Adding the mix part 1

[melted] / src / framework / mlt_field.c

/*
 * mlt_field.c -- A field for planting multiple transitions and filters
 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
 * Author: Charles Yates <charles.yates@pandora.be>
 *
 * 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 "mlt_field.h"
#include "mlt_service.h"
#include "mlt_filter.h"
#include "mlt_transition.h"
#include "mlt_multitrack.h"
#include "mlt_tractor.h"

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

/** Private structures.
*/

struct mlt_field_s
{
        // This is the producer we're connected to
        mlt_service producer;

        // Multitrack
        mlt_multitrack multitrack;

        // Tractor
        mlt_tractor tractor;
};

/** Constructor.
        
        We construct a multitrack and a tractor here.
*/

mlt_field mlt_field_init( )
{
        // Initialise the field
        mlt_field this = calloc( sizeof( struct mlt_field_s ), 1 );

        // Initialise it
        if ( this != NULL )
        {
                // Construct a multitrack
                this->multitrack = mlt_multitrack_init( );

                // Construct a tractor
                this->tractor = mlt_tractor_init( );

                // The first plant will be connected to the mulitrack
                this->producer = mlt_multitrack_service( this->multitrack );

                // Connect the tractor to the multitrack
                mlt_tractor_connect( this->tractor, this->producer );
        }

        // Return this
        return this;
}

mlt_field mlt_field_new( mlt_multitrack multitrack, mlt_tractor tractor )
{
        // Initialise the field
        mlt_field this = calloc( sizeof( struct mlt_field_s ), 1 );

        // Initialise it
        if ( this != NULL )
        {
                // Construct a multitrack
                this->multitrack = multitrack;

                // Construct a tractor
                this->tractor = tractor;

                // The first plant will be connected to the mulitrack
                this->producer = mlt_multitrack_service( this->multitrack );

                // Connect the tractor to the multitrack
                mlt_tractor_connect( this->tractor, this->producer );
        }

        // Return this
        return this;
}

/** Get the service associated to this field.
*/

mlt_service mlt_field_service( mlt_field this )
{
        return this != NULL ? mlt_tractor_service( this->tractor ) : NULL;
}

/** Get the multi track.
*/

mlt_multitrack mlt_field_multitrack( mlt_field this )
{
        return this != NULL ? this->multitrack : NULL;
}

/** Get the tractor.
*/

mlt_tractor mlt_field_tractor( mlt_field this )
{
        return this != NULL ? this->tractor : NULL;
}

/** Get the properties associated to this field.
*/

mlt_properties mlt_field_properties( mlt_field this )
{
        return mlt_service_properties( mlt_field_service( this ) );
}

/** Plant a filter.
*/

int mlt_field_plant_filter( mlt_field this, mlt_filter that, int track )
{
        // Connect the filter to the last producer
        int result = mlt_filter_connect( that, this->producer, track );

        // If sucessful, then we'll use this for connecting in the future
        if ( result == 0 )
        {
                // This is now the new producer
                this->producer = mlt_filter_service( that );

                // Reconnect tractor to new producer
                mlt_tractor_connect( this->tractor, this->producer );

                // Fire an event
                mlt_events_fire( mlt_field_properties( this ), "service-changed", NULL );
        }

        return result;
}

/** Plant a transition.
*/

int mlt_field_plant_transition( mlt_field this, mlt_transition that, int a_track, int b_track )
{
        // Connect the transition to the last producer
        int result = mlt_transition_connect( that, this->producer, a_track, b_track );

        // If sucessful, then we'll use this for connecting in the future
        if ( result == 0 )
        {
                // This is now the new producer
                this->producer = mlt_transition_service( that );

                // Reconnect tractor to new producer
                mlt_tractor_connect( this->tractor, this->producer );

                // Fire an event
                mlt_events_fire( mlt_field_properties( this ), "service-changed", NULL );
        }

        return 0;
}

/** Close the field.
*/

void mlt_field_close( mlt_field this )
{
        if ( this != NULL && mlt_properties_dec_ref( mlt_field_properties( this ) ) <= 0 )
        {
                //mlt_tractor_close( this->tractor );
                //mlt_multitrack_close( this->multitrack );
                free( this );
        }
}