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, "eof", "pause" );
  65                 mlt_properties_set( properties, "resource", "<producer>" );
  66
  67                 // Override service get_frame
  68                 parent->get_frame = producer_get_frame;
  69         }
  70
  71         return 0;
  72 }
  73
  74 /** Get the parent service object.
  75 */
  76
  77 mlt_service mlt_producer_service( mlt_producer this )
  78 {
  79         return &this->parent;
  80 }
  81
  82 /** Get the producer properties.
  83 */
  84
  85 mlt_properties mlt_producer_properties( mlt_producer this )
  86 {
  87         return mlt_service_properties( &this->parent );
  88 }
  89
  90 /** Seek to a specified position.
  91 */
  92
  93 int mlt_producer_seek( mlt_producer this, mlt_position position )
  94 {
  95         // Determine eof handling
  96         char *eof = mlt_properties_get( mlt_producer_properties( this ), "eof" );
  97
  98         // Check bounds
  99         if ( position < 0 )
 100                 position = 0;
 101         else if ( !strcmp( eof, "pause" ) && position >= mlt_producer_get_playtime( this ) )
 102                 position = mlt_producer_get_playtime( this ) - 1;
 103
 104         // Set the position
 105         mlt_properties_set_position( mlt_producer_properties( this ), "position", position );
 106
 107         // Calculate the absolute frame
 108         mlt_properties_set_position( mlt_producer_properties( this ), "frame", mlt_producer_get_in( this ) + position );
 109
 110         return 0;
 111 }
 112
 113 /** Get the current position (relative to in point).
 114 */
 115
 116 mlt_position mlt_producer_position( mlt_producer this )
 117 {
 118         return mlt_properties_get_position( mlt_producer_properties( this ), "position" );
 119 }
 120
 121 /** Get the current position (relative to start of producer).
 122 */
 123
 124 mlt_position mlt_producer_frame( mlt_producer this )
 125 {
 126         //char *resource = mlt_properties_get( mlt_producer_properties( this ), "resource" );
 127         //mlt_position frame = mlt_properties_get_position( mlt_producer_properties( this ), "frame" );
 128         //mlt_position position = mlt_properties_get_position( mlt_producer_properties( this ), "position" );
 129         //fprintf( stderr, "%s: %lld %lld\n", resource, frame, position );
 130         return mlt_properties_get_position( mlt_producer_properties( this ), "frame" );
 131 }
 132
 133 /** Set the playing speed.
 134 */
 135
 136 int mlt_producer_set_speed( mlt_producer this, double speed )
 137 {
 138         return mlt_properties_set_double( mlt_producer_properties( this ), "speed", speed );
 139 }
 140
 141 /** Get the playing speed.
 142 */
 143
 144 double mlt_producer_get_speed( mlt_producer this )
 145 {
 146         return mlt_properties_get_double( mlt_producer_properties( this ), "speed" );
 147 }
 148
 149 /** Get the frames per second.
 150 */
 151
 152 double mlt_producer_get_fps( mlt_producer this )
 153 {
 154         return mlt_properties_get_double( mlt_producer_properties( this ), "fps" );
 155 }
 156
 157 /** Set the in and out points.
 158 */
 159
 160 int mlt_producer_set_in_and_out( mlt_producer this, mlt_position in, mlt_position out )
 161 {
 162         // Correct ins and outs if necessary
 163         if ( in < 0 )
 164                 in = 0;
 165         else if ( in > mlt_producer_get_length( this ) )
 166                 in = mlt_producer_get_length( this );
 167
 168         if ( out < 0 )
 169                 out = 0;
 170         else if ( out > mlt_producer_get_length( this ) )
 171                 out = mlt_producer_get_length( this );
 172
 173         // Swap ins and outs if wrong
 174         if ( out < in )
 175         {
 176                 mlt_position t = in;
 177                 in = out;
 178                 out = t;
 179         }
 180
 181         // Set the values
 182         mlt_properties_set_position( mlt_producer_properties( this ), "in", in );
 183         mlt_properties_set_position( mlt_producer_properties( this ), "out", out );
 184
 185         return 0;
 186 }
 187
 188 /** Get the in point.
 189 */
 190
 191 mlt_position mlt_producer_get_in( mlt_producer this )
 192 {
 193         return mlt_properties_get_position( mlt_producer_properties( this ), "in" );
 194 }
 195
 196 /** Get the out point.
 197 */
 198
 199 mlt_position mlt_producer_get_out( mlt_producer this )
 200 {
 201         return mlt_properties_get_position( mlt_producer_properties( this ), "out" );
 202 }
 203
 204 /** Get the total play time.
 205 */
 206
 207 mlt_position mlt_producer_get_playtime( mlt_producer this )
 208 {
 209         return mlt_producer_get_out( this ) - mlt_producer_get_in( this ) + 1;
 210 }
 211
 212 /** Get the total length of the producer.
 213 */
 214
 215 mlt_position mlt_producer_get_length( mlt_producer this )
 216 {
 217         return mlt_properties_get_position( mlt_producer_properties( this ), "length" );
 218 }
 219
 220 /** Prepare for next frame.
 221 */
 222
 223 void mlt_producer_prepare_next( mlt_producer this )
 224 {
 225         mlt_producer_seek( this, mlt_producer_position( this ) + mlt_producer_get_speed( this ) );
 226 }
 227
 228 /** Get a frame.
 229 */
 230
 231 static int producer_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 232 {
 233         int result = 1;
 234         mlt_producer this = service->child;
 235
 236         // Determine eof handling
 237         char *eof = mlt_properties_get( mlt_producer_properties( this ), "eof" );
 238
 239         // A properly instatiated producer will have a get_frame method...
 240         if ( this->get_frame == NULL || ( !strcmp( eof, "continue" ) && mlt_producer_position( this ) > mlt_producer_get_out( this ) ) )
 241         {
 242                 // Generate a test frame
 243                 *frame = mlt_frame_init( );
 244
 245                 // Set the position
 246                 result = mlt_frame_set_position( *frame, mlt_producer_position( this ) );
 247
 248                 // Calculate the next position
 249                 mlt_producer_prepare_next( this );
 250         }
 251         else
 252         {
 253                 // Get the frame from the implementation
 254                 result = this->get_frame( this, frame, index );
 255         }
 256
 257         // Copy the fps and speed of the producer onto the frame
 258         mlt_properties properties = mlt_frame_properties( *frame );
 259         mlt_properties_set_double( properties, "fps", mlt_producer_get_fps( this ) );
 260         double speed = mlt_producer_get_speed( this );
 261         mlt_properties_set_double( properties, "speed", speed );
 262
 263         return 0;
 264 }
 265
 266 /** Close the producer.
 267 */
 268
 269 void mlt_producer_close( mlt_producer this )
 270 {
 271         if ( this->close != NULL )
 272                 this->close( this );
 273         else
 274                 mlt_service_close( &this->parent );
 275 }