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 library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "mlt.h"
  22 #include "mlt_repository.h"
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #define PREFIX_LIB LIBDIR "/mlt"
  29 #define PREFIX_DATA PREFIX "/share/mlt"
  30
  31 /** Singleton repositories
  32 */
  33
  34 static char *mlt_prefix = NULL;
  35 static mlt_properties global_properties = NULL;
  36 static mlt_properties object_list = NULL;
  37 static mlt_repository producers = NULL;
  38 static mlt_repository filters = NULL;
  39 static mlt_repository transitions = NULL;
  40 static mlt_repository consumers = NULL;
  41 static mlt_properties event_object = NULL;
  42 static int unique_id = 0;
  43
  44 /** Event transmitters.
  45 */
  46
  47 static void mlt_factory_create_request( mlt_listener listener, mlt_properties owner, mlt_service this, void **args )
  48 {
  49         if ( listener != NULL )
  50                 listener( owner, this, ( char * )args[ 0 ], ( char * )args[ 1 ], ( mlt_service * )args[ 2 ] );
  51 }
  52
  53 static void mlt_factory_create_done( mlt_listener listener, mlt_properties owner, mlt_service this, void **args )
  54 {
  55         if ( listener != NULL )
  56                 listener( owner, this, ( char * )args[ 0 ], ( char * )args[ 1 ], ( mlt_service )args[ 2 ] );
  57 }
  58
  59 /** Construct the factories.
  60 */
  61
  62 int mlt_factory_init( const char *prefix )
  63 {
  64         // Only initialise once
  65         if ( mlt_prefix == NULL )
  66         {
  67                 // Allow user over rides
  68                 if ( prefix == NULL || !strcmp( prefix, "" ) )
  69                         prefix = getenv( "MLT_REPOSITORY" );
  70
  71                 // If no directory is specified, default to install directory
  72                 if ( prefix == NULL )
  73                         prefix = PREFIX_LIB;
  74
  75                 // Store the prefix for later retrieval
  76                 mlt_prefix = strdup( prefix );
  77
  78                 // Initialise the pool
  79                 mlt_pool_init( );
  80
  81                 // Create and set up the events object
  82                 event_object = mlt_properties_new( );
  83                 mlt_events_init( event_object );
  84                 mlt_events_register( event_object, "producer-create-request", ( mlt_transmitter )mlt_factory_create_request );
  85                 mlt_events_register( event_object, "producer-create-done", ( mlt_transmitter )mlt_factory_create_done );
  86                 mlt_events_register( event_object, "filter-create-request", ( mlt_transmitter )mlt_factory_create_request );
  87                 mlt_events_register( event_object, "filter-create-done", ( mlt_transmitter )mlt_factory_create_done );
  88                 mlt_events_register( event_object, "transition-create-request", ( mlt_transmitter )mlt_factory_create_request );
  89                 mlt_events_register( event_object, "transition-create-done", ( mlt_transmitter )mlt_factory_create_done );
  90                 mlt_events_register( event_object, "consumer-create-request", ( mlt_transmitter )mlt_factory_create_request );
  91                 mlt_events_register( event_object, "consumer-create-done", ( mlt_transmitter )mlt_factory_create_done );
  92
  93                 // Create the global properties
  94                 global_properties = mlt_properties_new( );
  95
  96                 // Create the object list.
  97                 object_list = mlt_properties_new( );
  98
  99                 // Create a repository for each service type
 100                 producers = mlt_repository_init( object_list, prefix, "producers", "mlt_create_producer" );
 101                 filters = mlt_repository_init( object_list, prefix, "filters", "mlt_create_filter" );
 102                 transitions = mlt_repository_init( object_list, prefix, "transitions", "mlt_create_transition" );
 103                 consumers = mlt_repository_init( object_list, prefix, "consumers", "mlt_create_consumer" );
 104
 105                 // Force a clean up when app closes
 106                 atexit( mlt_factory_close );
 107         }
 108
 109         // Allow property refresh on a subsequent initialisation
 110         if ( global_properties != NULL )
 111         {
 112                 mlt_properties_set_or_default( global_properties, "MLT_NORMALISATION", getenv( "MLT_NORMALISATION" ), "PAL" );
 113                 mlt_properties_set_or_default( global_properties, "MLT_PRODUCER", getenv( "MLT_PRODUCER" ), "fezzik" );
 114                 mlt_properties_set_or_default( global_properties, "MLT_CONSUMER", getenv( "MLT_CONSUMER" ), "sdl" );
 115                 mlt_properties_set( global_properties, "MLT_TEST_CARD", getenv( "MLT_TEST_CARD" ) );
 116                 mlt_properties_set_or_default( global_properties, "MLT_PROFILE", getenv( "MLT_PROFILE" ), "dv_pal" );
 117                 mlt_properties_set_or_default( global_properties, "MLT_DATA", getenv( "MLT_DATA" ), PREFIX_DATA );
 118         }
 119
 120
 121         return 0;
 122 }
 123
 124 /** Fetch the events object.
 125 */
 126
 127 mlt_properties mlt_factory_event_object( )
 128 {
 129         return event_object;
 130 }
 131
 132 /** Fetch the prefix used in this instance.
 133 */
 134
 135 const char *mlt_factory_prefix( )
 136 {
 137         return mlt_prefix;
 138 }
 139
 140 /** Get a value from the environment.
 141 */
 142
 143 char *mlt_environment( const char *name )
 144 {
 145         if ( global_properties )
 146                 return mlt_properties_get( global_properties, name );
 147         else
 148                 return NULL;
 149 }
 150
 151 /** Set a value in the environment.
