1e32fe3113
These days, INT32 is a commonly-defined datatype in system headers. We cannot eliminate the definition of that datatype from jmorecfg.h, since the INT32 typedef has technically been part of the libjpeg API since version 5 (1994.) However, using INT32 internally is risky, because the inclusion of a particular header (Xmd.h, for instance) could change the definition of INT32 from long to int on 64-bit platforms and thus change the internal behavior of libjpeg-turbo in unexpected ways (for instance, failing to correctly set __INT32_IS_ACTUALLY_LONG to match the INT32 typedef-- perhaps as a result of including the wrong version of jpeglib.h-- could cause libjpeg-turbo to produce incorrect results.) The library has always been built in environments in which INT32 is effectively long (on Windows, long is always 32-bit, so effectively it's the same as int), so it makes sense to turn INT32 into an explicitly long datatype. This ensures that libjpeg-turbo will always behave consistently, regardless of the headers included at compile time. Addresses a concern expressed in #26.
187 lines
5.9 KiB
C
187 lines
5.9 KiB
C
/*
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* jdmrgext.c
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*
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* This file was part of the Independent JPEG Group's software:
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* Copyright (C) 1994-1996, Thomas G. Lane.
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* libjpeg-turbo Modifications:
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* Copyright (C) 2011, 2015, D. R. Commander.
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* For conditions of distribution and use, see the accompanying README.ijg
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* file.
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*
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* This file contains code for merged upsampling/color conversion.
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*/
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/* This file is included by jdmerge.c */
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/*
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* Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.
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*/
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INLINE
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LOCAL(void)
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h2v1_merged_upsample_internal (j_decompress_ptr cinfo,
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JSAMPIMAGE input_buf,
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JDIMENSION in_row_group_ctr,
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JSAMPARRAY output_buf)
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{
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my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
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register int y, cred, cgreen, cblue;
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int cb, cr;
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register JSAMPROW outptr;
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JSAMPROW inptr0, inptr1, inptr2;
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JDIMENSION col;
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/* copy these pointers into registers if possible */
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register JSAMPLE * range_limit = cinfo->sample_range_limit;
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int * Crrtab = upsample->Cr_r_tab;
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int * Cbbtab = upsample->Cb_b_tab;
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JLONG * Crgtab = upsample->Cr_g_tab;
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JLONG * Cbgtab = upsample->Cb_g_tab;
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SHIFT_TEMPS
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inptr0 = input_buf[0][in_row_group_ctr];
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inptr1 = input_buf[1][in_row_group_ctr];
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inptr2 = input_buf[2][in_row_group_ctr];
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outptr = output_buf[0];
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/* Loop for each pair of output pixels */
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for (col = cinfo->output_width >> 1; col > 0; col--) {
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/* Do the chroma part of the calculation */
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cb = GETJSAMPLE(*inptr1++);
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cr = GETJSAMPLE(*inptr2++);
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cred = Crrtab[cr];
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cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
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cblue = Cbbtab[cb];
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/* Fetch 2 Y values and emit 2 pixels */
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y = GETJSAMPLE(*inptr0++);
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outptr[RGB_RED] = range_limit[y + cred];
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outptr[RGB_GREEN] = range_limit[y + cgreen];
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outptr[RGB_BLUE] = range_limit[y + cblue];
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#ifdef RGB_ALPHA
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outptr[RGB_ALPHA] = 0xFF;
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#endif
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outptr += RGB_PIXELSIZE;
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y = GETJSAMPLE(*inptr0++);
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outptr[RGB_RED] = range_limit[y + cred];
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outptr[RGB_GREEN] = range_limit[y + cgreen];
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outptr[RGB_BLUE] = range_limit[y + cblue];
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#ifdef RGB_ALPHA
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outptr[RGB_ALPHA] = 0xFF;
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#endif
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outptr += RGB_PIXELSIZE;
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}
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/* If image width is odd, do the last output column separately */
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if (cinfo->output_width & 1) {
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cb = GETJSAMPLE(*inptr1);
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cr = GETJSAMPLE(*inptr2);
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cred = Crrtab[cr];
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cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
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cblue = Cbbtab[cb];
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y = GETJSAMPLE(*inptr0);
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outptr[RGB_RED] = range_limit[y + cred];
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outptr[RGB_GREEN] = range_limit[y + cgreen];
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outptr[RGB_BLUE] = range_limit[y + cblue];
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#ifdef RGB_ALPHA
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outptr[RGB_ALPHA] = 0xFF;
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#endif
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}
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}
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/*
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* Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical.
