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

   1 /**
   2  * \file mlt_multitrack.c
   3  * \brief multitrack service class
   4  *
   5  * Copyright (C) 2003-2008 Ushodaya Enterprises Limited
   6  * \author Charles Yates <charles.yates@pandora.be>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include "mlt_multitrack.h"
  24 #include "mlt_playlist.h"
  25 #include "mlt_frame.h"
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 /* Forward reference. */
  31
  32 static int producer_get_frame( mlt_producer producer, mlt_frame_ptr frame, int index );
  33
  34 /** Construct and initialize a new multitrack.
  35  *
  36  * Sets the resource property to "<multitrack>".
  37  *
  38  * \public \memberof mlt_multitrack_s
  39  * \return a new multitrack
  40  */
  41
  42 mlt_multitrack mlt_multitrack_init( )
  43 {
  44         // Allocate the multitrack object
  45         mlt_multitrack this = calloc( sizeof( struct mlt_multitrack_s ), 1 );
  46
  47         if ( this != NULL )
  48         {
  49                 mlt_producer producer = &this->parent;
  50                 if ( mlt_producer_init( producer, this ) == 0 )
  51                 {
  52                         mlt_properties properties = MLT_MULTITRACK_PROPERTIES( this );
  53                         producer->get_frame = producer_get_frame;
  54                         mlt_properties_set_data( properties, "multitrack", this, 0, NULL, NULL );
  55                         mlt_properties_set( properties, "log_id", "multitrack" );
  56                         mlt_properties_set( properties, "resource", "<multitrack>" );
  57                         mlt_properties_set_int( properties, "in", 0 );
  58                         mlt_properties_set_int( properties, "out", -1 );
  59                         mlt_properties_set_int( properties, "length", 0 );
  60                         producer->close = ( mlt_destructor )mlt_multitrack_close;
  61                 }
  62                 else
  63                 {
  64                         free( this );
  65                         this = NULL;
  66                 }
  67         }
  68
  69         return this;
  70 }
  71
  72 /** Get the producer associated to this multitrack.
  73  *
  74  * \public \memberof mlt_multitrack_s
  75  * \param this a multitrack
  76  * \return the producer object
  77  * \see MLT_MULTITRACK_PRODUCER
  78  */
  79
  80 mlt_producer mlt_multitrack_producer( mlt_multitrack this )
  81 {
  82         return this != NULL ? &this->parent : NULL;
  83 }
  84
  85 /** Get the service associated this multitrack.
  86  *
  87  * \public \memberof mlt_multitrack_s
  88  * \param this a multitrack
  89  * \return the service object
  90  * \see MLT_MULTITRACK_SERVICE
  91  */
  92
  93 mlt_service mlt_multitrack_service( mlt_multitrack this )
  94 {
  95         return MLT_MULTITRACK_SERVICE( this );
  96 }
  97
  98 /** Get the properties associated this multitrack.
  99  *
 100  * \public \memberof mlt_multitrack_s
 101  * \param this a multitrack
 102  * \return the multitrack's property list
 103  * \see MLT_MULTITRACK_PROPERTIES
 104  */
 105
 106 mlt_properties mlt_multitrack_properties( mlt_multitrack this )
 107 {
 108         return MLT_MULTITRACK_PROPERTIES( this );
 109 }
 110
 111 /** Initialize position related information.
 112  *
 113  * \public \memberof mlt_multitrack_s
 114  * \param this a multitrack
 115  */
 116
 117 void mlt_multitrack_refresh( mlt_multitrack this )
 118 {
 119         int i = 0;
 120
 121         // Obtain the properties of this multitrack
 122         mlt_properties properties = MLT_MULTITRACK_PROPERTIES( this );
 123
 124         // We need to ensure that the multitrack reports the longest track as its length
 125         mlt_position length = 0;
 126
 127         // Obtain stats on all connected services
 128         for ( i = 0; i < this->count; i ++ )
 129         {
 130                 // Get the producer from this index
 131                 mlt_track track = this->list[ i ];
 132                 mlt_producer producer = track->producer;
 133
 134                 // If it's allocated then, update our stats
 135                 if ( producer != NULL )
 136                 {
 137                         // If we have more than 1 track, we must be in continue mode
 138                         if ( this->count > 1 )
 139                                 mlt_properties_set( MLT_PRODUCER_PROPERTIES( producer ), "eof", "continue" );
 140
 141                         // Determine the longest length
 142                         //if ( !mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( producer ), "hide" ) )
 143                                 length = mlt_producer_get_playtime( producer ) > length ? mlt_producer_get_playtime( producer ) : length;
 144                 }
 145         }
 146
 147         // Update multitrack properties now - we'll not destroy the in point here
 148         mlt_events_block( properties, properties );
 149         mlt_properties_set_position( properties, "length", length );
 150         mlt_events_unblock( properties, properties );
 151         mlt_properties_set_position( properties, "out", length - 1 );
 152 }
 153
 154 /** Listener for producers on the playlist.
