/*
 * filter_grain.c -- grain filter
 * Copyright (c) 2007 Marco Gittler <g.marco@freenet.de>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <framework/mlt_filter.h>
#include <framework/mlt_frame.h>

#include <stdio.h>
#include <stdlib.h>
#include <math.h>


static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
{

	mlt_filter filter = mlt_frame_pop_service( this );
	int error = mlt_frame_get_image( this, image, format, width, height, 1 );
	
	if ( error == 0 && *image && *format == mlt_image_yuv422 )
	{
		int h = *height;
		int w = *width;

		int noise = mlt_properties_get_int( MLT_FILTER_PROPERTIES( filter ), "noise" );
		int x=0,y=0,pix=0;
		for (x=0;x<w;x++)
			for(y=0;y<h;y++){
				uint8_t* pixel=(*image+(y)*w*2+(x)*2);
				if (*pixel>20){
					pix=(*pixel)-(rand()%noise-noise);
					if (pix>0 && pix<255)
					*pixel=pix;
				}
			}
		
	}

	return error;
}

static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
{
	mlt_frame_push_service( frame, this );
	mlt_frame_push_get_image( frame, filter_get_image );
	return frame;
}

mlt_filter filter_grain_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
{
	mlt_filter this = mlt_filter_new( );
	if ( this != NULL )
	{
		this->process = filter_process;
		mlt_properties_set( MLT_FILTER_PROPERTIES( this ), "noise", "40" );
	}
	return this;
}