 152 */
 153
 154 int mlt_environment_set( const char *name, const char *value )
 155 {
 156         if ( global_properties )
 157                 return mlt_properties_set( global_properties, name, value );
 158         else
 159                 return -1;
 160 }
 161
 162 static void set_common_properties( mlt_properties properties, mlt_profile profile, const char *type, const char *service )
 163 {
 164         mlt_properties_set_int( properties, "_unique_id", ++ unique_id );
 165         mlt_properties_set( properties, "mlt_type", type );
 166         if ( mlt_properties_get_int( properties, "_mlt_service_hidden" ) == 0 )
 167                 mlt_properties_set( properties, "mlt_service", service );
 168         if ( profile != NULL )
 169                 mlt_properties_set_data( properties, "_profile", profile, 0, NULL, NULL );
 170 }
 171
 172 /** Fetch a producer from the repository.
 173 */
 174
 175 mlt_producer mlt_factory_producer( mlt_profile profile, const char *service, void *input )
 176 {
 177         mlt_producer obj = NULL;
 178
 179         // Pick up the default normalising producer if necessary
 180         if ( service == NULL )
 181                 service = mlt_environment( "MLT_PRODUCER" );
 182
 183         // Offer the application the chance to 'create'
 184         mlt_events_fire( event_object, "producer-create-request", service, input, &obj, NULL );
 185
 186         // Try to instantiate via the specified service
 187         if ( obj == NULL )
 188         {
 189                 obj = mlt_repository_fetch( producers, profile, producer_type, service, input );
 190                 mlt_events_fire( event_object, "producer-create-done", service, input, obj, NULL );
 191                 if ( obj != NULL )
 192                 {
 193                         mlt_properties properties = MLT_PRODUCER_PROPERTIES( obj );
 194                         set_common_properties( properties, profile, "producer", service );
 195                 }
 196         }
 197         return obj;
 198 }
 199
 200 /** Fetch a filter from the repository.
 201 */
 202
 203 mlt_filter mlt_factory_filter( mlt_profile profile, const char *service, void *input )
 204 {
 205         mlt_filter obj = NULL;
 206
 207         // Offer the application the chance to 'create'
 208         mlt_events_fire( event_object, "filter-create-request", service, input, &obj, NULL );
 209
 210         if ( obj == NULL )
 211         {
 212                 obj = mlt_repository_fetch( filters, profile, filter_type, service, input );
 213                 mlt_events_fire( event_object, "filter-create-done", service, input, obj, NULL );
 214         }
 215
 216         if ( obj != NULL )
 217         {
 218                 mlt_properties properties = MLT_FILTER_PROPERTIES( obj );
 219                 set_common_properties( properties, profile, "filter", service );
 220         }
 221         return obj;
 222 }
 223
 224 /** Fetch a transition from the repository.
 225 */
 226
 227 mlt_transition mlt_factory_transition( mlt_profile profile, const char *service, void *input )
 228 {
 229         mlt_transition obj = NULL;
 230
 231         // Offer the application the chance to 'create'
 232         mlt_events_fire( event_object, "transition-create-request", service, input, &obj, NULL );
 233
 234         if ( obj == NULL )
 235         {
 236                 obj = mlt_repository_fetch( transitions, profile, filter_type, service, input );
 237                 mlt_events_fire( event_object, "transition-create-done", service, input, obj, NULL );
 238         }
 239
 240         if ( obj != NULL )
 241         {
 242                 mlt_properties properties = MLT_TRANSITION_PROPERTIES( obj );
 243                 set_common_properties( properties, profile, "transition", service );
 244         }
 245         return obj;
 246 }
 247
 248 /** Fetch a consumer from the repository
 249 */
 250
 251 mlt_consumer mlt_factory_consumer( mlt_profile profile, const char *service, void *input )
 252 {
 253         mlt_consumer obj = NULL;
 254
 255         if ( service == NULL )
 256                 service = mlt_environment( "MLT_CONSUMER" );
 257
 258         // Offer the application the chance to 'create'
 259         mlt_events_fire( event_object, "consumer-create-request", service, input, &obj, NULL );
 260
 261         if ( obj == NULL )
 262         {
 263                 obj = mlt_repository_fetch( consumers, profile, consumer_type, service, input );
 264                 mlt_events_fire( event_object, "consumer-create-done", service, input, obj, NULL );
 265         }
 266
 267         if ( obj != NULL )
 268         {
 269                 mlt_properties properties = MLT_CONSUMER_PROPERTIES( obj );
 270                 set_common_properties( properties, profile, "consumer", service );
 271         }
 272         return obj;
 273 }
 274
 275 /** Register an object for clean up.
 276 */
 277
 278 void mlt_factory_register_for_clean_up( void *ptr, mlt_destructor destructor )
 279 {
 280         char unique[ 256 ];
 281         sprintf( unique, "%08d", mlt_properties_count( global_properties ) );
 282         mlt_properties_set_data( global_properties, unique, ptr, 0, destructor, NULL );
 283 }
 284
 285 /** Close the factory.
 286 */
 287
 288 void mlt_factory_close( )
 289 {
 290         if ( mlt_prefix != NULL )
 291         {
 292                 mlt_properties_close( event_object );
 293                 mlt_repository_close( producers );
 294                 mlt_repository_close( filters );
 295                 mlt_repository_close( transitions );
 296                 mlt_repository_close( consumers );
 297                 mlt_properties_close( global_properties );
 298                 mlt_properties_close( object_list );
 299                 free( mlt_prefix );
 300                 mlt_prefix = NULL;
 301                 mlt_pool_close( );
 302         }
 303 }