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

   1 /*
   2  * mlt_producer.c -- abstraction for all producer 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 #include "mlt_producer.h"
  23 #include "mlt_frame.h"
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <stdlib.h>
  27 #include <math.h>
  28
  29 /** Forward references.
  30 */
  31
  32 static int producer_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
  33
  34 /** Constructor
  35 */
  36
  37 int mlt_producer_init( mlt_producer this, void *child )
  38 {
  39         // Initialise the producer
  40         memset( this, 0, sizeof( struct mlt_producer_s ) );
  41
  42         // Associate with the child
  43         this->child = child;
  44
  45         // Initialise the service
  46         if ( mlt_service_init( &this->parent, this ) == 0 )
  47         {
  48                 // The parent is the service
  49                 mlt_service parent = &this->parent;
  50
  51                 // Get the properties of the parent
  52                 mlt_properties properties = mlt_service_properties( parent );
  53
  54                 // Set the default properties
  55                 mlt_properties_set( properties, "mlt_type", "mlt_producer" );
  56                 mlt_properties_set_position( properties, "position", 0.0 );
  57                 mlt_properties_set_double( properties, "frame", 0 );
  58                 mlt_properties_set_double( properties, "fps", 25.0 );
  59                 mlt_properties_set_double( properties, "speed", 1.0 );
  60                 mlt_properties_set_position( properties, "in", 0 );
  61                 mlt_properties_set_position( properties, "out", 1799999 );
  62                 mlt_properties_set_position( properties, "length", 1800000 );
  63                 mlt_properties_set_double( properties, "aspect_ratio", 4.0 / 3.0 );
  64                 mlt_properties_set( properties, "log_id", "multitrack" );
  65
  66                 // Override service get_frame
  67                 parent->get_frame = producer_get_frame;
  68         }
  69
  70         return 0;
  71 }
  72
  73 /** Get the parent service object.
  74 */
  75
  76 mlt_service mlt_producer_service( mlt_producer this )
  77 {
  78         return &this->parent;
  79 }
  80
  81 /** Get the producer properties.
  82 */
  83
  84 mlt_properties mlt_producer_properties( mlt_producer this )
  85 {
  86         return mlt_service_properties( &this->parent );
  87 }
  88
  89 /** Seek to a specified position.
  90 */
  91
  92 int mlt_producer_seek( mlt_producer this, mlt_position position )
  93 {
  94         // Check bounds
  95         if ( position < 0 )
  96                 position = 0;
  97         else if ( position > mlt_producer_get_playtime( this ) )
  98                 position = mlt_producer_get_playtime( this ) - 1;
  99
 100         // Set the position
 101         mlt_properties_set_position( mlt_producer_properties( this ), "position", position );
 102
 103         // Calculate the absolute frame
 104         mlt_properties_set_position( mlt_producer_properties( this ), "frame", mlt_producer_get_in( this ) + position );
 105
 106         return 0;
 107 }
 108
 109 /** Get the current position (relative to in point).
 110 */
 111
 112 mlt_position mlt_producer_position( mlt_producer this )
 113 {
 114         return mlt_properties_get_position( mlt_producer_properties( this ), "position" );
 115 }
 116
 117 /** Get the current position (relative to start of producer).
 118 */
 119
 120 mlt_position mlt_producer_frame( mlt_producer this )
 121 {
 122         return mlt_properties_get_double( mlt_producer_properties( this ), "frame" );
 123 }
 124
 125 /** Set the playing speed.
 126 */
 127
 128 int mlt_producer_set_speed( mlt_producer this, double speed )
 129 {
 130         return mlt_properties_set_double( mlt_producer_properties( this ), "speed", speed );
 131 }
 132
 133 /** Get the playing speed.
 134 */
 135
 136 double mlt_producer_get_speed( mlt_producer this )
 137 {
 138         return mlt_properties_get_double( mlt_producer_properties( this ), "speed" );
 139 }
 140
 141 /** Get the frames per second.
