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/*
* Copyright (c) 1995 The Regents of the University of California.
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose, without fee, and without written agreement is
* hereby granted, provided that the above copyright notice and the following
* two paragraphs appear in all copies of this software.
*
* IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
* OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
* CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/
/*
* Copyright (c) 1995 Erik Corry
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose, without fee, and without written agreement is
* hereby granted, provided that the above copyright notice and the following
* two paragraphs appear in all copies of this software.
*
* IN NO EVENT SHALL ERIK CORRY BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
* SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF
* THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF ERIK CORRY HAS BEEN ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* ERIK CORRY SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS"
* BASIS, AND ERIK CORRY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT,
* UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/
/*
* Portions of this software Copyright (c) 1995 Brown University.
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose, without fee, and without written agreement
* is hereby granted, provided that the above copyright notice and the
* following two paragraphs appear in all copies of this software.
*
* IN NO EVENT SHALL BROWN UNIVERSITY BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
* OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF BROWN
* UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* BROWN UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS"
* BASIS, AND BROWN UNIVERSITY HAS NO OBLIGATION TO PROVIDE MAINTENANCE,
* SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/
#include "video.h"
#include "dither.h"
#include "proto.h"
#include <math.h>
/* Use special optimized routines for color conversion */
#define OPTIMIZE_CODE
/*
Changes to make the code reentrant:
None
Additional changes:
do not define INTERPOLATE, add #ifdef INTERPOLATE
-lsh@cs.brown.edu (Loring Holden)
*/
/* #define INTERPOLATE */
/*
* Erik Corry's multi-byte dither routines.
*
* The basic idea is that the Init generates all the necessary tables.
* The tables incorporate the information about the layout of pixels
* in the XImage, so that it should be able to cope with 15-bit, 16-bit
* 24-bit (non-packed) and 32-bit (10-11 bits per color!) screens.
* At present it cannot cope with 24-bit packed mode, since this involves
* getting down to byte level again. It is assumed that the bits for each
* color are contiguous in the longword.
*
* Writing to memory is done in shorts or ints. (Unfortunately, short is not
* very fast on Alpha, so there is room for improvement here). There is no
* dither time check for overflow - instead the tables have slack at
* each end. This is likely to be faster than an 'if' test as many modern
* architectures are really bad at ifs. Potentially, each '&&' causes a
* pipeline flush!
*
* There is no shifting and fixed point arithmetic, as I really doubt you
* can see the difference, and it costs. This may be just my bias, since I
* heard that Intel is really bad at shifting.
*/
/*
* How many 1 bits are there in the longword.
* Low performance, do not call often.
*/
static int number_of_bits_set( unsigned long a )
{
if(!a) return 0;
if(a & 1) return 1 + number_of_bits_set(a >> 1);
return(number_of_bits_set(a >> 1));
}
/*
* Shift the 0s in the least significant end out of the longword.
* Low performance, do not call often.
*/
static unsigned long shifted_down( unsigned long a )
{
if(!a) return 0;
if(a & 1) return a;
return a >> 1;
}
/*
* How many 0 bits are there at most significant end of longword.
* Low performance, do not call often.
*/
static int free_bits_at_top( unsigned long a )
{
/* assume char is 8 bits */
if(!a) return sizeof(unsigned long) * 8;
/* assume twos complement */
if(((long)a) < 0l) return 0;
return 1 + free_bits_at_top ( a << 1);
}
/*
* How many 0 bits are there at least significant end of longword.
* Low performance, do not call often.
*/
static int free_bits_at_bottom( unsigned long a )
{
/* assume char is 8 bits */
if(!a) return sizeof(unsigned long) * 8;
if(((long)a) & 1l) return 0;
return 1 + free_bits_at_bottom ( a >> 1);
}
static int *L_tab=NULL;
static int *colortab=NULL,
*Cr_r_tab=NULL, *Cr_g_tab=NULL, *Cb_g_tab=NULL, *Cb_b_tab=NULL;
/*
* We define tables that convert a color value between -256 and 512
* into the R, G and B parts of the pixel. The normal range is 0-255.
*/
static long *r_2_pix=NULL;
static long *g_2_pix=NULL;
static long *b_2_pix=NULL;
static long *rgb_2_pix=NULL;
static long *r_2_pix_alloc=NULL;
static long *g_2_pix_alloc=NULL;
static long *b_2_pix_alloc=NULL;
/*
*--------------------------------------------------------------
*
* InitColor16Dither --
*
* To get rid of the multiply and other conversions in color
* dither, we use a lookup table.
*
* Results:
* None.
