veejay/veejay-current/veejay-server/libvje/effects/alphaselect.c

/* 
 * Linux VeeJay
 *
 * Copyright(C)2015 Niels Elburg <nelburg@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.
 */

/*
 * derived from greyselect.c
 */

#include "common.h"
#include <veejaycore/vjmem.h>
#include "alphaselect.h"

vj_effect *alphaselect_init(int w, int h)
{
	vj_effect *ve;
	ve = (vj_effect *) vj_calloc(sizeof(vj_effect));
	ve->num_params = 6;
	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] = 4500;	/* angle */
	ve->defaults[1] = 255;	/* r */
	ve->defaults[2] = 0;	/* g */
	ve->defaults[3] = 0;	/* b */
	ve->defaults[4] = 0;	/* swap */
	ve->defaults[5] = 0;	/* to alpha */

	ve->limits[0][0] = 1;
	ve->limits[1][0] = 9000;

	ve->limits[0][1] = 0;
	ve->limits[1][1] = 255;

	ve->limits[0][2] = 0;
	ve->limits[1][2] = 255;

	ve->limits[0][3] = 0;
	ve->limits[1][3] = 255;

	ve->limits[0][4] = 0;
	ve->limits[1][4] = 1;

	ve->limits[0][5] = 0;
	ve->limits[1][5] = 1;

	ve->has_user = 0;
	ve->parallel = 1;
	ve->description = "Alpha: Set by chroma key";
	ve->extra_frame = 0;
	ve->sub_format = 1;
	ve->rgb_conv = 1;

	ve->alpha = FLAG_ALPHA_OUT | FLAG_ALPHA_OPTIONAL | FLAG_ALPHA_SRC_A;

	ve->param_description = vje_build_param_list(ve->num_params,"Angle","Red","Green","Blue", "Invert", "To Alpha");

	return ve;
}

void alphaselect_apply(void *ptr, VJFrame *frame, int *args) {
    int i_angle = args[0];
    int r = args[1];
    int g = args[2];
    int b = args[3];
    int swap = args[4];

    uint8_t *fg_cb, *fg_cr;
    int accept_angle_tg;
    int cb, cr;
    float kg1, tmp, aa = 255.0f, bb = 255.0f;
    float angle = (float) i_angle / 100.0f;
    unsigned int pos;
    uint8_t val;
	const int len = frame->len;
	uint8_t *Y = frame->data[0];
	uint8_t *Cb = frame->data[1];
	uint8_t *Cr = frame->data[2];
	uint8_t *A  = frame->data[3];
	int iy=0,iu=128,iv=128;
	
	_rgb2yuv(r,g,b,iy,iu,iv);
	aa = (float) iu;
	bb = (float) iv;

    tmp = sqrt(((aa * aa) + (bb * bb)));
    cb = 255 * (aa / tmp);
    cr = 255 * (bb / tmp);
    kg1 = tmp;
   
    /* obtain coordinate system for cb / cr */
    accept_angle_tg = (int)( 15.0f * tanf(M_PI * angle / 180.0f));
	
    /* intialize pointers */
    fg_cb = Cb;
    fg_cr = Cr;

	if( swap == 0 ) {
		for (pos = len; pos != 0; pos--) {
			short xx, yy;
			xx = (((fg_cb[pos]) * cb) + ((fg_cr[pos]) * cr)) >> 7;
			yy = (((fg_cr[pos]) * cb) - ((fg_cb[pos]) * cr)) >> 7;

			val = (xx * accept_angle_tg) >> 4;
			if(A[pos] == 0 )
				continue;

			if (abs(yy) > val) {
				A[pos] = 0;
				Y[pos] = pixel_Y_lo_;
				Cb[pos] = 128;
				Cr[pos] = 128;
			} else {
				A[pos] = val;
			}
		}
	}
	else {
		for (pos = len; pos != 0; pos--) {
			short xx, yy;
			xx = (((fg_cb[pos]) * cb) + ((fg_cr[pos]) * cr)) >> 7;
			yy = (((fg_cr[pos]) * cb) - ((fg_cb[pos]) * cr)) >> 7;
			val = (xx * accept_angle_tg) >> 4;
			if( A[pos] == 0 )
				continue;

			if (abs(yy) <= val) {
				A[pos] = 0;
				Y[pos] = pixel_Y_lo_;
				Cb[pos] = 128;
				Cr[pos] = 128;
			}
			else {
				A[pos] = val;
			}
		}
	}
}