4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1991-1997, Thomas G. Lane.
6 * Lossless JPEG Modifications:
7 * Copyright (C) 1999, Ken Murchison.
8 * libjpeg-turbo Modifications:
9 * Copyright (C) 2020, 2022, D. R. Commander.
10 * For conditions of distribution and use, see the accompanying README.ijg
13 * This file contains initialization logic for the JPEG compressor.
14 * This routine is in charge of selecting the modules to be executed and
15 * making an initialization call to each one.
17 * Logically, this code belongs in jcmaster.c. It's split out because
18 * linking this routine implies linking the entire compression library.
19 * For a transcoding-only application, we want to be able to use jcmaster.c
20 * without linking in the whole library.
23 #define JPEG_INTERNALS
26 #include "jpegapicomp.h"
30 * Master selection of compression modules.
31 * This is done once at the start of processing an image. We determine
32 * which modules will be used and give them appropriate initialization calls.
36 jinit_compress_master(j_compress_ptr cinfo)
38 /* Initialize master control (includes parameter checking/processing) */
39 jinit_c_master_control(cinfo, FALSE /* full compression */);
42 if (!cinfo->raw_data_in) {
43 if (cinfo->data_precision == 16) {
44 #ifdef C_LOSSLESS_SUPPORTED
45 j16init_color_converter(cinfo);
46 j16init_downsampler(cinfo);
47 j16init_c_prep_controller(cinfo,
48 FALSE /* never need full buffer here */);
50 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
52 } else if (cinfo->data_precision == 12) {
53 j12init_color_converter(cinfo);
54 j12init_downsampler(cinfo);
55 j12init_c_prep_controller(cinfo,
56 FALSE /* never need full buffer here */);
58 jinit_color_converter(cinfo);
59 jinit_downsampler(cinfo);
60 jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
64 if (cinfo->master->lossless) {
65 #ifdef C_LOSSLESS_SUPPORTED
66 /* Prediction, sample differencing, and point transform */
67 if (cinfo->data_precision == 16)
68 j16init_lossless_compressor(cinfo);
69 else if (cinfo->data_precision == 12)
70 j12init_lossless_compressor(cinfo);
72 jinit_lossless_compressor(cinfo);
73 /* Entropy encoding: either Huffman or arithmetic coding. */
74 if (cinfo->arith_code) {
75 ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
77 jinit_lhuff_encoder(cinfo);
80 /* Need a full-image difference buffer in any multi-pass mode. */
81 if (cinfo->data_precision == 16)
82 j16init_c_diff_controller(cinfo, (boolean)(cinfo->num_scans > 1 ||
83 cinfo->optimize_coding));
84 else if (cinfo->data_precision == 12)
85 j12init_c_diff_controller(cinfo, (boolean)(cinfo->num_scans > 1 ||
86 cinfo->optimize_coding));
88 jinit_c_diff_controller(cinfo, (boolean)(cinfo->num_scans > 1 ||
89 cinfo->optimize_coding));
91 ERREXIT(cinfo, JERR_NOT_COMPILED);
94 if (cinfo->data_precision == 16)
95 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
97 if (cinfo->data_precision == 12)
98 j12init_forward_dct(cinfo);
100 jinit_forward_dct(cinfo);
101 /* Entropy encoding: either Huffman or arithmetic coding. */
102 if (cinfo->arith_code) {
103 #ifdef C_ARITH_CODING_SUPPORTED
104 jinit_arith_encoder(cinfo);
106 ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
109 if (cinfo->progressive_mode) {
110 #ifdef C_PROGRESSIVE_SUPPORTED
111 jinit_phuff_encoder(cinfo);
113 ERREXIT(cinfo, JERR_NOT_COMPILED);
116 jinit_huff_encoder(cinfo);
119 /* Need a full-image coefficient buffer in any multi-pass mode. */
120 if (cinfo->data_precision == 12)
121 j12init_c_coef_controller(cinfo, (boolean)(cinfo->num_scans > 1 ||
122 cinfo->optimize_coding));
124 jinit_c_coef_controller(cinfo, (boolean)(cinfo->num_scans > 1 ||
125 cinfo->optimize_coding));
128 if (cinfo->data_precision == 16)
129 #ifdef C_LOSSLESS_SUPPORTED
130 j16init_c_main_controller(cinfo, FALSE /* never need full buffer here */);
132 ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
134 else if (cinfo->data_precision == 12)
135 j12init_c_main_controller(cinfo, FALSE /* never need full buffer here */);
137 jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
139 jinit_marker_writer(cinfo);
141 /* We can now tell the memory manager to allocate virtual arrays. */
142 (*cinfo->mem->realize_virt_arrays) ((j_common_ptr)cinfo);
144 /* Write the datastream header (SOI) immediately.
145 * Frame and scan headers are postponed till later.
146 * This lets application insert special markers after the SOI.
148 (*cinfo->marker->write_file_header) (cinfo);