diff options
Diffstat (limited to 'src/jpeg-6/jdmerge.c')
| -rw-r--r-- | src/jpeg-6/jdmerge.c | 400 |
1 files changed, 0 insertions, 400 deletions
diff --git a/src/jpeg-6/jdmerge.c b/src/jpeg-6/jdmerge.c deleted file mode 100644 index 95585fb8..00000000 --- a/src/jpeg-6/jdmerge.c +++ /dev/null @@ -1,400 +0,0 @@ -/* - * jdmerge.c - * - * Copyright (C) 1994-1995, Thomas G. Lane. - * This file is part of the Independent JPEG Group's software. - * For conditions of distribution and use, see the accompanying README file. - * - * This file contains code for merged upsampling/color conversion. - * - * This file combines functions from jdsample.c and jdcolor.c; - * read those files first to understand what's going on. - * - * When the chroma components are to be upsampled by simple replication - * (ie, box filtering), we can save some work in color conversion by - * calculating all the output pixels corresponding to a pair of chroma - * samples at one time. In the conversion equations - * R = Y + K1 * Cr - * G = Y + K2 * Cb + K3 * Cr - * B = Y + K4 * Cb - * only the Y term varies among the group of pixels corresponding to a pair - * of chroma samples, so the rest of the terms can be calculated just once. - * At typical sampling ratios, this eliminates half or three-quarters of the - * multiplications needed for color conversion. - * - * This file currently provides implementations for the following cases: - * YCbCr => RGB color conversion only. - * Sampling ratios of 2h1v or 2h2v. - * No scaling needed at upsample time. - * Corner-aligned (non-CCIR601) sampling alignment. - * Other special cases could be added, but in most applications these are - * the only common cases. (For uncommon cases we fall back on the more - * general code in jdsample.c and jdcolor.c.) - */ - -#define JPEG_INTERNALS -#include "jinclude.h" -#include "jpeglib.h" - -#ifdef UPSAMPLE_MERGING_SUPPORTED - - -/* Private subobject */ - -typedef struct { - struct jpeg_upsampler pub; /* public fields */ - - /* Pointer to routine to do actual upsampling/conversion of one row group */ - JMETHOD(void, upmethod, (j_decompress_ptr cinfo, - JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, - JSAMPARRAY output_buf)); - - /* Private state for YCC->RGB conversion */ - int * Cr_r_tab; /* => table for Cr to R conversion */ - int * Cb_b_tab; /* => table for Cb to B conversion */ - INT32 * Cr_g_tab; /* => table for Cr to G conversion */ - INT32 * Cb_g_tab; /* => table for Cb to G conversion */ - - /* For 2:1 vertical sampling, we produce two output rows at a time. - * We need a "spare" row buffer to hold the second output row if the - * application provides just a one-row buffer; we also use the spare - * to discard the dummy last row if the image height is odd. - */ - JSAMPROW spare_row; - boolean spare_full; /* T if spare buffer is occupied */ - - JDIMENSION out_row_width; /* samples per output row */ - JDIMENSION rows_to_go; /* counts rows remaining in image */ -} my_upsampler; - -typedef my_upsampler * my_upsample_ptr; - -#define SCALEBITS 16 /* speediest right-shift on some machines */ -#define ONE_HALF ((INT32) 1 << (SCALEBITS-1)) -#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5)) - - -/* - * Initialize tables for YCC->RGB colorspace conversion. - * This is taken directly from jdcolor.c; see that file for more info. - */ - -LOCAL void -build_ycc_rgb_table (j_decompress_ptr cinfo) -{ - my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - int i; - INT32 x; - SHIFT_TEMPS - - upsample->Cr_r_tab = (int *) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - (MAXJSAMPLE+1) * SIZEOF(int)); - upsample->Cb_b_tab = (int *) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - (MAXJSAMPLE+1) * SIZEOF(int)); - upsample->Cr_g_tab = (INT32 *) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - (MAXJSAMPLE+1) * SIZEOF(INT32)); - upsample->Cb_g_tab = (INT32 *) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - (MAXJSAMPLE+1) * SIZEOF(INT32)); - - for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) { - /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */ - /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */ - /* Cr=>R value is nearest int to 1.40200 * x */ - upsample->Cr_r_tab[i] = (int) - RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS); - /* Cb=>B value is nearest int to 1.77200 * x */ - upsample->Cb_b_tab[i] = (int) - RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS); - /* Cr=>G value is scaled-up -0.71414 * x */ - upsample->Cr_g_tab[i] = (- FIX(0.71414)) * x; - /* Cb=>G value is scaled-up -0.34414 * x */ - /* We also add in ONE_HALF so