/*
 * jcinit.c
 *
 * Copyright (C) 1991-1995, 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.
 */

#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 ) {
        ERREXIT( cinfo, JERR_ARITH_NOTIMPL );
    } 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,
                            ( 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 );
}