media/libjpeg/jdmerge.h

   1 /*
   2  * jdmerge.h
   3  *
   4  * This file was part of the Independent JPEG Group's software:
   5  * Copyright (C) 1994-1996, Thomas G. Lane.
   6  * libjpeg-turbo Modifications:
   7  * Copyright (C) 2020, 2022, D. R. Commander.
   8  * For conditions of distribution and use, see the accompanying README.ijg
   9  * file.
  10  */
  11
  12 #define JPEG_INTERNALS
  13 #include "jpeglib.h"
  14 #include "jsamplecomp.h"
  15
  16 #ifdef UPSAMPLE_MERGING_SUPPORTED
  17
  18
  19 /* Private subobject */
  20
  21 typedef struct {
  22   struct jpeg_upsampler pub;    /* public fields */
  23
  24   /* Pointer to routine to do actual upsampling/conversion of one row group */
  25   void (*upmethod) (j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
  26                     JDIMENSION in_row_group_ctr, _JSAMPARRAY output_buf);
  27
  28   /* Private state for YCC->RGB conversion */
  29   int *Cr_r_tab;                /* => table for Cr to R conversion */
  30   int *Cb_b_tab;                /* => table for Cb to B conversion */
  31   JLONG *Cr_g_tab;              /* => table for Cr to G conversion */
  32   JLONG *Cb_g_tab;              /* => table for Cb to G conversion */
  33
  34   /* For 2:1 vertical sampling, we produce two output rows at a time.
  35    * We need a "spare" row buffer to hold the second output row if the
  36    * application provides just a one-row buffer; we also use the spare
  37    * to discard the dummy last row if the image height is odd.
  38    */
  39   _JSAMPROW spare_row;
  40   boolean spare_full;           /* T if spare buffer is occupied */
  41
  42   JDIMENSION out_row_width;     /* samples per output row */
  43   JDIMENSION rows_to_go;        /* counts rows remaining in image */
  44 } my_merged_upsampler;
  45
  46 typedef my_merged_upsampler *my_merged_upsample_ptr;
  47
  48 #endif /* UPSAMPLE_MERGING_SUPPORTED */