/*
 * jdmerge.h
 *
 * This file was part of the Independent JPEG Group's software:
 * Copyright (C) 1994-1996, Thomas G. Lane.
 * libjpeg-turbo Modifications:
 * Copyright (C) 2020, D. R. Commander.
 * For conditions of distribution and use, see the accompanying README.ijg
 * file.
 */
 
#define JPEG_INTERNALS
#include "jpeglib.h"
 
#ifdef UPSAMPLE_MERGING_SUPPORTED
 
 
/* Private subobject */
 
typedef struct {
  struct jpeg_upsampler pub;    /* public fields */
 
  /* Pointer to routine to do actual upsampling/conversion of one row group */
  void (*upmethod) (j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
                    JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf);
 
  /* Private state for YCC->RGB conversion */
  int *Cr_r_tab;                /* => table for Cr to R conversion */
  int *Cb_b_tab;                /* => table for Cb to B conversion */
  JLONG *Cr_g_tab;              /* => table for Cr to G conversion */
  JLONG *Cb_g_tab;              /* => table for Cb to G conversion */
 
  /* For 2:1 vertical sampling, we produce two output rows at a time.
   * We need a "spare" row buffer to hold the second output row if the
   * application provides just a one-row buffer; we also use the spare
   * to discard the dummy last row if the image height is odd.
   */
  JSAMPROW spare_row;
  boolean spare_full;           /* T if spare buffer is occupied */
 
  JDIMENSION out_row_width;     /* samples per output row */
  JDIMENSION rows_to_go;        /* counts rows remaining in image */
} my_merged_upsampler;
 
typedef my_merged_upsampler *my_merged_upsample_ptr;
 
#endif /* UPSAMPLE_MERGING_SUPPORTED */