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         {
 108                 position = 0;
 109         }
 110         else if ( !strcmp( eof, "pause" ) && position >= mlt_producer_get_playtime( this ) )
 111         {
 112                 mlt_producer_set_speed( this, 0 );
 113                 position = mlt_producer_get_playtime( this ) - 1;
 114         }
 115         else if ( !strcmp( eof, "loop" ) && position >= mlt_producer_get_playtime( this ) )
 116         {
 117                 position = position % mlt_producer_get_playtime( this );
 118         }
 119
 120         // Set the position
 121         mlt_properties_set_position( mlt_producer_properties( this ), "_position", position );
 122
 123         // Calculate the absolute frame
 124         mlt_properties_set_position( mlt_producer_properties( this ), "_frame", mlt_producer_get_in( this ) + position );
 125
 126         return 0;
 127 }
 128
 129 /** Get the current position (relative to in point).
 130 */
 131
 132 mlt_position mlt_producer_position( mlt_producer this )
 133 {
 134         return mlt_properties_get_position( mlt_producer_properties( this ), "_position" );
 135 }
 136
 137 /** Get the current position (relative to start of producer).
 138 */
 139
 140 mlt_position mlt_producer_frame( mlt_producer this )
 141 {
 142         return mlt_properties_get_position( mlt_producer_properties( this ), "_frame" );
 143 }
 144
 145 /** Set the playing speed.
 146 */
 147
 148 int mlt_producer_set_speed( mlt_producer this, double speed )
 149 {
 150         return mlt_properties_set_double( mlt_producer_properties( this ), "_speed", speed );
 151 }
 152
 153 /** Get the playing speed.
 154 */
 155
 156 double mlt_producer_get_speed( mlt_producer this )
 157 {
 158         return mlt_properties_get_double( mlt_producer_properties( this ), "_speed" );
 159 }
 160
 161 /** Get the frames per second.
 162 */
 163
 164 double mlt_producer_get_fps( mlt_producer this )
 165 {
 166         return mlt_properties_get_double( mlt_producer_properties( this ), "fps" );
 167 }
 168
 169 /** Set the in and out points.
 170 */
 171
 172 int mlt_producer_set_in_and_out( mlt_producer this, mlt_position in, mlt_position out )
 173 {
 174         // Correct ins and outs if necessary
 175         if ( in < 0 )
 176                 in = 0;
 177         else if ( in > mlt_producer_get_length( this ) )
 178                 in = mlt_producer_get_length( this );
 179
 180         if ( out < 0 )
 181                 out = 0;
 182         else if ( out > mlt_producer_get_length( this ) )
 183                 out = mlt_producer_get_length( this );
 184
 185         // Swap ins and outs if wrong
 186         if ( out < in )
 187         {
 188                 mlt_position t = in;
 189                 in = out;
 190                 out = t;
 191         }
 192
 193         // Set the values
 194         mlt_properties_set_position( mlt_producer_properties( this ), "in", in );
 195         mlt_properties_set_position( mlt_producer_properties( this ), "out", out );
 196
 197         return 0;
 198 }
 199
 200 /** Get the in point.
 201 */
 202
 203 mlt_position mlt_producer_get_in( mlt_producer this )
 204 {
 205         return mlt_properties_get_position( mlt_producer_properties( this ), "in" );
 206 }
 207
 208 /** Get the out point.
 209 */
 210
 211 mlt_position mlt_producer_get_out( mlt_producer this )
 212 {
 213         return mlt_properties_get_position( mlt_producer_properties( this ), "out" );
 214 }
 215
 216 /** Get the total play time.
 217 */
 218
 219 mlt_position mlt_producer_get_playtime( mlt_producer this )
 220 {
 221         return mlt_producer_get_out( this ) - mlt_producer_get_in( this ) + 1;
 222 }
 223
 224 /** Get the total length of the producer.
 225 */
 226
 227 mlt_position mlt_producer_get_length( mlt_producer this )
 228 {
 229         return mlt_properties_get_position( mlt_producer_properties( this ), "length" );
 230 }
 231
 232 /** Prepare for next frame.
 233 */
 234
 235 void mlt_producer_prepare_next( mlt_producer this )
 236 {
 237         mlt_producer_seek( this, mlt_producer_position( this ) + mlt_producer_get_speed( this ) );
 238 }
 239
 240 /** Get a frame.
 241 */
 242
 243 static int producer_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 244 {
 245         int result = 1;
 246         mlt_producer this = service->child;
 247
 248         // Determine eof handling
 249         char *eof = mlt_properties_get( mlt_producer_properties( this ), "eof" );
 250
 251         // A properly instatiated producer will have a get_frame method...
 252 //fprintf( stderr, "PRODUCER get_frame %p eof %s pos %lld out %lld\n",
 253 //this->get_frame, eof, mlt_producer_position( this ), mlt_producer_get_out( this ) );
 254         if ( this->get_frame == NULL || ( !strcmp( eof, "continue" ) && mlt_producer_position( this ) > mlt_producer_get_out( this ) ) )
 255         {
 256                 // Generate a test frame
 257                 *frame = mlt_frame_init( );
 258
 259                 // Set the position
 260                 result = mlt_frame_set_position( *frame, mlt_producer_position( this ) );
 261
 262                 // Calculate the next position
 263                 mlt_producer_prepare_next( this );
 264         }
 265         else
 266         {
 267                 // Get the frame from the implementation
 268                 result = this->get_frame( this, frame, index );
 269         }
 270
 271         // Copy the fps and speed of the producer onto the frame
 272         mlt_properties properties = mlt_frame_properties( *frame );
 273         mlt_properties_set_double( properties, "fps", mlt_producer_get_fps( this ) );
 274         double speed = mlt_producer_get_speed( this );
 275         mlt_properties_set_double( properties, "_speed", speed );
 276
 277         return 0;
 278 }
 279
 280 /** Close the producer.
 281 */
 282
 283 void mlt_producer_close( mlt_producer this )
 284 {
 285         if ( this->close != NULL )
 286                 this->close( this );
 287         else
 288                 mlt_service_close( &this->parent );
 289 }