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 library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "mlt_filter.h"
  22 #include "mlt_frame.h"
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 static int filter_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
  29
  30 /** Initialize a new filter.
  31  *
  32  * \public \memberof mlt_filter_s
  33  * \param this a filter
  34  * \param child the object of a subclass
  35  * \return true if there was an error
  36  */
  37
  38 int mlt_filter_init( mlt_filter this, void *child )
  39 {
  40         mlt_service service = &this->parent;
  41         memset( this, 0, sizeof( struct mlt_filter_s ) );
  42         this->child = child;
  43         if ( mlt_service_init( service, this ) == 0 )
  44         {
  45                 mlt_properties properties = MLT_SERVICE_PROPERTIES( service );
  46
  47                 // Override the get_frame method
  48                 service->get_frame = filter_get_frame;
  49
  50                 // Define the destructor
  51                 service->close = ( mlt_destructor )mlt_filter_close;
  52                 service->close_object = this;
  53
  54                 // Default in, out, track properties
  55                 mlt_properties_set_position( properties, "in", 0 );
  56                 mlt_properties_set_position( properties, "out", 0 );
  57                 mlt_properties_set_int( properties, "track", 0 );
  58
  59                 return 0;
  60         }
  61         return 1;
  62 }
  63
  64 /** Create a new filter and initialize it.
  65  *
  66  * \public \memberof mlt_filter_s
  67  * \return a new filter
  68  */
  69
  70 mlt_filter mlt_filter_new( )
  71 {
  72         mlt_filter this = calloc( 1, sizeof( struct mlt_filter_s ) );
  73         if ( this != NULL )
  74                 mlt_filter_init( this, NULL );
  75         return this;
  76 }
  77
  78 /** Get the service class interface.
  79  *
  80  * \public \memberof mlt_filter_s
  81  * \param this a filter
  82  * \return the service parent class
  83  * \see MLT_FILTER_SERVICE
  84  */
  85
  86 mlt_service mlt_filter_service( mlt_filter this )
  87 {
  88         return this != NULL ? &this->parent : NULL;
  89 }
  90
  91 /** Get the filter properties.
  92  *
  93  * \public \memberof mlt_filter_s
  94  * \param this a filter
  95  * \return the properties list for the filter
  96  * \see MLT_FILTER_PROPERTIES
  97  */
  98
  99 mlt_properties mlt_filter_properties( mlt_filter this )
 100 {
 101         return MLT_SERVICE_PROPERTIES( MLT_FILTER_SERVICE( this ) );
 102 }
 103
 104 /** Connect this filter to a producers track. Note that a filter only operates
 105  * on a single track, and by default it operates on the entirety of that track.
 106  *
 107  * \public \memberof mlt_filter_s
 108  * \param this a filter
 109  * \param producer the producer to which to connect this filter
 110  * \param index which of potentially multiple producers to this service (0 based)
 111  */
 112
 113 int mlt_filter_connect( mlt_filter this, mlt_service producer, int index )
 114 {
 115         int ret = mlt_service_connect_producer( &this->parent, producer, index );
 116
 117         // If the connection was successful, grab the producer, track and reset in/out
 118         if ( ret == 0 )
 119         {
 120                 mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 121                 mlt_properties_set_position( properties, "in", 0 );
 122                 mlt_properties_set_position( properties, "out", 0 );
 123                 mlt_properties_set_int( properties, "track", index );
 124         }
 125
 126         return ret;
 127 }
 128
 129 /** Set the starting and ending time.
 130  *
 131  * \public \memberof mlt_filter_s
 132  * \param this a filter
 133  * \param in the time relative to the producer at which start applying the filter
 134  * \param out the time relative to the producer at which to stop applying the filter
 135  */
 136
 137
 138 void mlt_filter_set_in_and_out( mlt_filter this, mlt_position in, mlt_position out )
 139 {
 140         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 141         mlt_properties_set_position( properties, "in", in );
 142         mlt_properties_set_position( properties, "out", out );
 143 }
 144
 145 /** Return the track that this filter is operating on.