*
* Side effects:
* The lookup tables are initialized.
*
*--------------------------------------------------------------
*/
void InitColorDither( int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask )
{
int L, CR, CB, i;
int thirty2;
if (L_tab==NULL)
L_tab = (int *)malloc(256*sizeof(int));
#if 0 /* We can exploit cache by allocating contiguous blocks */
if (Cr_r_tab==NULL)
Cr_r_tab = (int *)malloc(256*sizeof(int));
if (Cr_g_tab==NULL)
Cr_g_tab = (int *)malloc(256*sizeof(int));
if (Cb_g_tab==NULL)
Cb_g_tab = (int *)malloc(256*sizeof(int));
if (Cb_b_tab==NULL)
Cb_b_tab = (int *)malloc(256*sizeof(int));
if (r_2_pix_alloc==NULL)
r_2_pix_alloc = (long *)malloc(768*sizeof(long));
if (g_2_pix_alloc==NULL)
g_2_pix_alloc = (long *)malloc(768*sizeof(long));
if (b_2_pix_alloc==NULL)
b_2_pix_alloc = (long *)malloc(768*sizeof(long));
#else
if (colortab==NULL)
colortab = (int *)malloc(4*256*sizeof(int));
Cr_r_tab = &colortab[0*256];
Cr_g_tab = &colortab[1*256];
Cb_g_tab = &colortab[2*256];
Cb_b_tab = &colortab[3*256];
if (rgb_2_pix==NULL)
rgb_2_pix = (long *)malloc(3*768*sizeof(long));
r_2_pix_alloc = &rgb_2_pix[0*768];
g_2_pix_alloc = &rgb_2_pix[1*768];
b_2_pix_alloc = &rgb_2_pix[2*768];
#endif
if (L_tab == NULL ||
Cr_r_tab == NULL ||
Cr_g_tab == NULL ||
Cb_g_tab == NULL ||
Cb_b_tab == NULL ||
r_2_pix_alloc == NULL ||
g_2_pix_alloc == NULL ||
b_2_pix_alloc == NULL) {
fprintf(stderr, "Could not get enough memory in InitColorDither\n");
exit(1);
}
/* Set the 32-bpp flag */
thirty2 = (bpp >= 24);
for (i=0; i<256; i++) {
L_tab[i] = i;
if (gammaCorrectFlag) {
L_tab[i] = GAMMA_CORRECTION(i);
}
CB = CR = i;
if (chromaCorrectFlag) {
CB -= 128;
CB = CHROMA_CORRECTION128(CB);
CR -= 128;
CR = CHROMA_CORRECTION128(CR);
} else {
CB -= 128; CR -= 128;
}
/* was
Cr_r_tab[i] = 1.596 * CR;
Cr_g_tab[i] = -0.813 * CR;
Cb_g_tab[i] = -0.391 * CB;
Cb_b_tab[i] = 2.018 * CB;
but they were just messed up.
Then was (_Video Deymstified_):
Cr_r_tab[i] = 1.366 * CR;
Cr_g_tab[i] = -0.700 * CR;
Cb_g_tab[i] = -0.334 * CB;
Cb_b_tab[i] = 1.732 * CB;
but really should be:
(from ITU-R BT.470-2 System B, G and SMPTE 170M )
*/
Cr_r_tab[i] = (int) ( (0.419/0.299) * CR);
Cr_g_tab[i] = (int) (-(0.299/0.419) * CR);
Cb_g_tab[i] = (int) (-(0.114/0.331) * CB);
Cb_b_tab[i] = (int) ( (0.587/0.331) * CB);
/*
though you could argue for:
SMPTE 240M
Cr_r_tab[i] = (0.445/0.212) * CR;
Cr_g_tab[i] = -(0.212/0.445) * CR;
Cb_g_tab[i] = -(0.087/0.384) * CB;
Cb_b_tab[i] = (0.701/0.384) * CB;
FCC
Cr_r_tab[i] = (0.421/0.30) * CR;
Cr_g_tab[i] = -(0.30/0.421) * CR;
Cb_g_tab[i] = -(0.11/0.331) * CB;
Cb_b_tab[i] = (0.59/0.331) * CB;
ITU-R BT.709
Cr_r_tab[i] = (0.454/0.2125) * CR;
Cr_g_tab[i] = -(0.2125/0.454) * CR;
Cb_g_tab[i] = -(0.0721/0.386) * CB;
Cb_b_tab[i] = (0.7154/0.386) * CB;
*/
}
/*
* Set up entries 0-255 in rgb-to-pixel value tables.
