1/* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5/* 6 * jcinit.c 7 * 8 * Copyright (C) 1991-1997, Thomas G. Lane. 9 * This file is part of the Independent JPEG Group's software. 10 * For conditions of distribution and use, see the accompanying README file. 11 * 12 * This file contains initialization logic for the JPEG compressor. 13 * This routine is in charge of selecting the modules to be executed and 14 * making an initialization call to each one. 15 * 16 * Logically, this code belongs in jcmaster.c. It's split out because 17 * linking this routine implies linking the entire compression library. 18 * For a transcoding-only application, we want to be able to use jcmaster.c 19 * without linking in the whole library. 20 */ 21 22#define JPEG_INTERNALS 23#include "jinclude.h" 24#include "jpeglib.h" 25 26 27/* 28 * Master selection of compression modules. 29 * This is done once at the start of processing an image. We determine 30 * which modules will be used and give them appropriate initialization calls. 31 */ 32 33GLOBAL(void) 34jinit_compress_master (j_compress_ptr cinfo) 35{ 36 /* Initialize master control (includes parameter checking/processing) */ 37 jinit_c_master_control(cinfo, FALSE /* full compression */); 38 39 /* Preprocessing */ 40 if (! cinfo->raw_data_in) { 41 jinit_color_converter(cinfo); 42 jinit_downsampler(cinfo); 43 jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */); 44 } 45 /* Forward DCT */ 46 jinit_forward_dct(cinfo); 47 /* Entropy encoding: either Huffman or arithmetic coding. */ 48 if (cinfo->arith_code) { 49 ERREXIT(cinfo, JERR_ARITH_NOTIMPL); 50 } else { 51 if (cinfo->progressive_mode) { 52#ifdef C_PROGRESSIVE_SUPPORTED 53 jinit_phuff_encoder(cinfo); 54#else 55 ERREXIT(cinfo, JERR_NOT_COMPILED); 56#endif 57 } else 58 jinit_huff_encoder(cinfo); 59 } 60 61 /* Need a full-image coefficient buffer in any multi-pass mode. */ 62 jinit_c_coef_controller(cinfo, 63 (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding)); 64 jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */); 65 66 jinit_marker_writer(cinfo); 67 68 /* We can now tell the memory manager to allocate virtual arrays. */ 69 (*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 (*cinfo->marker->write_file_header) (cinfo); 76} 77