jcinit.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "mrpt_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, (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);
}