mlt/src/framework/mlt_factory.c

/*
 * mlt_factory.c -- the factory method interfaces
 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
 * Author: Charles Yates <charles.yates@pandora.be>
 *
 * 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 "config.h"
#include "mlt.h"
#include "mlt_repository.h"

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

/** Singleton repositories
*/

static char *mlt_prefix = NULL;
static mlt_properties global_properties = NULL;
static mlt_properties object_list = NULL;
static mlt_repository producers = NULL;
static mlt_repository filters = NULL;
static mlt_repository transitions = NULL;
static mlt_repository consumers = NULL;
static mlt_properties event_object = NULL;
static int unique_id = 0;

/** Event transmitters.
*/

static void mlt_factory_create_request( mlt_listener listener, mlt_properties owner, mlt_service this, void **args )
{
	if ( listener != NULL )
		listener( owner, this, ( char * )args[ 0 ], ( char * )args[ 1 ], ( mlt_service * )args[ 2 ] );
}

static void mlt_factory_create_done( mlt_listener listener, mlt_properties owner, mlt_service this, void **args )
{
	if ( listener != NULL )
		listener( owner, this, ( char * )args[ 0 ], ( char * )args[ 1 ], ( mlt_service )args[ 2 ] );
}

/** Construct the factories.
*/

int mlt_factory_init( const char *prefix )
{
	// Only initialise once
	if ( mlt_prefix == NULL )
	{
		// Allow user over rides
		if ( prefix == NULL || !strcmp( prefix, "" ) )
			prefix = getenv( "MLT_REPOSITORY" );

		// If no directory is specified, default to install directory
		if ( prefix == NULL )
			prefix = PREFIX_DATA;

		// Store the prefix for later retrieval
		mlt_prefix = strdup( prefix );

		// Initialise the pool
		mlt_pool_init( );

		// Create and set up the events object
		event_object = mlt_properties_new( );
		mlt_events_init( event_object );
		mlt_events_register( event_object, "producer-create-request", ( mlt_transmitter )mlt_factory_create_request );
		mlt_events_register( event_object, "producer-create-done", ( mlt_transmitter )mlt_factory_create_done );
		mlt_events_register( event_object, "filter-create-request", ( mlt_transmitter )mlt_factory_create_request );
		mlt_events_register( event_object, "filter-create-done", ( mlt_transmitter )mlt_factory_create_done );
		mlt_events_register( event_object, "transition-create-request", ( mlt_transmitter )mlt_factory_create_request );
		mlt_events_register( event_object, "transition-create-done", ( mlt_transmitter )mlt_factory_create_done );
		mlt_events_register( event_object, "consumer-create-request", ( mlt_transmitter )mlt_factory_create_request );
		mlt_events_register( event_object, "consumer-create-done", ( mlt_transmitter )mlt_factory_create_done );

		// Create the global properties
		global_properties = mlt_properties_new( );

		// Create the object list.
		object_list = mlt_properties_new( );

		// Create a repository for each service type
		producers = mlt_repository_init( object_list, prefix, "producers", "mlt_create_producer" );
		filters = mlt_repository_init( object_list, prefix, "filters", "mlt_create_filter" );
		transitions = mlt_repository_init( object_list, prefix, "transitions", "mlt_create_transition" );
		consumers = mlt_repository_init( object_list, prefix, "consumers", "mlt_create_consumer" );

		// Force a clean up when app closes
		atexit( mlt_factory_close );
	}

	// Allow property refresh on a subsequent initialisation
	if ( global_properties != NULL )
	{
		mlt_properties_set_or_default( global_properties, "MLT_NORMALISATION", getenv( "MLT_NORMALISATION" ), "PAL" );
		mlt_properties_set_or_default( global_properties, "MLT_PRODUCER", getenv( "MLT_PRODUCER" ), "fezzik" );
		mlt_properties_set_or_default( global_properties, "MLT_CONSUMER", getenv( "MLT_CONSUMER" ), "sdl" );
		mlt_properties_set( global_properties, "MLT_TEST_CARD", getenv( "MLT_TEST_CARD" ) );
		mlt_properties_set_or_default( global_properties, "MLT_PROFILE", getenv( "MLT_PROFILE" ), "dv_pal" );

		// Load the most appropriate profile
		// MLT_PROFILE preferred
		if ( getenv( "MLT_PROFILE" ) )
			mlt_profile_select( mlt_environment( "MLT_PROFILE" ) );
		// MLT_NORMALISATION backwards compatibility
		else if ( strcmp( mlt_environment( "MLT_NORMALISATION" ), "PAL" ) )
			mlt_profile_select( "dv_ntsc" );
		else
			mlt_profile_select( "dv_pal" );
	}


	return 0;
}

/** Fetch the events object.
*/

mlt_properties mlt_factory_event_object( )
{
	return event_object;
}

/** Fetch the prefix used in this instance.
*/

const char *mlt_factory_prefix( )
{
	return mlt_prefix;
}

/** Get a value from the environment.
*/

char *mlt_environment( const char *name )
{
	return mlt_properties_get( global_properties, name );
}

