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)
30 3 : jinit_compress_master (j_compress_ptr cinfo)
31 : {
32 : /* Initialize master control (includes parameter checking/processing) */
33 3 : jinit_c_master_control(cinfo, FALSE /* full compression */);
34 :
35 : /* Preprocessing */
36 3 : if (! cinfo->raw_data_in) {
37 3 : jinit_color_converter(cinfo);
38 3 : jinit_downsampler(cinfo);
39 3 : jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
40 : }
41 : /* Forward DCT */
42 3 : jinit_forward_dct(cinfo);
43 : /* Entropy encoding: either Huffman or arithmetic coding. */
44 3 : if (cinfo->arith_code) {
45 : #ifdef C_ARITH_CODING_SUPPORTED
46 : jinit_arith_encoder(cinfo);
47 : #else
48 0 : ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
49 : #endif
50 : } else {
51 3 : if (cinfo->progressive_mode) {
52 : #ifdef C_PROGRESSIVE_SUPPORTED
53 0 : jinit_phuff_encoder(cinfo);
54 : #else
55 : ERREXIT(cinfo, JERR_NOT_COMPILED);
56 : #endif
57 : } else
58 3 : jinit_huff_encoder(cinfo);
59 : }
60 :
61 : /* Need a full-image coefficient buffer in any multi-pass mode. */
62 6 : jinit_c_coef_controller(cinfo,
63 6 : (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
64 3 : jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
65 :
66 3 : jinit_marker_writer(cinfo);
67 :
68 : /* We can now tell the memory manager to allocate virtual arrays. */
69 3 : (*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 3 : (*cinfo->marker->write_file_header) (cinfo);
76 3 : }
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