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                 // Define the destructor
  48                 service->close = ( mlt_destructor )mlt_filter_close;
  49                 service->close_object = this;
  50
  51                 // Default in, out, track properties
  52                 mlt_properties_set_position( properties, "in", 0 );
  53                 mlt_properties_set_position( properties, "out", 0 );
  54                 mlt_properties_set_int( properties, "track", 0 );
  55
  56                 return 0;
  57         }
  58         return 1;
  59 }
  60
  61 /** Create a new filter.
  62 */
  63
  64 mlt_filter mlt_filter_new( )
  65 {
  66         mlt_filter this = calloc( 1, sizeof( struct mlt_filter_s ) );
  67         if ( this != NULL )
  68                 mlt_filter_init( this, NULL );
  69         return this;
  70 }
  71
  72 /** Get the service associated to this filter
  73 */
  74
  75 mlt_service mlt_filter_service( mlt_filter this )
  76 {
  77         return this != NULL ? &this->parent : NULL;
  78 }
  79
  80 /** Get the properties associated to this filter.
  81 */
  82
  83 mlt_properties mlt_filter_properties( mlt_filter this )
  84 {
  85         return mlt_service_properties( mlt_filter_service( this ) );
  86 }
  87
  88 /** Connect this filter to a producers track. Note that a filter only operates
  89         on a single track, and by default it operates on the entirety of that track.
  90 */
  91
  92 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
  93 {
  94         int ret = mlt_service_connect_producer( &this->parent, producer, index );
  95
  96         // If the connection was successful, grab the producer, track and reset in/out
  97         if ( ret == 0 )
  98         {
  99                 mlt_properties properties = mlt_service_properties( &this->parent );
 100                 mlt_properties_set_position( properties, "in", 0 );
 101                 mlt_properties_set_position( properties, "out", 0 );
 102                 mlt_properties_set_int( properties, "track", index );
 103         }
 104
 105         return ret;
 106 }
 107
 108 /** Tune the in/out points.
 109 */
 110
 111 void mlt_filter_set_in_and_out( mlt_filter this, mlt_position in, mlt_position out )
 112 {
 113         mlt_properties properties = mlt_service_properties( &this->parent );
 114         mlt_properties_set_position( properties, "in", in );
 115         mlt_properties_set_position( properties, "out", out );
 116 }
 117
 118 /** Return the track that this filter is operating on.
 119 */
 120
 121 int mlt_filter_get_track( mlt_filter this )
 122 {
 123         mlt_properties properties = mlt_service_properties( &this->parent );
 124         return mlt_properties_get_int( properties, "track" );
 125 }
 126
 127 /** Get the in point.
 128 */
 129
 130 mlt_position mlt_filter_get_in( mlt_filter this )
 131 {
 132         mlt_properties properties = mlt_service_properties( &this->parent );
 133         return mlt_properties_get_position( properties, "in" );
 134 }
 135
 136 /** Get the out point.
 137 */
 138
 139 mlt_position mlt_filter_get_out( mlt_filter this )
 140 {
 141         mlt_properties properties = mlt_service_properties( &this->parent );
 142         return mlt_properties_get_position( properties, "out" );
 143 }
 144
 145 /** Process the frame.
 146 */
 147
 148 mlt_frame mlt_filter_process( mlt_filter this, mlt_frame frame )
 149 {
 150         if ( this->process == NULL )
 151                 return frame;
 152         else
 153                 return this->process( this, frame );
 154 }
 155
 156 /** Get a frame from this filter.
 157 */
 158
 159 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 160 {
 161         mlt_filter this = service->child;
 162
 163         // Get coords in/out/track
 164         int track = mlt_filter_get_track( this );
 165         int in = mlt_filter_get_in( this );
 166         int out = mlt_filter_get_out( this );
 167
 168         // Get the producer this is connected to
 169         mlt_service producer = mlt_service_producer( &this->parent );
 170
 171         // If the frame request is for this filters track, we need to process it
 172         if ( index == track )
 173         {
 174                 int ret = mlt_service_get_frame( producer, frame, index );
 175                 if ( ret == 0 )
 176                 {
 177                         mlt_position position = mlt_frame_get_position( *frame );
 178                         if ( position >= in && ( out == 0 || position <= out ) )
 179                         {
 180                                 mlt_frame_set_position( *frame, position - in );
 181                                 *frame = mlt_filter_process( this, *frame );
 182                                 mlt_frame_set_position( *frame, position + in );
 183                         }
 184                         return 0;
 185                 }
 186                 else
 187                 {
 188                         *frame = mlt_frame_init( );
 189                         return 0;
 190                 }
 191         }
 192         else
 193         {
 194                 return mlt_service_get_frame( producer, frame, index );
 195         }
 196 }
 197
 198 /** Close the filter.
 199 */
 200
 201 void mlt_filter_close( mlt_filter this )
 202 {
 203         if ( this != NULL && mlt_properties_dec_ref( mlt_filter_properties( this ) ) <= 0 )
 204         {
 205                 if ( this->close != NULL )
 206                 {
 207                         this->close( this );
 208                 }
 209                 else
 210                 {
 211                         this->parent.close = NULL;
 212                         mlt_service_close( &this->parent );
 213                 }
 214                 free( this );
 215         }
 216 }