| /* | |
| * jcinit.c | |
| * | |
| * Copyright (C) 1991-1997, Thomas G. Lane. | |
| * This file is part of the Independent JPEG Group's software. | |
| * For conditions of distribution and use, see the accompanying README file. | |
| * | |
| * This file contains initialization logic for the JPEG compressor. | |
| * This routine is in charge of selecting the modules to be executed and | |
| * making an initialization call to each one. | |
| * | |
| * Logically, this code belongs in jcmaster.c. It's split out because | |
| * linking this routine implies linking the entire compression library. | |
| * For a transcoding-only application, we want to be able to use jcmaster.c | |
| * without linking in the whole library. | |
| */ | |
| /* | |
| * Master selection of compression modules. | |
| * This is done once at the start of processing an image. We determine | |
| * which modules will be used and give them appropriate initialization calls. | |
| */ | |
| GLOBAL(void) | |
| jinit_compress_master (j_compress_ptr cinfo) | |
| { | |
| /* Initialize master control (includes parameter checking/processing) */ | |
| jinit_c_master_control(cinfo, FALSE /* full compression */); | |
| /* Preprocessing */ | |
| if (! cinfo->raw_data_in) { | |
| jinit_color_converter(cinfo); | |
| jinit_downsampler(cinfo); | |
| jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */); | |
| } | |
| /* Forward DCT */ | |
| jinit_forward_dct(cinfo); | |
| /* Entropy encoding: either Huffman or arithmetic coding. */ | |
| if (cinfo->arith_code) | |
| jinit_arith_encoder(cinfo); | |
| else { | |
| jinit_huff_encoder(cinfo); | |
| } | |
| /* Need a full-image coefficient buffer in any multi-pass mode. */ | |
| jinit_c_coef_controller(cinfo, | |
| (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding)); | |
| jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */); | |
| jinit_marker_writer(cinfo); | |
| /* We can now tell the memory manager to allocate virtual arrays. */ | |
| (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo); | |
| /* Write the datastream header (SOI) immediately. | |
| * Frame and scan headers are postponed till later. | |
| * This lets application insert special markers after the SOI. | |
| */ | |
| (*cinfo->marker->write_file_header) (cinfo); | |
| } | |