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
  52                 return 0;
  53         }
  54         return 1;
  55 }
  56
  57 /** Create a new filter.
  58 */
  59
  60 mlt_filter mlt_filter_new( )
  61 {
  62         mlt_filter this = calloc( 1, sizeof( struct mlt_filter_s ) );
  63         if ( this != NULL )
  64                 mlt_filter_init( this, NULL );
  65         return this;
  66 }
  67
  68 /** Get the service associated to this filter
  69 */
  70
  71 mlt_service mlt_filter_service( mlt_filter this )
  72 {
  73         return &this->parent;
  74 }
  75
  76 /** Get the properties associated to this filter.
  77 */
  78
  79 mlt_properties mlt_filter_properties( mlt_filter this )
  80 {
  81         return mlt_service_properties( mlt_filter_service( this ) );
  82 }
  83
  84 /** Connect this filter to a producers track. Note that a filter only operates
  85         on a single track, and by default it operates on the entirety of that track.
  86 */
  87
  88 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
  89 {
  90         int ret = mlt_service_connect_producer( &this->parent, producer, index );
  91
  92         // If the connection was successful, grab the producer, track and reset in/out
  93         if ( ret == 0 )
  94         {
  95                 mlt_properties properties = mlt_service_properties( &this->parent );
  96                 this->producer = producer;
  97                 mlt_properties_set_position( properties, "in", 0 );
  98                 mlt_properties_set_position( properties, "out", 0 );
  99                 mlt_properties_set_int( properties, "track", index );
 100         }
 101
 102         return ret;
 103 }
 104
 105 /** Tune the in/out points.
 106 */
 107
 108 void mlt_filter_set_in_and_out( mlt_filter this, mlt_position in, mlt_position out )
 109 {
 110         mlt_properties properties = mlt_service_properties( &this->parent );
 111         mlt_properties_set_position( properties, "in", in );
 112         mlt_properties_set_position( properties, "out", out );
 113 }
 114
 115 /** Return the track that this filter is operating on.
 116 */
 117
 118 int mlt_filter_get_track( mlt_filter this )
 119 {
 120         mlt_properties properties = mlt_service_properties( &this->parent );
 121         return mlt_properties_get_int( properties, "track" );
 122 }
 123
 124 /** Get the in point.
 125 */
 126
 127 mlt_position mlt_filter_get_in( mlt_filter this )
 128 {
 129         mlt_properties properties = mlt_service_properties( &this->parent );
 130         return mlt_properties_get_position( properties, "in" );
 131 }
 132
 133 /** Get the out point.
 134 */
 135
 136 mlt_position mlt_filter_get_out( mlt_filter this )
 137 {
 138         mlt_properties properties = mlt_service_properties( &this->parent );
 139         return mlt_properties_get_position( properties, "out" );
 140 }
 141
 142 /** Process the frame.
 143 */
 144
 145 mlt_frame mlt_filter_process( mlt_filter this, mlt_frame frame )
 146 {
 147         if ( this->process == NULL )
 148                 return frame;
 149         else
 150                 return this->process( this, frame );
 151 }
 152
 153 /** Get a frame from this filter.
 154 */
 155
 156 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 157 {
 158         mlt_filter this = service->child;
 159
 160         // Get coords in/out/track
 161         int track = mlt_filter_get_track( this );
 162         int in = mlt_filter_get_in( this );
 163         int out = mlt_filter_get_out( this );
 164
 165         // If the frame request is for this filters track, we need to process it
 166         if ( index == track )
 167         {
 168                 int ret = mlt_service_get_frame( this->producer, frame, index );
 169                 if ( ret == 0 )
 170                 {
 171                         mlt_position position = mlt_frame_get_position( *frame );
 172                         if ( position >= in && ( out == 0 || position <= out ) )
 173                                 *frame = mlt_filter_process( this, *frame );
 174                         return 0;
 175                 }
 176                 else
 177                 {
 178                         *frame = mlt_frame_init( );
 179                         return 0;
 180                 }
 181         }
 182         else
 183         {
 184                 return mlt_service_get_frame( this->producer, frame, index );
 185         }
 186 }
 187
 188 /** Close the filter.
 189 */
 190
 191 void mlt_filter_close( mlt_filter this )
 192 {
 193         if ( this->close != NULL )
 194                 this->close( this );
 195         else
 196                 mlt_service_close( &this->parent );
 197 }