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_timecode( properties, "in", 0 );
  49                 mlt_properties_set_timecode( properties, "out", 0 );
  50                 mlt_properties_set_int( properties, "track", 0 );
  51
  52                 return 0;
  53         }
  54         return 1;
  55 }
  56
  57 /** Get the service associated to this filter
  58 */
  59
  60 mlt_service mlt_filter_service( mlt_filter this )
  61 {
  62         return &this->parent;
  63 }
  64
  65 /** Connect this filter to a producers track. Note that a filter only operates
  66         on a single track, and by default it operates on the entirety of that track.
  67 */
  68
  69 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
  70 {
  71         int ret = mlt_service_connect_producer( &this->parent, producer, index );
  72
  73         // If the connection was successful, grab the producer, track and reset in/out
  74         if ( ret == 0 )
  75         {
  76                 mlt_properties properties = mlt_service_properties( &this->parent );
  77                 this->producer = producer;
  78                 mlt_properties_set_timecode( properties, "in", 0 );
  79                 mlt_properties_set_timecode( properties, "out", 0 );
  80                 mlt_properties_set_int( properties, "track", index );
  81         }
  82
  83         return ret;
  84 }
  85
  86 /** Tune the in/out points.
  87 */
  88
  89 void mlt_filter_set_in_and_out( mlt_filter this, mlt_timecode in, mlt_timecode out )
  90 {
  91         mlt_properties properties = mlt_service_properties( &this->parent );
  92         mlt_properties_set_timecode( properties, "in", in );
  93         mlt_properties_set_timecode( properties, "out", out );
  94 }
  95
  96 /** Return the track that this filter is operating on.
  97 */
  98
  99 int mlt_filter_get_track( mlt_filter this )
 100 {
 101         mlt_properties properties = mlt_service_properties( &this->parent );
 102         return mlt_properties_get_int( properties, "track" );
 103 }
 104
 105 /** Get the in point.
 106 */
 107
 108 mlt_timecode mlt_filter_get_in( mlt_filter this )
 109 {
 110         mlt_properties properties = mlt_service_properties( &this->parent );
 111         return mlt_properties_get_timecode( properties, "in" );
 112 }
 113
 114 /** Get the out point.
 115 */
 116
 117 mlt_timecode mlt_filter_get_out( mlt_filter this )
 118 {
 119         mlt_properties properties = mlt_service_properties( &this->parent );
 120         return mlt_properties_get_timecode( properties, "out" );
 121 }
 122
 123 /** Process the frame.
 124 */
 125
 126 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 127 {
 128         if ( this->process == NULL )
 129                 return frame;
 130         else
 131                 return this->process( this, frame );
 132 }
 133
 134 /** Get a frame from this filter.
 135 */
 136
 137 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 138 {
 139         mlt_filter this = service->child;
 140
 141         // Get coords in/out/track
 142         int track = mlt_filter_get_track( this );
 143         int in = mlt_filter_get_in( this );
 144         int out = mlt_filter_get_out( this );
 145
 146         // If the frame request is for this filters track, we need to process it
 147         if ( index == track )
 148         {
 149                 int ret = mlt_service_get_frame( this->producer, frame, index );
 150                 if ( ret == 0 )
 151                 {
 152                         if ( !mlt_frame_is_test_card( *frame ) )
 153                         {
 154                                 mlt_timecode timecode = mlt_frame_get_timecode( *frame );
 155                                 if ( timecode >= in && ( out == 0 || timecode < out ) )
 156                                         *frame = filter_process( this, *frame );
 157                         }
 158                         return 0;
 159                 }
 160                 else
 161                 {
 162                         *frame = mlt_frame_init( );
 163                         return 0;
 164                 }
 165         }
 166         else
 167         {
 168                 return mlt_service_get_frame( this->producer, frame, index );
 169         }
 170 }
 171
 172 /** Close the filter.
 173 */
 174
 175 void mlt_filter_close( mlt_filter this )
 176 {
 177         if ( this->close != NULL )
 178                 this->close( this );
 179         else
 180                 mlt_service_close( &this->parent );
 181 }
 182