[melted] / src / modules / westley / producer_westley.c

/*
 * producer_westley.c -- a libxml2 parser of mlt service networks
 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
 * Author: Dan Dennedy <dan@dennedy.org>
 *
 * 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.
 */

// TODO: destroy unreferenced producers
 
#include "producer_westley.h"
#include <framework/mlt.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include <libxml/parser.h>

#define STACK_SIZE 1000

struct deserialise_context_s
{
        mlt_service stack_service[ STACK_SIZE ];
        int stack_service_size;
        int track_count;
        mlt_properties producer_map;
        mlt_properties destructors;
};
typedef struct deserialise_context_s *deserialise_context;


/** Push a service.
*/

static int context_push_service( deserialise_context this, mlt_service that )
{
        int ret = this->stack_service_size >= STACK_SIZE;
        if ( ret == 0 )
                this->stack_service[ this->stack_service_size ++ ] = that;
        return ret;
}

/** Pop a service.
*/

static mlt_service context_pop_service( deserialise_context this )
{
        mlt_service result = NULL;
        if ( this->stack_service_size > 0 )
                result = this->stack_service[ -- this->stack_service_size ];
        return result;
}

// Set the destructor on a new service
static void track_service( mlt_properties properties, void *service, mlt_destructor destructor )
{
        int registered = mlt_properties_get_int( properties, "registered" );
        char *key = mlt_properties_get( properties, "registered" );
        mlt_properties_set_data( properties, key, service, 0, destructor, NULL );
        mlt_properties_set_int( properties, "registered", ++ registered );
}

static void on_start_tractor( deserialise_context context, const xmlChar *name, const xmlChar **atts)
{
        mlt_service service = mlt_tractor_service( mlt_tractor_init() );

        track_service( context->destructors, service, (mlt_destructor) mlt_tractor_close );

        for ( ; atts != NULL && *atts != NULL; atts += 2 )
                mlt_properties_set( mlt_service_properties( service ), (char*) atts[0], (char*) atts[1] );

        context_push_service( context, service );
}

static void on_start_multitrack( deserialise_context context, const xmlChar *name, const xmlChar **atts)
{
        mlt_service service = mlt_multitrack_service( mlt_multitrack_init() );

        track_service( context->destructors, service, (mlt_destructor) mlt_multitrack_close );

        for ( ; atts != NULL && *atts != NULL; atts += 2 )
                mlt_properties_set( mlt_service_properties( service ), (char*) atts[0], (char*) atts[1] );

        context_push_service( context, service );
}

static void on_start_playlist( deserialise_context context, const xmlChar *name, const xmlChar **atts)
{
        mlt_service service = mlt_playlist_service( mlt_playlist_init() );
        mlt_properties properties = mlt_service_properties( service );

        track_service( context->destructors, service, (mlt_destructor) mlt_playlist_close );

        for ( ; atts != NULL && *atts != NULL; atts += 2 )
                mlt_properties_set( properties, (char*) atts[0], (char*) atts[1] );

        if ( mlt_properties_get( properties, "id" ) != NULL )
                mlt_properties_set_data( context->producer_map, mlt_properties_get( properties, "id" ), service, 0, NULL, NULL );

        context_push_service( context, service );
}

static void on_start_producer( deserialise_context context, const xmlChar *name, const xmlChar **atts)
{
        mlt_properties properties = mlt_properties_new();
        mlt_service service = NULL;

        for ( ; atts != NULL && *atts != NULL; atts += 2 )
                mlt_properties_set( properties, (char*) atts[0], (char*) atts[1] );

        if ( mlt_properties_get( properties, "mlt_service" ) != NULL )
        {
                service = MLT_SERVICE( mlt_factory_producer( mlt_properties_get( properties, "mlt_service" ),
                        mlt_properties_get( properties, "resource" ) ) );
        }
        else
        {
                // Unspecified producer, use inigo
                char *args[2] = { mlt_properties_get( properties, "resource" ), 0 };
                service = MLT_SERVICE( mlt_factory_producer( "inigo", args ) );
        }

        track_service( context->destructors, service, (mlt_destructor) mlt_producer_close );

        // Add the producer to the producer map 
        if ( mlt_properties_get( properties, "id" ) != NULL )
                mlt_properties_set_data( context->producer_map, mlt_properties_get( properties, "id" ), service, 0, NULL, NULL );

        mlt_properties_inherit( mlt_service_properties( service ), properties );
        mlt_properties_close( properties );

        context_push_service( context, service );
}

static void on_start_blank( deserialise_context context, const xmlChar *name, const xmlChar **atts)
{
        // Get the playlist from the stack
        mlt_service service = context_pop_service( context );
        mlt_position length = 0;

        // Look for the length attribute
        for ( ; atts != NULL && *atts != NULL; atts += 2 )
        {
                if ( strcmp( atts[0], "length" ) == 0 )
                {
                        length = atoll( atts[1] );
                        break;
                }
        }

        // Append a blank to the playlist
        mlt_playlist_blank( MLT_PLAYLIST( service ), length );

