research.m1stereo.tv/gitweb/ - melted/blob - src/framework/mlt_service.h

   1 /**
   2  * \file mlt_service.h
   3  * \brief interface declaration for all service classes
   4  * \see mlt_service_s
   5  *
   6  * Copyright (C) 2003-2009 Ushodaya Enterprises Limited
   7  * \author Charles Yates <charles.yates@pandora.be>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #ifndef _MLT_SERVICE_H_
  25 #define _MLT_SERVICE_H_
  26
  27 #include "mlt_properties.h"
  28 #include "mlt_types.h"
  29
  30 /** \brief Service abstract base class
  31  *
  32  * \extends mlt_properties
  33  * The service is the base class for all of the interesting classes and
  34  * plugins for MLT. A service can have multiple inputs connections to
  35  * other services called its "producers" but only a single output to another
  36  * service called its "consumer." A service that has both producer and
  37  * consumer connections is called a filter. Any service can have zero or more
  38  * filters "attached" to it. We call any collection of services and their
  39  * connections a "service network," which is similar to what DirectShow calls
  40  * a filter graph or what gstreamer calls an element pipeline.
  41  *
  42  * \event \em service-changed
  43  * \event \em property-changed
  44  * \properties \em mlt_type identifies the subclass
  45  * \properties \em _mlt_service_hidden a flag that indicates whether to hide the mlt_service
  46  * \properties \em mlt_service is the name of the implementation of the service
  47  * \properties \em resource is either the stream identifier or grandchild-class
  48  * \properties \em in when to start, what is started is service-specific
  49  * \properties \em out when to stop
  50  * \properties \em _filter_private Set this on a service to ensure that attached filters are handled privately.
  51  * See modules/core/filter_region.c and modules/core/filter_watermark.c for examples.
  52  * \properties \em disable Set this on a filter to disable it while keeping it in the object model.
  53  * \properties \em _profile stores the mlt_profile for a service
  54  * \properties \em _unique_id is a unique identifier
  55  */
  56
  57 struct mlt_service_s
  58 {
  59         struct mlt_properties_s parent; /**< \private */
  60
  61         /** Get a frame of data (virtual function).
  62          *
  63          * \param mlt_producer a producer
  64          * \param mlt_frame_ptr a frame pointer by reference
  65          * \param int an index
  66          * \return true if there was an error
  67          */
  68         int ( *get_frame )( mlt_service self, mlt_frame_ptr frame, int index );
  69
  70         /** the destructor virtual function */
  71         mlt_destructor close;
  72         void *close_object; /**< the object supplied to the close virtual function */
  73
  74         void *local; /**< \private instance object */
  75         void *child; /**< \private the object of a subclass */
  76 };
  77
  78 #define MLT_SERVICE_PROPERTIES( service )       ( &( service )->parent )
  79
  80 extern int mlt_service_init( mlt_service self, void *child );
  81 extern void mlt_service_lock( mlt_service self );
  82 extern void mlt_service_unlock( mlt_service self );
  83 extern mlt_service_type mlt_service_identify( mlt_service self );
  84 extern int mlt_service_connect_producer( mlt_service self, mlt_service producer, int index );
  85 extern mlt_service mlt_service_get_producer( mlt_service self );
  86 extern int mlt_service_get_frame( mlt_service self, mlt_frame_ptr frame, int index );
  87 extern mlt_properties mlt_service_properties( mlt_service self );
  88 extern mlt_service mlt_service_consumer( mlt_service self );
  89 extern mlt_service mlt_service_producer( mlt_service self );
  90 extern int mlt_service_attach( mlt_service self, mlt_filter filter );
  91 extern int mlt_service_detach( mlt_service self, mlt_filter filter );
  92 extern void mlt_service_apply_filters( mlt_service self, mlt_frame frame, int index );
  93 extern mlt_filter mlt_service_filter( mlt_service self, int index );
  94 extern mlt_profile mlt_service_profile( mlt_service self );
  95 extern void mlt_service_close( mlt_service self );
  96 extern void mlt_service_cache_put( mlt_service self, const char *name, void* data, int size, mlt_destructor destructor );
  97 extern mlt_cache_item mlt_service_cache_get( mlt_service self, const char *name );
  98
  99 #endif
 100