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

   1 /*
   2  * mlt_service.c -- interface for all service classes
   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_service.h"
  23 #include "mlt_filter.h"
  24 #include "mlt_frame.h"
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28
  29 /** IMPORTANT NOTES
  30
  31         The base service implements a null frame producing service - as such,
  32         it is functional without extension and will produce test cards frames
  33         and PAL sized audio frames.
  34
  35         PLEASE DO NOT CHANGE THIS BEHAVIOUR!!! OVERRIDE THE METHODS THAT
  36         CONTROL THIS IN EXTENDING CLASSES.
  37 */
  38
  39 /** Private service definition.
  40 */
  41
  42 typedef struct
  43 {
  44         int size;
  45         int count;
  46         mlt_service *in;
  47         mlt_service out;
  48         int filter_count;
  49         int filter_size;
  50         mlt_filter *filters;
  51 }
  52 mlt_service_base;
  53
  54 /** Private methods
  55 */
  56
  57 static void mlt_service_disconnect( mlt_service this );
  58 static void mlt_service_connect( mlt_service this, mlt_service that );
  59 static int service_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
  60 static void mlt_service_property_changed( mlt_listener, mlt_properties owner, mlt_service this, void **args );
  61
  62 /** Constructor
  63 */
  64
  65 int mlt_service_init( mlt_service this, void *child )
  66 {
  67         int error = 0;
  68
  69         // Initialise everything to NULL
  70         memset( this, 0, sizeof( struct mlt_service_s ) );
  71
  72         // Assign the child
  73         this->child = child;
  74
  75         // Generate local space
  76         this->local = calloc( sizeof( mlt_service_base ), 1 );
  77
  78         // Associate the methods
  79         this->get_frame = service_get_frame;
  80
  81         // Initialise the properties
  82         error = mlt_properties_init( &this->parent, this );
  83         if ( error == 0 )
  84         {
  85                 this->parent.close = ( mlt_destructor )mlt_service_close;
  86                 this->parent.close_object = this;
  87
  88                 mlt_events_init( &this->parent );
  89                 mlt_events_register( &this->parent, "service-changed", NULL );
  90                 mlt_events_register( &this->parent, "property-changed", ( mlt_transmitter )mlt_service_property_changed );
  91         }
  92
  93         return error;
  94 }
  95
  96 static void mlt_service_property_changed( mlt_listener listener, mlt_properties owner, mlt_service this, void **args )
  97 {
  98         if ( listener != NULL )
  99                 listener( owner, this, ( char * )args[ 0 ] );
 100 }
 101
 102 /** Connect a producer service.
 103         Returns: > 0 warning, == 0 success, < 0 serious error
 104                          1 = this service does not accept input
 105                          2 = the producer is invalid
 106                          3 = the producer is already registered with this consumer
 107 */
 108
 109 int mlt_service_connect_producer( mlt_service this, mlt_service producer, int index )
 110 {
 111         int i = 0;
 112
 113         // Get the service base
 114         mlt_service_base *base = this->local;
 115
 116         // Check if the producer is already registered with this service
 117         for ( i = 0; i < base->count; i ++ )
 118                 if ( base->in[ i ] == producer )
 119                         return 3;
 120
 121         // Allocate space
 122         if ( index >= base->size )
 123         {
 124                 int new_size = base->size + index + 10;
 125                 base->in = realloc( base->in, new_size * sizeof( mlt_service ) );
 126                 if ( base->in != NULL )
 127                 {
 128                         for ( i = base->size; i < new_size; i ++ )
 129                                 base->in[ i ] = NULL;
 130                         base->size = new_size;
 131                 }
 132         }
 133
 134         // If we have space, assign the input
 135         if ( base->in != NULL && index >= 0 && index < base->size )
 136         {
 137                 // Get the current service
 138                 mlt_service current = base->in[ index ];
 139
 140                 // Increment the reference count on this producer
 141                 if ( producer != NULL )
 142                         mlt_properties_inc_ref( mlt_service_properties( producer ) );
 143
 144                 // Now we disconnect the producer service from its consumer
 145                 mlt_service_disconnect( producer );
 146
 147                 // Add the service to index specified
 148                 base->in[ index ] = producer;
 149
 150                 // Determine the number of active tracks
 151                 if ( index >= base->count )
 152                         base->count = index + 1;
 153
 154                 // Now we connect the producer to its connected consumer
 155                 mlt_service_connect( producer, this );
 156
 157                 // Close the current service
 158                 mlt_service_close( current );
 159
 160                 // Inform caller that all went well
 161                 return 0;
 162         }
 163         else
 164         {
 165                 return -1;
 166         }
 167 }
 168
 169 /** Disconnect this service from its consumer.
