research.m1stereo.tv/gitweb/ - melted/blob - src/framework/mlt_factory.c

   1 /*
   2  * mlt_factory.c -- the factory method interfaces
   3  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include "config.h"
  22 #include "mlt.h"
  23 #include "mlt_repository.h"
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28
  29 /** Singleton repositories
  30 */
  31
  32 static char *mlt_prefix = NULL;
  33 static mlt_properties global_properties = NULL;
  34 static mlt_properties object_list = NULL;
  35 static mlt_repository producers = NULL;
  36 static mlt_repository filters = NULL;
  37 static mlt_repository transitions = NULL;
  38 static mlt_repository consumers = NULL;
  39 static mlt_properties event_object = NULL;
  40 static int unique_id = 0;
  41
  42 /** Event transmitters.
  43 */
  44
  45 static void mlt_factory_create_request( mlt_listener listener, mlt_properties owner, mlt_service this, void **args )
  46 {
  47         if ( listener != NULL )
  48                 listener( owner, this, ( char * )args[ 0 ], ( char * )args[ 1 ], ( mlt_service * )args[ 2 ] );
  49 }
  50
  51 static void mlt_factory_create_done( mlt_listener listener, mlt_properties owner, mlt_service this, void **args )
  52 {
  53         if ( listener != NULL )
  54                 listener( owner, this, ( char * )args[ 0 ], ( char * )args[ 1 ], ( mlt_service )args[ 2 ] );
  55 }
  56
  57 /** Construct the factories.
  58 */
  59
  60 int mlt_factory_init( const char *prefix )
  61 {
  62         // Only initialise once
  63         if ( mlt_prefix == NULL )
  64         {
  65                 // Allow user over rides
  66                 if ( prefix == NULL || !strcmp( prefix, "" ) )
  67                         prefix = getenv( "MLT_REPOSITORY" );
  68
  69                 // If no directory is specified, default to install directory
  70                 if ( prefix == NULL )
  71                         prefix = PREFIX_DATA;
  72
  73                 // Store the prefix for later retrieval
  74                 mlt_prefix = strdup( prefix );
  75
  76                 // Initialise the pool
  77                 mlt_pool_init( );
  78
  79                 // Create and set up the events object
  80                 event_object = mlt_properties_new( );
  81                 mlt_events_init( event_object );
  82                 mlt_events_register( event_object, "producer-create-request", ( mlt_transmitter )mlt_factory_create_request );
  83                 mlt_events_register( event_object, "producer-create-done", ( mlt_transmitter )mlt_factory_create_done );
  84                 mlt_events_register( event_object, "filter-create-request", ( mlt_transmitter )mlt_factory_create_request );
  85                 mlt_events_register( event_object, "filter-create-done", ( mlt_transmitter )mlt_factory_create_done );
  86                 mlt_events_register( event_object, "transition-create-request", ( mlt_transmitter )mlt_factory_create_request );
  87                 mlt_events_register( event_object, "transition-create-done", ( mlt_transmitter )mlt_factory_create_done );
  88                 mlt_events_register( event_object, "consumer-create-request", ( mlt_transmitter )mlt_factory_create_request );
  89                 mlt_events_register( event_object, "consumer-create-done", ( mlt_transmitter )mlt_factory_create_done );
  90
  91                 // Create the global properties
  92                 global_properties = mlt_properties_new( );
  93
  94                 // Create the object list.
  95                 object_list = mlt_properties_new( );
  96
  97                 // Create a repository for each service type
  98                 producers = mlt_repository_init( object_list, prefix, "producers", "mlt_create_producer" );
  99                 filters = mlt_repository_init( object_list, prefix, "filters", "mlt_create_filter" );
 100                 transitions = mlt_repository_init( object_list, prefix, "transitions", "mlt_create_transition" );
 101                 consumers = mlt_repository_init( object_list, prefix, "consumers", "mlt_create_consumer" );
 102
 103                 // Force a clean up when app closes
 104                 atexit( mlt_factory_close );
 105         }
 106
 107         // Allow property refresh on a subsequent initialisation
 108         if ( global_properties != NULL )
 109         {
 110                 mlt_properties_set_or_default( global_properties, "MLT_NORMALISATION", getenv( "MLT_NORMALISATION" ), "PAL" );
 111                 mlt_properties_set_or_default( global_properties, "MLT_PRODUCER", getenv( "MLT_PRODUCER" ), "fezzik" );
 112                 mlt_properties_set_or_default( global_properties, "MLT_CONSUMER", getenv( "MLT_CONSUMER" ), "sdl" );
 113                 mlt_properties_set( global_properties, "MLT_TEST_CARD", getenv( "MLT_TEST_CARD" ) );
 114         }
 115
 116         return 0;
 117 }
 118
 119 /** Fetch the events object.
 120 */
 121
 122 mlt_properties mlt_factory_event_object( )
 123 {
 124         return event_object;
 125 }
 126
 127 /** Fetch the prefix used in this instance.
 128 */
 129
 130 const char *mlt_factory_prefix( )
 131 {
 132         return mlt_prefix;
 133 }
 134
 135 /** Get a value from the environment.
 136 */
 137
 138 char *mlt_environment( const char *name )
 139 {
 140         return mlt_properties_get( global_properties, name );
 141 }
 142
 143 /** Fetch a producer from the repository.
