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

   1 /**
   2  * \file mlt_field.c
   3  * \brief a field for planting multiple transitions and filters
   4  * \see mlt_field_s
   5  *
   6  * Copyright (C) 2003-2009 Ushodaya Enterprises Limited
   7  * \author Charles Yates <charles.yates@pandora.be>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include "mlt_field.h"
  25 #include "mlt_service.h"
  26 #include "mlt_filter.h"
  27 #include "mlt_transition.h"
  28 #include "mlt_multitrack.h"
  29 #include "mlt_tractor.h"
  30
  31 #include <stdlib.h>
  32 #include <string.h>
  33
  34 /** \brief Field class
  35  *
  36  * The field is a convenience class that works with the tractor and multitrack classes to manage track filters and transitions.
  37  */
  38
  39 struct mlt_field_s
  40 {
  41         /// This is the producer we're connected to
  42         mlt_service producer;
  43
  44         /// Multitrack
  45         mlt_multitrack multitrack;
  46
  47         /// Tractor
  48         mlt_tractor tractor;
  49 };
  50
  51 /** Construct a field, mulitrack, and tractor.
  52  *
  53  * \public \memberof mlt_field_s
  54  * \return a new field
  55  */
  56
  57 mlt_field mlt_field_init( )
  58 {
  59         // Initialise the field
  60         mlt_field this = calloc( sizeof( struct mlt_field_s ), 1 );
  61
  62         // Initialise it
  63         if ( this != NULL )
  64         {
  65                 // Construct a multitrack
  66                 this->multitrack = mlt_multitrack_init( );
  67
  68                 // Construct a tractor
  69                 this->tractor = mlt_tractor_init( );
  70
  71                 // The first plant will be connected to the mulitrack
  72                 this->producer = MLT_MULTITRACK_SERVICE( this->multitrack );
  73
  74                 // Connect the tractor to the multitrack
  75                 mlt_tractor_connect( this->tractor, this->producer );
  76         }
  77
  78         // Return this
  79         return this;
  80 }
  81
  82 /** Construct a field and initialize with supplied multitrack and tractor.
  83  *
  84  * \public \memberof mlt_field_s
  85  * \param multitrack a multitrack
  86  * \param tractor a tractor
  87  * \return a new field
  88  */
  89
  90 mlt_field mlt_field_new( mlt_multitrack multitrack, mlt_tractor tractor )
  91 {
  92         // Initialise the field
  93         mlt_field this = calloc( sizeof( struct mlt_field_s ), 1 );
  94
  95         // Initialise it
  96         if ( this != NULL )
  97         {
  98                 // Construct a multitrack
  99                 this->multitrack = multitrack;
 100
 101                 // Construct a tractor
 102                 this->tractor = tractor;
 103
 104                 // The first plant will be connected to the mulitrack
 105                 this->producer = MLT_MULTITRACK_SERVICE( this->multitrack );
 106
 107                 // Connect the tractor to the multitrack
 108                 mlt_tractor_connect( this->tractor, this->producer );
 109         }
 110
 111         // Return this
 112         return this;
 113 }
 114
 115 /** Get the service associated to this field.
 116  *
 117  * \public \memberof mlt_field_s
 118  * \param this a field
 119  * \return the tractor as a service
 120  */
 121
 122 mlt_service mlt_field_service( mlt_field this )
 123 {
 124         return MLT_TRACTOR_SERVICE( this->tractor );
 125 }
 126
 127 /** Get the multitrack.
 128  *
 129  * \public \memberof mlt_field_s
 130  * \param this a field
 131  * \return the multitrack
 132  */
 133
 134 mlt_multitrack mlt_field_multitrack( mlt_field this )
 135 {
 136         return this != NULL ? this->multitrack : NULL;
 137 }
 138
 139 /** Get the tractor.
 140  *
 141  * \public \memberof mlt_field_s
 142  * \param this a field
 143  * \return the tractor
 144  */
 145
 146 mlt_tractor mlt_field_tractor( mlt_field this )
 147 {
 148         return this != NULL ? this->tractor : NULL;
 149 }
 150
 151 /** Get the properties associated to this field.
