research.m1stereo.tv/gitweb/ - melted/blob - 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         // Check that we haven't received NULL
  40         int error = this == NULL;
  41
  42         // Continue if no error
  43         if ( error == 0 )
  44         {
  45                 // Initialise the producer
  46                 memset( this, 0, sizeof( struct mlt_producer_s ) );
  47
  48                 // Associate with the child
  49                 this->child = child;
  50
  51                 // Initialise the service
  52                 if ( mlt_service_init( &this->parent, this ) == 0 )
  53                 {
  54                         // The parent is the service
  55                         mlt_service parent = &this->parent;
  56
  57                         // Get the properties of the parent
  58                         mlt_properties properties = mlt_service_properties( parent );
  59
  60                         // Set the default properties
  61                         mlt_properties_set( properties, "mlt_type", "mlt_producer" );
  62                         mlt_properties_set_position( properties, "position", 0.0 );
  63                         mlt_properties_set_double( properties, "frame", 0 );
  64                         mlt_properties_set_double( properties, "fps", 25.0 );
  65                         mlt_properties_set_double( properties, "speed", 1.0 );
  66                         mlt_properties_set_position( properties, "in", 0 );
  67                         mlt_properties_set_position( properties, "out", 1799999 );
  68                         mlt_properties_set_position( properties, "length", 1800000 );
  69                         mlt_properties_set_double( properties, "aspect_ratio", 4.0 / 3.0 );
  70                         mlt_properties_set( properties, "eof", "pause" );
  71                         mlt_properties_set( properties, "resource", "<producer>" );
  72
  73                         // Override service get_frame
  74                         parent->get_frame = producer_get_frame;
  75                 }
  76         }
  77
  78         return error;
  79 }
  80
  81 /** Get the parent service object.
  82 */
  83
  84 mlt_service mlt_producer_service( mlt_producer this )
  85 {
  86         return &this->parent;
  87 }
  88
  89 /** Get the producer properties.
  90 */
  91
  92 mlt_properties mlt_producer_properties( mlt_producer this )
  93 {
  94         return mlt_service_properties( &this->parent );
  95 }
  96
  97 /** Seek to a specified position.
  98 */
  99
 100 int mlt_producer_seek( mlt_producer this, mlt_position position )
 101 {
 102         // Determine eof handling
 103         char *eof = mlt_properties_get( mlt_producer_properties( this ), "eof" );
 104
 105         // Check bounds
 106         if ( position < 0 )
 107                 position = 0;
 108         else if ( !strcmp( eof, "pause" ) && position >= mlt_producer_get_playtime( this ) )
 109                 position = mlt_producer_get_playtime( this ) - 1;
 110
 111         // Set the position
 112         mlt_properties_set_position( mlt_producer_properties( this ), "position", position );
 113
 114         // Calculate the absolute frame
 115         mlt_properties_set_position( mlt_producer_properties( this ), "frame", mlt_producer_get_in( this ) + position );
 116
 117         return 0;
 118 }
 119
 120 /** Get the current position (relative to in point).
 121 */
 122
 123 mlt_position mlt_producer_position( mlt_producer this )
 124 {
 125         return mlt_properties_get_position( mlt_producer_properties( this ), "position" );
 126 }
 127
 128 /** Get the current position (relative to start of producer).
 129 */
 130
 131 mlt_position mlt_producer_frame( mlt_producer this )
 132 {
 133         return mlt_properties_get_position( mlt_producer_properties( this ), "frame" );
 134 }
 135
 136 /** Set the playing speed.
 137 */
 138
 139 int mlt_producer_set_speed( mlt_producer this, double speed )
 140 {
 141         return mlt_properties_set_double( mlt_producer_properties( this ), "speed", speed );
 142 }
 143
 144 /** Get the playing speed.
 145 */
 146
 147 double mlt_producer_get_speed( mlt_producer this )
 148 {
 149         return mlt_properties_get_double( mlt_producer_properties( this ), "speed" );
 150 }
 151
 152 /** Get the frames per second.
