#if !defined(_FX_JPEG_TURBO_) | |
/* | |
* jdmerge.c | |
* | |
* Copyright (C) 1994-1996, 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 | |
#ifdef _FX_MANAGED_CODE_ | |
#define my_upsampler my_upsampler_m | |
#endif | |
/* 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 */ | |
#endif //_FX_JPEG_TURBO_ |