/** Set a value in the environment.
*/

int mlt_environment_set( const char *name, const char *value )
{
	return mlt_properties_set( global_properties, name, value );
}

/** Fetch a producer from the repository.
*/

mlt_producer mlt_factory_producer( const char *service, void *input )
{
	mlt_producer obj = NULL;

	// Pick up the default normalising producer if necessary
	if ( service == NULL )
		service = mlt_environment( "MLT_PRODUCER" );

	// Offer the application the chance to 'create'
	mlt_events_fire( event_object, "producer-create-request", service, input, &obj, NULL );

	// Try to instantiate via the specified service
	if ( obj == NULL )
	{
		obj = mlt_repository_fetch( producers, service, input );
		mlt_events_fire( event_object, "producer-create-done", service, input, obj, NULL );
		if ( obj != NULL )
		{
			mlt_properties properties = MLT_PRODUCER_PROPERTIES( obj );
			mlt_properties_set_int( properties, "_unique_id", ++ unique_id );
			mlt_properties_set( properties, "mlt_type", "producer" );
			if ( mlt_properties_get_int( properties, "_mlt_service_hidden" ) == 0 )
				mlt_properties_set( properties, "mlt_service", service );
		}
	}
	return obj;
}

/** Fetch a filter from the repository.
*/

mlt_filter mlt_factory_filter( const char *service, void *input )
{
	mlt_filter obj = NULL;

	// Offer the application the chance to 'create'
	mlt_events_fire( event_object, "filter-create-request", service, input, &obj, NULL );

	if ( obj == NULL )
	{
   		obj = mlt_repository_fetch( filters, service, input );
		mlt_events_fire( event_object, "filter-create-done", service, input, obj, NULL );
	}

	if ( obj != NULL )
	{
		mlt_properties properties = MLT_FILTER_PROPERTIES( obj );
		mlt_properties_set_int( properties, "_unique_id", ++ unique_id );
		mlt_properties_set( properties, "mlt_type", "filter" );
		mlt_properties_set( properties, "mlt_service", service );
	}
	return obj;
}

/** Fetch a transition from the repository.
*/

mlt_transition mlt_factory_transition( const char *service, void *input )
{
	mlt_transition obj = NULL;

	// Offer the application the chance to 'create'
	mlt_events_fire( event_object, "transition-create-request", service, input, &obj, NULL );

	if ( obj == NULL )
	{
   		obj = mlt_repository_fetch( transitions, service, input );
		mlt_events_fire( event_object, "transition-create-done", service, input, obj, NULL );
	}

	if ( obj != NULL )
	{
		mlt_properties properties = MLT_TRANSITION_PROPERTIES( obj );
		mlt_properties_set_int( properties, "_unique_id", ++ unique_id );
		mlt_properties_set( properties, "mlt_type", "transition" );
		mlt_properties_set( properties, "mlt_service", service );
	}
	return obj;
}

/** Fetch a consumer from the repository
*/

mlt_consumer mlt_factory_consumer( const char *service, void *input )
{
	mlt_consumer obj = NULL;

	if ( service == NULL )
		service = mlt_environment( "MLT_CONSUMER" );

	// Offer the application the chance to 'create'
	mlt_events_fire( event_object, "consumer-create-request", service, input, &obj, NULL );

	if ( obj == NULL )
	{
		obj = mlt_repository_fetch( consumers, service, input );
		mlt_events_fire( event_object, "consumer-create-done", service, input, obj, NULL );
	}

	if ( obj != NULL )
	{
		mlt_properties properties = MLT_CONSUMER_PROPERTIES( obj );
		mlt_properties_set_int( properties, "_unique_id", ++ unique_id );
		mlt_properties_set( properties, "mlt_type", "consumer" );
		mlt_properties_set( properties, "mlt_service", service );
	}
	return obj;
}

/** Register an object for clean up.
*/

void mlt_factory_register_for_clean_up( void *ptr, mlt_destructor destructor )
{
	char unique[ 256 ];
	sprintf( unique, "%08d", mlt_properties_count( global_properties ) );
	mlt_properties_set_data( global_properties, unique, ptr, 0, destructor, NULL );
}

/** Close the factory.
*/

void mlt_factory_close( )
{
	if ( mlt_prefix != NULL )
	{
		mlt_properties_close( event_object );
		mlt_repository_close( producers );
		mlt_repository_close( filters );
		mlt_repository_close( transitions );
		mlt_repository_close( consumers );
		mlt_properties_close( global_properties );
		mlt_properties_close( object_list );
		free( mlt_prefix );
		mlt_prefix = NULL;
		mlt_pool_close( );
		mlt_profile_close();
	}
}