 170 */
 171
 172 static void mlt_service_disconnect( mlt_service this )
 173 {
 174         if ( this != NULL )
 175         {
 176                 // Get the service base
 177                 mlt_service_base *base = this->local;
 178
 179                 // Disconnect
 180                 base->out = NULL;
 181         }
 182 }
 183
 184 /** Obtain the consumer this service is connected to.
 185 */
 186
 187 mlt_service mlt_service_consumer( mlt_service this )
 188 {
 189         // Get the service base
 190         mlt_service_base *base = this->local;
 191
 192         // Return the connected consumer
 193         return base->out;
 194 }
 195
 196 /** Obtain the producer this service is connected to.
 197 */
 198
 199 mlt_service mlt_service_producer( mlt_service this )
 200 {
 201         // Get the service base
 202         mlt_service_base *base = this->local;
 203
 204         // Return the connected producer
 205         return base->count > 0 ? base->in[ base->count - 1 ] : NULL;
 206 }
 207
 208 /** Associate this service to the consumer.
 209 */
 210
 211 static void mlt_service_connect( mlt_service this, mlt_service that )
 212 {
 213         if ( this != NULL )
 214         {
 215                 // Get the service base
 216                 mlt_service_base *base = this->local;
 217
 218                 // There's a bit more required here...
 219                 base->out = that;
 220         }
 221 }
 222
 223 /** Get the first connected producer service.
 224 */
 225
 226 mlt_service mlt_service_get_producer( mlt_service this )
 227 {
 228         mlt_service producer = NULL;
 229
 230         // Get the service base
 231         mlt_service_base *base = this->local;
 232
 233         if ( base->in != NULL )
 234                 producer = base->in[ 0 ];
 235
 236         return producer;
 237 }
 238
 239 /** Default implementation of get_frame.
 240 */
 241
 242 static int service_get_frame( mlt_service this, mlt_frame_ptr frame, int index )
 243 {
 244         mlt_service_base *base = this->local;
 245         if ( index < base->count )
 246         {
 247                 mlt_service producer = base->in[ index ];
 248                 if ( producer != NULL )
 249                         return mlt_service_get_frame( producer, frame, index );
 250         }
 251         *frame = mlt_frame_init( );
 252         return 0;
 253 }
 254
 255 /** Return the properties object.
 256 */
 257
 258 mlt_properties mlt_service_properties( mlt_service self )
 259 {
 260         return self != NULL ? &self->parent : NULL;
 261 }
 262
 263 /** Recursively apply attached filters
 264 */
 265
 266 static void apply_filters( mlt_service this, mlt_frame frame, int index )
 267 {
 268         mlt_properties properties = mlt_service_properties( this );
 269         mlt_service_base *base = this->local;
 270         int i;
 271
 272         if ( mlt_properties_get_int( properties, "_filter_private" ) == 0 )
 273         {
 274                 // Process the frame with the attached filters
 275                 for ( i = 0; i < base->filter_count; i ++ )
 276                 {
 277                         if ( base->filters[ i ] != NULL )
 278                         {
 279                                 mlt_filter_process( base->filters[ i ], frame );
 280                                 apply_filters( mlt_filter_service( base->filters[ i ] ), frame, index );
 281                         }
 282                 }
 283         }
 284 }
 285
 286 /** Obtain a frame.
 287 */
 288
 289 int mlt_service_get_frame( mlt_service this, mlt_frame_ptr frame, int index )
 290 {
 291         if ( this != NULL )
 292         {
 293                 int result = this->get_frame( this, frame, index );
 294                 if ( result == 0 )
 295                         apply_filters( this, *frame, index );
 296                 return result;
 297         }
 298         *frame = mlt_frame_init( );
 299         return 0;
 300 }
 301
 302 static void mlt_service_filter_changed( mlt_service owner, mlt_service this )
 303 {
 304         mlt_events_fire( mlt_service_properties( this ), "service-changed", NULL );
 305 }
 306
 307 /** Attach a filter.
