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 /** Connect a producer service.
79 Returns: > 0 warning, == 0 success, < 0 serious error
80 1 = this service does not accept input
81 2 = the producer is invalid
82 3 = the producer is already registered with this consumer
85 int mlt_service_connect_producer( mlt_service
this, mlt_service producer
, int index
)
89 // Get the service base
90 mlt_service_base
*base
= this->private;
92 // Does this service accept input?
93 if ( mlt_service_accepts_input( this ) == 0 )
96 // Does the producer service accept output connections?
97 if ( mlt_service_accepts_output( producer
) == 0 )
100 // Check if the producer is already registered with this service
101 for ( i
= 0; i
< base
->count
; i
++ )
102 if ( base
->in
[ i
] == producer
)
106 if ( index
>= base
->size
)
108 int new_size
= base
->size
+ index
+ 10;
109 base
->in
= realloc( base
->in
, new_size
* sizeof( mlt_service
) );
110 if ( base
->in
!= NULL
)
112 for ( i
= base
->size
; i
< new_size
; i
++ )
113 base
->in
[ i
] = NULL
;
114 base
->size
= new_size
;
118 // If we have space, assign the input
119 if ( base
->in
!= NULL
&& index
>= 0 && index
< base
->size
)
121 // Now we disconnect the producer service from its consumer
122 mlt_service_disconnect( producer
);
124 // Add the service to index specified
125 base
->in
[ index
] = producer
;
127 // Determine the number of active tracks
128 if ( index
>= base
->count
)
129 base
->count
= index
+ 1;
131 // Now we connect the producer to its connected consumer
132 mlt_service_connect( producer
, this );
134 // Inform caller that all went well
143 /** Disconnect this service from its consumer.
146 void mlt_service_disconnect( mlt_service
this )
148 // Get the service base
149 mlt_service_base
*base
= this->private;
151 // There's a bit more required here...
155 /** Associate this service to the its consumer.
158 void mlt_service_connect( mlt_service
this, mlt_service that
)
160 // Get the service base
161 mlt_service_base
*base
= this->private;
163 // There's a bit more required here...
168 /** Get the first connected producer service.
171 mlt_service
mlt_service_get_producer( mlt_service
this )
173 mlt_service producer
= NULL
;
175 // Get the service base
176 mlt_service_base
*base
= this->private;
178 if ( base
->in
!= NULL
)
179 producer
= base
->in
[ 0 ];
185 /** Get the service state.
188 mlt_service_state
mlt_service_get_state( mlt_service
this )
190 mlt_service_state state
= mlt_state_unknown
;
191 if ( mlt_service_has_input( this ) )
192 state
|= mlt_state_providing
;
193 if ( mlt_service_has_output( this ) )
194 state
|= mlt_state_connected
;
195 if ( state
!= ( mlt_state_providing
| mlt_state_connected
) )
196 state
|= mlt_state_dormant
;
200 /** Get the maximum number of inputs accepted.
201 Returns: -1 for many, 0 for none or n for fixed.
204 int mlt_service_accepts_input( mlt_service
this )
206 if ( this->accepts_input
== NULL
)
209 return this->accepts_input( this );
212 /** Get the maximum number of outputs accepted.
215 int mlt_service_accepts_output( mlt_service
this )
217 if ( this->accepts_output
== NULL
)
220 return this->accepts_output( this );
223 /** Determines if this service has input
226 int mlt_service_has_input( mlt_service
this )
228 if ( this->has_input
== NULL
)
231 return this->has_input( this );
234 /** Determine if this service has output
237 int mlt_service_has_output( mlt_service
this )
239 mlt_service_base
*base
= this->private;
240 if ( this->has_output
== NULL
)
241 return base
->out
!= NULL
;
243 return this->has_output( this );
246 /** Check if the service is active.
249 int mlt_service_is_active( mlt_service
this )
251 return !( mlt_service_get_state( this ) & mlt_state_dormant
);
254 /** Obtain a frame to pass on.
257 static int service_get_frame( mlt_service
this, mlt_frame_ptr frame
, int index
)
259 mlt_service_base
*base
= this->private;
260 if ( index
< base
->count
)
262 mlt_service producer
= base
->in
[ index
];
263 if ( producer
!= NULL
)
264 return mlt_service_get_frame( producer
, frame
, index
);
266 *frame
= mlt_frame_init( );
270 int mlt_service_get_frame( mlt_service
this, mlt_frame_ptr frame
, int index
)
272 return this->get_frame( this, frame
, index
);
275 /** Close the service.
278 void mlt_service_close( mlt_service
this )
280 mlt_service_base
*base
= this->private;
283 mlt_properties_close( &this->parent
);