 153 */
 154
 155 double mlt_producer_get_fps( mlt_producer this )
 156 {
 157         return mlt_properties_get_double( mlt_producer_properties( this ), "fps" );
 158 }
 159
 160 /** Set the in and out points.
 161 */
 162
 163 int mlt_producer_set_in_and_out( mlt_producer this, mlt_position in, mlt_position out )
 164 {
 165         // Correct ins and outs if necessary
 166         if ( in < 0 )
 167                 in = 0;
 168         else if ( in > mlt_producer_get_length( this ) )
 169                 in = mlt_producer_get_length( this );
 170
 171         if ( out < 0 )
 172                 out = 0;
 173         else if ( out > mlt_producer_get_length( this ) )
 174                 out = mlt_producer_get_length( this );
 175
 176         // Swap ins and outs if wrong
 177         if ( out < in )
 178         {
 179                 mlt_position t = in;
 180                 in = out;
 181                 out = t;
 182         }
 183
 184         // Set the values
 185         mlt_properties_set_position( mlt_producer_properties( this ), "in", in );
 186         mlt_properties_set_position( mlt_producer_properties( this ), "out", out );
 187
 188         return 0;
 189 }
 190
 191 /** Get the in point.
 192 */
 193
 194 mlt_position mlt_producer_get_in( mlt_producer this )
 195 {
 196         return mlt_properties_get_position( mlt_producer_properties( this ), "in" );
 197 }
 198
 199 /** Get the out point.
 200 */
 201
 202 mlt_position mlt_producer_get_out( mlt_producer this )
 203 {
 204         return mlt_properties_get_position( mlt_producer_properties( this ), "out" );
 205 }
 206
 207 /** Get the total play time.
 208 */
 209
 210 mlt_position mlt_producer_get_playtime( mlt_producer this )
 211 {
 212         return mlt_producer_get_out( this ) - mlt_producer_get_in( this ) + 1;
 213 }
 214
 215 /** Get the total length of the producer.
 216 */
 217
 218 mlt_position mlt_producer_get_length( mlt_producer this )
 219 {
 220         return mlt_properties_get_position( mlt_producer_properties( this ), "length" );
 221 }
 222
 223 /** Prepare for next frame.
 224 */
 225
 226 void mlt_producer_prepare_next( mlt_producer this )
 227 {
 228         mlt_producer_seek( this, mlt_producer_position( this ) + mlt_producer_get_speed( this ) );
 229 }
 230
 231 /** Get a frame.
 232 */
 233
 234 static int producer_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 235 {
 236         int result = 1;
 237         mlt_producer this = service->child;
 238
 239         // Determine eof handling
 240         char *eof = mlt_properties_get( mlt_producer_properties( this ), "eof" );
 241
 242         // A properly instatiated producer will have a get_frame method...
 243         if ( this->get_frame == NULL || ( !strcmp( eof, "continue" ) && mlt_producer_position( this ) > mlt_producer_get_out( this ) ) )
 244         {
 245                 // Generate a test frame
 246                 *frame = mlt_frame_init( );
 247
 248                 // Set the position
 249                 result = mlt_frame_set_position( *frame, mlt_producer_position( this ) );
 250
 251                 // Calculate the next position
 252                 mlt_producer_prepare_next( this );
 253         }
 254         else
 255         {
 256                 // Get the frame from the implementation
 257                 result = this->get_frame( this, frame, index );
 258         }
 259
 260         // Copy the fps and speed of the producer onto the frame
 261         mlt_properties properties = mlt_frame_properties( *frame );
 262         mlt_properties_set_double( properties, "fps", mlt_producer_get_fps( this ) );
 263         double speed = mlt_producer_get_speed( this );
 264         mlt_properties_set_double( properties, "speed", speed );
 265
 266         return 0;
 267 }
 268
 269 /** Close the producer.
 270 */
 271
 272 void mlt_producer_close( mlt_producer this )
 273 {
 274         if ( this->close != NULL )
 275                 this->close( this );
 276         else
 277                 mlt_service_close( &this->parent );
 278 }