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

/* 
 * Linux VeeJay
 *
 * Copyright(C)2004-2015 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 <libavutil/pixdesc.h>
#include <libswscale/swscale.h>
#include "rgbkey.h"

extern int yuv_sws_get_cpu_flags();

vj_effect *rgbkey_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] = 15;	/* tolerance near */
    ve->defaults[1] = 0;	/* r */
    ve->defaults[2] = 255;	/* g */
    ve->defaults[3] = 0;	/* b */
    ve->defaults[4] = 1;	/* tolerance far */
	ve->defaults[5] = 0;    /* alpha-in operator */

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

    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] = 255;

    ve->limits[0][5] = 0;
    ve->limits[1][5] = 4; 

	ve->alpha = FLAG_ALPHA_SRC_A | FLAG_ALPHA_SRC_B | FLAG_ALPHA_OPTIONAL | FLAG_ALPHA_IN_OPERATOR;

	ve->param_description = vje_build_param_list(ve->num_params, 
			"Tolerance Near", "Red", "Green", "Blue", "Tolerance Far","Alpha-IN operator");

	ve->hints = vje_init_value_hint_list( ve->num_params );

	ve->has_user = 0;
    ve->description = "Chroma Key (RGB)";
    ve->extra_frame = 1;
    ve->sub_format = 1;
	ve->rgb_conv = 1;
    ve->parallel = 1;

	vje_build_value_hint_list( ve->hints, ve->limits[1][5],5, 
			
			"Ignore Alpha-IN", "Alpha-IN A", "Alpha-IN B", "Alpha-IN A or B", "Alpha-In A and B" );

	return ve;
}

/*
 * originally from http://gc-films.com/chromakey.html
 */
static inline double color_distance( uint8_t Cb, uint8_t Cr, int Cbk, int Crk, double dA, double dB )
{
//		double tmp = 0.0; 
//		fast_sqrt( tmp, (Cbk - Cb) * (Cbk-Cb) + (Crk - Cr) * (Crk - Cr) );

		double tmp = sqrt_table_get_pixel( (Cbk-Cb), (Crk-Cr) );
	
		if( tmp < dA ) { /* near color key == bg */
			return 0.0; /* near */
		}
		if( tmp < dB ) { /* middle region */
			return (tmp - dA)/(dB - dA); /* distance to key color */
		}
		return 1.0; /* far from color key == fg */
}

void rgbkey_apply(void *ptr, VJFrame *frame, VJFrame *frame2, int *args) {
    
    int tola = args[0];
    int r = args[1];
    int g = args[2];
    int b = args[3];
    int tolb = args[4];
    int operator = args[5];
	unsigned int pos;
	uint8_t *Y = frame->data[0];
	uint8_t *Cb = frame->data[1];
	uint8_t *Cr = frame->data[2];
	uint8_t *Y2 = frame2->data[0];
	uint8_t *Cb2= frame2->data[1];
	uint8_t *Cr2= frame2->data[2];
	uint8_t *A = frame->data[3];
	uint8_t *B = frame2->data[3];
	const int len = frame->len;
	int iy=0,iu=128,iv=128;
	uint8_t op0,op1;

	double dtola = (double) tola + 0.5f;
	double dtolb = (double) tolb + 0.5f;

	/* get key color */
	_rgb2yuv(r,g,b,iy,iu,iv);

	/* euclidean distance between key color and chroma */
	// introduces spill 
	switch( operator ) {
		case ALPHA_IGNORE:	
			//ignore alpha-in
			for (pos = len; pos != 0; pos--) {
				A[pos] = (uint8_t)( 255.0 * color_distance( Cb[pos],Cr[pos],iu,iv,dtola,dtolb ) );
			}
			break;
		case ALPHA_IN_A:
			for (pos = len; pos != 0; pos--) {
				if(A[pos] == 0)
					continue;
				A[pos] = (uint8_t)( 255.0 * color_distance( Cb[pos],Cr[pos],iu,iv,dtola,dtolb ) );
			}
			break;
		case ALPHA_IN_A_OR_B:
			for (pos = len; pos != 0; pos--) {
				if(A[pos] == 0 || B[pos] == 0)
					continue;
				A[pos] = (uint8_t)( 255.0 * color_distance( Cb[pos],Cr[pos],iu,iv,dtola,dtolb ) );
			}
			break;
		case ALPHA_IN_A_AND_B:
			for (pos = len; pos != 0; pos--) {
				if(A[pos] == 0 && B[pos] == 0)
					continue;
				A[pos] = (uint8_t)( 255.0 * color_distance( Cb[pos],Cr[pos],iu,iv,dtola,dtolb ) );
			}
			break;
		case ALPHA_IN_B:
			for (pos = len; pos != 0; pos--) {
				if(B[pos] == 0)
					continue;
				A[pos] = (uint8_t)( 255.0 * color_distance( Cb[pos],Cr[pos],iu,iv,dtola,dtolb ) );
			}
			break;
	}

	/* composite bg onto fg */
	for( pos = 0; pos < len; pos ++ ) {
		op0     = A[pos];
		op1     = 0xff - op0;
		Y[pos]  = ((op0 * Y[pos]) + (op1 * Y2[pos]))>> 8;
	    Cb[pos] = ((op0 * Cb[pos]) + (op1 * Cb2[pos]))>> 8;
		Cr[pos] = ((op0 * Cr[pos]) + (op1 * Cr2[pos]))>>8;
	}

	/* Set by color key
       Gaussblur on alpha channel
       Mixdown */

}