jlossls.h

   1 /*
   2  * jlossls.h
   3  *
   4  * This file was part of the Independent JPEG Group's software:
   5  * Copyright (C) 1998, Thomas G. Lane.
   6  * Lossless JPEG Modifications:
   7  * Copyright (C) 1999, Ken Murchison.
   8  * libjpeg-turbo Modifications:
   9  * Copyright (C) 2022, D. R. Commander.
  10  * For conditions of distribution and use, see the accompanying README.ijg
  11  * file.
  12  *
  13  * This include file contains common declarations for the lossless JPEG
  14  * codec modules.
  15  */
  16
  17 #ifndef JLOSSLS_H
  18 #define JLOSSLS_H
  19
  20 #if defined(C_LOSSLESS_SUPPORTED) || defined(D_LOSSLESS_SUPPORTED)
  21
  22 #define JPEG_INTERNALS
  23 #include "jpeglib.h"
  24 #include "jsamplecomp.h"
  25
  26
  27 #define ALLOC_DARRAY(pool_id, diffsperrow, numrows) \
  28   (JDIFFARRAY)(*cinfo->mem->alloc_sarray) \
  29     ((j_common_ptr)cinfo, pool_id, \
  30      (diffsperrow) * sizeof(JDIFF) / sizeof(_JSAMPLE), numrows)
  31
  32
  33 /*
  34  * Table H.1: Predictors for lossless coding.
  35  */
  36
  37 #define PREDICTOR1  Ra
  38 #define PREDICTOR2  Rb
  39 #define PREDICTOR3  Rc
  40 #define PREDICTOR4  (int)((JLONG)Ra + (JLONG)Rb - (JLONG)Rc)
  41 #define PREDICTOR5  (int)((JLONG)Ra + RIGHT_SHIFT((JLONG)Rb - (JLONG)Rc, 1))
  42 #define PREDICTOR6  (int)((JLONG)Rb + RIGHT_SHIFT((JLONG)Ra - (JLONG)Rc, 1))
  43 #define PREDICTOR7  (int)RIGHT_SHIFT((JLONG)Ra + (JLONG)Rb, 1)
  44
  45 #endif
  46
  47
  48 #ifdef C_LOSSLESS_SUPPORTED
  49
  50 typedef void (*predict_difference_method_ptr) (j_compress_ptr cinfo, int ci,
  51                                                _JSAMPROW input_buf,
  52                                                _JSAMPROW prev_row,
  53                                                JDIFFROW diff_buf,
  54                                                JDIMENSION width);
  55
  56 /* Lossless compressor */
  57 typedef struct {
  58   struct jpeg_forward_dct pub;  /* public fields */
  59
  60   /* It is useful to allow each component to have a separate diff method. */
  61   predict_difference_method_ptr predict_difference[MAX_COMPONENTS];
  62
  63   /* MCU rows left in the restart interval for each component */
  64   unsigned int restart_rows_to_go[MAX_COMPONENTS];
  65
  66   /* Sample scaling */
  67   void (*scaler_scale) (j_compress_ptr cinfo, _JSAMPROW input_buf,
  68                         _JSAMPROW output_buf, JDIMENSION width);
  69 } jpeg_lossless_compressor;
  70
  71 typedef jpeg_lossless_compressor *lossless_comp_ptr;
  72
  73 #endif /* C_LOSSLESS_SUPPORTED */
  74
  75
  76 #ifdef D_LOSSLESS_SUPPORTED
  77
  78 typedef void (*predict_undifference_method_ptr) (j_decompress_ptr cinfo,
  79                                                  int comp_index,
  80                                                  JDIFFROW diff_buf,
  81                                                  JDIFFROW prev_row,
  82                                                  JDIFFROW undiff_buf,
  83                                                  JDIMENSION width);
  84
  85 /* Lossless decompressor */
  86 typedef struct {
  87   struct jpeg_inverse_dct pub;  /* public fields */
  88
  89   /* It is useful to allow each component to have a separate undiff method. */
  90   predict_undifference_method_ptr predict_undifference[MAX_COMPONENTS];
  91
  92   /* Sample scaling */
  93   void (*scaler_scale) (j_decompress_ptr cinfo, JDIFFROW diff_buf,
  94                         _JSAMPROW output_buf, JDIMENSION width);
  95 } jpeg_lossless_decompressor;
  96
  97 typedef jpeg_lossless_decompressor *lossless_decomp_ptr;
  98
  99 #endif /* D_LOSSLESS_SUPPORTED */
 100
 101 #endif /* JLOSSLS_H */