research.m1stereo.tv/gitweb/ - melted/blob - mlt/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
  30 /** Private structure.
  31 */
  32
  33 struct mlt_tractor_s
  34 {
  35         struct mlt_producer_s parent;
  36         mlt_service producer;
  37 };
  38
  39 /** Forward references to static methods.
  40 */
  41
  42 static int producer_get_frame( mlt_producer this, mlt_frame_ptr frame, int track );
  43
  44 /** Constructor for the tractor.
  45
  46         TODO: thread this service...
  47 */
  48
  49 mlt_tractor mlt_tractor_init( )
  50 {
  51         mlt_tractor this = calloc( sizeof( struct mlt_tractor_s ), 1 );
  52         if ( this != NULL )
  53         {
  54                 mlt_producer producer = &this->parent;
  55                 if ( mlt_producer_init( producer, this ) == 0 )
  56                 {
  57                         producer->get_frame = producer_get_frame;
  58                 }
  59                 else
  60                 {
  61                         free( this );
  62                         this = NULL;
  63                 }
  64         }
  65         return this;
  66 }
  67
  68 /** Get the service object associated to the tractor.
  69 */
  70
  71 mlt_service mlt_tractor_service( mlt_tractor this )
  72 {
  73         return mlt_producer_service( &this->parent );
  74 }
  75
  76 /** Get the producer object associated to the tractor.
  77 */
  78
  79 mlt_producer mlt_tractor_producer( mlt_tractor this )
  80 {
  81         return &this->parent;
  82 }
  83
  84 /** Get the properties object associated to the tractor.
  85 */
  86
  87 mlt_properties mlt_tractor_properties( mlt_tractor this )
  88 {
  89         return mlt_producer_properties( &this->parent );
  90 }
  91
  92 /** Connect the tractor.
  93 */
  94
  95 int mlt_tractor_connect( mlt_tractor this, mlt_service producer )
  96 {
  97         int ret = mlt_service_connect_producer( mlt_tractor_service( this ), producer, 0 );
  98
  99         // This is the producer we're going to connect to
 100         if ( ret == 0 )
 101                 this->producer = producer;
 102
 103         return ret;
 104 }
 105
 106 /** Get the next frame.
 107
 108         TODO: This should be reading a pump being populated by the thread...
 109 */
 110
 111 static int producer_get_frame( mlt_producer parent, mlt_frame_ptr frame, int track )
 112 {
 113         mlt_tractor this = parent->child;
 114
 115         // We only respond to the first track requests
 116         if ( track == 0 && this->producer != NULL )
 117         {
 118                 int i = 0;
 119                 int looking = 1;
 120                 int done = 0;
 121                 mlt_frame temp = NULL;
 122
 123                 // Get the properties of the parent producer
 124                 mlt_properties properties = mlt_producer_properties( parent );
 125
 126                 // Try to obtain the multitrack associated to the tractor
 127                 mlt_multitrack multitrack = mlt_properties_get_data( properties, "multitrack", NULL );
 128
 129                 // If we don't have one, we're in trouble...
 130                 if ( multitrack != NULL )
 131                 {
 132                         mlt_producer target = mlt_multitrack_producer( multitrack );
 133                         mlt_producer_seek( target, mlt_producer_frame( parent ) );
 134                         mlt_producer_set_speed( target, mlt_producer_get_speed( parent ) );
 135                         mlt_producer_set_in_and_out( parent, mlt_producer_get_in( target ), mlt_producer_get_out( target ) );
 136                 }
 137                 else
 138                 {
 139                         fprintf( stderr, "tractor without a multitrack!!\n" );
 140                 }
 141
 142                 // Loop through each of the tracks we're harvesting
 143                 for ( i = 0; !done; i ++ )
 144                 {
 145                         // Get a frame from the producer
 146                         mlt_service_get_frame( this->producer, &temp, i );
 147
 148                         // Check for last track
 149                         done = mlt_properties_get_int( mlt_frame_properties( temp ), "last_track" );
 150
 151                         // Handle the frame
 152                         if ( done && looking )
 153                         {
 154                                 // Use this as output if we don't have one already
 155                                 *frame = temp;
 156                         }
 157                         else if ( ( !mlt_frame_is_test_card( temp ) || !mlt_frame_is_test_audio( temp ) ) &&
 158                                             mlt_producer_frame( parent ) == mlt_properties_get_position( mlt_frame_properties( temp ), "position" ) )
 159                         {
 160                                 *frame = temp;
 161                                 looking = 0;
 162                         }
 163                         else if ( ( !mlt_frame_is_test_card( temp ) || !mlt_frame_is_test_audio( temp ) ) && looking )
 164                         {
 165                                 // This is the one we want and we can stop looking
 166                                 *frame = temp;
 167                                 looking = 0;
 168                         }
 169                         else
 170                         {
 171                                 // We discard all other frames
 172                                 mlt_frame_close( temp );
 173                         }
 174                 }
 175
 176                 // Prepare the next frame
 177                 mlt_producer_prepare_next( parent );
 178
 179                 // Indicate our found status
 180                 return 0;
 181         }
 182         else
 183         {
 184                 // Generate a test card
 185                 *frame = mlt_frame_init( );
 186                 return 0;
 187         }
 188 }
 189
 190 /** Close the tractor.
 191 */
 192
 193 void mlt_tractor_close( mlt_tractor this )
 194 {
 195         mlt_producer_close( &this->parent );
 196         free( this );
 197 }
 198