/*
 * 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.ijg
 * 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.
 */

#define JPEG_INTERNALS

#include "jinclude.h"
#include "jpeglib.h"


/*
 * 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) {
#ifdef C_ARITH_CODING_SUPPORTED
		jinit_arith_encoder(cinfo);
#else
		ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
#endif
	} else {
		if (cinfo->progressive_mode) {
#ifdef C_PROGRESSIVE_SUPPORTED
			jinit_phuff_encoder(cinfo);
#else
			ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
		} 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);
}
