/*
 * filter_affine.c -- affine filter
 * Copyright (C) 2003-2020 Meltytech, LLC
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

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

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

#define MLT_AFFINE_COUNT_PROPERTY "filter_affine.count"

/** Do it :-).
*/

static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
{
	// Get the filter
	mlt_filter filter = mlt_frame_pop_service( frame );

	// Get the properties
	mlt_properties properties = MLT_FILTER_PROPERTIES( filter );

	// Get the image
	int error = 0;
	*format = mlt_image_rgb24a;

	mlt_service_lock( MLT_FILTER_SERVICE( filter ) );
	mlt_producer producer = mlt_properties_get_data( properties, "producer", NULL );
	mlt_transition transition = mlt_properties_get_data( properties, "transition", NULL );
	mlt_frame a_frame = NULL;
	mlt_profile profile = mlt_service_profile( MLT_FILTER_SERVICE( filter ) );
	char *background = mlt_properties_get( properties, "background" );
	char *previous = mlt_properties_get( properties, "_background" );

	if ( producer == NULL || (background && previous && strcmp(background, previous)) )
	{
		producer = mlt_factory_producer( profile, NULL, background );
		mlt_properties_set_data( properties, "producer", producer, 0, (mlt_destructor)mlt_producer_close, NULL );
		mlt_properties_set(properties, "_background", background);
	}

	if ( transition == NULL )
	{
		transition = mlt_factory_transition( profile, "affine", NULL );
		mlt_properties_set_data( properties, "transition", transition, 0, (mlt_destructor)mlt_transition_close, NULL );
		if ( transition )
			mlt_properties_set_int( MLT_TRANSITION_PROPERTIES( transition ), "b_alpha", 1 );
	}

	if ( producer != NULL && transition != NULL )
	{
		mlt_position position = mlt_filter_get_position( filter, frame );
		mlt_properties frame_properties = MLT_FRAME_PROPERTIES( frame );
		mlt_position in = mlt_filter_get_in( filter );
		mlt_position out = mlt_filter_get_out( filter );
		double consumer_ar = mlt_profile_sar( profile );
		mlt_transition_set_in_and_out( transition, in, out );
		if ( out > 0 ) {
			mlt_properties_set_position( MLT_PRODUCER_PROPERTIES( producer ), "length", out - in + 1 );
			mlt_producer_set_in_and_out( producer, in, out );
		}
		mlt_producer_seek( producer, in + position );
		mlt_properties_pass( MLT_PRODUCER_PROPERTIES( producer ), properties, "producer." );
		mlt_properties_pass( MLT_TRANSITION_PROPERTIES( transition ), properties, "transition." );
		mlt_service_get_frame( MLT_PRODUCER_SERVICE( producer ), &a_frame, 0 );
		mlt_frame_set_position( a_frame, in + position );

		// Set the rescale interpolation to match the frame
		mlt_properties_set( MLT_FRAME_PROPERTIES( a_frame ), "rescale.interp", mlt_properties_get( frame_properties, "rescale.interp" ) );

		// Special case - aspect_ratio = 0
		if ( mlt_frame_get_aspect_ratio( frame ) == 0 )
			mlt_frame_set_aspect_ratio( frame, consumer_ar );
		if ( mlt_frame_get_aspect_ratio( a_frame ) == 0 )
			mlt_frame_set_aspect_ratio( a_frame, consumer_ar );

		// Add the affine transition onto the frame stack
		mlt_transition_process( transition, a_frame, frame );

		if ( mlt_properties_get_int( properties, "use_normalised" ) )
		{
			// Use the normalised width & height
			mlt_profile profile = mlt_service_profile( MLT_FILTER_SERVICE( filter ) );
			*width = profile->width;
			*height = profile->height;
		}

		// Prescale the image before applying affine filters if more than 1
		if (mlt_properties_get_int(frame_properties, MLT_AFFINE_COUNT_PROPERTY) > 1) {
			mlt_properties_set_int(frame_properties, "always_scale", 1);
		}

		mlt_frame_get_image( a_frame, image, format, width, height, writable );
		mlt_properties_set_data( frame_properties, "affine_frame", a_frame, 0, (mlt_destructor)mlt_frame_close, NULL );
		mlt_frame_set_image( frame, *image, *width * *height * 4, NULL );
		mlt_frame_set_alpha( frame, mlt_frame_get_alpha_mask( a_frame ), *width * *height, NULL );
		mlt_service_unlock( MLT_FILTER_SERVICE( filter ) );
	}
	else
	{
		mlt_service_unlock( MLT_FILTER_SERVICE( filter ) );
	}

	return error;
}

/** Filter processing.
*/

static mlt_frame filter_process( mlt_filter filter, mlt_frame frame )
{
	// Push the frame filter
	mlt_frame_push_service( frame, filter );
	mlt_frame_push_get_image( frame, filter_get_image );

	// Count the number of affine filters on this frame
	if (mlt_properties_get_int(MLT_FRAME_PROPERTIES(frame), MLT_AFFINE_COUNT_PROPERTY)) {
		int count = mlt_properties_get_int(MLT_FRAME_PROPERTIES(frame), MLT_AFFINE_COUNT_PROPERTY);
		mlt_properties_set_int(MLT_FRAME_PROPERTIES(frame), MLT_AFFINE_COUNT_PROPERTY, count + 1);
	} else {
		mlt_properties_set_int(MLT_FRAME_PROPERTIES(frame), MLT_AFFINE_COUNT_PROPERTY, 1);
	}

	return frame;
}

/** Constructor for the filter.
*/

mlt_filter filter_affine_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
{
	mlt_filter filter = mlt_filter_new( );
	if ( filter != NULL )
	{
		filter->process = filter_process;
		mlt_properties_set( MLT_FILTER_PROPERTIES( filter ), "background", arg ? arg : "colour:0" );
	}
	return filter;
}