*/
for (i = 0; i < 256; i++) {
r_2_pix_alloc[i + 256] = i >> (8 - number_of_bits_set(Rmask));
r_2_pix_alloc[i + 256] <<= free_bits_at_bottom(Rmask);
g_2_pix_alloc[i + 256] = i >> (8 - number_of_bits_set(Gmask));
g_2_pix_alloc[i + 256] <<= free_bits_at_bottom(Gmask);
b_2_pix_alloc[i + 256] = i >> (8 - number_of_bits_set(Bmask));
b_2_pix_alloc[i + 256] <<= free_bits_at_bottom(Bmask);
/*
* If we have 16-bit output depth, then we double the value
* in the top word. This means that we can write out both
* pixels in the pixel doubling mode with one op. It is
* harmless in the normal case as storing a 32-bit value
* through a short pointer will lose the top bits anyway.
* A similar optimisation for Alpha for 64 bit has been
* prepared for, but is not yet implemented.
*/
if(!thirty2) {
r_2_pix_alloc[i + 256] |= (r_2_pix_alloc[i + 256]) << 16;
g_2_pix_alloc[i + 256] |= (g_2_pix_alloc[i + 256]) << 16;
b_2_pix_alloc[i + 256] |= (b_2_pix_alloc[i + 256]) << 16;
}
#ifdef SIXTYFOUR_BIT
if(thirty2) {
r_2_pix_alloc[i + 256] |= (r_2_pix_alloc[i + 256]) << 32;
g_2_pix_alloc[i + 256] |= (g_2_pix_alloc[i + 256]) << 32;
b_2_pix_alloc[i + 256] |= (b_2_pix_alloc[i + 256]) << 32;
}
#endif
}
/*
* Spread out the values we have to the rest of the array so that
* we do not need to check for overflow.
*/
for (i = 0; i < 256; i++) {
r_2_pix_alloc[i] = r_2_pix_alloc[256];
r_2_pix_alloc[i+ 512] = r_2_pix_alloc[511];
g_2_pix_alloc[i] = g_2_pix_alloc[256];
g_2_pix_alloc[i+ 512] = g_2_pix_alloc[511];
b_2_pix_alloc[i] = b_2_pix_alloc[256];
b_2_pix_alloc[i+ 512] = b_2_pix_alloc[511];
}
r_2_pix = r_2_pix_alloc + 256;
g_2_pix = g_2_pix_alloc + 256;
b_2_pix = b_2_pix_alloc + 256;
}
/*
* Profiling results:
* This function takes about 5ms per call, and is called once per
* frame, taking about 30% of the total time used by playback.
*
*--------------------------------------------------------------
*/
void Color16DitherImageMod( unsigned char *lum, unsigned char *cr,
unsigned char *cb, unsigned char *out,
int rows, int cols, int mod )
{
unsigned short* row1;
unsigned short* row2;
unsigned char* lum2;
int x, y;
int cr_r;
int crb_g;
int cb_b;
int cols_2 = cols / 2;
row1 = (unsigned short*) out;
row2 = row1 + cols + mod;
lum2 = lum + cols;
mod += cols + mod;
y = rows / 2;
while( y-- )
{
x = cols_2;
while( x-- )
{
register int L;
cr_r = 0*768+256 + colortab[ cr[0] + 0*256 ];
crb_g = 1*768+256 + colortab[ cr[0] + 1*256 ]
+ colortab[ cb[0] + 2*256 ];
cb_b = 2*768+256 + colortab[ cb[0] + 3*256 ];
++cr; ++cb;
L = L_tab[ (int) *lum++ ];
*row1++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
L = L_tab[ (int) *lum++ ];
*row1++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
/* Now, do second row. */
L = L_tab[ (int) *lum2++ ];
*row2++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
L = L_tab[ (int) *lum2++ ];
*row2++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
}
/*
* These values are at the start of the next line, (due
* to the ++'s above),but they need to be at the start
* of the line after that.
