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/*
* jdcolext.c
*
* This file was part of the Independent JPEG Group's software:
* Copyright (C) 1991-1997, Thomas G. Lane.
* libjpeg-turbo Modifications:
* Copyright (C) 2009, 2011, 2015, D. R. Commander.
* For conditions of distribution and use, see the accompanying README.ijg
* file.
*
* This file contains output colorspace conversion routines.
*/
/* This file is included by jdcolor.c */
/*
* Convert some rows of samples to the output colorspace.
*
* Note that we change from noninterleaved, one-plane-per-component format
* to interleaved-pixel format. The output buffer is therefore three times
* as wide as the input buffer.
* A starting row offset is provided only for the input buffer. The caller
* can easily adjust the passed output_buf value to accommodate any row
* offset required on that side.
*/
INLINE
LOCAL(void)
ycc_rgb_convert_internal(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
JDIMENSION input_row, JSAMPARRAY output_buf,
int num_rows)
{
my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;
register int y, cb, cr;
register JSAMPROW outptr;
register JSAMPROW inptr0, inptr1, inptr2;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->output_width;
/* copy these pointers into registers if possible */
register JSAMPLE *range_limit = cinfo->sample_range_limit;
register int *Crrtab = cconvert->Cr_r_tab;
register int *Cbbtab = cconvert->Cb_b_tab;
register JLONG *Crgtab = cconvert->Cr_g_tab;
register JLONG *Cbgtab = cconvert->Cb_g_tab;
SHIFT_TEMPS
while (--num_rows >= 0) {
inptr0 = input_buf[0][input_row];
inptr1 = input_buf[1][input_row];
inptr2 = input_buf[2][input_row];
input_row++;
outptr = *output_buf++;
for (col = 0; col < num_cols; col++) {
y = inptr0[col];
cb = inptr1[col];
cr = inptr2[col];
/* Range-limiting is essential due to noise introduced by DCT losses. */
outptr[RGB_RED] = range_limit[y + Crrtab[cr]];
outptr[RGB_GREEN] = range_limit[y +
((int)RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
SCALEBITS))];
outptr[RGB_BLUE] = range_limit[y + Cbbtab[cb]];
/* Set unused byte to 0xFF so it can be interpreted as an opaque */
/* alpha channel value */
#ifdef RGB_ALPHA
outptr[RGB_ALPHA] = 0xFF;
#endif
outptr += RGB_PIXELSIZE;
}
}
}
/*
* Convert grayscale to RGB: just duplicate the graylevel three times.
* This is provided to support applications that don't want to cope
* with grayscale as a separate case.
*/
INLINE
LOCAL(void)
gray_rgb_convert_internal(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
JDIMENSION input_row, JSAMPARRAY output_buf,
int num_rows)
{
register JSAMPROW inptr, outptr;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->output_width;
while (--num_rows >= 0) {
inptr = input_buf[0][input_row++];
outptr = *output_buf++;
for (col = 0; col < num_cols; col++) {
outptr[RGB_RED] = outptr[RGB_GREEN] = outptr[RGB_BLUE] = inptr[col];
/* Set unused byte to 0xFF so it can be interpreted as an opaque */
/* alpha channel value */
#ifdef RGB_ALPHA
outptr[RGB_ALPHA] = 0xFF;
#endif
outptr += RGB_PIXELSIZE;
}
}
}
/*
* Convert RGB to extended RGB: just swap the order of source pixels
*/
INLINE
LOCAL(void)
rgb_rgb_convert_internal(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
JDIMENSION input_row, JSAMPARRAY output_buf,
int num_rows)
{
register JSAMPROW inptr0, inptr1, inptr2;
register JSAMPROW outptr;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->output_width;
while (--num_rows >= 0) {
inptr0 = input_buf[0][input_row];
inptr1 = input_buf[1][input_row];
inptr2 = input_buf[2][input_row];
input_row++;
outptr = *output_buf++;
for (col = 0; col < num_cols; col++) {
outptr[RGB_RED] = inptr0[col];
outptr[RGB_GREEN] = inptr1[col];
outptr[RGB_BLUE] = inptr2[col];
/* Set unused byte to 0xFF so it can be interpreted as an opaque */
/* alpha channel value */
#ifdef RGB_ALPHA
outptr[RGB_ALPHA] = 0xFF;
#endif
outptr += RGB_PIXELSIZE;
}
}
}