that need not do it in inner loop */ - upsample->Cb_g_tab[i] = (- FIX(0.34414)) * x + ONE_HALF; - } -} - - -/* - * Initialize for an upsampling pass. - */ - -METHODDEF void -start_pass_merged_upsample (j_decompress_ptr cinfo) -{ - my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - - /* Mark the spare buffer empty */ - upsample->spare_full = FALSE; - /* Initialize total-height counter for detecting bottom of image */ - upsample->rows_to_go = cinfo->output_height; -} - - -/* - * Control routine to do upsampling (and color conversion). - * - * The control routine just handles the row buffering considerations. - */ - -METHODDEF void -merged_2v_upsample (j_decompress_ptr cinfo, - JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, - JDIMENSION in_row_groups_avail, - JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, - JDIMENSION out_rows_avail) -/* 2:1 vertical sampling case: may need a spare row. */ -{ - my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - JSAMPROW work_ptrs[2]; - JDIMENSION num_rows; /* number of rows returned to caller */ - - if (upsample->spare_full) { - /* If we have a spare row saved from a previous cycle, just return it. */ - jcopy_sample_rows(& upsample->spare_row, 0, output_buf + *out_row_ctr, 0, - 1, upsample->out_row_width); - num_rows = 1; - upsample->spare_full = FALSE; - } else { - /* Figure number of rows to return to caller. */ - num_rows = 2; - /* Not more than the distance to the end of the image. */ - if (num_rows > upsample->rows_to_go) - num_rows = upsample->rows_to_go; - /* And not more than what the client can accept: */ - out_rows_avail -= *out_row_ctr; - if (num_rows > out_rows_avail) - num_rows = out_rows_avail; - /* Create output pointer array for upsampler. */ - work_ptrs[0] = output_buf[*out_row_ctr]; - if (num_rows > 1) { - work_ptrs[1] = output_buf[*out_row_ctr + 1]; - } else { - work_ptrs[1] = upsample->spare_row; - upsample->spare_full = TRUE; - } - /* Now do the upsampling. */ - (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, work_ptrs); - } - - /* Adjust counts */ - *out_row_ctr += num_rows; - upsample->rows_to_go -= num_rows; - /* When the buffer is emptied, declare this input row group consumed */ - if (! upsample->spare_full) - (*in_row_group_ctr)++; -} - - -METHODDEF void -merged_1v_upsample (j_decompress_ptr cinfo, - JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr, - JDIMENSION in_row_groups_avail, - JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, - JDIMENSION out_rows_avail) -/* 1:1 vertical sampling case: much easier, never need a spare row. */ -{ - my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - - /* Just do the upsampling. */ - (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, - output_buf + *out_row_ctr); - /* Adjust counts */ - (*out_row_ctr)++; - (*in_row_group_ctr)++; -} - - -/* - * These are the routines invoked by the control routines to do - * the actual upsampling/conversion. One row group is processed per call. - * - * Note: since we may be writing directly into application-supplied buffers, - * we have to be honest about the output width; we can't assume the buffer - * has been rounded up to an even width. - */ - - -/* - * Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical. - */ - -METHODDEF void -h2v1_merged_upsample (j_decompress_ptr cinfo, - JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, - JSAMPARRAY output_buf) -{ - my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - register int y, cred, cgreen, cblue; - int cb, cr; - register JSAMPROW outptr; - JSAMPROW inptr0, inptr1, inptr2; - JDIMENSION col; - /* copy these pointers into registers if possible */ - register JSAMPLE * range_limit = cinfo->sample_range_limit; - int * Crrtab = upsample->Cr_r_tab; - int * Cbbtab = upsample->Cb_b_tab; - INT32 * Crgtab = upsample->Cr_g_tab; - INT32 * Cbgtab = upsample->Cb_g_tab; - SHIFT_TEMPS - - inptr0 = input_buf[0][in_row_group_ctr]; - inptr1 = input_buf[1][in_row_group_ctr]; - inptr2 = input_buf[2][in_row_group_ctr]; - outptr = output_buf[0]; - /* Loop for each pair of output pixels */ - for (col = cinfo->output_width >> 1; col > 0; col--) { - /* Do the chroma part of the calculation */ - cb = GETJSAMPLE(*inptr1++); - cr = GETJSAMPLE(*inptr2++); - cred = Crrtab[cr]; - cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS); - cblue = Cbbtab[cb]; - /* Fetch 2 Y values and emit 2 pixels */ - y = GETJSAMPLE(*inptr0++); - outptr[RGB_RED] = range_limit[y + cred]; - outptr[RGB_GREEN] = range_limit[y + cgreen]; - outptr[RGB_BLUE] = range_limit[y + cblue]; - outptr += RGB_PIXELSIZE; - y = GETJSAMPLE(*inptr0++); - outptr[RGB_RED] = range_limit[y + cred]; - outptr[RGB_GREEN] = range_limit[y + cgreen]; - outptr[RGB_BLUE] = range_limit[y + cblue]; - outptr += RGB_PIXELSIZE; - } - /* If image width is odd, do the last output column separately */ - if (cinfo->output_width & 1) { - cb = GETJSAMPLE(*inptr1); - cr = GETJSAMPLE(*inptr2); - cred = Crrtab[cr]; - cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS); - cblue = Cbbtab[cb]; - y = GETJSAMPLE(*inptr0); - outptr[RGB_RED] = range_limit[y + cred]; - outptr[RGB_GREEN] = range_limit[y + cgreen]; - outptr[RGB_BLUE] = range_limit[y + cblue]; - } -} - - -/* - * Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical. - */ - -METHODDEF void -h2v2_merged_upsample (j_decompress_ptr cinfo, - JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr, - JSAMPARRAY output_buf) -{ - my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample; - register int y, cred, cgreen, cblue; - int cb, cr; - register JSAMPROW outptr0, outptr1; - JSAMPROW inptr00, inptr01, inptr1, inptr2; - JDIMENSION col; - /* copy these pointers into registers if possible */ - register JSAMPLE * range_limit = cinfo->sample_range_limit; - int * Crrtab = upsample->Cr_r_tab; - int * Cbbtab = upsample->Cb_b_tab; - INT32 * Crgtab = upsample->Cr_g_tab; - INT32 * Cbgtab = upsample->Cb_g_tab; - SHIFT_TEMPS - - inptr00 = input_buf[0][in_row_group_ctr*2]; - inptr01 = input_buf[0][in_row_group_ctr*2 + 1]; - inptr1 = input_buf[1][in_row_group_ctr]; - inptr2 = input_buf[2][in_row_group_ctr]; - outptr0 = output_buf[0]; - outptr1 = output_buf[1]; - /* Loop for each group of output pixels */ - for (col = cinfo->output_width >> 1; col > 0; col--) { - /* Do the chroma part of the calculation */ - cb = GETJSAMPLE(*inptr1++); - cr = GETJSAMPLE(*inptr2++); - cred = Crrtab[cr]; - cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS); - cblue = Cbbtab[cb]; - /* Fetch 4 Y values and emit 4 pixels */ - y = GETJSAMPLE(*inptr00++); - outptr0[RGB_RED] = range_limit[y + cred]; - outptr0[RGB_GREEN] = range_limit[y + cgreen]; - outptr0[RGB_BLUE] = range_limit[y + cblue]; - outptr0 += RGB_PIXELSIZE; - y = GETJSAMPLE(*inptr00++); - outptr0[RGB_RED] = range_limit[y + cred]; - outptr0[RGB_GREEN] = range_limit[y + cgreen]; - outptr0[RGB_BLUE] = range_limit[y + cblue]; - outptr0 += RGB_PIXELSIZE; - y = GETJSAMPLE(*inptr01++); - outptr1[RGB_RED] = range_limit[y + cred]; - outptr1[RGB_GREEN] = range_limit[y + cgreen]; - outptr1[RGB_BLUE] = range_limit[y + cblue]; - outptr1 += RGB_PIXELSIZE; - y = GETJSAMPLE(*inptr01++); - outptr1[RGB_RED] = range_limit[y + cred]; - outptr1[RGB_GREEN] = range_limit[y + cgreen]; - outptr1[RGB_BLUE] = range_limit[y + cblue]; - outptr1 += RGB_PIXELSIZE; - } - /* If image width is odd, do the last output column separately */ - if (cinfo->output_width & 1) { - cb = GETJSAMPLE(*inptr1); - cr = GETJSAMPLE(*inptr2); - cred = Crrtab[cr]; - cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS); - cblue = Cbbtab[cb]; - y = GETJSAMPLE(*inptr00); - outptr0[RGB_RED] = range_limit[y + cred]; - outptr0[RGB_GREEN] = range_limit[y + cgreen]; - outptr0[RGB_BLUE] = range_limit[y + cblue]; - y = GETJSAMPLE(*inptr01); - outptr1[RGB_RED] = range_limit[y + cred]; - outptr1[RGB_GREEN] = range_limit[y + cgreen]; - outptr1[RGB_BLUE] = range_limit[y + cblue]; - } -} - - -/* - * Module initialization routine for merged upsampling/color conversion. - * - * NB: this is called under the conditions determined by use_merged_upsample() - * in jdmaster.c. That routine MUST correspond to the actual capabilities - * of this module; no safety checks are made here. - */ - -GLOBAL void -jinit_merged_upsampler (j_decompress_ptr cinfo) -{ - my_upsample_ptr upsample; - - upsample = (my_upsample_ptr) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - SIZEOF(my_upsampler)); - cinfo->upsample = (struct jpeg_upsampler *) upsample; - upsample->pub.start_pass = start_pass_merged_upsample; - upsample->pub.need_context_rows = FALSE; - - upsample->out_row_width = cinfo->output_width * cinfo->out_color_components; - - if (cinfo->max_v_samp_factor == 2) { - upsample->pub.upsample = merged_2v_upsample; - upsample->upmethod = h2v2_merged_upsample; - /* Allocate a spare row buffer */ - upsample->spare_row = (JSAMPROW) - (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE, - (size_t) (upsample->out_row_width * SIZEOF(JSAMPLE))); - } else { - upsample->pub.upsample = merged_1v_upsample; - upsample->upmethod = h2v1_merged_upsample; - /* No spare row needed */ - upsample->spare_row = NULL; - } - - build_ycc_rgb_table(cinfo); -} - -#endif /* UPSAMPLE_MERGING_SUPPORTED */ |