modules/core/transition_region.c

/*
 * transition_region.c -- region transition
 * Copyright (C) 2003-2017 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 "transition_region.h"
#include "transition_composite.h"

#include <framework/mlt.h>

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

static int create_instance( mlt_transition transition, char *name, char *value, int count )
{
	// Return from this function
	int error = 0;

	// Duplicate the value
	char *type = strdup( value );

	// Pointer to filter argument
	char *arg = type == NULL ? NULL : strchr( type, ':' );

	// New filter being created
	mlt_filter filter = NULL;

	// Cleanup type and arg
	if ( arg != NULL )
		*arg ++ = '\0';

	// Create the filter
	mlt_profile profile = mlt_service_profile( MLT_TRANSITION_SERVICE( transition ) );
	if ( type )
		filter = mlt_factory_filter( profile, type, arg );

	// If we have a filter, then initialise and store it
	if ( filter != NULL )
	{
		// Properties of transition
		mlt_properties properties = MLT_TRANSITION_PROPERTIES( transition );

		// String to hold the property name
		char id[ 256 ];

		// String to hold the passdown key
		char key[ 256 ];

		// Construct id
		sprintf( id, "_filter_%d", count );

		// Counstruct key
		sprintf( key, "%s.", name );

		// Just in case, let's assume that the filter here has a composite
		//mlt_properties_set( MLT_FILTER_PROPERTIES( filter ), "composite.geometry", "0%/0%:100%x100%" );
		//mlt_properties_set_int( MLT_FILTER_PROPERTIES( filter ), "composite.fill", 1 );

		// Pass all the key properties on the filter down
		mlt_properties_pass( MLT_FILTER_PROPERTIES( filter ), properties, key );
		mlt_properties_pass_list( MLT_FILTER_PROPERTIES( filter ), properties, "in, out, length" );

		// Ensure that filter is assigned
		mlt_properties_set_data( properties, id, filter, 0, ( mlt_destructor )mlt_filter_close, NULL );
	}
	else
	{
		// Indicate that an error has occurred
		error = 1;
	}

	// Cleanup
	free( type );

	// Return error condition
	return error;
}

static uint8_t *filter_get_alpha_mask( mlt_frame frame )
{
	uint8_t *alpha = NULL;

	// Obtain properties of frame
	mlt_properties properties = MLT_FRAME_PROPERTIES( frame );

	// Get the shape frame
	mlt_frame shape_frame = mlt_properties_get_data( properties, "shape_frame", NULL );

	// Get the width and height of the image
	int region_width = mlt_properties_get_int( properties, "width" );
	int region_height = mlt_properties_get_int( properties, "height" );
	uint8_t *image = NULL;
	mlt_image_format format = mlt_image_yuv422;

	// Get the shape image to trigger alpha creation
	mlt_properties_set_int( MLT_FRAME_PROPERTIES( shape_frame ), "distort", 1 );
	mlt_frame_get_image( shape_frame, &image, &format, &region_width, &region_height, 0 );

	alpha = mlt_frame_get_alpha_mask( shape_frame );

	int size = region_width * region_height;
	uint8_t *alpha_duplicate = mlt_pool_alloc( size );

	// Generate from the Y component of the image if no alpha available
	if ( alpha == NULL )
	{
		alpha = alpha_duplicate;
		while ( size -- )
		{
			*alpha ++ = ( int )( ( ( *image ++ - 16 ) * 299 ) / 255 );
			image ++;
		}
	}
	else
	{
		memcpy( alpha_duplicate, alpha, size );
	}
	mlt_frame_set_alpha( frame, alpha_duplicate, region_width * region_height, mlt_pool_release );

	return alpha_duplicate;
}

/** Do it :-).
*/

static int transition_get_image( mlt_frame frame, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
{
	// Error we will return
	int error = 0;

	// We will get the 'b frame' from the frame stack
	mlt_frame b_frame = mlt_frame_pop_frame( frame );

	// Get the watermark transition object
	mlt_transition transition = mlt_frame_pop_service( frame );

	// Get the properties of the transition
	mlt_properties properties = MLT_TRANSITION_PROPERTIES( transition );

	// Get the properties of the a frame
	mlt_properties a_props = MLT_FRAME_PROPERTIES( frame );

	mlt_service_lock( MLT_TRANSITION_SERVICE( transition ) );

	// Get the composite from the transition
	mlt_transition composite = mlt_properties_get_data( properties, "composite", NULL );

	// Look for the first filter
	mlt_filter filter = mlt_properties_get_data( properties, "_filter_0", NULL );

