1 /*
2 * jclossls.c
3 *
4 * Copyright (C) 1998, 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 the control logic for the lossless JPEG compressor.
9 */
10
11 #define JPEG_INTERNALS
12 #include "jinclude16.h"
13 #include "jpeglib16.h"
14 #include "jlossls16.h"
15
16
17 #ifdef C_LOSSLESS_SUPPORTED
18
19 /*
20 * Initialize for a processing pass.
21 */
22
23 METHODDEF(void)
start_pass(j_compress_ptr cinfo,J_BUF_MODE pass_mode)24 start_pass (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
25 {
26 j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
27
28 (*losslsc->scaler_start_pass) (cinfo);
29 (*losslsc->predict_start_pass) (cinfo);
30 (*losslsc->diff_start_pass) (cinfo, pass_mode);
31 }
32
33
34 /*
35 * Initialize the lossless compression codec.
36 * This is called only once, during master selection.
37 */
38
39 GLOBAL(void)
jinit_lossless_c_codec(j_compress_ptr cinfo)40 jinit_lossless_c_codec(j_compress_ptr cinfo)
41 {
42 j_lossless_c_ptr losslsc;
43
44 /* Create subobject in permanent pool */
45 losslsc = (j_lossless_c_ptr)
46 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
47 SIZEOF(jpeg_lossless_c_codec));
48 cinfo->codec = (struct jpeg_c_codec *) losslsc;
49
50 /* Initialize sub-modules */
51
52 /* Scaler */
53 jinit_c_scaler(cinfo);
54
55 /* Differencer */
56 jinit_differencer(cinfo);
57
58 /* Entropy encoding: either Huffman or arithmetic coding. */
59 if (cinfo->arith_code) {
60 #ifdef WITH_ARITHMETIC_PATCH
61 jinit_arith_encoder(cinfo);
62 #else
63 ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
64 #endif
65 } else {
66 jinit_lhuff_encoder(cinfo);
67 }
68
69 /* Need a full-image difference buffer in any multi-pass mode. */
70 jinit_c_diff_controller(cinfo,
71 (boolean) (cinfo->num_scans > 1 ||
72 cinfo->optimize_coding));
73
74 /* Initialize method pointers.
75 *
76 * Note: entropy_start_pass and entropy_finish_pass are assigned in
77 * jclhuff.c and compress_data is assigned in jcdiffct.c.
78 */
79 losslsc->pub.start_pass = start_pass;
80 }
81
82 #endif /* C_LOSSLESS_SUPPORTED */
83