xref: /plan9/sys/src/cmd/gs/jpeg/jcinit.c (revision 593dc095aefb2a85c828727bbfa9da139a49bdf4)
17dd7cddfSDavid du Colombier /*
27dd7cddfSDavid du Colombier  * jcinit.c
37dd7cddfSDavid du Colombier  *
4*593dc095SDavid du Colombier  * Copyright (C) 1991-1997, Thomas G. Lane.
57dd7cddfSDavid du Colombier  * This file is part of the Independent JPEG Group's software.
67dd7cddfSDavid du Colombier  * For conditions of distribution and use, see the accompanying README file.
77dd7cddfSDavid du Colombier  *
87dd7cddfSDavid du Colombier  * This file contains initialization logic for the JPEG compressor.
97dd7cddfSDavid du Colombier  * This routine is in charge of selecting the modules to be executed and
107dd7cddfSDavid du Colombier  * making an initialization call to each one.
117dd7cddfSDavid du Colombier  *
127dd7cddfSDavid du Colombier  * Logically, this code belongs in jcmaster.c.  It's split out because
137dd7cddfSDavid du Colombier  * linking this routine implies linking the entire compression library.
147dd7cddfSDavid du Colombier  * For a transcoding-only application, we want to be able to use jcmaster.c
157dd7cddfSDavid du Colombier  * without linking in the whole library.
167dd7cddfSDavid du Colombier  */
177dd7cddfSDavid du Colombier 
187dd7cddfSDavid du Colombier #define JPEG_INTERNALS
197dd7cddfSDavid du Colombier #include "jinclude.h"
207dd7cddfSDavid du Colombier #include "jpeglib.h"
217dd7cddfSDavid du Colombier 
227dd7cddfSDavid du Colombier 
237dd7cddfSDavid du Colombier /*
247dd7cddfSDavid du Colombier  * Master selection of compression modules.
257dd7cddfSDavid du Colombier  * This is done once at the start of processing an image.  We determine
267dd7cddfSDavid du Colombier  * which modules will be used and give them appropriate initialization calls.
277dd7cddfSDavid du Colombier  */
287dd7cddfSDavid du Colombier 
297dd7cddfSDavid du Colombier GLOBAL(void)
jinit_compress_master(j_compress_ptr cinfo)307dd7cddfSDavid du Colombier jinit_compress_master (j_compress_ptr cinfo)
317dd7cddfSDavid du Colombier {
327dd7cddfSDavid du Colombier   /* Initialize master control (includes parameter checking/processing) */
337dd7cddfSDavid du Colombier   jinit_c_master_control(cinfo, FALSE /* full compression */);
347dd7cddfSDavid du Colombier 
357dd7cddfSDavid du Colombier   /* Preprocessing */
367dd7cddfSDavid du Colombier   if (! cinfo->raw_data_in) {
377dd7cddfSDavid du Colombier     jinit_color_converter(cinfo);
387dd7cddfSDavid du Colombier     jinit_downsampler(cinfo);
397dd7cddfSDavid du Colombier     jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
407dd7cddfSDavid du Colombier   }
417dd7cddfSDavid du Colombier   /* Forward DCT */
427dd7cddfSDavid du Colombier   jinit_forward_dct(cinfo);
437dd7cddfSDavid du Colombier   /* Entropy encoding: either Huffman or arithmetic coding. */
447dd7cddfSDavid du Colombier   if (cinfo->arith_code) {
457dd7cddfSDavid du Colombier     ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
467dd7cddfSDavid du Colombier   } else {
477dd7cddfSDavid du Colombier     if (cinfo->progressive_mode) {
487dd7cddfSDavid du Colombier #ifdef C_PROGRESSIVE_SUPPORTED
497dd7cddfSDavid du Colombier       jinit_phuff_encoder(cinfo);
507dd7cddfSDavid du Colombier #else
517dd7cddfSDavid du Colombier       ERREXIT(cinfo, JERR_NOT_COMPILED);
527dd7cddfSDavid du Colombier #endif
537dd7cddfSDavid du Colombier     } else
547dd7cddfSDavid du Colombier       jinit_huff_encoder(cinfo);
557dd7cddfSDavid du Colombier   }
567dd7cddfSDavid du Colombier 
577dd7cddfSDavid du Colombier   /* Need a full-image coefficient buffer in any multi-pass mode. */
587dd7cddfSDavid du Colombier   jinit_c_coef_controller(cinfo,
59*593dc095SDavid du Colombier 		(boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
607dd7cddfSDavid du Colombier   jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
617dd7cddfSDavid du Colombier 
627dd7cddfSDavid du Colombier   jinit_marker_writer(cinfo);
637dd7cddfSDavid du Colombier 
647dd7cddfSDavid du Colombier   /* We can now tell the memory manager to allocate virtual arrays. */
657dd7cddfSDavid du Colombier   (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
667dd7cddfSDavid du Colombier 
677dd7cddfSDavid du Colombier   /* Write the datastream header (SOI) immediately.
687dd7cddfSDavid du Colombier    * Frame and scan headers are postponed till later.
697dd7cddfSDavid du Colombier    * This lets application insert special markers after the SOI.
707dd7cddfSDavid du Colombier    */
717dd7cddfSDavid du Colombier   (*cinfo->marker->write_file_header) (cinfo);
727dd7cddfSDavid du Colombier }
73