00001 /* 00002 * jcinit.c 00003 * 00004 * Copyright (C) 1991-1997, Thomas G. Lane. 00005 * This file is part of the Independent JPEG Group's software. 00006 * For conditions of distribution and use, see the accompanying README file. 00007 * 00008 * This file contains initialization logic for the JPEG compressor. 00009 * This routine is in charge of selecting the modules to be executed and 00010 * making an initialization call to each one. 00011 * 00012 * Logically, this code belongs in jcmaster.c. It's split out because 00013 * linking this routine implies linking the entire compression library. 00014 * For a transcoding-only application, we want to be able to use jcmaster.c 00015 * without linking in the whole library. 00016 */ 00017 00018 #define JPEG_INTERNALS 00019 #include "jinclude.h" 00020 #include "jpeglib.h" 00021 00022 00023 /* 00024 * Master selection of compression modules. 00025 * This is done once at the start of processing an image. We determine 00026 * which modules will be used and give them appropriate initialization calls. 00027 */ 00028 00029 GLOBAL(void) 00030 jinit_compress_master (j_compress_ptr cinfo) 00031 { 00032 /* Initialize master control (includes parameter checking/processing) */ 00033 jinit_c_master_control(cinfo, FALSE /* full compression */); 00034 00035 /* Preprocessing */ 00036 if (! cinfo->raw_data_in) { 00037 jinit_color_converter(cinfo); 00038 jinit_downsampler(cinfo); 00039 jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */); 00040 } 00041 /* Forward DCT */ 00042 jinit_forward_dct(cinfo); 00043 /* Entropy encoding: either Huffman or arithmetic coding. */ 00044 if (cinfo->arith_code) { 00045 ERREXIT(cinfo, JERR_ARITH_NOTIMPL); 00046 } else { 00047 if (cinfo->progressive_mode) { 00048 #ifdef C_PROGRESSIVE_SUPPORTED 00049 jinit_phuff_encoder(cinfo); 00050 #else 00051 ERREXIT(cinfo, JERR_NOT_COMPILED); 00052 #endif 00053 } else 00054 jinit_huff_encoder(cinfo); 00055 } 00056 00057 /* Need a full-image coefficient buffer in any multi-pass mode. */ 00058 jinit_c_coef_controller(cinfo, 00059 (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding)); 00060 jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */); 00061 00062 jinit_marker_writer(cinfo); 00063 00064 /* We can now tell the memory manager to allocate virtual arrays. */ 00065 (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo); 00066 00067 /* Write the datastream header (SOI) immediately. 00068 * Frame and scan headers are postponed till later. 00069 * This lets application insert special markers after the SOI. 00070 */ 00071 (*cinfo->marker->write_file_header) (cinfo); 00072 }