2 * mlt_service.c -- interface for all service classes
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.
22 #include "mlt_service.h"
23 #include "mlt_frame.h"
30 The base service implements a null frame producing service - as such,
31 it is functional without extension and will produce test cards frames
32 and PAL sized audio frames.
34 PLEASE DO NOT CHANGE THIS BEHAVIOUR!!! OVERRIDE THE METHODS THAT
35 CONTROL THIS IN EXTENDING CLASSES.
38 /** Private service definition.
53 static void mlt_service_disconnect( mlt_service
this );
54 static void mlt_service_connect( mlt_service
this, mlt_service that
);
55 static int service_get_frame( mlt_service
this, mlt_frame_ptr frame
, int index
);
60 int mlt_service_init( mlt_service
this, void *child
)
62 // Initialise everything to NULL
63 memset( this, 0, sizeof( struct mlt_service_s
) );
68 // Generate private space
69 this->private = calloc( sizeof( mlt_service_base
), 1 );
71 // Associate the methods
72 this->get_frame
= service_get_frame
;
74 // Initialise the properties
75 return mlt_properties_init( &this->parent
, this );
78 /** Return the properties object.
81 mlt_properties
mlt_service_properties( mlt_service
this )
86 /** Connect a producer service.
87 Returns: > 0 warning, == 0 success, < 0 serious error
88 1 = this service does not accept input
89 2 = the producer is invalid
90 3 = the producer is already registered with this consumer
93 int mlt_service_connect_producer( mlt_service
this, mlt_service producer
, int index
)
97 // Get the service base
98 mlt_service_base
*base
= this->private;
100 // Does this service accept input?
101 if ( mlt_service_accepts_input( this ) == 0 )
104 // Does the producer service accept output connections?
105 if ( mlt_service_accepts_output( producer
) == 0 )
108 // Check if the producer is already registered with this service
109 for ( i
= 0; i
< base
->count
; i
++ )
110 if ( base
->in
[ i
] == producer
)
114 if ( index
>= base
->size
)
116 int new_size
= base
->size
+ index
+ 10;
117 base
->in
= realloc( base
->in
, new_size
* sizeof( mlt_service
) );
118 if ( base
->in
!= NULL
)
120 for ( i
= base
->size
; i
< new_size
; i
++ )
121 base
->in
[ i
] = NULL
;
122 base
->size
= new_size
;
126 // If we have space, assign the input
127 if ( base
->in
!= NULL
&& index
>= 0 && index
< base
->size
)
129 // Now we disconnect the producer service from its consumer
130 mlt_service_disconnect( producer
);
132 // Add the service to index specified
133 base
->in
[ index
] = producer
;
135 // Determine the number of active tracks
136 if ( index
>= base
->count
)
137 base
->count
= index
+ 1;
139 // Now we connect the producer to its connected consumer
140 mlt_service_connect( producer
, this );
142 // Inform caller that all went well
151 /** Disconnect this service from its consumer.
154 void mlt_service_disconnect( mlt_service
this )
156 // Get the service base
157 mlt_service_base
*base
= this->private;
159 // There's a bit more required here...
163 /** Associate this service to the its consumer.
166 void mlt_service_connect( mlt_service
this, mlt_service that
)
168 // Get the service base
169 mlt_service_base
*base
= this->private;
171 // There's a bit more required here...
176 /** Get the first connected producer service.
179 mlt_service
mlt_service_get_producer( mlt_service
this )
181 mlt_service producer
= NULL
;
183 // Get the service base
184 mlt_service_base
*base
= this->private;
186 if ( base
->in
!= NULL
)
187 producer
= base
->in
[ 0 ];
193 /** Get the service state.
196 mlt_service_state
mlt_service_get_state( mlt_service
this )
198 mlt_service_state state
= mlt_state_unknown
;
199 if ( mlt_service_has_input( this ) )
200 state
|= mlt_state_providing
;
201 if ( mlt_service_has_output( this ) )
202 state
|= mlt_state_connected
;
203 if ( state
!= ( mlt_state_providing
| mlt_state_connected
) )
204 state
|= mlt_state_dormant
;
208 /** Get the maximum number of inputs accepted.
209 Returns: -1 for many, 0 for none or n for fixed.
212 int mlt_service_accepts_input( mlt_service
this )
214 if ( this->accepts_input
== NULL
)
217 return this->accepts_input( this );
220 /** Get the maximum number of outputs accepted.
223 int mlt_service_accepts_output( mlt_service
this )
225 if ( this->accepts_output
== NULL
)
228 return this->accepts_output( this );
231 /** Determines if this service has input
234 int mlt_service_has_input( mlt_service
this )
236 if ( this->has_input
== NULL
)
239 return this->has_input( this );
242 /** Determine if this service has output
245 int mlt_service_has_output( mlt_service
this )
247 mlt_service_base
*base
= this->private;
248 if ( this->has_output
== NULL
)
249 return base
->out
!= NULL
;
251 return this->has_output( this );
254 /** Check if the service is active.
257 int mlt_service_is_active( mlt_service
this )
259 return !( mlt_service_get_state( this ) & mlt_state_dormant
);
262 /** Obtain a frame to pass on.
265 static int service_get_frame( mlt_service
this, mlt_frame_ptr frame
, int index
)
267 mlt_service_base
*base
= this->private;
268 if ( index
< base
->count
)
270 mlt_service producer
= base
->in
[ index
];
271 if ( producer
!= NULL
)
272 return mlt_service_get_frame( producer
, frame
, index
);
274 *frame
= mlt_frame_init( );
278 int mlt_service_get_frame( mlt_service
this, mlt_frame_ptr frame
, int index
)
280 return this->get_frame( this, frame
, index
);
283 /** Close the service.
286 void mlt_service_close( mlt_service
this )
288 mlt_service_base
*base
= this->private;
291 mlt_properties_close( &this->parent
);