Files
veejay/veejay-current/veejay-server/libvje/effects/gamma.c
2019-09-08 15:08:29 +02:00

96 lines
2.5 KiB
C

/*
* Linux VeeJay
*
* Copyright(C)2002 Niels Elburg <nwelburg@gmail.com>
*
* 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 "common.h"
#include <veejaycore/vjmem.h>
#include "gamma.h"
typedef struct {
int gamma_flag;
uint8_t table[256];
} gamma_t;
vj_effect *gamma_init(int w, int h)
{
vj_effect *ve = (vj_effect *) vj_calloc(sizeof(vj_effect));
ve->num_params = 1;
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] = 124;
ve->limits[0][0] = 0;
ve->limits[1][0] = 500;
ve->description = "Gamma Correction";
ve->extra_frame = 0;
ve->sub_format = -1;
ve->has_user = 0;
ve->param_description = vje_build_param_list(ve->num_params, "Gamma");
ve->parallel = 1;
return ve;
}
void *gamma_malloc(int w, int h) {
gamma_t *g = (gamma_t*) vj_calloc( sizeof(gamma_t) );
if(!g) {
return NULL;
}
return (void*) g;
}
void gamma_free(void *ptr) {
gamma_t *g = (gamma_t*) ptr;
free(g);
}
static void gamma_setup(gamma_t *g, int width, int height, double gamma_value)
{
int i;
double val;
for (i = 0; i < 256; i++) {
val = i / 256.0;
val = pow(val, gamma_value);
val = 256.0 * val;
g->table[i] = val;
}
}
void gamma_apply(void *ptr, VJFrame *frame, int *args ) {
int gamma_value = args[0];
gamma_t *g = (gamma_t*) ptr;
unsigned int i;
const int len = frame->len;
uint8_t *Y = frame->data[0];
if (gamma_value != g->gamma_flag) {
gamma_setup(g, frame->width, frame->height, (double) (gamma_value / 100.0));
g->gamma_flag = gamma_value;
}
uint8_t *table = g->table;
for (i = 0; i < len; i++) {
Y[i] = (uint8_t) table[Y[i]];
}
}