 146  *
 147  * \public \memberof mlt_filter_s
 148  * \param this a filter
 149  * \return true on error
 150  */
 151
 152
 153 int mlt_filter_get_track( mlt_filter this )
 154 {
 155         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 156         return mlt_properties_get_int( properties, "track" );
 157 }
 158
 159 /** Get the in point.
 160  *
 161  * \public \memberof mlt_filter_s
 162  * \param this a filter
 163  * \return the start time for the filter relative to the producer
 164  */
 165
 166
 167 mlt_position mlt_filter_get_in( mlt_filter this )
 168 {
 169         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 170         return mlt_properties_get_position( properties, "in" );
 171 }
 172
 173 /** Get the out point.
 174  *
 175  * \public \memberof mlt_filter_s
 176  * \param this a filter
 177  * \return the ending time for the filter relative to the producer
 178  */
 179
 180
 181 mlt_position mlt_filter_get_out( mlt_filter this )
 182 {
 183         mlt_properties properties = MLT_SERVICE_PROPERTIES( &this->parent );
 184         return mlt_properties_get_position( properties, "out" );
 185 }
 186
 187 /** Process the frame.
 188  *
 189  * \public \memberof mlt_filter_s
 190  * \param this a filter
 191  * \param frame a frame
 192  * \return a frame
 193  */
 194
 195
 196 mlt_frame mlt_filter_process( mlt_filter this, mlt_frame frame )
 197 {
 198         int disable = mlt_properties_get_int( MLT_FILTER_PROPERTIES( this ), "disable" );
 199         if ( disable || this->process == NULL )
 200                 return frame;
 201         else
 202                 return this->process( this, frame );
 203 }
 204
 205 /** Get a frame from this filter.
 206  *
 207  * \private \memberof mlt_filter_s
 208  * \param service a service
 209  * \param[out] frame a frame by reference
 210  * \param index as determined by the producer
 211  * \return true on error
 212  */
 213
 214
 215 static int filter_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 216 {
 217         mlt_filter this = service->child;
 218
 219         // Get coords in/out/track
 220         int track = mlt_filter_get_track( this );
 221         int in = mlt_filter_get_in( this );
 222         int out = mlt_filter_get_out( this );
 223
 224         // Get the producer this is connected to
 225         mlt_service producer = mlt_service_producer( &this->parent );
 226
 227         // If the frame request is for this filters track, we need to process it
 228         if ( index == track || track == -1 )
 229         {
 230                 int ret = mlt_service_get_frame( producer, frame, index );
 231                 if ( ret == 0 )
 232                 {
 233                         mlt_position position = mlt_frame_get_position( *frame );
 234                         if ( position >= in && ( out == 0 || position <= out ) )
 235                                 *frame = mlt_filter_process( this, *frame );
 236                         return 0;
 237                 }
 238                 else
 239                 {
 240                         *frame = mlt_frame_init( service );
 241                         return 0;
 242                 }
 243         }
 244         else
 245         {
 246                 return mlt_service_get_frame( producer, frame, index );
 247         }
 248 }
 249
 250 /** Close and destroy the filter.
 251  *
 252  * \public \memberof mlt_filter_s
 253  * \param this a filter
 254  */
 255
 256
 257 void mlt_filter_close( mlt_filter this )
 258 {
 259         if ( this != NULL && mlt_properties_dec_ref( MLT_FILTER_PROPERTIES( this ) ) <= 0 )
 260         {
 261                 if ( this->close != NULL )
 262                 {
 263                         this->close( this );
 264                 }
 265                 else
 266                 {
 267                         this->parent.close = NULL;
 268                         mlt_service_close( &this->parent );
 269                 }
 270                 free( this );
 271         }
 272 }