 155  *
 156  * \private \memberof mlt_multitrack_s
 157  * \param producer a producer
 158  * \param this a multitrack
 159  */
 160
 161 static void mlt_multitrack_listener( mlt_producer producer, mlt_multitrack this )
 162 {
 163         mlt_multitrack_refresh( this );
 164 }
 165
 166 /** Connect a producer to a given track.
 167  *
 168  * Note that any producer can be connected here, but see special case treatment
 169  * of playlist in clip point determination below.
 170  *
 171  * \public \memberof mlt_multitrack_s
 172  * \param this a multitrack
 173  * \param producer the producer to connect to the multitrack producer
 174  * \param track the 0-based index of the track on which to connect the multitrack
 175  * \return true on error
 176  */
 177
 178 int mlt_multitrack_connect( mlt_multitrack this, mlt_producer producer, int track )
 179 {
 180         // Connect to the producer to ourselves at the specified track
 181         int result = mlt_service_connect_producer( MLT_MULTITRACK_SERVICE( this ), MLT_PRODUCER_SERVICE( producer ), track );
 182
 183         if ( result == 0 )
 184         {
 185                 // Resize the producer list if need be
 186                 if ( track >= this->size )
 187                 {
 188                         int i;
 189                         this->list = realloc( this->list, ( track + 10 ) * sizeof( mlt_track ) );
 190                         for ( i = this->size; i < track + 10; i ++ )
 191                                 this->list[ i ] = NULL;
 192                         this->size = track + 10;
 193                 }
 194
 195                 if ( this->list[ track ] != NULL )
 196                 {
 197                         mlt_event_close( this->list[ track ]->event );
 198                         mlt_producer_close( this->list[ track ]->producer );
 199                 }
 200                 else
 201                 {
 202                         this->list[ track ] = malloc( sizeof( struct mlt_track_s ) );
 203                 }
 204
 205                 // Assign the track in our list here
 206                 this->list[ track ]->producer = producer;
 207                 this->list[ track ]->event = mlt_events_listen( MLT_PRODUCER_PROPERTIES( producer ), this,
 208                                                                          "producer-changed", ( mlt_listener )mlt_multitrack_listener );
 209                 mlt_properties_inc_ref( MLT_PRODUCER_PROPERTIES( producer ) );
 210                 mlt_event_inc_ref( this->list[ track ]->event );
 211
 212                 // Increment the track count if need be
 213                 if ( track >= this->count )
 214                         this->count = track + 1;
 215
 216                 // Refresh our stats
 217                 mlt_multitrack_refresh( this );
 218         }
 219
 220         return result;
 221 }
 222
 223 /** Get the number of tracks.
 224  *
 225  * \public \memberof mlt_multitrack_s
 226  * \param this a multitrack
 227  * \return the number of tracks
 228  */
 229
 230 int mlt_multitrack_count( mlt_multitrack this )
 231 {
 232         return this->count;
 233 }
 234
 235 /** Get an individual track as a producer.
 236  *
 237  * \public \memberof mlt_multitrack_s
 238  * \param this a multitrack
 239  * \param track the 0-based index of the producer to get
 240  * \return the producer or NULL if not valid
 241  */
 242
 243 mlt_producer mlt_multitrack_track( mlt_multitrack this, int track )
 244 {
 245         mlt_producer producer = NULL;
 246
 247         if ( this->list != NULL && track < this->count )
 248                 producer = this->list[ track ]->producer;
 249
 250         return producer;
 251 }
 252
 253 /** Position comparison function for sorting.
 254  *
 255  * \private \memberof mlt_multitrack_s
 256  * \param p1 a position
 257  * \param p2 another position
 258  * \return <0 if \p p1 is less than \p p2, 0 if equal, >0 if greater
 259  */
 260
 261 static int position_compare( const void *p1, const void *p2 )
 262 {
 263         return *( mlt_position * )p1 - *( mlt_position * )p2;
 264 }
 265
 266 /** Add a position to a set.