*/
lum += cols;
lum2 += cols;
row1 += mod;
row2 += mod;
}
}
void Color32DitherImageMod( unsigned char *lum, unsigned char *cr,
unsigned char *cb, unsigned char *out,
int rows, int cols, int mod )
{
unsigned int* row1;
unsigned int* row2;
unsigned char* lum2;
int x, y;
int cr_r;
int crb_g;
int cb_b;
int cols_2 = cols / 2;
row1 = (unsigned int*) out;
row2 = row1 + cols + mod;
lum2 = lum + cols;
mod += cols + mod;
y = rows / 2;
while( y-- )
{
x = cols_2;
while( x-- )
{
register int L;
cr_r = 0*768+256 + colortab[ cr[0] + 0*256 ];
crb_g = 1*768+256 + colortab[ cr[0] + 1*256 ]
+ colortab[ cb[0] + 2*256 ];
cb_b = 2*768+256 + colortab[ cb[0] + 3*256 ];
++cr; ++cb;
L = L_tab[ (int) *lum++ ];
*row1++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
L = L_tab[ (int) *lum++ ];
*row1++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
/* Now, do second row. */
L = L_tab[ (int) *lum2++ ];
*row2++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
L = L_tab[ (int) *lum2++ ];
*row2++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
}
/*
* These values are at the start of the next line, (due
* to the ++'s above),but they need to be at the start
* of the line after that.
*/
lum += cols;
lum2 += cols;
row1 += mod;
row2 += mod;
}
}
/* This allows interlaced video display
- Actually the current implementation only renders even scanlines since
rendering alternating even and odd scanlines gives terrible results.
- This is made a compile-time option because it doesn't increase the
framerate very much. Optimization is better done in stream parsing.
*/
#ifdef USE_INTERLACED_VIDEO
void Color16DitherImageModInterlace( unsigned char *lum, unsigned char *cr,
unsigned char *cb, unsigned char *out,
int rows, int cols, int mod, int start )
{
unsigned short* row1;
unsigned short* row2;
unsigned char* lum2;
int x, y;
int cr_r;
int crb_g;
int cb_b;
int cols_2 = cols / 2;
row1 = (unsigned short*) out;
// Uncomment this to enable even-odd scanline rendering (looks terrible)
//row1 += start * (cols + mod);
//lum += start * cols;
row2 = row1 + 2*(cols + mod);
lum2 = lum + 2*cols;
mod += cols + mod;
y = ((rows-2) / 2);
while( y-- )
{
x = cols_2;
while( x-- )
{
register int L;
cr_r = 0*768+256 + colortab[ cr[0] + 0*256 ];
crb_g = 1*768+256 + colortab[ cr[0] + 1*256 ]
+ colortab[ cb[0] + 2*256 ];
cb_b = 2*768+256 + colortab[ cb[0] + 3*256 ];
++cr; ++cb;
L = L_tab[ (int) *lum++ ];
*row1++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
L = L_tab[ (int) *lum++ ];
*row1++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
/* Now, do second row. */
L = L_tab[ (int) *lum2++ ];
*row2++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
L = L_tab[ (int) *lum2++ ];
*row2++ = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
}
/*
* These values are at the start of the next line, (due
* to the ++'s above),but they need to be at the start
* of the line after that.
*/
lum += cols;
lum2 += cols;
row1 += mod;
row2 += mod;
}
}
#endif /* USE_INTERLACED_VIDEO */
/*
* Erik Corry's pixel doubling routines for 15/16/24/32 bit screens.
*/
/*
*--------------------------------------------------------------
*
* Twox2Color16DitherImage --
*
* Converts image into 16 bit color at double size.
*
* Results:
* None.
*
* Side effects:
* None.
*
* Profiling results:
* This function takes about 10ms per call, and is called once per
* frame, taking about 40% of the total time used by playback.
*
*--------------------------------------------------------------
*/
/*
* In this function I make use of a nasty trick. The tables have the lower
* 16 bits replicated in the upper 16. This means I can write ints and get
* the horisontal doubling for free (almost).
*/
void Twox2Color16DitherImageMod( unsigned char *lum, unsigned char *cr,
unsigned char *cb, unsigned char *out,
int rows, int cols, int mod )
{
unsigned int* row1 = (unsigned int*) out;
const int next_row = cols+(mod/2);
unsigned int* row2 = row1 + 2*next_row;
unsigned char* lum2;
int x, y;
int cr_r;
int crb_g;
int cb_b;
int cols_2 = cols / 2;
lum2 = lum + cols;
mod = (next_row * 3) + (mod/2);
y = rows / 2;
while( y-- )
{
x = cols_2;
while( x-- )
{
register int L;
cr_r = 0*768+256 + colortab[ cr[0] + 0*256 ];
crb_g = 1*768+256 + colortab[ cr[0] + 1*256 ]
+ colortab[ cb[0] + 2*256 ];
cb_b = 2*768+256 + colortab[ cb[0] + 3*256 ];
++cr; ++cb;
L = L_tab[ (int) *lum++ ];
row1[0] = row1[next_row] = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row1++;
L = L_tab[ (int) *lum++ ];
row1[0] = row1[next_row] = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row1++;
/* Now, do second row. */
L = L_tab[ (int) *lum2++ ];
row2[0] = row2[next_row] = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row2++;
L = L_tab[ (int) *lum2++ ];
row2[0] = row2[next_row] = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row2++;
}
/*
* These values are at the start of the next line, (due
* to the ++'s above),but they need to be at the start
* of the line after that.