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*/
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INLINE
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LOCAL(void)
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h2v2_merged_upsample_internal (j_decompress_ptr cinfo,
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JSAMPIMAGE input_buf,
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JDIMENSION in_row_group_ctr,
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JSAMPARRAY output_buf)
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{
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my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
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register int y, cred, cgreen, cblue;
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int cb, cr;
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register JSAMPROW outptr0, outptr1;
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JSAMPROW inptr00, inptr01, inptr1, inptr2;
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JDIMENSION col;
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/* copy these pointers into registers if possible */
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register JSAMPLE * range_limit = cinfo->sample_range_limit;
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int * Crrtab = upsample->Cr_r_tab;
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int * Cbbtab = upsample->Cb_b_tab;
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JLONG * Crgtab = upsample->Cr_g_tab;
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JLONG * Cbgtab = upsample->Cb_g_tab;
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SHIFT_TEMPS
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inptr00 = input_buf[0][in_row_group_ctr*2];
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inptr01 = input_buf[0][in_row_group_ctr*2 + 1];
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inptr1 = input_buf[1][in_row_group_ctr];
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inptr2 = input_buf[2][in_row_group_ctr];
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outptr0 = output_buf[0];
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outptr1 = output_buf[1];
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/* Loop for each group of output pixels */
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for (col = cinfo->output_width >> 1; col > 0; col--) {
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/* Do the chroma part of the calculation */
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cb = GETJSAMPLE(*inptr1++);
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cr = GETJSAMPLE(*inptr2++);
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cred = Crrtab[cr];
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cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
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cblue = Cbbtab[cb];
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/* Fetch 4 Y values and emit 4 pixels */
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y = GETJSAMPLE(*inptr00++);
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outptr0[RGB_RED] = range_limit[y + cred];
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outptr0[RGB_GREEN] = range_limit[y + cgreen];
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outptr0[RGB_BLUE] = range_limit[y + cblue];
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#ifdef RGB_ALPHA
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outptr0[RGB_ALPHA] = 0xFF;
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#endif
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outptr0 += RGB_PIXELSIZE;
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y = GETJSAMPLE(*inptr00++);
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outptr0[RGB_RED] = range_limit[y + cred];
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outptr0[RGB_GREEN] = range_limit[y + cgreen];
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outptr0[RGB_BLUE] = range_limit[y + cblue];
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#ifdef RGB_ALPHA
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outptr0[RGB_ALPHA] = 0xFF;
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#endif
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outptr0 += RGB_PIXELSIZE;
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y = GETJSAMPLE(*inptr01++);
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outptr1[RGB_RED] = range_limit[y + cred];
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outptr1[RGB_GREEN] = range_limit[y + cgreen];
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outptr1[RGB_BLUE] = range_limit[y + cblue];
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#ifdef RGB_ALPHA
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outptr1[RGB_ALPHA] = 0xFF;
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#endif
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outptr1 += RGB_PIXELSIZE;
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y = GETJSAMPLE(*inptr01++);
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outptr1[RGB_RED] = range_limit[y + cred];
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outptr1[RGB_GREEN] = range_limit[y + cgreen];
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outptr1[RGB_BLUE] = range_limit[y + cblue];
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#ifdef RGB_ALPHA
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outptr1[RGB_ALPHA] = 0xFF;
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#endif
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outptr1 += RGB_PIXELSIZE;
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}
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/* If image width is odd, do the last output column separately */
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if (cinfo->output_width & 1) {
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cb = GETJSAMPLE(*inptr1);
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cr = GETJSAMPLE(*inptr2);
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cred = Crrtab[cr];
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cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
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cblue = Cbbtab[cb];
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y = GETJSAMPLE(*inptr00);
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outptr0[RGB_RED] = range_limit[y + cred];
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outptr0[RGB_GREEN] = range_limit[y + cgreen];
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outptr0[RGB_BLUE] = range_limit[y + cblue];
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#ifdef RGB_ALPHA
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outptr0[RGB_ALPHA] = 0xFF;
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#endif
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y = GETJSAMPLE(*inptr01);
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outptr1[RGB_RED] = range_limit[y + cred];
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outptr1[RGB_GREEN] = range_limit[y + cgreen];
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outptr1[RGB_BLUE] = range_limit[y + cblue];
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#ifdef RGB_ALPHA
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outptr1[RGB_ALPHA] = 0xFF;
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#endif
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}
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}
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