 267  *
 268  * \private \memberof mlt_multitrack_s
 269  * \param array an array of positions (the set)
 270  * \param size the current number of positions in the array (not the capacity of the array)
 271  * \param position the position to add
 272  * \return the new size of the array
 273  */
 274
 275 static int add_unique( mlt_position *array, int size, mlt_position position )
 276 {
 277         int i = 0;
 278         for ( i = 0; i < size; i ++ )
 279                 if ( array[ i ] == position )
 280                         break;
 281         if ( i == size )
 282                 array[ size ++ ] = position;
 283         return size;
 284 }
 285
 286 /** Determine the clip point.
 287  *
 288  * <pre>
 289  * Special case here: a 'producer' has no concept of multiple clips - only the
 290  * playlist and multitrack producers have clip functionality. Further to that a
 291  * multitrack determines clip information from any connected tracks that happen
 292  * to be playlists.
 293  *
 294  * Additionally, it must locate clips in the correct order, for example, consider
 295  * the following track arrangement:
 296  *
 297  * playlist1 |0.0     |b0.0      |0.1          |0.1         |0.2           |
 298  * playlist2 |b1.0  |1.0           |b1.1     |1.1             |
 299  *
 300  * Note - b clips represent blanks. They are also reported as clip positions.
 301  *
 302  * When extracting clip positions from these playlists, we should get a sequence of:
 303  *
 304  * 0.0, 1.0, b0.0, 0.1, b1.1, 1.1, 0.1, 0.2, [out of playlist2], [out of playlist1]
 305  * </pre>
 306  *
 307  * \public \memberof mlt_multitrack_s
 308  * \param this a multitrack
 309  * \param whence from where to extract
 310  * \param index the 0-based index of which clip to extract
 311  * \return the position of clip \p index relative to \p whence
 312  */
 313
 314 mlt_position mlt_multitrack_clip( mlt_multitrack this, mlt_whence whence, int index )
 315 {
 316         mlt_position position = 0;
 317         int i = 0;
 318         int j = 0;
 319         mlt_position *map = malloc( 1000 * sizeof( mlt_position ) );
 320         int count = 0;
 321
 322         for ( i = 0; i < this->count; i ++ )
 323         {
 324                 // Get the producer for this track
 325                 mlt_producer producer = this->list[ i ]->producer;
 326
 327                 // If it's assigned and not a hidden track
 328                 if ( producer != NULL )
 329                 {
 330                         // Get the properties of this producer
 331                         mlt_properties properties = MLT_PRODUCER_PROPERTIES( producer );
 332
 333                         // Determine if it's a playlist
 334                         mlt_playlist playlist = mlt_properties_get_data( properties, "playlist", NULL );
 335
 336                         // Special case consideration of playlists
 337                         if ( playlist != NULL )
 338                         {
 339                                 for ( j = 0; j < mlt_playlist_count( playlist ); j ++ )
 340                                         count = add_unique( map, count, mlt_playlist_clip( playlist, mlt_whence_relative_start, j ) );
 341                                 count = add_unique( map, count, mlt_producer_get_out( producer ) + 1 );
 342                         }
 343                         else
 344                         {
 345                                 count = add_unique( map, count, 0 );
 346                                 count = add_unique( map, count, mlt_producer_get_out( producer ) + 1 );
 347                         }
 348                 }
 349         }
 350
 351         // Now sort the map
 352         qsort( map, count, sizeof( mlt_position ), position_compare );
 353
 354         // Now locate the requested index
 355         switch( whence )
 356         {
 357                 case mlt_whence_relative_start:
 358                         if ( index < count )
 359                                 position = map[ index ];
 360                         else
 361                                 position = map[ count - 1 ];
 362                         break;
 363
 364                 case mlt_whence_relative_current:
 365                         position = mlt_producer_position( MLT_MULTITRACK_PRODUCER( this ) );
 366                         for ( i = 0; i < count - 2; i ++ )
 367                                 if ( position >= map[ i ] && position < map[ i + 1 ] )
 368                                         break;
 369                         index += i;
 370                         if ( index >= 0 && index < count )
 371                                 position = map[ index ];
 372                         else if ( index < 0 )
 373                                 position = map[ 0 ];
 374                         else
 375                                 position = map[ count - 1 ];
 376                         break;
 377
 378                 case mlt_whence_relative_end:
 379                         if ( index < count )
 380                                 position = map[ count - index - 1 ];
 381                         else
 382                                 position = map[ 0 ];
 383                         break;
 384         }
 385
 386         // Free the map
 387         free( map );
 388
 389         return position;
 390 }
 391
 392 /** Get frame method.