*/
lum += cols;
lum2 += cols;
row1 += mod;
row2 += mod;
}
}
void Twox2Color32DitherImageMod( unsigned char *lum, unsigned char *cr,
unsigned char *cb, unsigned char *out,
int rows, int cols, int mod )
{
unsigned int* row1 = (unsigned int*) out;
const int next_row = cols*2+mod;
unsigned int* row2 = row1 + 2*next_row;
unsigned char* lum2;
int x, y;
int cr_r;
int crb_g;
int cb_b;
int cols_2 = cols / 2;
lum2 = lum + cols;
mod = (next_row * 3) + mod;
y = rows / 2;
while( y-- )
{
x = cols_2;
while( x-- )
{
register int L;
cr_r = 0*768+256 + colortab[ cr[0] + 0*256 ];
crb_g = 1*768+256 + colortab[ cr[0] + 1*256 ]
+ colortab[ cb[0] + 2*256 ];
cb_b = 2*768+256 + colortab[ cb[0] + 3*256 ];
++cr; ++cb;
L = L_tab[ (int) *lum++ ];
row1[0] = row1[1] = row1[next_row] = row1[next_row+1] =
(rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row1 += 2;
L = L_tab[ (int) *lum++ ];
row1[0] = row1[1] = row1[next_row] = row1[next_row+1] =
(rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row1 += 2;
/* Now, do second row. */
L = L_tab[ (int) *lum2++ ];
row2[0] = row2[1] = row2[next_row] = row2[next_row+1] =
(rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row2 += 2;
L = L_tab[ (int) *lum2++ ];
row2[0] = row2[1] = row2[next_row] = row2[next_row+1] =
(rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row2 += 2;
}
/*
* These values are at the start of the next line, (due
* to the ++'s above),but they need to be at the start
* of the line after that.
*/
lum += cols;
lum2 += cols;
row1 += mod;
row2 += mod;
}
}
/* This allows interlaced video display
- Actually the current implementation only renders even scanlines since
rendering alternating even and odd scanlines gives terrible results.
- This is made a compile-time option because it doesn't increase the
framerate very much. Optimization is better done in stream parsing.
*/
#ifdef USE_INTERLACED_VIDEO
void Twox2Color16DitherImageModInterlace( unsigned char *lum, unsigned char *cr,
unsigned char *cb, unsigned char *out,
int rows, int cols, int mod, int start )
{
unsigned long* row1;
const int next_row = cols+(mod/2);
unsigned long* row2;
unsigned char* lum2;
int x, y;
int cr_r;
int crb_g;
int cb_b;
int cols_2 = cols / 2;
row1 = (unsigned long*) out;
// Uncomment this to enable even-odd scanline rendering (looks terrible)
//row1 += 2*start * next_row;
//lum += start * cols;
row2 = row1 + 4*next_row;
lum2 = lum + 2*cols;
mod = ((cols + (mod/2)) * 3) + (mod/2);
y = ((rows-2) / 2);
while( y-- )
{
x = cols_2;
while( x-- )
{
register int L;
cr_r = 0*768+256 + colortab[ cr[0] + 0*256 ];
crb_g = 1*768+256 + colortab[ cr[0] + 1*256 ]
+ colortab[ cb[0] + 2*256 ];
cb_b = 2*768+256 + colortab[ cb[0] + 3*256 ];
++cr; ++cb;
L = L_tab[ (int) *lum++ ];
row1[0] = row1[next_row] = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row1++;
L = L_tab[ (int) *lum++ ];
row1[0] = row1[next_row] = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row1++;
/* Now, do second row. */
L = L_tab[ (int) *lum2++ ];
row2[0] = row2[next_row] = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row2++;
L = L_tab[ (int) *lum2++ ];
row2[0] = row2[next_row] = (rgb_2_pix[ L + cr_r ] |
rgb_2_pix[ L + crb_g ] |
rgb_2_pix[ L + cb_b ]);
row2++;
}
/*
* These values are at the start of the next line, (due
* to the ++'s above),but they need to be at the start
* of the line after that.
*/
lum += cols;
lum2 += cols;
row1 += mod;
row2 += mod;
}
}
#endif /* USE_INTERLACED_VIDEO */
/* EOF */
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