2 * mlt_filter.c -- abstraction for all filter services
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Charles Yates <charles.yates@pandora.be>
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.
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.
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.
23 #include "mlt_filter.h"
24 #include "mlt_frame.h"
30 static int filter_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
32 /** Constructor method.
35 int mlt_filter_init( mlt_filter this, void *child )
37 mlt_service service = &this->parent;
38 memset( this, 0, sizeof( struct mlt_filter_s ) );
40 if ( mlt_service_init( service, this ) == 0 )
42 service->get_frame = filter_get_frame;
48 /** Get the service associated to this filter
51 mlt_service mlt_filter_service( mlt_filter this )
56 /** Connect this filter to a producers track. Note that a filter only operates
57 on a single track, and by default it operates on the entirety of that track.
60 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
62 int ret = mlt_service_connect_producer( &this->parent, producer, index );
64 // If the connection was successful, grab the producer, track and reset in/out
67 this->producer = producer;
76 /** Tune the in/out points.
79 void mlt_filter_set_in_and_out( mlt_filter this, mlt_timecode in, mlt_timecode out )
85 /** Return the track that this filter is operating on.
88 int mlt_filter_get_track( mlt_filter this )
96 mlt_timecode mlt_filter_get_in( mlt_filter this )
101 /** Get the out point.
104 mlt_timecode mlt_filter_get_out( mlt_filter this )
109 /** Process the frame.
112 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
114 if ( this->process == NULL )
117 return this->process( this, frame );
120 /** Get a frame from this filter.
123 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
125 mlt_filter this = service->child;
127 // If the frame request is for this filters track, we need to process it
128 if ( index == this->track )
130 int ret = mlt_service_get_frame( this->producer, frame, index );
133 if ( !mlt_frame_is_test_card( *frame ) )
135 mlt_timecode timecode = mlt_frame_get_timecode( *frame );
136 if ( timecode >= this->in && ( this->out == 0 || timecode < this->out ) )
137 *frame = filter_process( this, *frame );
143 *frame = mlt_frame_init( );
149 return mlt_service_get_frame( this->producer, frame, index );
153 /** Close the filter.
156 void mlt_filter_close( mlt_filter this )
158 if ( this->close != NULL )
161 mlt_service_close( &this->parent );