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                 service->get_frame = filter_get_frame;
  43                 return 0;
  44         }
  45         return 1;
  46 }
  47
  48 /** Get the service associated to this filter
  49 */
  50
  51 mlt_service mlt_filter_service( mlt_filter this )
  52 {
  53         return &this->parent;
  54 }
  55
  56 /** Connect this filter to a producers track. Note that a filter only operates
  57         on a single track, and by default it operates on the entirety of that track.
  58 */
  59
  60 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
  61 {
  62         int ret = mlt_service_connect_producer( &this->parent, producer, index );
  63
  64         // If the connection was successful, grab the producer, track and reset in/out
  65         if ( ret == 0 )
  66         {
  67                 this->producer = producer;
  68                 this->track = index;
  69                 this->in = 0;
  70                 this->out = 0;
  71         }
  72
  73         return ret;
  74 }
  75
  76 /** Tune the in/out points.
  77 */
  78
  79 void mlt_filter_set_in_and_out( mlt_filter this, mlt_timecode in, mlt_timecode out )
  80 {
  81         this->in = in;
  82         this->out = out;
  83 }
  84
  85 /** Return the track that this filter is operating on.
  86 */
  87
  88 int mlt_filter_get_track( mlt_filter this )
  89 {
  90         return this->track;
  91 }
  92
  93 /** Get the in point.
  94 */
  95
  96 mlt_timecode mlt_filter_get_in( mlt_filter this )
  97 {
  98         return this->in;
  99 }
 100
 101 /** Get the out point.
 102 */
 103
 104 mlt_timecode mlt_filter_get_out( mlt_filter this )
 105 {
 106         return this->out;
 107 }
 108
 109 /** Process the frame.
 110 */
 111
 112 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 113 {
 114         if ( this->process == NULL )
 115                 return frame;
 116         else
 117                 return this->process( this, frame );
 118 }
 119
 120 /** Get a frame from this filter.
 121 */
 122
 123 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 124 {
 125         mlt_filter this = service->child;
 126
 127         // If the frame request is for this filters track, we need to process it
 128         if ( index == this->track )
 129         {
 130                 int ret = mlt_service_get_frame( this->producer, frame, index );
 131                 if ( ret == 0 )
 132                 {
 133                         if ( !mlt_frame_is_test_card( *frame ) )
 134                         {
 135                                 mlt_timecode timecode = mlt_frame_get_timecode( *frame );
 136                                 if ( timecode >= this->in && ( this->out == 0 || timecode < this->out ) )
 137                                         *frame = filter_process( this, *frame );
 138                         }
 139                         return 0;
 140                 }
 141                 else
 142                 {
 143                         *frame = mlt_frame_init( );
 144                         return 0;
 145                 }
 146         }
 147         else
 148         {
 149                 return mlt_service_get_frame( this->producer, frame, index );
 150         }
 151 }
 152
 153 /** Close the filter.
 154 */
 155
 156 void mlt_filter_close( mlt_filter this )
 157 {
 158         if ( this->close != NULL )
 159                 this->close( this );
 160         else
 161                 mlt_service_close( &this->parent );
 162 }
 163