 152  *
 153  * \public \memberof mlt_field_s
 154  * \param this a field
 155  * \return a properties list
 156  */
 157
 158 mlt_properties mlt_field_properties( mlt_field this )
 159 {
 160         return MLT_SERVICE_PROPERTIES( mlt_field_service( this ) );
 161 }
 162
 163 /** Plant a filter.
 164  *
 165  * \public \memberof mlt_field_s
 166  * \param this a field
 167  * \param that a filter
 168  * \param track the track index
 169  * \return true if there was an error
 170  */
 171
 172 int mlt_field_plant_filter( mlt_field this, mlt_filter that, int track )
 173 {
 174         // Connect the filter to the last producer
 175         int result = mlt_filter_connect( that, this->producer, track );
 176
 177         // If sucessful, then we'll use this for connecting in the future
 178         if ( result == 0 )
 179         {
 180                 // This is now the new producer
 181                 this->producer = MLT_FILTER_SERVICE( that );
 182
 183                 // Reconnect tractor to new producer
 184                 mlt_tractor_connect( this->tractor, this->producer );
 185
 186                 // Fire an event
 187                 mlt_events_fire( mlt_field_properties( this ), "service-changed", NULL );
 188         }
 189
 190         return result;
 191 }
 192
 193 /** Plant a transition.
 194  *
 195  * \public \memberof mlt_field_s
 196  * \param this a field
 197  * \param that a transition
 198  * \param a_track input A's track index
 199  * \param b_track input B's track index
 200  * \return true if there was an error
 201  */
 202
 203 int mlt_field_plant_transition( mlt_field this, mlt_transition that, int a_track, int b_track )
 204 {
 205         // Connect the transition to the last producer
 206         int result = mlt_transition_connect( that, this->producer, a_track, b_track );
 207
 208         // If sucessful, then we'll use this for connecting in the future
 209         if ( result == 0 )
 210         {
 211                 // This is now the new producer
 212                 this->producer = MLT_TRANSITION_SERVICE( that );
 213
 214                 // Reconnect tractor to new producer
 215                 mlt_tractor_connect( this->tractor, this->producer );
 216
 217                 // Fire an event
 218                 mlt_events_fire( mlt_field_properties( this ), "service-changed", NULL );
 219         }
 220
 221         return 0;
 222 }
 223
 224 /** Close the field.
 225  *
 226  * \public \memberof mlt_field_s
 227  * \param this a field
 228  */
 229
 230 void mlt_field_close( mlt_field this )
 231 {
 232         if ( this != NULL && mlt_properties_dec_ref( mlt_field_properties( this ) ) <= 0 )
 233         {
 234                 //mlt_tractor_close( this->tractor );
 235                 //mlt_multitrack_close( this->multitrack );
 236                 free( this );
 237         }
 238 }
 239
 240 /** Remove a filter or transition from the field.
 241  *
 242  * \public \memberof mlt_field_s
 243  * \param self a field
 244  * \param service the filter or transition to remove
 245  */
 246
 247 void mlt_field_disconnect_service( mlt_field self, mlt_service service )
 248 {
 249         mlt_service p = mlt_service_producer( service );
 250         mlt_service c = mlt_service_consumer( service);
 251         int i;
 252         switch ( mlt_service_identify(c) )
 253         {
 254                 case filter_type:
 255                         i = mlt_filter_get_track( MLT_FILTER(c) );
 256                         mlt_service_connect_producer( c, p, i );
 257                         break;
 258                 case transition_type:
 259                         i = mlt_transition_get_a_track ( MLT_TRANSITION(c) );
 260                         mlt_service_connect_producer( c, p, i );
 261                         MLT_TRANSITION(c)->producer = p;
 262                         break;
 263                 case tractor_type:
 264                         self->producer = p;
 265                         mlt_tractor_connect( MLT_TRACTOR(c), p );
 266                 default:
 267                         break;
 268         }
 269         mlt_events_fire( mlt_field_properties( self ), "service-changed", NULL );
 270 }