research.m1stereo.tv/gitweb/ - melted/blob - src/framework/mlt_filter.c

   1 /**
   2  * \file mlt_filter.c
   3  * \brief abstraction for all filter services
   4  * \see mlt_filter_s
   5  *
   6  * Copyright (C) 2003-2009 Ushodaya Enterprises Limited
   7  * \author Charles Yates <charles.yates@pandora.be>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include "mlt_filter.h"
  25 #include "mlt_frame.h"
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 static int filter_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
  32
  33 /** Initialize a new filter.
  34  *
  35  * \public \memberof mlt_filter_s
  36  * \param this a filter
  37  * \param child the object of a subclass
  38  * \return true if there was an error
  39  */
  40
  41 int mlt_filter_init( mlt_filter this, void *child )
  42 {
  43         mlt_service service = &this->parent;
  44         memset( this, 0, sizeof( struct mlt_filter_s ) );
  45         this->child = child;
  46         if ( mlt_service_init( service, this ) == 0 )
  47         {
  48                 mlt_properties properties = MLT_SERVICE_PROPERTIES( service );
  49
  50                 // Override the get_frame method
  51                 service->get_frame = filter_get_frame;
  52
  53                 // Define the destructor
  54                 service->close = ( mlt_destructor )mlt_filter_close;
  55                 service->close_object = this;
  56
  57                 // Default in, out, track properties
  58                 mlt_properties_set_position( properties, "in", 0 );
  59                 mlt_properties_set_position( properties, "out", 0 );
  60                 mlt_properties_set_int( properties, "track", 0 );
  61
  62                 return 0;
  63         }
  64         return 1;
  65 }
  66
  67 /** Create a new filter and initialize it.
  68  *
  69  * \public \memberof mlt_filter_s
  70  * \return a new filter
  71  */
  72
  73 mlt_filter mlt_filter_new( )
  74 {
  75         mlt_filter this = calloc( 1, sizeof( struct mlt_filter_s ) );
  76         if ( this != NULL )
  77                 mlt_filter_init( this, NULL );
  78         return this;
  79 }
  80
  81 /** Get the service class interface.
  82  *
  83  * \public \memberof mlt_filter_s
  84  * \param this a filter
  85  * \return the service parent class
  86  * \see MLT_FILTER_SERVICE
  87  */
  88
  89 mlt_service mlt_filter_service( mlt_filter this )
  90 {
  91         return this != NULL ? &this->parent : NULL;
  92 }
  93
  94 /** Get the filter properties.
  95  *
  96  * \public \memberof mlt_filter_s
  97  * \param this a filter
  98  * \return the properties list for the filter
  99  * \see MLT_FILTER_PROPERTIES
 100  */
 101
 102 mlt_properties mlt_filter_properties( mlt_filter this )
 103 {
 104         return MLT_SERVICE_PROPERTIES( MLT_FILTER_SERVICE( this ) );
 105 }
 106
 107 /** Connect this filter to a producers track. Note that a filter only operates
 108  * on a single track, and by default it operates on the entirety of that track.
 109  *
 110  * \public \memberof mlt_filter_s
 111  * \param this a filter
 112  * \param producer the producer to which to connect this filter
 113  * \param index which of potentially multiple producers to this service (0 based)
 114  */
 115
 116 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
 117 {
 118         int ret = mlt_service_connect_producer( &this->parent, producer, index );
 119
 120         // If the connection was successful, grab the producer, track and reset in/out
 121         if ( ret == 0 )
 122         {
 123                 mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 124                 mlt_properties_set_position( properties, "in", 0 );
 125                 mlt_properties_set_position( properties, "out", 0 );
 126                 mlt_properties_set_int( properties, "track", index );
 127         }
 128
 129         return ret;
 130 }
 131
 132 /** Set the starting and ending time.
