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https://github.com/game-stop/veejay.git
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74 lines
2.1 KiB
C
74 lines
2.1 KiB
C
/*
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* Linux VeeJay
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*
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* Copyright(C)2002 Niels Elburg <elburg@hio.hen.nl>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License , or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307 , USA.
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*/
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#include "gamma.h"
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#include <stdlib.h>
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#include <math.h>
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static int gamma_flag = 0;
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static uint8_t table[256];
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vj_effect *gamma_init(int w, int h)
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{
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vj_effect *ve = (vj_effect *) vj_malloc(sizeof(vj_effect));
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ve->num_params = 1;
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ve->defaults = (int *) vj_malloc(sizeof(int) * ve->num_params); /* default values */
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ve->limits[0] = (int *) vj_malloc(sizeof(int) * ve->num_params); /* min */
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ve->limits[1] = (int *) vj_malloc(sizeof(int) * ve->num_params); /* max */
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ve->defaults[0] = 124;
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ve->limits[0][0] = 0;
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ve->limits[1][0] = 500;
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ve->description = "Gamma Correction";
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ve->extra_frame = 0;
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ve->sub_format = 0;
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ve->has_user = 0;
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return ve;
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}
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// FIXME private
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inline void gamma_setup(int width, int height,
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double gamma_value)
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{
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int i;
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double val;
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for (i = 0; i < 256; i++) {
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val = i / 256.0;
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val = pow(val, gamma_value);
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val = 256.0 * val;
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table[i] = val;
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}
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}
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void gamma_apply(VJFrame *frame, int width,
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int height, int gamma_value)
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{
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unsigned int i, len = frame->len;
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uint8_t *Y = frame->data[0];
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/* gamma correction YCbCr, only on luminance not on chroma */
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if (gamma_value != gamma_flag)
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gamma_setup(width, height, (double) (gamma_value / 100.0));
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for (i = 0; i < len; i++) {
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Y[i] = (uint8_t) table[Y[i]];
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}
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}
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void gamma_free(){}
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