compiler/libjpeg/main/jclossls.c

   1 /*
   2     $Id$
   3 */
   4
   5 /*
   6  * jclossls.c
   7  *
   8  * Copyright (C) 1998, Thomas G. Lane.
   9  * This file is part of the Independent JPEG Group's software.
  10  * For conditions of distribution and use, see the accompanying README file.
  11  *
  12  * This file contains the control logic for the lossless JPEG compressor.
  13  */
  14
  15 #define JPEG_INTERNALS
  16 #include "jinclude.h"
  17 #include "jpeglib.h"
  18 #include "jlossls.h"
  19
  20
  21 #ifdef C_LOSSLESS_SUPPORTED
  22
  23 /*
  24  * Initialize for a processing pass.
  25  */
  26
  27 METHODDEF(void)
  28 start_pass (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
  29 {
  30   j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
  31
  32   (*losslsc->scaler_start_pass) (cinfo);
  33   (*losslsc->predict_start_pass) (cinfo);
  34   (*losslsc->diff_start_pass) (cinfo, pass_mode);
  35 }
  36
  37
  38 /*
  39  * Initialize the lossless compression codec.
  40  * This is called only once, during master selection.
  41  */
  42
  43 JGLOBAL(void)
  44 jinit_lossless_c_codec(j_compress_ptr cinfo)
  45 {
  46   j_lossless_c_ptr losslsc;
  47
  48   /* Create subobject in permanent pool */
  49   losslsc = (j_lossless_c_ptr)
  50     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
  51                                 SIZEOF(jpeg_lossless_c_codec));
  52   cinfo->codec = (struct jpeg_c_codec *) losslsc;
  53
  54   /* Initialize sub-modules */
  55
  56   /* Scaler */
  57   jinit_c_scaler(cinfo);
  58
  59   /* Differencer */
  60   jinit_differencer(cinfo);
  61
  62   /* Entropy encoding: either Huffman or arithmetic coding. */
  63   if (cinfo->arith_code) {
  64     ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
  65   } else {
  66     jinit_lhuff_encoder(cinfo);
  67   }
  68
  69   /* Need a full-image difference buffer in any multi-pass mode. */
  70   jinit_c_diff_controller(cinfo,
  71                           (boolean) (cinfo->num_scans > 1 ||
  72                                      cinfo->optimize_coding));
  73
  74   /* Initialize method pointers.
  75    *
  76    * Note: entropy_start_pass and entropy_finish_pass are assigned in
  77    * jclhuff.c and compress_data is assigned in jcdiffct.c.
  78    */
  79   losslsc->pub.start_pass = start_pass;
  80 }
  81
  82 #endif /* C_LOSSLESS_SUPPORTED */