinit_huff_encoder(cinfo);
59  }
60
61  /* Need a full-image coefficient buffer in any multi-pass mode. */
62  jinit_c_coef_controller(cinfo,
63		(boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
64  jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
65
66  jinit_marker_writer(cinfo);
67
68  /* We can now tell the memory manager to allocate virtual arrays. */
69  (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
70
71  /* Write the datastream header (SOI) immediately.
72   * Frame and scan headers are postponed till later.
73   * This lets application insert special markers after the SOI.
74   */
75  (*cinfo->marker->write_file_header) (cinfo);
76}
77