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_factory.h"
  24 #include "mlt_frame.h"
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28 #include <math.h>
  29
  30 /** Forward references.
  31 */
  32
  33 static int producer_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
  34
  35 /** Constructor
  36 */
  37
  38 int mlt_producer_init( mlt_producer this, void *child )
  39 {
  40         // Check that we haven't received NULL
  41         int error = this == NULL;
  42
  43         // Continue if no error
  44         if ( error == 0 )
  45         {
  46                 // Initialise the producer
  47                 memset( this, 0, sizeof( struct mlt_producer_s ) );
  48
  49                 // Associate with the child
  50                 this->child = child;
  51
  52                 // Initialise the service
  53                 if ( mlt_service_init( &this->parent, this ) == 0 )
  54                 {
  55                         // Get the normalisation preference
  56                         char *normalisation = mlt_environment( "MLT_NORMALISATION" );
  57
  58                         // The parent is the service
  59                         mlt_service parent = &this->parent;
  60
  61                         // Get the properties of the parent
  62                         mlt_properties properties = mlt_service_properties( parent );
  63
  64                         // Set the default properties
  65                         mlt_properties_set( properties, "mlt_type", "mlt_producer" );
  66                         mlt_properties_set_position( properties, "_position", 0.0 );
  67                         mlt_properties_set_double( properties, "_frame", 0 );
  68                         if ( normalisation == NULL || strcmp( normalisation, "NTSC" ) )
  69                         {
  70                                 mlt_properties_set_double( properties, "fps", 25.0 );
  71                                 mlt_properties_set_double( properties, "aspect_ratio", 72.0 / 79.0 );
  72                         }
  73                         else
  74                         {
  75                                 mlt_properties_set_double( properties, "fps", 30000.0 / 1001.0 );
  76                                 mlt_properties_set_double( properties, "aspect_ratio", 128.0 / 117.0 );
  77                         }
  78                         mlt_properties_set_double( properties, "_speed", 1.0 );
  79                         mlt_properties_set_position( properties, "in", 0 );
  80                         mlt_properties_set_position( properties, "out", 14999 );
  81                         mlt_properties_set_position( properties, "length", 15000 );
  82                         mlt_properties_set( properties, "eof", "pause" );
  83                         mlt_properties_set( properties, "resource", "<producer>" );
  84
  85                         // Override service get_frame
  86                         parent->get_frame = producer_get_frame;
  87                 }
  88         }
  89
  90         return error;
  91 }
  92
  93 /** Create a new producer.
  94 */
  95
  96 mlt_producer mlt_producer_new( )
  97 {
  98         mlt_producer this = malloc( sizeof( struct mlt_producer_s ) );
  99         mlt_producer_init( this, NULL );
 100         return this;
 101 }
 102
 103 /** Get the parent service object.
 104 */
 105
 106 mlt_service mlt_producer_service( mlt_producer this )
 107 {
 108         return &this->parent;
 109 }
 110
 111 /** Get the producer properties.
 112 */
 113
 114 mlt_properties mlt_producer_properties( mlt_producer this )
 115 {
 116         return mlt_service_properties( &this->parent );
 117 }
 118
 119 /** Seek to a specified position.
 120 */
 121
 122 int mlt_producer_seek( mlt_producer this, mlt_position position )
 123 {
 124         // Determine eof handling
 125         char *eof = mlt_properties_get( mlt_producer_properties( this ), "eof" );
 126
 127         // Check bounds
 128         if ( position < 0 )
 129         {
 130                 position = 0;
 131         }
 132         else if ( !strcmp( eof, "pause" ) && position >= mlt_producer_get_playtime( this ) )
 133         {
 134                 mlt_producer_set_speed( this, 0 );
 135                 position = mlt_producer_get_playtime( this ) - 1;
 136         }
 137         else if ( !strcmp( eof, "loop" ) && position >= mlt_producer_get_playtime( this ) )
 138         {
 139                 position = position % mlt_producer_get_playtime( this );
 140         }
 141
 142         // Set the position
 143         mlt_properties_set_position( mlt_producer_properties( this ), "_position", position );
 144
 145         // Calculate the absolute frame
 146         mlt_properties_set_position( mlt_producer_properties( this ), "_frame", mlt_producer_get_in( this ) + position );
 147
 148         return 0;
 149 }
 150
 151 /** Get the current position (relative to in point).
 152 */
 153
 154 mlt_position mlt_producer_position( mlt_producer this )
 155 {
 156         return mlt_properties_get_position( mlt_producer_properties( this ), "_position" );
 157 }
 158
 159 /** Get the current position (relative to start of producer).
 160 */
 161
 162 mlt_position mlt_producer_frame( mlt_producer this )
 163 {
 164         return mlt_properties_get_position( mlt_producer_properties( this ), "_frame" );
 165 }
 166
 167 /** Set the playing speed.
