Files
veejay/veejay-current/veejay-server/libvje/effects/dither.c
2015-11-08 00:28:44 +01:00

79 lines
2.3 KiB
C

/*
* Linux VeeJay
*
* Copyright(C)2002 Niels Elburg <elburg@hio.hen.nl>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License , or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307 , USA.
*/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <libvjmem/vjmem.h>
#include "dither.h"
vj_effect *dither_init(int w, int h)
{
vj_effect *ve = (vj_effect *) vj_calloc(sizeof(vj_effect));
ve->num_params = 2;
ve->defaults = (int *) vj_calloc(sizeof(int) * ve->num_params); /* default values */
ve->limits[0] = (int *) vj_calloc(sizeof(int) * ve->num_params); /* min */
ve->limits[1] = (int *) vj_calloc(sizeof(int) * ve->num_params); /* max */
ve->defaults[0] = 2;
ve->defaults[1] = 0;
ve->limits[0][0] = 2;
ve->limits[1][0] = w;
ve->limits[0][1] = 0;
ve->limits[1][1] = 1;
ve->description = "Matrix Dithering";
ve->sub_format = -1;
ve->extra_frame = 0;
ve->has_user = 0;
ve->param_description = vje_build_param_list( ve->num_params, "Mode", "Value" );
return ve;
}
static last_size = 0;
void dither_apply(VJFrame *frame, int width, int height, int size, int random_on)
{
long int w_, h_;
long int dith[size][size];
long int i, j, d, v, l, m;
uint8_t *Y = frame->data[0];
if( last_size != size || random_on ) {
for (l = 0; l < size; l++) {
for (m = 0; m < size; m++) {
dith[l][m] =
(int) ((double) (size) * rand() / (RAND_MAX + 1.0));
}
}
last_size = size;
}
for (h_ = 0; h_ < height; h_++) {
j = h_ % size;
for (w_ = 0; w_ < width; w_++) {
i = w_ % size;
d = dith[i][j] << 4;
v = ((long) Y[((h_ * width) + w_)] + d);
Y[(h_ * width) + w_] = (uint8_t) ((v >> 7) << 7);
}
}
}
void dither_free(){}