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/*
* jcinit.c
*
* This file was part of the Independent JPEG Group's software:
* Copyright (C) 1991-1997, Thomas G. Lane.
* libjpeg-turbo Modifications:
* Copyright (C) 2020, D. R. Commander.
* 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"
#include "jpegcomp.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);
}
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