 133  *
 134  * \public \memberof mlt_filter_s
 135  * \param this a filter
 136  * \param in the time relative to the producer at which start applying the filter
 137  * \param out the time relative to the producer at which to stop applying the filter
 138  */
 139
 140
 141 void mlt_filter_set_in_and_out( mlt_filter this, mlt_position in, mlt_position out )
 142 {
 143         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 144         mlt_properties_set_position( properties, "in", in );
 145         mlt_properties_set_position( properties, "out", out );
 146 }
 147
 148 /** Return the track that this filter is operating on.
 149  *
 150  * \public \memberof mlt_filter_s
 151  * \param this a filter
 152  * \return true on error
 153  */
 154
 155
 156 int mlt_filter_get_track( mlt_filter this )
 157 {
 158         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 159         return mlt_properties_get_int( properties, "track" );
 160 }
 161
 162 /** Get the in point.
 163  *
 164  * \public \memberof mlt_filter_s
 165  * \param this a filter
 166  * \return the start time for the filter relative to the producer
 167  */
 168
 169
 170 mlt_position mlt_filter_get_in( mlt_filter this )
 171 {
 172         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 173         return mlt_properties_get_position( properties, "in" );
 174 }
 175
 176 /** Get the out point.
 177  *
 178  * \public \memberof mlt_filter_s
 179  * \param this a filter
 180  * \return the ending time for the filter relative to the producer
 181  */
 182
 183
 184 mlt_position mlt_filter_get_out( mlt_filter this )
 185 {
 186         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 187         return mlt_properties_get_position( properties, "out" );
 188 }
 189
 190 /** Process the frame.
 191  *
 192  * \public \memberof mlt_filter_s
 193  * \param this a filter
 194  * \param frame a frame
 195  * \return a frame
 196  */
 197
 198
 199 mlt_frame mlt_filter_process( mlt_filter this, mlt_frame frame )
 200 {
 201         int disable = mlt_properties_get_int( MLT_FILTER_PROPERTIES( this ), "disable" );
 202         if ( disable || this->process == NULL )
 203                 return frame;
 204         else
 205                 return this->process( this, frame );
 206 }
 207
 208 /** Get a frame from this filter.
 209  *
 210  * \private \memberof mlt_filter_s
 211  * \param service a service
 212  * \param[out] frame a frame by reference
 213  * \param index as determined by the producer
 214  * \return true on error
 215  */
 216
 217
 218 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 219 {
 220         mlt_filter this = service->child;
 221
 222         // Get coords in/out/track
 223         int track = mlt_filter_get_track( this );
 224         int in = mlt_filter_get_in( this );
 225         int out = mlt_filter_get_out( this );
 226
 227         // Get the producer this is connected to
 228         mlt_service producer = mlt_service_producer( &this->parent );
 229
 230         // If the frame request is for this filters track, we need to process it
 231         if ( index == track || track == -1 )
 232         {
 233                 int ret = mlt_service_get_frame( producer, frame, index );
 234                 if ( ret == 0 )
 235                 {
 236                         mlt_position position = mlt_frame_get_position( *frame );
 237                         if ( position >= in && ( out == 0 || position <= out ) )
 238                                 *frame = mlt_filter_process( this, *frame );
 239                         return 0;
 240                 }
 241                 else
 242                 {
 243                         *frame = mlt_frame_init( service );
 244                         return 0;
 245                 }
 246         }
 247         else
 248         {
 249                 return mlt_service_get_frame( producer, frame, index );
 250         }
 251 }
 252
 253 /** Close and destroy the filter.
 254  *
 255  * \public \memberof mlt_filter_s
 256  * \param this a filter
 257  */
 258
 259
 260 void mlt_filter_close( mlt_filter this )
 261 {
 262         if ( this != NULL && mlt_properties_dec_ref( MLT_FILTER_PROPERTIES( this ) ) <= 0 )
 263         {
 264                 if ( this->close != NULL )
 265                 {
 266                         this->close( this );
 267                 }
 268                 else
 269                 {
 270                         this->parent.close = NULL;
 271                         mlt_service_close( &this->parent );
 272                 }
 273                 free( this );
 274         }
 275 }