 308 */
 309
 310 int mlt_service_attach( mlt_service this, mlt_filter filter )
 311 {
 312         int error = this == NULL || filter == NULL;
 313         if ( error == 0 )
 314         {
 315                 int i = 0;
 316                 mlt_properties properties = mlt_service_properties( this );
 317                 mlt_service_base *base = this->local;
 318
 319                 for ( i = 0; error == 0 && i < base->filter_count; i ++ )
 320                         if ( base->filters[ i ] == filter )
 321                                 error = 1;
 322
 323                 if ( error == 0 )
 324                 {
 325                         if ( base->filter_count == base->filter_size )
 326                         {
 327                                 base->filter_size += 10;
 328                                 base->filters = realloc( base->filters, base->filter_size * sizeof( mlt_filter ) );
 329                         }
 330
 331                         if ( base->filters != NULL )
 332                         {
 333                                 mlt_properties props = mlt_filter_properties( filter );
 334                                 mlt_properties_inc_ref( mlt_filter_properties( filter ) );
 335                                 base->filters[ base->filter_count ++ ] = filter;
 336                                 mlt_events_fire( properties, "service-changed", NULL );
 337                                 mlt_events_listen( props, this, "service-changed", ( mlt_listener )mlt_service_filter_changed );
 338                                 mlt_events_listen( props, this, "property-changed", ( mlt_listener )mlt_service_filter_changed );
 339                         }
 340                         else
 341                         {
 342                                 error = 2;
 343                         }
 344                 }
 345         }
 346         return error;
 347 }
 348
 349 /** Detach a filter.
 350 */
 351
 352 int mlt_service_detach( mlt_service this, mlt_filter filter )
 353 {
 354         int error = this == NULL || filter == NULL;
 355         if ( error == 0 )
 356         {
 357                 int i = 0;
 358                 mlt_service_base *base = this->local;
 359                 mlt_properties properties = mlt_service_properties( this );
 360
 361                 for ( i = 0; i < base->filter_count; i ++ )
 362                         if ( base->filters[ i ] == filter )
 363                                 break;
 364
 365                 if ( i < base->filter_count )
 366                 {
 367                         base->filters[ i ] = NULL;
 368                         for ( i ++ ; i < base->filter_count; i ++ )
 369                                 base->filters[ i - 1 ] = base->filters[ i ];
 370                         base->filter_count --;
 371                         mlt_events_disconnect( mlt_filter_properties( filter ), this );
 372                         mlt_filter_close( filter );
 373                         mlt_events_fire( properties, "service-changed", NULL );
 374                 }
 375         }
 376         return error;
 377 }
 378
 379 /** Retrieve a filter.
 380 */
 381
 382 mlt_filter mlt_service_filter( mlt_service this, int index )
 383 {
 384         mlt_filter filter = NULL;
 385         if ( this != NULL )
 386         {
 387                 mlt_service_base *base = this->local;
 388                 if ( index >= 0 && index < base->filter_count )
 389                         filter = base->filters[ index ];
 390         }
 391         return filter;
 392 }
 393
 394 /** Close the service.
 395 */
 396
 397 void mlt_service_close( mlt_service this )
 398 {
 399         if ( this != NULL && mlt_properties_dec_ref( mlt_service_properties( this ) ) <= 0 )
 400         {
 401                 if ( this->close != NULL )
 402                 {
 403                         this->close( this->close_object );
 404                 }
 405                 else
 406                 {
 407                         mlt_service_base *base = this->local;
 408                         int i = 0;
 409                         int count = base->filter_count;
 410                         mlt_events_block( mlt_service_properties( this ), this );
 411                         while( count -- )
 412                                 mlt_service_detach( this, base->filters[ 0 ] );
 413                         free( base->filters );
 414                         for ( i = 0; i < base->count; i ++ )
 415                                 if ( base->in[ i ] != NULL )
 416                                         mlt_service_close( base->in[ i ] );
 417                         this->parent.close = NULL;
 418                         free( base->in );
 419                         free( base );
 420                         mlt_properties_close( &this->parent );
 421                 }
 422         }
 423 }
 424