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 void mlt_service_apply_filters( mlt_service this, mlt_frame frame, int index )
 267 {
 268         int i;
 269         mlt_properties frame_properties = mlt_frame_properties( frame );
 270         mlt_properties filter_properties = mlt_service_properties( this );
 271         mlt_service_base *base = this->local;
 272         mlt_position position = mlt_properties_get_position( frame_properties, "_position" );
 273
 274         if ( index == 0 || mlt_properties_get_int( filter_properties, "_filter_private" ) == 0 )
 275         {
 276                 // Process the frame with the attached filters
 277                 for ( i = 0; i < base->filter_count; i ++ )
 278                 {
 279                         if ( base->filters[ i ] != NULL )
 280                         {
 281                                 mlt_properties properties = mlt_filter_properties( base->filters[ i ] );
 282                                 mlt_position in = mlt_properties_get_position( properties, "in" );
 283                                 mlt_position out = mlt_properties_get_position( properties, "out" );
 284                                 if ( ( in == 0 && out == 0 ) || ( position >= in && position <= out ) )
 285                                 {
 286                                         mlt_properties_set_position( frame_properties, "_position", position - in );
 287                                         mlt_filter_process( base->filters[ i ], frame );
 288                                         mlt_service_apply_filters( mlt_filter_service( base->filters[ i ] ), frame, index + 1 );
 289                                         mlt_properties_set_position( frame_properties, "_position", position + in );
 290                                 }
 291                         }
 292                 }
 293         }
 294 }
 295
 296 /** Obtain a frame.
 297 */
 298
 299 int mlt_service_get_frame( mlt_service this, mlt_frame_ptr frame, int index )
 300 {
 301         if ( this != NULL )
 302         {
 303                 int result = this->get_frame( this, frame, index );
 304                 if ( result == 0 )
 305                         mlt_service_apply_filters( this, *frame, 1 );
 306                 return result;
 307         }
 308         *frame = mlt_frame_init( );
 309         return 0;
 310 }
 311
 312 static void mlt_service_filter_changed( mlt_service owner, mlt_service this )
 313 {
 314         mlt_events_fire( mlt_service_properties( this ), "service-changed", NULL );
 315 }
 316
 317 /** Attach a filter.
 318 */
 319
 320 int mlt_service_attach( mlt_service this, mlt_filter filter )
 321 {
 322         int error = this == NULL || filter == NULL;
 323         if ( error == 0 )
 324         {
 325                 int i = 0;
 326                 mlt_properties properties = mlt_service_properties( this );
 327                 mlt_service_base *base = this->local;
 328
 329                 for ( i = 0; error == 0 && i < base->filter_count; i ++ )
 330                         if ( base->filters[ i ] == filter )
 331                                 error = 1;
 332
 333                 if ( error == 0 )
 334                 {
 335                         if ( base->filter_count == base->filter_size )
 336                         {
 337                                 base->filter_size += 10;
 338                                 base->filters = realloc( base->filters, base->filter_size * sizeof( mlt_filter ) );
 339                         }
 340
 341                         if ( base->filters != NULL )
 342                         {
 343                                 mlt_properties props = mlt_filter_properties( filter );
 344                                 mlt_properties_inc_ref( mlt_filter_properties( filter ) );
 345                                 base->filters[ base->filter_count ++ ] = filter;
 346                                 mlt_events_fire( properties, "service-changed", NULL );
 347                                 mlt_events_listen( props, this, "service-changed", ( mlt_listener )mlt_service_filter_changed );
 348                                 mlt_events_listen( props, this, "property-changed", ( mlt_listener )mlt_service_filter_changed );
 349                         }
 350                         else
 351                         {
 352                                 error = 2;
 353                         }
 354                 }
 355         }
 356         return error;
 357 }
 358
 359 /** Detach a filter.
 360 */
 361
 362 int mlt_service_detach( mlt_service this, mlt_filter filter )
 363 {
 364         int error = this == NULL || filter == NULL;
 365         if ( error == 0 )
 366         {
 367                 int i = 0;
 368                 mlt_service_base *base = this->local;
 369                 mlt_properties properties = mlt_service_properties( this );
 370
 371                 for ( i = 0; i < base->filter_count; i ++ )
 372                         if ( base->filters[ i ] == filter )
 373                                 break;
 374
 375                 if ( i < base->filter_count )
 376                 {
 377                         base->filters[ i ] = NULL;
 378                         for ( i ++ ; i < base->filter_count; i ++ )
 379                                 base->filters[ i - 1 ] = base->filters[ i ];
 380                         base->filter_count --;
 381                         mlt_events_disconnect( mlt_filter_properties( filter ), this );
 382                         mlt_filter_close( filter );
 383                         mlt_events_fire( properties, "service-changed", NULL );
 384                 }
 385         }
 386         return error;
 387 }
 388
 389 /** Retrieve a filter.
 390 */
 391
 392 mlt_filter mlt_service_filter( mlt_service this, int index )
 393 {
 394         mlt_filter filter = NULL;
 395         if ( this != NULL )
 396         {
 397                 mlt_service_base *base = this->local;
 398                 if ( index >= 0 && index < base->filter_count )
 399                         filter = base->filters[ index ];
 400         }
 401         return filter;
 402 }
 403
 404 /** Close the service.
 405 */
 406
 407 void mlt_service_close( mlt_service this )
 408 {
 409         if ( this != NULL && mlt_properties_dec_ref( mlt_service_properties( this ) ) <= 0 )
 410         {
 411                 if ( this->close != NULL )
 412                 {
 413                         this->close( this->close_object );
 414                 }
 415                 else
 416                 {
 417                         mlt_service_base *base = this->local;
 418                         int i = 0;
 419                         int count = base->filter_count;
 420                         mlt_events_block( mlt_service_properties( this ), this );
 421                         while( count -- )
 422                                 mlt_service_detach( this, base->filters[ 0 ] );
 423                         free( base->filters );
 424                         for ( i = 0; i < base->count; i ++ )
 425                                 if ( base->in[ i ] != NULL )
 426                                         mlt_service_close( base->in[ i ] );
 427                         this->parent.close = NULL;
 428                         free( base->in );
 429                         free( base );
 430                         mlt_properties_close( &this->parent );
 431                 }
 432         }
 433 }
 434