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

   1 /*
   2  * mlt_tractor.c -- tractor service class
   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
  23 #include "mlt_tractor.h"
  24 #include "mlt_frame.h"
  25 #include "mlt_multitrack.h"
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 /** Private structure.
  32 */
  33
  34 struct mlt_tractor_s
  35 {
  36         struct mlt_producer_s parent;
  37         mlt_service producer;
  38 };
  39
  40 /** Forward references to static methods.
  41 */
  42
  43 static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int track );
  44
  45 /** Constructor for the tractor.
  46
  47         TODO: thread this service...
  48 */
  49
  50 mlt_tractor mlt_tractor_init( )
  51 {
  52         mlt_tractor this = calloc( sizeof( struct mlt_tractor_s ), 1 );
  53         if ( this != NULL )
  54         {
  55                 mlt_producer producer = &this->parent;
  56                 if ( mlt_producer_init( producer, this ) == 0 )
  57                 {
  58                         producer->get_frame = producer_get_frame;
  59                         mlt_properties_set( mlt_producer_properties( producer ), "resource", "<tractor>" );
  60                 }
  61                 else
  62                 {
  63                         free( this );
  64                         this = NULL;
  65                 }
  66         }
  67         return this;
  68 }
  69
  70 /** Get the service object associated to the tractor.
  71 */
  72
  73 mlt_service mlt_tractor_service( mlt_tractor this )
  74 {
  75         return mlt_producer_service( &this->parent );
  76 }
  77
  78 /** Get the producer object associated to the tractor.
  79 */
  80
  81 mlt_producer mlt_tractor_producer( mlt_tractor this )
  82 {
  83         return &this->parent;
  84 }
  85
  86 /** Get the properties object associated to the tractor.
  87 */
  88
  89 mlt_properties mlt_tractor_properties( mlt_tractor this )
  90 {
  91         return mlt_producer_properties( &this->parent );
  92 }
  93
  94 /** Connect the tractor.
  95 */
  96
  97 int mlt_tractor_connect( mlt_tractor this, mlt_service producer )
  98 {
  99         int ret = mlt_service_connect_producer( mlt_tractor_service( this ), producer, 0 );
 100
 101         // This is the producer we're going to connect to
 102         if ( ret == 0 )
 103                 this->producer = producer;
 104
 105         return ret;
 106 }
 107
 108 /** Get the next frame.
 109
 110         TODO: This should be reading a pump being populated by the thread...
 111 */
 112
 113 static int producer_get_frame( mlt_producer parent, mlt_frame_ptr frame, int track )
 114 {
 115         mlt_tractor this = parent->child;
 116
 117         // We only respond to the first track requests
 118         if ( track == 0 && this->producer != NULL )
 119         {
 120                 int i = 0;
 121                 int looking = 1;
 122                 int done = 0;
 123                 mlt_frame temp = NULL;
 124                 mlt_frame store[ 10 ];
 125                 int count = 0;
 126
 127                 // Get the properties of the parent producer
 128                 mlt_properties properties = mlt_producer_properties( parent );
 129
 130                 // Try to obtain the multitrack associated to the tractor
 131                 mlt_multitrack multitrack = mlt_properties_get_data( properties, "multitrack", NULL );
 132
 133                 // If we don't have one, we're in trouble...
 134                 if ( multitrack != NULL )
 135                 {
 136                         mlt_producer target = mlt_multitrack_producer( multitrack );
 137                         mlt_producer_seek( target, mlt_producer_frame( parent ) );
 138                         mlt_producer_set_speed( target, mlt_producer_get_speed( parent ) );
 139                 }
 140                 else
 141                 {
 142                         fprintf( stderr, "tractor without a multitrack!!\n" );
 143                 }
 144
 145                 // Loop through each of the tracks we're harvesting
 146                 for ( i = 0; !done; i ++ )
 147                 {
 148                         // Get a frame from the producer
 149                         mlt_service_get_frame( this->producer, &temp, i );
 150
 151                         // Check for last track
 152                         done = mlt_properties_get_int( mlt_frame_properties( temp ), "last_track" );
 153
 154                         // Handle the frame
 155                         if ( done && looking )
 156                         {
 157                                 // Use this as output if we don't have one already
 158                                 *frame = temp;
 159                         }
 160                         else if ( ( !mlt_frame_is_test_card( temp ) || !mlt_frame_is_test_audio( temp ) ) && looking &&
 161                                             mlt_producer_frame( parent ) == mlt_frame_get_position( temp ) )
 162                         {
 163                                 *frame = temp;
 164                                 looking = 0;
 165                         }
 166                         else
 167                         {
 168                                 // We store all other frames for now
 169                                 store[ count ++ ] = temp;
 170                         }
 171                 }
 172
 173                 // Now place all the unused frames on to the properties (will be destroyed automatically)
 174                 while ( count -- )
 175                 {
 176                         mlt_properties frame_properties = mlt_frame_properties( *frame );
 177                         char label[ 30 ];
 178                         sprintf( label, "tractor_%d", count );
 179                         while ( mlt_properties_get_data( frame_properties, label, NULL ) != NULL )
 180                                 strcat( label, "+" );
 181                         mlt_properties_set_data( frame_properties, label, store[ count ], 0, ( mlt_destructor )mlt_frame_close, NULL );
 182                 }
 183
 184                 // Prepare the next frame
 185                 mlt_producer_prepare_next( parent );
 186
 187                 // Indicate our found status
 188                 return 0;
 189         }
 190         else
 191         {
 192                 // Generate a test card
 193                 *frame = mlt_frame_init( );
 194                 return 0;
 195         }
 196 }
 197
 198 /** Close the tractor.
 199 */
 200
 201 void mlt_tractor_close( mlt_tractor this )
 202 {
 203         mlt_producer_close( &this->parent );
 204         free( this );
 205 }
 206