        // Push the playlist back onto the stack
        context_push_service( context, service );
}

static void on_start_entry_track( deserialise_context context, const xmlChar *name, const xmlChar **atts)
{
        // Look for the producer attribute
        for ( ; atts != NULL && *atts != NULL; atts += 2 )
        {
                if ( strcmp( atts[0], "producer" ) == 0 )
                {
                        if ( mlt_properties_get_data( context->producer_map, (char*) atts[1], NULL ) !=  NULL )
                                // Push the referenced producer onto the stack
                                context_push_service( context, MLT_SERVICE( mlt_properties_get_data( context->producer_map, (char*) atts[1], NULL ) ) );
                        break;
                }
        }
}

static void on_start_filter( deserialise_context context, const xmlChar *name, const xmlChar **atts)
{
        char *id;
        mlt_properties properties = mlt_properties_new();
        char key[11];
        key[ 10 ] = '\0';

        // Get the producer from the stack
        mlt_service producer = context_pop_service( context );

        // Set the properties
        for ( ; atts != NULL && *atts != NULL; atts += 2 )
                mlt_properties_set( properties, (char*) atts[0], (char*) atts[1] );

        // Create the filter
        mlt_service service = MLT_SERVICE( mlt_factory_filter( mlt_properties_get( properties, "mlt_service" ), NULL ) );

        track_service( context->destructors, service, (mlt_destructor) mlt_filter_close );
        
        // Connect the filter to the producer
        mlt_filter_connect( MLT_FILTER( service ), producer,
                mlt_properties_get_int( properties, "track" ) );

        // Propogate the properties
        mlt_properties_inherit( mlt_service_properties( service ), properties );
        mlt_properties_close( properties );

        // Get the parent producer from the stack
        mlt_service tractor = context_pop_service( context );

        if ( tractor != NULL )
        {
                // Connect the filter to the tractor
                if ( strcmp( mlt_properties_get( mlt_service_properties( tractor ), "resource" ), "<tractor>" ) == 0 )
                        mlt_tractor_connect( MLT_TRACTOR( tractor ), service );

                // Push the parent producer back onto the stack
                context_push_service( context, tractor );
        }

        // If a producer alias is in the producer_map, get it
        snprintf( key, 10, "%p", producer );
        if ( mlt_properties_get_data( context->producer_map, key, NULL ) != NULL )
                producer = mlt_properties_get_data( context->producer_map, key, NULL );
        
        // Put the producer in the producer map
        id = mlt_properties_get( mlt_service_properties( producer ), "id" );
        if ( id != NULL )
                mlt_properties_set_data( context->producer_map, id, service, 0, NULL, NULL );
        
        // For filter chain support, add an alias to the producer map
        snprintf( key, 10, "%p", service );
        mlt_properties_set_data( context->producer_map, key, producer, 0, NULL, NULL );

        // Push the filter onto the stack
        context_push_service( context, service );
}

static void on_start_transition( deserialise_context context, const xmlChar *name, const xmlChar **atts)
{
        mlt_properties properties = mlt_properties_new();

        // Get the producer from the stack
        mlt_service producer = context_pop_service( context );

        // Set the properties
        for ( ; atts != NULL && *atts != NULL; atts += 2 )
                mlt_properties_set( properties, (char*) atts[0], (char*) atts[1] );

        // Create the transition
        mlt_service service = MLT_SERVICE( mlt_factory_transition( mlt_properties_get( properties, "mlt_service" ), NULL ) );

        track_service( context->destructors, service, (mlt_destructor) mlt_transition_close );

        // Propogate the properties
        mlt_properties_inherit( mlt_service_properties( service ), properties );
        mlt_properties_close( properties );

        // Connect the filter to the producer
        mlt_transition_connect( MLT_TRANSITION( service ), producer,
                mlt_properties_get_int( mlt_service_properties( service ), "a_track" ),
                mlt_properties_get_int( mlt_service_properties( service ), "b_track" ) );

        // Get the tractor from the stack
        mlt_service tractor = context_pop_service( context );

        // Connect the tractor to the transition
        mlt_tractor_connect( MLT_TRACTOR( tractor ), service );

        // Push the tractor back onto the stack
        context_push_service( context, tractor );

        // Push the transition onto the stack
        context_push_service( context, service );
}

static void on_end_multitrack( deserialise_context context, const xmlChar *name )
{
        // Get the producer (multitrack) from the stack
        mlt_service producer = context_pop_service( context );

        // Get the tractor from the stack
        mlt_service service = context_pop_service( context );

        // Connect the tractor to the producer
        mlt_tractor_connect( MLT_TRACTOR( service ), producer );
        mlt_properties_set_data( mlt_service_properties( service ), "multitrack",
                MLT_MULTITRACK( producer ), 0, NULL, NULL );

        // Push the tractor back onto the stack
        context_push_service( context, service );

        // Push the producer back onto the stack
        context_push_service( context, producer );
}

static void on_end_playlist( deserialise_context context, const xmlChar *name )
{
        // Get the producer (playlist) from the stack
        mlt_service producer = context_pop_service( context );

        // Push the producer back onto the stack
        context_push_service( context, producer );
}

static void on_end_track( deserialise_context context, const xmlChar *name )
{
        // Get the producer from the stack
        mlt_service producer = context_pop_service( context );

