michael@0: /*
michael@0:  * jdcolext.c
michael@0:  *
michael@0:  * This file was part of the Independent JPEG Group's software:
michael@0:  * Copyright (C) 1991-1997, Thomas G. Lane.
michael@0:  * libjpeg-turbo Modifications:
michael@0:  * Copyright (C) 2009, 2011, D. R. Commander.
michael@0:  * For conditions of distribution and use, see the accompanying README file.
michael@0:  *
michael@0:  * This file contains output colorspace conversion routines.
michael@0:  */
michael@0: 
michael@0: 
michael@0: /* This file is included by jdcolor.c */
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Convert some rows of samples to the output colorspace.
michael@0:  *
michael@0:  * Note that we change from noninterleaved, one-plane-per-component format
michael@0:  * to interleaved-pixel format.  The output buffer is therefore three times
michael@0:  * as wide as the input buffer.
michael@0:  * A starting row offset is provided only for the input buffer.  The caller
michael@0:  * can easily adjust the passed output_buf value to accommodate any row
michael@0:  * offset required on that side.
michael@0:  */
michael@0: 
michael@0: INLINE
michael@0: LOCAL(void)
michael@0: ycc_rgb_convert_internal (j_decompress_ptr cinfo,
michael@0:                           JSAMPIMAGE input_buf, JDIMENSION input_row,
michael@0:                           JSAMPARRAY output_buf, int num_rows)
michael@0: {
michael@0:   my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
michael@0:   register int y, cb, cr;
michael@0:   register JSAMPROW outptr;
michael@0:   register JSAMPROW inptr0, inptr1, inptr2;
michael@0:   register JDIMENSION col;
michael@0:   JDIMENSION num_cols = cinfo->output_width;
michael@0:   /* copy these pointers into registers if possible */
michael@0:   register JSAMPLE * range_limit = cinfo->sample_range_limit;
michael@0:   register int * Crrtab = cconvert->Cr_r_tab;
michael@0:   register int * Cbbtab = cconvert->Cb_b_tab;
michael@0:   register INT32 * Crgtab = cconvert->Cr_g_tab;
michael@0:   register INT32 * Cbgtab = cconvert->Cb_g_tab;
michael@0:   SHIFT_TEMPS
michael@0: 
michael@0:   while (--num_rows >= 0) {
michael@0:     inptr0 = input_buf[0][input_row];
michael@0:     inptr1 = input_buf[1][input_row];
michael@0:     inptr2 = input_buf[2][input_row];
michael@0:     input_row++;
michael@0:     outptr = *output_buf++;
michael@0:     for (col = 0; col < num_cols; col++) {
michael@0:       y  = GETJSAMPLE(inptr0[col]);
michael@0:       cb = GETJSAMPLE(inptr1[col]);
michael@0:       cr = GETJSAMPLE(inptr2[col]);
michael@0:       /* Range-limiting is essential due to noise introduced by DCT losses. */
michael@0:       outptr[RGB_RED] =   range_limit[y + Crrtab[cr]];
michael@0:       outptr[RGB_GREEN] = range_limit[y +
michael@0: 			      ((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
michael@0: 						 SCALEBITS))];
michael@0:       outptr[RGB_BLUE] =  range_limit[y + Cbbtab[cb]];
michael@0:       /* Set unused byte to 0xFF so it can be interpreted as an opaque */
michael@0:       /* alpha channel value */
michael@0: #ifdef RGB_ALPHA
michael@0:       outptr[RGB_ALPHA] = 0xFF;
michael@0: #endif
michael@0:       outptr += RGB_PIXELSIZE;
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Convert grayscale to RGB: just duplicate the graylevel three times.
michael@0:  * This is provided to support applications that don't want to cope
michael@0:  * with grayscale as a separate case.
michael@0:  */
michael@0: 
michael@0: INLINE
michael@0: LOCAL(void)
michael@0: gray_rgb_convert_internal (j_decompress_ptr cinfo,
michael@0:                            JSAMPIMAGE input_buf, JDIMENSION input_row,
michael@0:                            JSAMPARRAY output_buf, int num_rows)
michael@0: {
michael@0:   register JSAMPROW inptr, outptr;
michael@0:   register JDIMENSION col;
michael@0:   JDIMENSION num_cols = cinfo->output_width;
michael@0: 
michael@0:   while (--num_rows >= 0) {
michael@0:     inptr = input_buf[0][input_row++];
michael@0:     outptr = *output_buf++;
michael@0:     for (col = 0; col < num_cols; col++) {
michael@0:       /* We can dispense with GETJSAMPLE() here */
michael@0:       outptr[RGB_RED] = outptr[RGB_GREEN] = outptr[RGB_BLUE] = inptr[col];
michael@0:       /* Set unused byte to 0xFF so it can be interpreted as an opaque */
michael@0:       /* alpha channel value */
michael@0: #ifdef RGB_ALPHA
michael@0:       outptr[RGB_ALPHA] = 0xFF;
michael@0: #endif
michael@0:       outptr += RGB_PIXELSIZE;
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Convert RGB to extended RGB: just swap the order of source pixels
michael@0:  */
michael@0: 
michael@0: INLINE
michael@0: LOCAL(void)
michael@0: rgb_rgb_convert_internal (j_decompress_ptr cinfo,
michael@0:                           JSAMPIMAGE input_buf, JDIMENSION input_row,
michael@0:                           JSAMPARRAY output_buf, int num_rows)
michael@0: {
michael@0:   register JSAMPROW inptr0, inptr1, inptr2;
michael@0:   register JSAMPROW outptr;
michael@0:   register JDIMENSION col;
michael@0:   JDIMENSION num_cols = cinfo->output_width;
michael@0: 
michael@0:   while (--num_rows >= 0) {
michael@0:     inptr0 = input_buf[0][input_row];
michael@0:     inptr1 = input_buf[1][input_row];
michael@0:     inptr2 = input_buf[2][input_row];
michael@0:     input_row++;
michael@0:     outptr = *output_buf++;
michael@0:     for (col = 0; col < num_cols; col++) {
michael@0:       /* We can dispense with GETJSAMPLE() here */
michael@0:       outptr[RGB_RED] = inptr0[col];
michael@0:       outptr[RGB_GREEN] = inptr1[col];
michael@0:       outptr[RGB_BLUE] = inptr2[col];
michael@0:       /* Set unused byte to 0xFF so it can be interpreted as an opaque */
michael@0:       /* alpha channel value */
michael@0: #ifdef RGB_ALPHA
michael@0:       outptr[RGB_ALPHA] = 0xFF;
michael@0: #endif
michael@0:       outptr += RGB_PIXELSIZE;
michael@0:     }
michael@0:   }
michael@0: }