 142 */
 143
 144 double mlt_producer_get_fps( mlt_producer this )
 145 {
 146         return mlt_properties_get_double( mlt_producer_properties( this ), "fps" );
 147 }
 148
 149 /** Set the in and out points.
 150 */
 151
 152 int mlt_producer_set_in_and_out( mlt_producer this, mlt_position in, mlt_position out )
 153 {
 154         // Correct ins and outs if necessary
 155         if ( in < 0 )
 156                 in = 0;
 157         else if ( in > mlt_producer_get_length( this ) )
 158                 in = mlt_producer_get_length( this );
 159
 160         if ( out < 0 )
 161                 out = 0;
 162         else if ( out > mlt_producer_get_length( this ) )
 163                 out = mlt_producer_get_length( this );
 164
 165         // Swap ins and outs if wrong
 166         if ( out < in )
 167         {
 168                 mlt_position t = in;
 169                 in = out;
 170                 out = t;
 171         }
 172
 173         // Set the values
 174         mlt_properties_set_position( mlt_producer_properties( this ), "in", in );
 175         mlt_properties_set_position( mlt_producer_properties( this ), "out", out );
 176
 177         return 0;
 178 }
 179
 180 /** Get the in point.
 181 */
 182
 183 mlt_position mlt_producer_get_in( mlt_producer this )
 184 {
 185         return mlt_properties_get_position( mlt_producer_properties( this ), "in" );
 186 }
 187
 188 /** Get the out point.
 189 */
 190
 191 mlt_position mlt_producer_get_out( mlt_producer this )
 192 {
 193         return mlt_properties_get_position( mlt_producer_properties( this ), "out" );
 194 }
 195
 196 /** Get the total play time.
 197 */
 198
 199 mlt_position mlt_producer_get_playtime( mlt_producer this )
 200 {
 201         return mlt_producer_get_out( this ) - mlt_producer_get_in( this ) + 1;
 202 }
 203
 204 /** Get the total length of the producer.
 205 */
 206
 207 mlt_position mlt_producer_get_length( mlt_producer this )
 208 {
 209         return mlt_properties_get_position( mlt_producer_properties( this ), "length" );
 210 }
 211
 212 /** Prepare for next frame.
 213 */
 214
 215 void mlt_producer_prepare_next( mlt_producer this )
 216 {
 217         mlt_producer_seek( this, mlt_producer_frame( this ) + mlt_producer_get_speed( this ) );
 218 }
 219
 220 /** Get a frame.
 221 */
 222
 223 static int producer_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 224 {
 225         int result = 1;
 226         mlt_producer this = service->child;
 227
 228         // A properly instatiated producer will have a get_frame method...
 229         if ( this->get_frame != NULL )
 230         {
 231                 // Get the frame from the implementation
 232                 result = this->get_frame( this, frame, index );
 233         }
 234         else
 235         {
 236                 // Generate a test frame
 237                 *frame = mlt_frame_init( );
 238
 239                 // Set the position
 240                 result = mlt_frame_set_position( *frame, mlt_producer_position( this ) );
 241
 242                 // Calculate the next position
 243                 mlt_producer_prepare_next( this );
 244         }
 245
 246         // Copy the fps and speed of the producer onto the frame
 247         mlt_properties properties = mlt_frame_properties( *frame );
 248         mlt_properties_set_double( properties, "fps", mlt_producer_get_fps( this ) );
 249         double speed = mlt_producer_get_speed( this );
 250         mlt_properties_set_double( properties, "speed", speed );
 251
 252         return 0;
 253 }
 254
 255 /** Close the producer.
 256 */
 257
 258 void mlt_producer_close( mlt_producer this )
 259 {
 260         if ( this->close != NULL )
 261                 this->close( this );
 262         else
 263                 mlt_service_close( &this->parent );
 264 }