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 "filter_data.h"
  24 #include <framework/mlt.h>
  25
  26 /** This filter should be used in conjuction with the data_show filter.
  27         The concept of the data_feed is that it can be used to pass titles
  28         or images to render on the frame, but doesn't actually do it
  29         itself. data_feed imposes few rules on what's passed on and the
  30         validity is confirmed in data_show before use.
  31 */
  32
  33 /** Data queue destructor.
  34 */
  35
  36 static void destroy_data_queue( void *arg )
  37 {
  38         if ( arg != NULL )
  39         {
  40                 // Assign the correct type
  41                 mlt_deque queue = arg;
  42
  43                 // Iterate through each item and destroy them
  44                 while ( mlt_deque_peek_front( queue ) != NULL )
  45                         mlt_properties_close( mlt_deque_pop_back( queue ) );
  46
  47                 // Close the deque
  48                 mlt_deque_close( queue );
  49         }
  50 }
  51
  52 /** Filter processing.
  53 */
  54
  55 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
  56 {
  57         // Get the filter properties
  58         mlt_properties filter_properties = MLT_FILTER_PROPERTIES( this );
  59
  60         // Get the frame properties
  61         mlt_properties frame_properties = MLT_FRAME_PROPERTIES( frame );
  62
  63         // Get the data queue
  64         mlt_deque data_queue = mlt_properties_get_data( frame_properties, "data_queue", NULL );
  65
  66         // Get the type of the data feed
  67         char *type = mlt_properties_get( filter_properties, "type" );
  68
  69         // Get the in and out points of this filter
  70         int in = mlt_filter_get_in( this );
  71         int out = mlt_filter_get_out( this );
  72
  73         // Create the data queue if it doesn't exist
  74         if ( data_queue == NULL )
  75         {
  76                 // Create the queue
  77                 data_queue = mlt_deque_init( );
  78
  79                 // Assign it to the frame with the destructor
  80                 mlt_properties_set_data( frame_properties, "data_queue", data_queue, 0, destroy_data_queue, NULL );
  81         }
  82
  83         // Now create the data feed
  84         if ( data_queue != NULL && type != NULL && !strcmp( type, "attr_check" ) )
  85         {
  86                 int i = 0;
  87                 int count = mlt_properties_count( frame_properties );
  88
  89                 for ( i = 0; i < count; i ++ )
  90                 {
  91                         char *name = mlt_properties_get_name( frame_properties, i );
  92
  93                         // Only deal with meta.attr.name values here - these should have a value of 1 to be considered
  94                         // Additional properties of the form are meta.attr.name.property are passed down on the feed
  95                         if ( !strncmp( name, "meta.attr.", 10 ) && strchr( name + 10, '.' ) == NULL && mlt_properties_get_int( frame_properties, name ) == 1 )
  96                         {
  97                                 // Temp var to hold name + '.' for pass method
  98                                 char temp[ 132 ];
  99
 100                                 // Create a new data feed
 101                                 mlt_properties feed = mlt_properties_new( );
 102
 103                                 // Assign it the base properties
 104                                 mlt_properties_set( feed, "id", mlt_properties_get( filter_properties, "_unique_id" ) );
 105                                 mlt_properties_set( feed, "type", strrchr( name, '.' ) + 1 );
 106                                 mlt_properties_set_position( feed, "position", mlt_frame_get_position( frame ) );
 107
 108                                 // Assign in/out of service we're connected to
 109                                 mlt_properties_set_position( feed, "in", mlt_properties_get_position( frame_properties, "in" ) );
 110                                 mlt_properties_set_position( feed, "out", mlt_properties_get_position( frame_properties, "out" ) );
 111
 112                                 // Pass all meta properties
 113                                 sprintf( temp, "%s.", name );
 114                                 mlt_properties_pass( feed, frame_properties, temp );
 115
 116                                 // Push it on to the queue
 117                                 mlt_deque_push_back( data_queue, feed );
 118
 119                                 // Make sure this attribute only gets processed once
 120                                 mlt_properties_set_int( frame_properties, name, 0 );
 121                         }
 122                 }
 123         }
 124         else if ( data_queue != NULL )
 125         {
 126                 // Create a new data feed
 127                 mlt_properties feed = mlt_properties_new( );
 128
 129                 // Assign it the base properties
 130                 mlt_properties_set( feed, "id", mlt_properties_get( filter_properties, "_unique_id" ) );
 131                 mlt_properties_set( feed, "type", type );
 132                 mlt_properties_set_position( feed, "position", mlt_frame_get_position( frame ) );
 133
 134                 // Assign in/out of service we're connected to
 135                 mlt_properties_set_position( feed, "in", mlt_properties_get_position( frame_properties, "in" ) );
 136                 mlt_properties_set_position( feed, "out", mlt_properties_get_position( frame_properties, "out" ) );
 137
 138                 // Correct in/out to the filter if specified
 139                 if ( in != 0 )
 140                         mlt_properties_set_position( feed, "in", in );
 141                 if ( out != 0 )
 142                         mlt_properties_set_position( feed, "out", out );
 143
 144                 // Pass the properties which start with a "feed." prefix
 145                 // Note that 'feed.text' in the filter properties becomes 'text' on the feed
 146                 mlt_properties_pass( feed, filter_properties, "feed." );
 147
 148                 // Push it on to the queue
 149                 mlt_deque_push_back( data_queue, feed );
 150         }
 151
 152         return frame;
 153 }
 154
 155 /** Constructor for the filter.
 156 */
 157
 158 mlt_filter filter_data_feed_init( char *arg )
 159 {
 160         // Create the filter
 161         mlt_filter this = mlt_filter_new( );
 162
 163         // Initialise it
 164         if ( this != NULL )
 165         {
 166                 // Get the properties
 167                 mlt_properties properties = MLT_FILTER_PROPERTIES( this );
 168
 169                 // Assign the argument (default to titles)
 170                 mlt_properties_set( properties, "type", arg == NULL ? "titles" : arg );
 171
 172                 // Specify the processing method
 173                 this->process = filter_process;
 174         }
 175
 176         return this;
 177 }
 178