        // Get the multitrack from the stack
        mlt_service service = context_pop_service( context );

        // Set the track on the multitrack
        mlt_multitrack_connect( MLT_MULTITRACK( service ),
                MLT_PRODUCER( producer ),
                context->track_count++ );

        // Push the multitrack back onto the stack
        context_push_service( context, service );
}

static void on_end_entry( deserialise_context context, const xmlChar *name )
{
        // Get the producer from the stack
        mlt_service producer = context_pop_service( context );

        // Get the playlist from the stack
        mlt_service service = context_pop_service( context );

        // Append the producer to the playlist
        mlt_playlist_append_io( MLT_PLAYLIST( service ),
                MLT_PRODUCER( producer ),
                mlt_properties_get_position( mlt_service_properties( producer ), "in" ),
                mlt_properties_get_position( mlt_service_properties( producer ), "out" ) );

        // Push the playlist back onto the stack
        context_push_service( context, service );
}

static void on_end_tractor( deserialise_context context, const xmlChar *name )
{
        // Discard the last producer
        mlt_producer multitrack = MLT_PRODUCER( context_pop_service( context ) );

        // Inherit the producer's properties
        mlt_properties properties = mlt_producer_properties( multitrack );
        mlt_properties_set_position( properties, "length", mlt_producer_get_out( multitrack ) + 1 );
        mlt_producer_set_in_and_out( multitrack, 0, mlt_producer_get_out( multitrack ) );
        mlt_properties_set_double( properties, "fps", mlt_producer_get_fps( multitrack ) );
}

static void on_start_element( void *ctx, const xmlChar *name, const xmlChar **atts)
{
        deserialise_context context = ( deserialise_context ) ctx;
        
        if ( strcmp( name, "tractor" ) == 0 )
                on_start_tractor( context, name, atts );
        else if ( strcmp( name, "multitrack" ) == 0 )
                on_start_multitrack( context, name, atts );
        else if ( strcmp( name, "playlist" ) == 0 )
                on_start_playlist( context, name, atts );
        else if ( strcmp( name, "producer" ) == 0 )
                on_start_producer( context, name, atts );
        else if ( strcmp( name, "blank" ) == 0 )
                on_start_blank( context, name, atts );
        else if ( strcmp( name, "entry" ) == 0 || strcmp( name, "track" ) == 0 )
                on_start_entry_track( context, name, atts );
        else if ( strcmp( name, "filter" ) == 0 )
                on_start_filter( context, name, atts );
        else if ( strcmp( name, "transition" ) == 0 )
                on_start_transition( context, name, atts );
}

static void on_end_element( void *ctx, const xmlChar *name )
{
        deserialise_context context = ( deserialise_context ) ctx;
        
        if ( strcmp( name, "multitrack" ) == 0 )
                on_end_multitrack( context, name );
        else if ( strcmp( name, "playlist" ) == 0 )
                on_end_playlist( context, name );
        else if ( strcmp( name, "track" ) == 0 )
                on_end_track( context, name );
        else if ( strcmp( name, "entry" ) == 0 )
                on_end_entry( context, name );
        else if ( strcmp( name, "tractor" ) == 0 )
                on_end_tractor( context, name );
}


mlt_producer producer_westley_init( char *filename )
{
        static int init = 0;
        xmlSAXHandler *sax = calloc( 1, sizeof( xmlSAXHandler ) );
        struct deserialise_context_s *context = calloc( 1, sizeof( struct deserialise_context_s ) );
        mlt_properties properties = NULL;
        int i = 0;

        context->producer_map = mlt_properties_new();
        context->destructors = mlt_properties_new();
        // We need to track the number of registered filters
        mlt_properties_set_int( context->destructors, "registered", 0 );
        sax->startElement = on_start_element;
        sax->endElement = on_end_element;

        if ( !init )
        {
                xmlInitParser();
                init = 1;
        }

        xmlSAXUserParseFile( sax, context, filename );
        free( sax );

        // Need the complete producer list for various reasons
        properties = context->destructors;

        // Get the last producer on the stack
        mlt_service service = context_pop_service( context );

        // Do we actually have a producer here?
        if ( service != NULL )
        {
                // Now make sure we don't have a reference to the service in the properties
                for ( i = mlt_properties_count( properties ) - 1; i >= 1; i -- )
                {
                        char *name = mlt_properties_get_name( properties, i );
                        if ( mlt_properties_get_data( properties, name, NULL ) == service )
                        {
                                mlt_properties_set_data( properties, name, service, 0, NULL, NULL );
                                break;
                        }
                }
        
                // make the returned service destroy the connected services
                mlt_properties_set_data( mlt_service_properties( service ), "__destructors__", context->destructors, 0, (mlt_destructor) mlt_properties_close, NULL );

                // Now assign additional properties
                mlt_properties_set( mlt_service_properties( service ), "resource", filename );
        }
        else
        {
                // Clean up
                mlt_properties_close( properties );
        }

        free( context->stack_service );
        mlt_properties_close( context->producer_map );
        free( context );

        return MLT_PRODUCER( service );
}