research.m1stereo.tv/gitweb/ - melted/blob - src/modules/core/filter_data_feed.c

   1 /*
   2  * filter_data_feed.c -- data feed filter
   3  * Copyright (C) 2004-2005 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <framework/mlt.h>
  24
  25 /** This filter should be used in conjuction with the data_show filter.
  26         The concept of the data_feed is that it can be used to pass titles
  27         or images to render on the frame, but doesn't actually do it
  28         itself. data_feed imposes few rules on what's passed on and the
  29         validity is confirmed in data_show before use.
  30 */
  31
  32 /** Data queue destructor.
  33 */
  34
  35 static void destroy_data_queue( void *arg )
  36 {
  37         if ( arg != NULL )
  38         {
  39                 // Assign the correct type
  40                 mlt_deque queue = arg;
  41
  42                 // Iterate through each item and destroy them
  43                 while ( mlt_deque_peek_front( queue ) != NULL )
  44                         mlt_properties_close( mlt_deque_pop_back( queue ) );
  45
  46                 // Close the deque
  47                 mlt_deque_close( queue );
  48         }
  49 }
  50
  51 /** Filter processing.
  52 */
  53
  54 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
  55 {
  56         // Get the filter properties
  57         mlt_properties filter_properties = MLT_FILTER_PROPERTIES( this );
  58
  59         // Get the frame properties
  60         mlt_properties frame_properties = MLT_FRAME_PROPERTIES( frame );
  61
  62         // Get the data queue
  63         mlt_deque data_queue = mlt_properties_get_data( frame_properties, "data_queue", NULL );
  64
  65         // Get the type of the data feed
  66         char *type = mlt_properties_get( filter_properties, "type" );
  67
  68         // Get the in and out points of this filter
  69         int in = mlt_filter_get_in( this );
  70         int out = mlt_filter_get_out( this );
  71
  72         // Create the data queue if it doesn't exist
  73         if ( data_queue == NULL )
  74         {
  75                 // Create the queue
  76                 data_queue = mlt_deque_init( );
  77
  78                 // Assign it to the frame with the destructor
  79                 mlt_properties_set_data( frame_properties, "data_queue", data_queue, 0, destroy_data_queue, NULL );
  80         }
  81
  82         // Now create the data feed
  83         if ( data_queue != NULL && type != NULL && !strcmp( type, "attr_check" ) )
  84         {
  85                 int i = 0;
  86                 int count = mlt_properties_count( frame_properties );
  87
  88                 for ( i = 0; i < count; i ++ )
  89                 {
  90                         char *name = mlt_properties_get_name( frame_properties, i );
  91
  92                         // Only deal with meta.attr.name values here - these should have a value of 1 to be considered
  93                         // Additional properties of the form are meta.attr.name.property are passed down on the feed
  94                         if ( !strncmp( name, "meta.attr.", 10 ) && strchr( name + 10, '.' ) == NULL && mlt_properties_get_int( frame_properties, name ) == 1 )
  95                         {
  96                                 // Temp var to hold name + '.' for pass method
  97                                 char temp[ 132 ];
  98
  99                                 // Create a new data feed
 100                                 mlt_properties feed = mlt_properties_new( );
 101
 102                                 // Assign it the base properties
 103                                 mlt_properties_set( feed, "id", mlt_properties_get( filter_properties, "_unique_id" ) );
 104                                 mlt_properties_set( feed, "type", strrchr( name, '.' ) + 1 );
 105                                 mlt_properties_set_position( feed, "position", mlt_frame_get_position( frame ) );
 106
 107                                 // Assign in/out of service we're connected to
 108                                 mlt_properties_set_position( feed, "in", mlt_properties_get_position( frame_properties, "in" ) );
 109                                 mlt_properties_set_position( feed, "out", mlt_properties_get_position( frame_properties, "out" ) );
 110
 111                                 // Pass all meta properties
 112                                 sprintf( temp, "%s.", name );
 113                                 mlt_properties_pass( feed, frame_properties, temp );
 114
 115                                 // Push it on to the queue
 116                                 mlt_deque_push_back( data_queue, feed );
 117
 118                                 // Make sure this attribute only gets processed once
 119                                 mlt_properties_set_int( frame_properties, name, 0 );
 120                         }
 121                 }
 122         }
 123         else if ( data_queue != NULL )
 124         {
 125                 // Create a new data feed
 126                 mlt_properties feed = mlt_properties_new( );
 127
 128                 // Assign it the base properties
 129                 mlt_properties_set( feed, "id", mlt_properties_get( filter_properties, "_unique_id" ) );
 130                 mlt_properties_set( feed, "type", type );
 131                 mlt_properties_set_position( feed, "position", mlt_frame_get_position( frame ) );
 132
 133                 // Assign in/out of service we're connected to
 134                 mlt_properties_set_position( feed, "in", mlt_properties_get_position( frame_properties, "in" ) );
 135                 mlt_properties_set_position( feed, "out", mlt_properties_get_position( frame_properties, "out" ) );
 136
 137                 // Correct in/out to the filter if specified
 138                 if ( in != 0 )
 139                         mlt_properties_set_position( feed, "in", in );
 140                 if ( out != 0 )
 141                         mlt_properties_set_position( feed, "out", out );
 142
 143                 // Pass the properties which start with a "feed." prefix
 144                 // Note that 'feed.text' in the filter properties becomes 'text' on the feed
 145                 mlt_properties_pass( feed, filter_properties, "feed." );
 146
 147                 // Push it on to the queue
 148                 mlt_deque_push_back( data_queue, feed );
 149         }
 150
 151         return frame;
 152 }
 153
 154 /** Constructor for the filter.
 155 */
 156
 157 mlt_filter filter_data_feed_init( mlt_profile profile, mlt_service_type type, const char *id, char *arg )
 158 {
 159         // Create the filter
 160         mlt_filter this = mlt_filter_new( );
 161
 162         // Initialise it
 163         if ( this != NULL )
 164         {
 165                 // Get the properties
 166                 mlt_properties properties = MLT_FILTER_PROPERTIES( this );
 167
 168                 // Assign the argument (default to titles)
 169                 mlt_properties_set( properties, "type", arg == NULL ? "titles" : arg );
 170
 171                 // Specify the processing method
 172                 this->process = filter_process;
 173         }
 174
 175         return this;
 176 }
 177