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
29 GLOBAL(void)
jinit_compress_master(j_compress_ptr cinfo)30 jinit_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 ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
46 } else {
47 if (cinfo->progressive_mode) {
48 #ifdef C_PROGRESSIVE_SUPPORTED
49 jinit_phuff_encoder(cinfo);
50 #else
51 ERREXIT(cinfo, JERR_NOT_COMPILED);
52 #endif
53 } else
54 jinit_huff_encoder(cinfo);
55 }
56
57 /* Need a full-image coefficient buffer in any multi-pass mode. */
58 jinit_c_coef_controller(cinfo,
59 (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
60 jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
61
62 jinit_marker_writer(cinfo);
63
64 /* We can now tell the memory manager to allocate virtual arrays. */
65 (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
66
67 /* Write the datastream header (SOI) immediately.
68 * Frame and scan headers are postponed till later.
69 * This lets application insert special markers after the SOI.
70 */
71 (*cinfo->marker->write_file_header) (cinfo);
72 }
73