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 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.
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.
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
21 #include "mlt_filter.h"
22 #include "mlt_frame.h"
28 static int filter_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
30 /** Initialize a new filter.
32 * \public \memberof mlt_filter_s
33 * \param this a filter
34 * \param child the object of a subclass
35 * \return true if there was an error
38 int mlt_filter_init( mlt_filter this, void *child )
40 mlt_service service = &this->parent;
41 memset( this, 0, sizeof( struct mlt_filter_s ) );
43 if ( mlt_service_init( service, this ) == 0 )
45 mlt_properties properties = MLT_SERVICE_PROPERTIES( service );
47 // Override the get_frame method
48 service->get_frame = filter_get_frame;
50 // Define the destructor
51 service->close = ( mlt_destructor )mlt_filter_close;
52 service->close_object = this;
54 // Default in, out, track properties
55 mlt_properties_set_position( properties, "in", 0 );
56 mlt_properties_set_position( properties, "out", 0 );
57 mlt_properties_set_int( properties, "track", 0 );
64 /** Create a new filter and initialize it.
66 * \public \memberof mlt_filter_s
67 * \return a new filter
70 mlt_filter mlt_filter_new( )
72 mlt_filter this = calloc( 1, sizeof( struct mlt_filter_s ) );
74 mlt_filter_init( this, NULL );
78 /** Get the service class interface.
80 * \public \memberof mlt_filter_s
81 * \param this a filter
82 * \return the service parent class
83 * \see MLT_FILTER_SERVICE
86 mlt_service mlt_filter_service( mlt_filter this )
88 return this != NULL ? &this->parent : NULL;
91 /** Get the filter properties.
93 * \public \memberof mlt_filter_s
94 * \param this a filter
95 * \return the properties list for the filter
96 * \see MLT_FILTER_PROPERTIES
99 mlt_properties mlt_filter_properties( mlt_filter this )
101 return MLT_SERVICE_PROPERTIES( MLT_FILTER_SERVICE( this ) );
104 /** Connect this filter to a producers track. Note that a filter only operates
105 * on a single track, and by default it operates on the entirety of that track.
107 * \public \memberof mlt_filter_s
108 * \param this a filter
109 * \param producer the producer to which to connect this filter
110 * \param index which of potentially multiple producers to this service (0 based)
113 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
115 int ret = mlt_service_connect_producer( &this->parent, producer, index );
117 // If the connection was successful, grab the producer, track and reset in/out
120 mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
121 mlt_properties_set_position( properties, "in", 0 );
122 mlt_properties_set_position( properties, "out", 0 );
123 mlt_properties_set_int( properties, "track", index );
129 /** Set the starting and ending time.
131 * \public \memberof mlt_filter_s
132 * \param this a filter
133 * \param in the time relative to the producer at which start applying the filter
134 * \param out the time relative to the producer at which to stop applying the filter
138 void mlt_filter_set_in_and_out( mlt_filter this, mlt_position in, mlt_position out )
140 mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
141 mlt_properties_set_position( properties, "in", in );
142 mlt_properties_set_position( properties, "out", out );
145 /** Return the track that this filter is operating on.
147 * \public \memberof mlt_filter_s
148 * \param this a filter
149 * \return true on error
153 int mlt_filter_get_track( mlt_filter this )
155 mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
156 return mlt_properties_get_int( properties, "track" );
159 /** Get the in point.
161 * \public \memberof mlt_filter_s
162 * \param this a filter
163 * \return the start time for the filter relative to the producer
167 mlt_position mlt_filter_get_in( mlt_filter this )
169 mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
170 return mlt_properties_get_position( properties, "in" );
173 /** Get the out point.
175 * \public \memberof mlt_filter_s
176 * \param this a filter
177 * \return the ending time for the filter relative to the producer
181 mlt_position mlt_filter_get_out( mlt_filter this )
183 mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
184 return mlt_properties_get_position( properties, "out" );
187 /** Process the frame.
189 * \public \memberof mlt_filter_s
190 * \param this a filter
191 * \param frame a frame
196 mlt_frame mlt_filter_process( mlt_filter this, mlt_frame frame )
198 int disable = mlt_properties_get_int( MLT_FILTER_PROPERTIES( this ), "disable" );
199 if ( disable || this->process == NULL )
202 return this->process( this, frame );
205 /** Get a frame from this filter.
207 * \private \memberof mlt_filter_s
208 * \param service a service
209 * \param[out] frame a frame by reference
210 * \param index as determined by the producer
211 * \return true on error
215 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
217 mlt_filter this = service->child;
219 // Get coords in/out/track
220 int track = mlt_filter_get_track( this );
221 int in = mlt_filter_get_in( this );
222 int out = mlt_filter_get_out( this );
224 // Get the producer this is connected to
225 mlt_service producer = mlt_service_producer( &this->parent );
227 // If the frame request is for this filters track, we need to process it
228 if ( index == track || track == -1 )
230 int ret = mlt_service_get_frame( producer, frame, index );
233 mlt_position position = mlt_frame_get_position( *frame );
234 if ( position >= in && ( out == 0 || position <= out ) )
235 *frame = mlt_filter_process( this, *frame );
240 *frame = mlt_frame_init( service );
246 return mlt_service_get_frame( producer, frame, index );
250 /** Close and destroy the filter.
252 * \public \memberof mlt_filter_s
253 * \param this a filter
257 void mlt_filter_close( mlt_filter this )
259 if ( this != NULL && mlt_properties_dec_ref( MLT_FILTER_PROPERTIES( this ) ) <= 0 )
261 if ( this->close != NULL )
267 this->parent.close = NULL;
268 mlt_service_close( &this->parent );