	// Get the position
	mlt_position position = mlt_transition_get_position( transition, frame );

	// Create a composite if we don't have one
	if ( composite == NULL )
	{
		// Create composite via the factory
		mlt_profile profile = mlt_service_profile( MLT_TRANSITION_SERVICE( transition ) );
		composite = mlt_factory_transition( profile, "composite", NULL );

		// If we have one
		if ( composite != NULL )
		{
			// Get the properties
			mlt_properties composite_properties = MLT_TRANSITION_PROPERTIES( composite );

			// We want to ensure that we don't get a wobble...
			//mlt_properties_set_int( composite_properties, "distort", 1 );
			mlt_properties_set_int( composite_properties, "progressive", 1 );

			// Pass all the composite. properties on the transition down
			mlt_properties_pass( composite_properties, properties, "composite." );

			// Register the composite for reuse/destruction
			mlt_properties_set_data( properties, "composite", composite, 0, ( mlt_destructor )mlt_transition_close, NULL );
		}
	}
	else
	{
		// Pass all current properties down
		mlt_properties composite_properties = MLT_TRANSITION_PROPERTIES( composite );
		mlt_properties_pass( composite_properties, properties, "composite." );
	}

	// Create filters
	if ( filter == NULL )
	{
		// Loop Variable
		int i = 0;

		// Number of filters created
		int count = 0;

		// Loop for all properties
		for ( i = 0; i < mlt_properties_count( properties ); i ++ )
		{
			// Get the name of this property
			char *name = mlt_properties_get_name( properties, i );

			// If the name does not contain a . and matches filter
			if ( strchr( name, '.' ) == NULL && !strncmp( name, "filter", 6 ) )
			{
				// Get the filter constructor
				char *value = mlt_properties_get_value( properties, i );

				// Create an instance
				if ( create_instance( transition, name, value, count ) == 0 )
					count ++;
			}
		}

		// Look for the first filter again
		filter = mlt_properties_get_data( properties, "_filter_0", NULL );
	}
	else
	{
		// Pass all properties down
		mlt_filter temp = NULL;

		// Loop Variable
		int i = 0;

		// Number of filters found
		int count = 0;

		// Loop for all properties
		for ( i = 0; i < mlt_properties_count( properties ); i ++ )
		{
			// Get the name of this property
			char *name = mlt_properties_get_name( properties, i );

			// If the name does not contain a . and matches filter
			if ( strchr( name, '.' ) == NULL && !strncmp( name, "filter", 6 ) )
			{
				// Strings to hold the id and pass down key
				char id[ 256 ];
				char key[ 256 ];

				// Construct id and key
				sprintf( id, "_filter_%d", count );
				sprintf( key, "%s.", name );

				// Get the filter
				temp = mlt_properties_get_data( properties, id, NULL );

				if ( temp != NULL )
				{
					mlt_properties_pass( MLT_FILTER_PROPERTIES( temp ), properties, key );
					count ++;
				}
			}
		}
	}

	mlt_properties_set_int( a_props, "width", *width );
	mlt_properties_set_int( a_props, "height", *height );

	// Only continue if we have both filter and composite
	if ( composite != NULL )
	{
		// Get the resource of this filter (could be a shape [rectangle/circle] or an alpha provider of choice
		const char *resource =  mlt_properties_get( properties, "resource" );

		// Get the old resource in case it's changed
		char *old_resource =  mlt_properties_get( properties, "_old_resource" );

		// String to hold the filter to query on
		char id[ 256 ];

		// Index to hold the count
		int i = 0;

		// We will get the 'b frame' from the composite only if it's NULL (region filter)
		if ( b_frame == NULL )
		{
			// Copy the region
			b_frame = composite_copy_region( composite, frame, position );

			// Ensure a destructor
			char name[64];
			snprintf( name, sizeof(name), "region %s", mlt_properties_get( properties, "_unique_id" ) );
			mlt_properties_set_data( a_props, name, b_frame, 0, ( mlt_destructor )mlt_frame_close, NULL );
		}

		// Properties of the B frame
		mlt_properties b_props = MLT_FRAME_PROPERTIES( b_frame );

		// filter_only prevents copying the alpha channel of the shape to the output frame
		// by compositing filtered frame over itself
		if ( mlt_properties_get_int( properties, "filter_only" ) )
		{
			char name[64];
			snprintf( name, sizeof(name), "region %s", mlt_properties_get( properties, "_unique_id" ) );
			frame = composite_copy_region( composite, b_frame, position );
			mlt_properties_set_data( b_props, name, frame, 0, ( mlt_destructor )mlt_frame_close, NULL );
		}

