kc3-lang/libjpeg-turbo/jccolext.c

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• Hash : 01e30323
  Author :
  Date : 2019-01-23T14:58:24
  

  Eliminate support for compilers w/o unsigned char
  
  libjpeg-turbo has never really supported such compilers, since (AFAIK)
  they are non-existent on any modern computing platform and thus
  impossible for us to test.  (Also, the TurboJPEG API would break without
  unsigned chars.)
  
  Furthermore, the unified CMake-based build system introduced in 2.0
  always defines HAVE_UNSIGNED_CHAR, so retaining other code paths is
  pointless.  Eliminating support for compilers without unsigned char
  eliminates the need for the GETJSAMPLE() macro, which improves the
  readability of many parts of the code as well as improving the
  performance of writing Targa and Windows BMP files.
  
  Fixes #317
  

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• jccolext.c

• /*
   * jccolext.c
   *
   * This file was part of the Independent JPEG Group's software:
   * Copyright (C) 1991-1996, Thomas G. Lane.
   * libjpeg-turbo Modifications:
   * Copyright (C) 2009-2012, 2015, D. R. Commander.
   * For conditions of distribution and use, see the accompanying README.ijg
   * file.
   *
   * This file contains input colorspace conversion routines.
   */
  
  
  /* This file is included by jccolor.c */
  
  
  /*
   * Convert some rows of samples to the JPEG colorspace.
   *
   * Note that we change from the application's interleaved-pixel format
   * to our internal noninterleaved, one-plane-per-component format.
   * The input buffer is therefore three times as wide as the output buffer.
   *
   * A starting row offset is provided only for the output buffer.  The caller
   * can easily adjust the passed input_buf value to accommodate any row
   * offset required on that side.
   */
  
  INLINE
  LOCAL(void)
  rgb_ycc_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf,
                           JSAMPIMAGE output_buf, JDIMENSION output_row,
                           int num_rows)
  {
    my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
    register int r, g, b;
    register JLONG *ctab = cconvert->rgb_ycc_tab;
    register JSAMPROW inptr;
    register JSAMPROW outptr0, outptr1, outptr2;
    register JDIMENSION col;
    JDIMENSION num_cols = cinfo->image_width;
  
    while (--num_rows >= 0) {
      inptr = *input_buf++;
      outptr0 = output_buf[0][output_row];
      outptr1 = output_buf[1][output_row];
      outptr2 = output_buf[2][output_row];
      output_row++;
      for (col = 0; col < num_cols; col++) {
        r = inptr[RGB_RED];
        g = inptr[RGB_GREEN];
        b = inptr[RGB_BLUE];
        inptr += RGB_PIXELSIZE;
        /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
         * must be too; we do not need an explicit range-limiting operation.
         * Hence the value being shifted is never negative, and we don't
         * need the general RIGHT_SHIFT macro.
         */
        /* Y */
        outptr0[col] = (JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] +
                                  ctab[b + B_Y_OFF]) >> SCALEBITS);
        /* Cb */
        outptr1[col] = (JSAMPLE)((ctab[r + R_CB_OFF] + ctab[g + G_CB_OFF] +
                                  ctab[b + B_CB_OFF]) >> SCALEBITS);
        /* Cr */
        outptr2[col] = (JSAMPLE)((ctab[r + R_CR_OFF] + ctab[g + G_CR_OFF] +
                                  ctab[b + B_CR_OFF]) >> SCALEBITS);
      }
    }
  }
  
  
  /**************** Cases other than RGB -> YCbCr **************/
  
  
  /*
   * Convert some rows of samples to the JPEG colorspace.
   * This version handles RGB->grayscale conversion, which is the same
   * as the RGB->Y portion of RGB->YCbCr.
   * We assume rgb_ycc_start has been called (we only use the Y tables).
   */
  
  INLINE
  LOCAL(void)
  rgb_gray_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf,
                            JSAMPIMAGE output_buf, JDIMENSION output_row,
                            int num_rows)
  {
    my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
    register int r, g, b;
    register JLONG *ctab = cconvert->rgb_ycc_tab;
    register JSAMPROW inptr;
    register JSAMPROW outptr;
    register JDIMENSION col;
    JDIMENSION num_cols = cinfo->image_width;
  
    while (--num_rows >= 0) {
      inptr = *input_buf++;
      outptr = output_buf[0][output_row];
      output_row++;
      for (col = 0; col < num_cols; col++) {
        r = inptr[RGB_RED];
        g = inptr[RGB_GREEN];
        b = inptr[RGB_BLUE];
        inptr += RGB_PIXELSIZE;
        /* Y */
        outptr[col] = (JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] +
                                 ctab[b + B_Y_OFF]) >> SCALEBITS);
      }
    }
  }
  
  
  /*
   * Convert some rows of samples to the JPEG colorspace.
   * This version handles extended RGB->plain RGB conversion
   */
  
  INLINE
  LOCAL(void)
  rgb_rgb_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf,
                           JSAMPIMAGE output_buf, JDIMENSION output_row,
                           int num_rows)
  {
    register JSAMPROW inptr;
    register JSAMPROW outptr0, outptr1, outptr2;
    register JDIMENSION col;
    JDIMENSION num_cols = cinfo->image_width;
  
    while (--num_rows >= 0) {
      inptr = *input_buf++;
      outptr0 = output_buf[0][output_row];
      outptr1 = output_buf[1][output_row];
      outptr2 = output_buf[2][output_row];
      output_row++;
      for (col = 0; col < num_cols; col++) {
        outptr0[col] = inptr[RGB_RED];
        outptr1[col] = inptr[RGB_GREEN];
        outptr2[col] = inptr[RGB_BLUE];
        inptr += RGB_PIXELSIZE;
      }
    }
  }
  

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