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

   1 /*
   2  * mlt_field.c -- A field for planting multiple transitions and filters
   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 "mlt_field.h"
  22 #include "mlt_service.h"
  23 #include "mlt_filter.h"
  24 #include "mlt_transition.h"
  25 #include "mlt_multitrack.h"
  26 #include "mlt_tractor.h"
  27
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 /** Private structures.
  32 */
  33
  34 struct mlt_field_s
  35 {
  36         // This is the producer we're connected to
  37         mlt_service producer;
  38
  39         // Multitrack
  40         mlt_multitrack multitrack;
  41
  42         // Tractor
  43         mlt_tractor tractor;
  44 };
  45
  46 /** Constructor.
  47
  48         We construct a multitrack and a tractor here.
  49 */
  50
  51 mlt_field mlt_field_init( )
  52 {
  53         // Initialise the field
  54         mlt_field this = calloc( sizeof( struct mlt_field_s ), 1 );
  55
  56         // Initialise it
  57         if ( this != NULL )
  58         {
  59                 // Construct a multitrack
  60                 this->multitrack = mlt_multitrack_init( );
  61
  62                 // Construct a tractor
  63                 this->tractor = mlt_tractor_init( );
  64
  65                 // The first plant will be connected to the mulitrack
  66                 this->producer = mlt_multitrack_service( this->multitrack );
  67
  68                 // Connect the tractor to the multitrack
  69                 mlt_tractor_connect( this->tractor, this->producer );
  70         }
  71
  72         // Return this
  73         return this;
  74 }
  75
  76 /** Get the service associated to this field.
  77 */
  78
  79 mlt_service mlt_field_service( mlt_field this )
  80 {
  81         return mlt_tractor_service( this->tractor );
  82 }
  83
  84 /** Get the multi track.
  85 */
  86
  87 mlt_multitrack mlt_field_multitrack( mlt_field this )
  88 {
  89         return this->multitrack;
  90 }
  91
  92 /** Get the properties associated to this field.
  93 */
  94
  95 mlt_properties mlt_field_properties( mlt_field this )
  96 {
  97         return mlt_service_properties( mlt_field_service( this ) );
  98 }
  99
 100 /** Plant a filter.
 101 */
 102
 103 int mlt_field_plant_filter( mlt_field this, mlt_filter that, int track )
 104 {
 105         // Connect the filter to the last producer
 106         int result = mlt_filter_connect( that, this->producer, track );
 107
 108         // If sucessful, then we'll use this for connecting in the future
 109         if ( result == 0 )
 110         {
 111                 // This is now the new producer
 112                 this->producer = mlt_filter_service( that );
 113
 114                 // Reconnect tractor to new producer
 115                 mlt_tractor_connect( this->tractor, this->producer );
 116         }
 117
 118         return result;
 119 }
 120
 121 /** Plant a transition.
 122 */
 123
 124 int mlt_field_plant_transition( mlt_field this, mlt_transition that, int a_track, int b_track )
 125 {
 126         // Connect the transition to the last producer
 127         int result = mlt_transition_connect( that, this->producer, a_track, b_track );
 128
 129         // If sucessful, then we'll use this for connecting in the future
 130         if ( result == 0 )
 131         {
 132                 // This is now the new producer
 133                 this->producer = mlt_transition_service( that );
 134
 135                 // Reconnect tractor to new producer
 136                 mlt_tractor_connect( this->tractor, this->producer );
 137         }
 138
 139         return 0;
 140 }
 141
 142 /** Close the field.
 143 */
 144
 145 void mlt_field_close( mlt_field this )
 146 {
 147         mlt_tractor_close( this->tractor );
 148         mlt_multitrack_close( this->multitrack );
 149         free( this );
 150 }
 151