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 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.
  10  *
  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.
  15  *
  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
  19  */
  20
  21 #include "mlt_filter.h"
  22 #include "mlt_frame.h"
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 static int filter_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
  29
  30 /** Constructor method.
  31 */
  32
  33 int mlt_filter_init( mlt_filter this, void *child )
  34 {
  35         mlt_service service = &this->parent;
  36         memset( this, 0, sizeof( struct mlt_filter_s ) );
  37         this->child = child;
  38         if ( mlt_service_init( service, this ) == 0 )
  39         {
  40                 mlt_properties properties = MLT_SERVICE_PROPERTIES( service );
  41
  42                 // Override the get_frame method
  43                 service->get_frame = filter_get_frame;
  44
  45                 // Define the destructor
  46                 service->close = ( mlt_destructor )mlt_filter_close;
  47                 service->close_object = this;
  48
  49                 // Default in, out, track properties
  50                 mlt_properties_set_position( properties, "in", 0 );
  51                 mlt_properties_set_position( properties, "out", 0 );
  52                 mlt_properties_set_int( properties, "track", 0 );
  53
  54                 return 0;
  55         }
  56         return 1;
  57 }
  58
  59 /** Create a new filter.
  60 */
  61
  62 mlt_filter mlt_filter_new( )
  63 {
  64         mlt_filter this = calloc( 1, sizeof( struct mlt_filter_s ) );
  65         if ( this != NULL )
  66                 mlt_filter_init( this, NULL );
  67         return this;
  68 }
  69
  70 /** Get the service associated to this filter
  71 */
  72
  73 mlt_service mlt_filter_service( mlt_filter this )
  74 {
  75         return this != NULL ? &this->parent : NULL;
  76 }
  77
  78 /** Get the properties associated to this filter.
  79 */
  80
  81 mlt_properties mlt_filter_properties( mlt_filter this )
  82 {
  83         return MLT_SERVICE_PROPERTIES( MLT_FILTER_SERVICE( this ) );
  84 }
  85
  86 /** Connect this filter to a producers track. Note that a filter only operates
  87         on a single track, and by default it operates on the entirety of that track.
  88 */
  89
  90 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
  91 {
  92         int ret = mlt_service_connect_producer( &this->parent, producer, index );
  93
  94         // If the connection was successful, grab the producer, track and reset in/out
  95         if ( ret == 0 )
  96         {
  97                 mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
  98                 mlt_properties_set_position( properties, "in", 0 );
  99                 mlt_properties_set_position( properties, "out", 0 );
 100                 mlt_properties_set_int( properties, "track", index );
 101         }
 102
 103         return ret;
 104 }
 105
 106 /** Tune the in/out points.
 107 */
 108
 109 void mlt_filter_set_in_and_out( mlt_filter this, mlt_position in, mlt_position out )
 110 {
 111         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 112         mlt_properties_set_position( properties, "in", in );
 113         mlt_properties_set_position( properties, "out", out );
 114 }
 115
 116 /** Return the track that this filter is operating on.
 117 */
 118
 119 int mlt_filter_get_track( mlt_filter this )
 120 {
 121         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 122         return mlt_properties_get_int( properties, "track" );
 123 }
 124
 125 /** Get the in point.
 126 */
 127
 128 mlt_position mlt_filter_get_in( mlt_filter this )
 129 {
 130         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 131         return mlt_properties_get_position( properties, "in" );
 132 }
 133
 134 /** Get the out point.
 135 */
 136
 137 mlt_position mlt_filter_get_out( mlt_filter this )
 138 {
 139         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 140         return mlt_properties_get_position( properties, "out" );
 141 }
 142
 143 /** Process the frame.
 144 */
 145
 146 mlt_frame mlt_filter_process( mlt_filter this, mlt_frame frame )
 147 {
 148         int disable = mlt_properties_get_int( MLT_FILTER_PROPERTIES( this ), "disable" );
 149         if ( disable || this->process == NULL )
 150                 return frame;
 151         else
 152                 return this->process( this, frame );
 153 }
 154
 155 /** Get a frame from this filter.
 156 */
 157
 158 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 159 {
 160         mlt_filter this = service->child;
 161
 162         // Get coords in/out/track
 163         int track = mlt_filter_get_track( this );
 164         int in = mlt_filter_get_in( this );
 165         int out = mlt_filter_get_out( this );
 166
 167         // Get the producer this is connected to
 168         mlt_service producer = mlt_service_producer( &this->parent );
 169
 170         // If the frame request is for this filters track, we need to process it
 171         if ( index == track || track == -1 )
 172         {
 173                 int ret = mlt_service_get_frame( producer, frame, index );
 174                 if ( ret == 0 )
 175                 {
 176                         mlt_position position = mlt_frame_get_position( *frame );
 177                         if ( position >= in && ( out == 0 || position <= out ) )
 178                                 *frame = mlt_filter_process( this, *frame );
 179                         return 0;
 180                 }
 181                 else
 182                 {
 183                         *frame = mlt_frame_init( service );
 184                         return 0;
 185                 }
 186         }
 187         else
 188         {
 189                 return mlt_service_get_frame( producer, frame, index );
 190         }
 191 }
 192
 193 /** Close the filter.
 194 */
 195
 196 void mlt_filter_close( mlt_filter this )
 197 {
 198         if ( this != NULL && mlt_properties_dec_ref( MLT_FILTER_PROPERTIES( this ) ) <= 0 )
 199         {
 200                 if ( this->close != NULL )
 201                 {
 202                         this->close( this );
 203                 }
 204                 else
 205                 {
 206                         this->parent.close = NULL;
 207                         mlt_service_close( &this->parent );
 208                 }
 209                 free( this );
 210         }
 211 }