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 static void producer_close( mlt_producer this );
  45
  46 /** Constructor for the tractor.
  47
  48         TODO: thread this service...
  49 */
  50
  51 mlt_tractor mlt_tractor_init( )
  52 {
  53         mlt_tractor this = calloc( sizeof( struct mlt_tractor_s ), 1 );
  54         if ( this != NULL )
  55         {
  56                 mlt_producer producer = &this->parent;
  57                 if ( mlt_producer_init( producer, this ) == 0 )
  58                 {
  59                         mlt_properties_set( mlt_producer_properties( producer ), "resource", "<tractor>" );
  60                         mlt_properties_set( mlt_producer_properties( producer ), "mlt_type", "mlt_producer" );
  61                         mlt_properties_set( mlt_producer_properties( producer ), "mlt_service", "tractor" );
  62
  63                         producer->get_frame = producer_get_frame;
  64                         producer->close = producer_close;
  65                 }
  66                 else
  67                 {
  68                         free( this );
  69                         this = NULL;
  70                 }
  71         }
  72         return this;
  73 }
  74
  75 /** Get the service object associated to the tractor.
  76 */
  77
  78 mlt_service mlt_tractor_service( mlt_tractor this )
  79 {
  80         return mlt_producer_service( &this->parent );
  81 }
  82
  83 /** Get the producer object associated to the tractor.
  84 */
  85
  86 mlt_producer mlt_tractor_producer( mlt_tractor this )
  87 {
  88         return &this->parent;
  89 }
  90
  91 /** Get the properties object associated to the tractor.
  92 */
  93
  94 mlt_properties mlt_tractor_properties( mlt_tractor this )
  95 {
  96         return mlt_producer_properties( &this->parent );
  97 }
  98
  99 /** Connect the tractor.
 100 */
 101
 102 int mlt_tractor_connect( mlt_tractor this, mlt_service producer )
 103 {
 104         int ret = mlt_service_connect_producer( mlt_tractor_service( this ), producer, 0 );
 105
 106         // This is the producer we're going to connect to
 107         if ( ret == 0 )
 108                 this->producer = producer;
 109
 110         return ret;
 111 }
 112
 113 /** Get the next frame.
 114
 115         TODO: This should be reading a pump being populated by the thread...
 116 */
 117
 118 static int producer_get_frame( mlt_producer parent, mlt_frame_ptr frame, int track )
 119 {
 120         mlt_tractor this = parent->child;
 121
 122         // We only respond to the first track requests
 123         if ( track == 0 && this->producer != NULL )
 124         {
 125                 int i = 0;
 126                 int looking = 1;
 127                 int done = 0;
 128                 mlt_frame temp = NULL;
 129                 mlt_frame store[ 10 ];
 130                 int count = 0;
 131
 132                 // Get the properties of the parent producer
 133                 mlt_properties properties = mlt_producer_properties( parent );
 134
 135                 // Try to obtain the multitrack associated to the tractor
 136                 mlt_multitrack multitrack = mlt_properties_get_data( properties, "multitrack", NULL );
 137
 138                 // Or a specific producer
 139                 mlt_producer producer = mlt_properties_get_data( properties, "producer", NULL );
 140
 141                 // If we don't have one, we're in trouble...
 142                 if ( multitrack != NULL )
 143                 {
 144                         mlt_producer target = mlt_multitrack_producer( multitrack );
 145                         mlt_producer_seek( target, mlt_producer_frame( parent ) );
 146                         mlt_producer_set_speed( target, mlt_producer_get_speed( parent ) );
 147
 148                         // Loop through each of the tracks we're harvesting
 149                         for ( i = 0; !done; i ++ )
 150                         {
 151                                 // Get a frame from the producer
 152                                 mlt_service_get_frame( this->producer, &temp, i );
 153
 154                                 // Check for last track
 155                                 done = mlt_properties_get_int( mlt_frame_properties( temp ), "last_track" );
 156
 157                                 // Handle the frame
 158                                 if ( done && looking )
 159                                 {
 160                                         // Use this as output if we don't have one already
 161                                         *frame = temp;
 162                                 }
 163                                 else if ( ( !mlt_frame_is_test_card( temp ) || !mlt_frame_is_test_audio( temp ) ) && looking &&
 164                                                 mlt_producer_frame( parent ) == mlt_frame_get_position( temp ) )
 165                                 {
 166                                         *frame = temp;
 167                                         looking = 0;
 168                                 }
 169                                 else
 170                                 {
 171                                         // We store all other frames for now
 172                                         store[ count ++ ] = temp;
 173                                 }
 174                         }
 175
 176                         // Now place all the unused frames on to the properties (will be destroyed automatically)
 177                         while ( count -- )
 178                         {
 179                                 mlt_properties frame_properties = mlt_frame_properties( *frame );
 180                                 char label[ 30 ];
 181                                 sprintf( label, "tractor_%d", count );
 182                                 while ( mlt_properties_get_data( frame_properties, label, NULL ) != NULL )
 183                                         strcat( label, "+" );
 184                                 mlt_properties_set_data( frame_properties, label, store[ count ], 0, ( mlt_destructor )mlt_frame_close, NULL );
 185                         }
 186                 }
 187                 else if ( producer != NULL )
 188                 {
 189                         mlt_producer_seek( producer, mlt_producer_frame( parent ) );
 190                         mlt_producer_set_speed( producer, mlt_producer_get_speed( parent ) );
 191                         mlt_service_get_frame( this->producer, frame, track );
 192                 }
 193                 else
 194                 {
 195                         fprintf( stderr, "tractor without a multitrack!!\n" );
 196                         mlt_service_get_frame( this->producer, frame, track );
 197                 }
 198
 199                 // Prepare the next frame
 200                 mlt_producer_prepare_next( parent );
 201
 202                 // Indicate our found status
 203                 return 0;
 204         }
 205         else
 206         {
 207                 // Generate a test card
 208                 *frame = mlt_frame_init( );
 209                 return 0;
 210         }
 211 }
 212
 213 /** Close the tractor.
 214 */
 215
 216 void mlt_tractor_close( mlt_tractor this )
 217 {
 218         this->parent.close = NULL;
 219         mlt_producer_close( &this->parent );
 220         free( this );
 221 }
 222
 223 /** Close the producer.
 224 */
 225
 226 static void producer_close( mlt_producer this )
 227 {
 228         mlt_tractor_close( this->child );
 229 }
 230