research.m1stereo.tv/gitweb/ - melted/blob - src/framework/mlt_filter.c

   1 /*
   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>
   5  *
   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.
  10  *
  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.
  15  *
  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.
  19  */
  20
  21 #include "config.h"
  22
  23 #include "mlt_filter.h"
  24 #include "mlt_frame.h"
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30 static int filter_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
  31
  32 /** Constructor method.
  33 */
  34
  35 int mlt_filter_init( mlt_filter this, void *child )
  36 {
  37         mlt_service service = &this->parent;
  38         memset( this, 0, sizeof( struct mlt_filter_s ) );
  39         this->child = child;
  40         if ( mlt_service_init( service, this ) == 0 )
  41         {
  42                 mlt_properties properties = mlt_service_properties( service );
  43
  44                 // Override the get_frame method
  45                 service->get_frame = filter_get_frame;
  46
  47                 // Default in, out, track properties
  48                 mlt_properties_set_position( properties, "in", 0 );
  49                 mlt_properties_set_position( properties, "out", 0 );
  50                 mlt_properties_set_int( properties, "track", 0 );
  51                 mlt_properties_set( properties, "resource", "<filter>" );
  52
  53                 return 0;
  54         }
  55         return 1;
  56 }
  57
  58 /** Get the service associated to this filter
  59 */
  60
  61 mlt_service mlt_filter_service( mlt_filter this )
  62 {
  63         return &this->parent;
  64 }
  65
  66 /** Get the properties associated to this filter.
  67 */
  68
  69 mlt_properties mlt_filter_properties( mlt_filter this )
  70 {
  71         return mlt_service_properties( mlt_filter_service( this ) );
  72 }
  73
  74 /** Connect this filter to a producers track. Note that a filter only operates
  75         on a single track, and by default it operates on the entirety of that track.
  76 */
  77
  78 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
  79 {
  80         int ret = mlt_service_connect_producer( &this->parent, producer, index );
  81
  82         // If the connection was successful, grab the producer, track and reset in/out
  83         if ( ret == 0 )
  84         {
  85                 mlt_properties properties = mlt_service_properties( &this->parent );
  86                 this->producer = producer;
  87                 mlt_properties_set_position( properties, "in", 0 );
  88                 mlt_properties_set_position( properties, "out", 0 );
  89                 mlt_properties_set_int( properties, "track", index );
  90         }
  91
  92         return ret;
  93 }
  94
  95 /** Tune the in/out points.
  96 */
  97
  98 void mlt_filter_set_in_and_out( mlt_filter this, mlt_position in, mlt_position out )
  99 {
 100         mlt_properties properties = mlt_service_properties( &this->parent );
 101         mlt_properties_set_position( properties, "in", in );
 102         mlt_properties_set_position( properties, "out", out );
 103 }
 104
 105 /** Return the track that this filter is operating on.
 106 */
 107
 108 int mlt_filter_get_track( mlt_filter this )
 109 {
 110         mlt_properties properties = mlt_service_properties( &this->parent );
 111         return mlt_properties_get_int( properties, "track" );
 112 }
 113
 114 /** Get the in point.
 115 */
 116
 117 mlt_position mlt_filter_get_in( mlt_filter this )
 118 {
 119         mlt_properties properties = mlt_service_properties( &this->parent );
 120         return mlt_properties_get_position( properties, "in" );
 121 }
 122
 123 /** Get the out point.
 124 */
 125
 126 mlt_position mlt_filter_get_out( mlt_filter this )
 127 {
 128         mlt_properties properties = mlt_service_properties( &this->parent );
 129         return mlt_properties_get_position( properties, "out" );
 130 }
 131
 132 /** Process the frame.
 133 */
 134
 135 mlt_frame mlt_filter_process( mlt_filter this, mlt_frame frame )
 136 {
 137         if ( this->process == NULL )
 138                 return frame;
 139         else
 140                 return this->process( this, frame );
 141 }
 142
 143 /** Get a frame from this filter.
 144 */
 145
 146 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 147 {
 148         mlt_filter this = service->child;
 149
 150         // Get coords in/out/track
 151         int track = mlt_filter_get_track( this );
 152         int in = mlt_filter_get_in( this );
 153         int out = mlt_filter_get_out( this );
 154
 155         // If the frame request is for this filters track, we need to process it
 156         if ( index == track )
 157         {
 158                 int ret = mlt_service_get_frame( this->producer, frame, index );
 159                 if ( ret == 0 )
 160                 {
 161                         mlt_position position = mlt_frame_get_position( *frame );
 162                         if ( position >= in && ( out == 0 || position < out ) )
 163                                 *frame = mlt_filter_process( this, *frame );
 164                         return 0;
 165                 }
 166                 else
 167                 {
 168                         *frame = mlt_frame_init( );
 169                         return 0;
 170                 }
 171         }
 172         else
 173         {
 174                 return mlt_service_get_frame( this->producer, frame, index );
 175         }
 176 }
 177
 178 /** Close the filter.
 179 */
 180
 181 void mlt_filter_close( mlt_filter this )
 182 {
 183         if ( this->close != NULL )
 184                 this->close( this );
 185         else
 186                 mlt_service_close( &this->parent );
 187 }
 188