 393  *
 394  * <pre>
 395  * Special case here: The multitrack must be used in a conjunction with a downstream
 396  * tractor-type service, ie:
 397  *
 398  * Producer1 \
 399  * Producer2 - multitrack - { filters/transitions } - tractor - consumer
 400  * Producer3 /
 401  *
 402  * The get_frame of a tractor pulls frames from it's connected service on all tracks and
 403  * will terminate as soon as it receives a test card with a last_track property. The
 404  * important case here is that the mulitrack does not move to the next frame until all
 405  * tracks have been pulled.
 406  *
 407  * Reasoning: In order to seek on a network such as above, the multitrack needs to ensure
 408  * that all producers are positioned on the same frame. It uses the 'last track' logic
 409  * to determine when to move to the next frame.
 410  *
 411  * Flaw: if a transition is configured to read from a b-track which happens to trigger
 412  * the last frame logic (ie: it's configured incorrectly), then things are going to go
 413  * out of sync.
 414  *
 415  * See playlist logic too.
 416  * </pre>
 417  *
 418  * \private \memberof mlt_multitrack_s
 419  * \param parent the producer interface to a mulitrack
 420  * \param[out] frame a frame by reference
 421  * \param index the 0-based track index
 422  * \return true if there was an error
 423  */
 424
 425 static int producer_get_frame( mlt_producer parent, mlt_frame_ptr frame, int index )
 426 {
 427         // Get the mutiltrack object
 428         mlt_multitrack this = parent->child;
 429
 430         // Check if we have a track for this index
 431         if ( index < this->count && this->list[ index ] != NULL )
 432         {
 433                 // Get the producer for this track
 434                 mlt_producer producer = this->list[ index ]->producer;
 435
 436                 // Get the track hide property
 437                 int hide = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( mlt_producer_cut_parent( producer ) ), "hide" );
 438
 439                 // Obtain the current position
 440                 mlt_position position = mlt_producer_frame( parent );
 441
 442                 // Get the parent properties
 443                 mlt_properties producer_properties = MLT_PRODUCER_PROPERTIES( parent );
 444
 445                 // Get the speed
 446                 double speed = mlt_properties_get_double( producer_properties, "_speed" );
 447
 448                 // Make sure we're at the same point
 449                 mlt_producer_seek( producer, position );
 450
 451                 // Get the frame from the producer
 452                 mlt_service_get_frame( MLT_PRODUCER_SERVICE( producer ), frame, 0 );
 453
 454                 // Indicate speed of this producer
 455                 mlt_properties properties = MLT_FRAME_PROPERTIES( *frame );
 456                 mlt_properties_set_double( properties, "_speed", speed );
 457                 mlt_properties_set_position( properties, "_position", position );
 458                 mlt_properties_set_int( properties, "hide", hide );
 459         }
 460         else
 461         {
 462                 // Generate a test frame
 463                 *frame = mlt_frame_init( MLT_PRODUCER_SERVICE( parent ) );
 464
 465                 // Update position on the frame we're creating
 466                 mlt_frame_set_position( *frame, mlt_producer_position( parent ) );
 467
 468                 // Move on to the next frame
 469                 if ( index >= this->count )
 470                 {
 471                         // Let tractor know if we've reached the end
 472                         mlt_properties_set_int( MLT_FRAME_PROPERTIES( *frame ), "last_track", 1 );
 473
 474                         // Move to the next frame
 475                         mlt_producer_prepare_next( parent );
 476                 }
 477         }
 478
 479         return 0;
 480 }
 481
 482 /** Close this instance and free its resources.
 483  *
 484  * \public \memberof mlt_multitrack_s
 485  * \param this a multitrack
 486  */
 487
 488 void mlt_multitrack_close( mlt_multitrack this )
 489 {
 490         if ( this != NULL && mlt_properties_dec_ref( MLT_MULTITRACK_PROPERTIES( this ) ) <= 0 )
 491         {
 492                 int i = 0;
 493                 for ( i = 0; i < this->count; i ++ )
 494                 {
 495                         if ( this->list[ i ] != NULL )
 496                         {
 497                                 mlt_event_close( this->list[ i ]->event );
 498                                 mlt_producer_close( this->list[ i ]->producer );
 499                                 free( this->list[ i ] );
 500                         }
 501                 }
 502
 503                 // Close the producer
 504                 this->parent.close = NULL;
 505                 mlt_producer_close( &this->parent );
 506
 507                 // Free the list
 508                 free( this->list );
 509
 510                 // Free the object
 511                 free( this );
 512         }
 513 }