/*

 * 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 */