 144 */
 145
 146 mlt_producer mlt_factory_producer( const char *service, void *input )
 147 {
 148         mlt_producer obj = NULL;
 149
 150         // Pick up the default normalising producer if necessary
 151         if ( service == NULL )
 152                 service = mlt_environment( "MLT_PRODUCER" );
 153
 154         // Offer the application the chance to 'create'
 155         mlt_events_fire( event_object, "producer-create-request", service, input, &obj, NULL );
 156
 157         // Try to instantiate via the specified service
 158         if ( obj == NULL )
 159         {
 160                 obj = mlt_repository_fetch( producers, service, input );
 161                 mlt_events_fire( event_object, "producer-create-done", service, input, obj, NULL );
 162                 if ( obj != NULL )
 163                 {
 164                         mlt_properties properties = MLT_PRODUCER_PROPERTIES( obj );
 165                         mlt_properties_set_int( properties, "_unique_id", ++ unique_id );
 166                         mlt_properties_set( properties, "mlt_type", "producer" );
 167                         if ( mlt_properties_get_int( properties, "_mlt_service_hidden" ) == 0 )
 168                                 mlt_properties_set( properties, "mlt_service", service );
 169                 }
 170         }
 171         return obj;
 172 }
 173
 174 /** Fetch a filter from the repository.
 175 */
 176
 177 mlt_filter mlt_factory_filter( const char *service, void *input )
 178 {
 179         mlt_filter obj = NULL;
 180
 181         // Offer the application the chance to 'create'
 182         mlt_events_fire( event_object, "filter-create-request", service, input, &obj, NULL );
 183
 184         if ( obj == NULL )
 185         {
 186                 obj = mlt_repository_fetch( filters, service, input );
 187                 mlt_events_fire( event_object, "filter-create-done", service, input, obj, NULL );
 188         }
 189
 190         if ( obj != NULL )
 191         {
 192                 mlt_properties properties = MLT_FILTER_PROPERTIES( obj );
 193                 mlt_properties_set_int( properties, "_unique_id", ++ unique_id );
 194                 mlt_properties_set( properties, "mlt_type", "filter" );
 195                 mlt_properties_set( properties, "mlt_service", service );
 196         }
 197         return obj;
 198 }
 199
 200 /** Fetch a transition from the repository.
 201 */
 202
 203 mlt_transition mlt_factory_transition( const char *service, void *input )
 204 {
 205         mlt_transition obj = NULL;
 206
 207         // Offer the application the chance to 'create'
 208         mlt_events_fire( event_object, "transition-create-request", service, input, &obj, NULL );
 209
 210         if ( obj == NULL )
 211         {
 212                 obj = mlt_repository_fetch( transitions, service, input );
 213                 mlt_events_fire( event_object, "transition-create-done", service, input, obj, NULL );
 214         }
 215
 216         if ( obj != NULL )
 217         {
 218                 mlt_properties properties = MLT_TRANSITION_PROPERTIES( obj );
 219                 mlt_properties_set_int( properties, "_unique_id", ++ unique_id );
 220                 mlt_properties_set( properties, "mlt_type", "transition" );
 221                 mlt_properties_set( properties, "mlt_service", service );
 222         }
 223         return obj;
 224 }
 225
 226 /** Fetch a consumer from the repository
 227 */
 228
 229 mlt_consumer mlt_factory_consumer( const char *service, void *input )
 230 {
 231         mlt_consumer obj = NULL;
 232
 233         if ( service == NULL )
 234                 service = mlt_environment( "MLT_CONSUMER" );
 235
 236         // Offer the application the chance to 'create'
 237         mlt_events_fire( event_object, "consumer-create-request", service, input, &obj, NULL );
 238
 239         if ( obj == NULL )
 240         {
 241                 obj = mlt_repository_fetch( consumers, service, input );
 242                 mlt_events_fire( event_object, "consumer-create-done", service, input, obj, NULL );
 243         }
 244
 245         if ( obj != NULL )
 246         {
 247                 mlt_filter filter = mlt_factory_filter( "data_show", NULL );
 248                 mlt_properties properties = MLT_CONSUMER_PROPERTIES( obj );
 249                 mlt_properties_set_int( properties, "_unique_id", ++ unique_id );
 250                 mlt_properties_set( properties, "mlt_type", "consumer" );
 251                 mlt_properties_set( properties, "mlt_service", service );
 252                 mlt_service_attach( MLT_CONSUMER_SERVICE( obj ), filter );
 253                 mlt_filter_close( filter );
 254         }
 255         return obj;
 256 }
 257
 258 /** Register an object for clean up.
 259 */
 260
 261 void mlt_factory_register_for_clean_up( void *ptr, mlt_destructor destructor )
 262 {
 263         char unique[ 256 ];
 264         sprintf( unique, "%08d", mlt_properties_count( global_properties ) );
 265         mlt_properties_set_data( global_properties, unique, ptr, 0, destructor, NULL );
 266 }
 267
 268 /** Close the factory.
 269 */
 270
 271 void mlt_factory_close( )
 272 {
 273         if ( mlt_prefix != NULL )
 274         {
 275                 mlt_properties_close( event_object );
 276                 mlt_repository_close( producers );
 277                 mlt_repository_close( filters );
 278                 mlt_repository_close( transitions );
 279                 mlt_repository_close( consumers );
 280                 mlt_properties_close( global_properties );
 281                 mlt_properties_close( object_list );
 282                 free( mlt_prefix );
 283                 mlt_prefix = NULL;
 284                 mlt_pool_close( );
 285         }
 286 }
 287