 168 */
 169
 170 int mlt_producer_set_speed( mlt_producer this, double speed )
 171 {
 172         return mlt_properties_set_double( mlt_producer_properties( this ), "_speed", speed );
 173 }
 174
 175 /** Get the playing speed.
 176 */
 177
 178 double mlt_producer_get_speed( mlt_producer this )
 179 {
 180         return mlt_properties_get_double( mlt_producer_properties( this ), "_speed" );
 181 }
 182
 183 /** Get the frames per second.
 184 */
 185
 186 double mlt_producer_get_fps( mlt_producer this )
 187 {
 188         return mlt_properties_get_double( mlt_producer_properties( this ), "fps" );
 189 }
 190
 191 /** Set the in and out points.
 192 */
 193
 194 int mlt_producer_set_in_and_out( mlt_producer this, mlt_position in, mlt_position out )
 195 {
 196         // Correct ins and outs if necessary
 197         if ( in < 0 )
 198                 in = 0;
 199         else if ( in > mlt_producer_get_length( this ) )
 200                 in = mlt_producer_get_length( this );
 201
 202         if ( out < 0 )
 203                 out = 0;
 204         else if ( out > mlt_producer_get_length( this ) )
 205                 out = mlt_producer_get_length( this );
 206
 207         // Swap ins and outs if wrong
 208         if ( out < in )
 209         {
 210                 mlt_position t = in;
 211                 in = out;
 212                 out = t;
 213         }
 214
 215         // Set the values
 216         mlt_properties_set_position( mlt_producer_properties( this ), "in", in );
 217         mlt_properties_set_position( mlt_producer_properties( this ), "out", out );
 218
 219         return 0;
 220 }
 221
 222 /** Get the in point.
 223 */
 224
 225 mlt_position mlt_producer_get_in( mlt_producer this )
 226 {
 227         return mlt_properties_get_position( mlt_producer_properties( this ), "in" );
 228 }
 229
 230 /** Get the out point.
 231 */
 232
 233 mlt_position mlt_producer_get_out( mlt_producer this )
 234 {
 235         return mlt_properties_get_position( mlt_producer_properties( this ), "out" );
 236 }
 237
 238 /** Get the total play time.
 239 */
 240
 241 mlt_position mlt_producer_get_playtime( mlt_producer this )
 242 {
 243         return mlt_producer_get_out( this ) - mlt_producer_get_in( this ) + 1;
 244 }
 245
 246 /** Get the total length of the producer.
 247 */
 248
 249 mlt_position mlt_producer_get_length( mlt_producer this )
 250 {
 251         return mlt_properties_get_position( mlt_producer_properties( this ), "length" );
 252 }
 253
 254 /** Prepare for next frame.
 255 */
 256
 257 void mlt_producer_prepare_next( mlt_producer this )
 258 {
 259         mlt_producer_seek( this, mlt_producer_position( this ) + mlt_producer_get_speed( this ) );
 260 }
 261
 262 /** Get a frame.
 263 */
 264
 265 static int producer_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 266 {
 267         int result = 1;
 268         mlt_producer this = service->child;
 269
 270         // Determine eof handling
 271         char *eof = mlt_properties_get( mlt_producer_properties( this ), "eof" );
 272
 273         // A properly instatiated producer will have a get_frame method...
 274         if ( this->get_frame == NULL || ( !strcmp( eof, "continue" ) && mlt_producer_position( this ) > mlt_producer_get_out( this ) ) )
 275         {
 276                 // Generate a test frame
 277                 *frame = mlt_frame_init( );
 278
 279                 // Set the position
 280                 result = mlt_frame_set_position( *frame, mlt_producer_position( this ) );
 281
 282                 // Mark as a test card
 283                 mlt_properties_set_int( mlt_frame_properties( *frame ), "test_image", 1 );
 284                 mlt_properties_set_int( mlt_frame_properties( *frame ), "test_audio", 1 );
 285
 286                 // Calculate the next position
 287                 mlt_producer_prepare_next( this );
 288         }
 289         else
 290         {
 291                 // Get the frame from the implementation
 292                 result = this->get_frame( this, frame, index );
 293         }
 294
 295         // Copy the fps and speed of the producer onto the frame
 296         mlt_properties properties = mlt_frame_properties( *frame );
 297         mlt_properties_set_double( properties, "fps", mlt_producer_get_fps( this ) );
 298         double speed = mlt_producer_get_speed( this );
 299         mlt_properties_set_double( properties, "_speed", speed );
 300
 301         return 0;
 302 }
 303
 304 /** Close the producer.
 305 */
 306
 307 void mlt_producer_close( mlt_producer this )
 308 {
 309         if ( this->close != NULL )
 310                 this->close( this );
 311         else
 312                 mlt_service_close( &this->parent );
 313 }