		// Make sure the filter is in the correct position
		while ( filter != NULL )
		{
			// Stack this filter
			if ( mlt_properties_get_int( MLT_FILTER_PROPERTIES( filter ), "off" ) == 0 )
				mlt_filter_process( filter, b_frame );

			// Generate the key for the next
			sprintf( id, "_filter_%d", ++ i );

			// Get the next filter
			filter = mlt_properties_get_data( properties, id, NULL );
		}

		// Allow filters to be attached to a region filter
		filter = mlt_properties_get_data( properties, "_region_filter", NULL );
		if ( filter != NULL )
			mlt_service_apply_filters( MLT_FILTER_SERVICE( filter ), b_frame, 0 );

		// Hmm - this is probably going to go wrong....
		mlt_frame_set_position( frame, position );

		// Get the b frame and process with composite if successful
		mlt_transition_process( composite, frame, b_frame );

		// If we have a shape producer copy the alpha mask from the shape frame to the b_frame
		if ( strcmp( resource, "rectangle" ) != 0 )
		{
			// Get the producer from the transition
			mlt_producer producer = mlt_properties_get_data( properties, "producer", NULL );

			// If We have no producer then create one
			if ( producer == NULL || ( old_resource != NULL && strcmp( resource, old_resource ) ) )
			{
				// Get the factory producer service
				char *factory = mlt_properties_get( properties, "factory" );

				// Store the old resource
				mlt_properties_set( properties, "_old_resource", resource );

				// Special case circle resource
				if ( strcmp( resource, "circle" ) == 0 )
					resource = "pixbuf:<svg width='100' height='100'><circle cx='50' cy='50' r='50' fill='black'/></svg>";

				// Create the producer
				mlt_profile profile = mlt_service_profile( MLT_TRANSITION_SERVICE( transition ) );
				producer = mlt_factory_producer( profile, factory, resource );

				// If we have one
				if ( producer != NULL )
				{
					// Get the producer properties
					mlt_properties producer_properties = MLT_PRODUCER_PROPERTIES( producer );

					// Ensure that we loop
					mlt_properties_set( producer_properties, "eof", "loop" );

					// Now pass all producer. properties on the transition down
					mlt_properties_pass( producer_properties, properties, "producer." );

					// Register the producer for reuse/destruction
					mlt_properties_set_data( properties, "producer", producer, 0, ( mlt_destructor )mlt_producer_close, NULL );
				}
			}

			// Now use the shape producer
			if ( producer != NULL )
			{
				// We will get the alpha frame from the producer
				mlt_frame shape_frame = NULL;

				// Make sure the producer is in the correct position
				mlt_producer_seek( producer, position );

				// Get the shape frame
				if ( mlt_service_get_frame( MLT_PRODUCER_SERVICE( producer ), &shape_frame, 0 ) == 0 )
				{
					// Ensure that the shape frame will be closed
					mlt_properties_set_data( b_props, "shape_frame", shape_frame, 0, ( mlt_destructor )mlt_frame_close, NULL );

					// Specify the callback for evaluation
					b_frame->get_alpha_mask = filter_get_alpha_mask;
				}
			}
		}

		// Get the image
		error = mlt_frame_get_image( frame, image, format, width, height, 0 );
	}

	mlt_service_unlock( MLT_TRANSITION_SERVICE( transition ) );

	return error;
}

/** Filter processing.
*/

static mlt_frame transition_process( mlt_transition transition, mlt_frame a_frame, mlt_frame b_frame )
{
	// Push the transition on to the frame
	mlt_frame_push_service( a_frame, transition );

	// Push the b_frame on to the stack
	mlt_frame_push_frame( a_frame, b_frame );

	// Push the transition method
	mlt_frame_push_get_image( a_frame, transition_get_image );

	// Return the frame
	return a_frame;
}

/** Constructor for the transition.
*/

mlt_transition transition_region_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
{
	// Create a new transition
	mlt_transition transition = mlt_transition_new( );

	// Further initialisation
	if ( transition != NULL )
	{
		// Get the properties from the transition
		mlt_properties properties = MLT_TRANSITION_PROPERTIES( transition );

		// Assign the transition process method
		transition->process = transition_process;

		// Default factory
		mlt_properties_set( properties, "factory", mlt_environment( "MLT_PRODUCER" ) );

		// Resource defines the shape of the region
		mlt_properties_set( properties, "resource", arg == NULL ? "rectangle" : arg );

		// Inform apps and framework that this is a video only transition
		mlt_properties_set_int( properties, "_transition_type", 1 );
	}

	// Return the transition
	return transition;
}