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         // 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_timecode( 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_timecode( properties, "in", 0.0 );
  61                 mlt_properties_set_timecode( properties, "out", 3600.0 );
  62                 mlt_properties_set_timecode( properties, "length", 3600.0 );
  63                 mlt_properties_set_int( properties, "known_length", 1 );
  64                 mlt_properties_set_double( properties, "aspect_ratio", 4.0 / 3.0 );
  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 time code.
  90 */
  91
  92 int mlt_producer_seek( mlt_producer this, mlt_timecode timecode )
  93 {
  94         // Check bounds
  95         if ( timecode < 0 )
  96                 timecode = 0;
  97         if ( timecode > mlt_producer_get_playtime( this ) )
  98                 timecode = mlt_producer_get_playtime( this );
  99
 100         // Set the position
 101         mlt_properties_set_timecode( mlt_producer_properties( this ), "position", timecode );
 102
 103         // Calculate the absolute frame
 104         double frame = ( mlt_producer_get_in( this ) + timecode ) * mlt_producer_get_fps( this );
 105         mlt_properties_set_double( mlt_producer_properties( this ), "frame", floor( frame + 0.5 ) );
 106
 107         return 0;
 108 }
 109
 110 /** Seek to a specified absolute frame.
 111 */
 112
 113 int mlt_producer_seek_frame( mlt_producer this, uint64_t frame )
 114 {
 115         // Calculate the time code
 116         double timecode = ( frame / mlt_producer_get_fps( this ) ) - mlt_producer_get_in( this );
 117
 118         // If timecode is invalid, then seek on time
 119         if ( timecode < 0 )
 120         {
 121                 // Seek to the in point
 122                 mlt_producer_seek( this, 0 );
 123         }
 124         else if ( timecode > mlt_producer_get_playtime( this ) )
 125         {
 126                 // Seek to the out point
 127                 mlt_producer_seek( this, mlt_producer_get_playtime( this ) );
 128         }
 129         else
 130         {
 131                 // Set the position
 132                 mlt_properties_set_timecode( mlt_producer_properties( this ), "position", timecode );
 133
 134                 // Set the absolute frame
 135                 mlt_properties_set_double( mlt_producer_properties( this ), "frame", frame );
 136         }
 137
 138         return 0;
 139 }
 140
 141 /** Get the current time code.
 142 */
 143
 144 mlt_timecode mlt_producer_position( mlt_producer this )
 145 {
 146         return mlt_properties_get_timecode( mlt_producer_properties( this ), "position" );
 147 }
 148
 149 /** Get the current frame.
 150 */
 151
 152 uint64_t mlt_producer_frame( mlt_producer this )
 153 {
 154         return mlt_properties_get_double( mlt_producer_properties( this ), "frame" );
 155 }
 156
 157 /** Set the playing speed.
 158 */
 159
 160 int mlt_producer_set_speed( mlt_producer this, double speed )
 161 {
 162         return mlt_properties_set_double( mlt_producer_properties( this ), "speed", speed );
 163 }
 164
 165 /** Get the playing speed.
 166 */
 167
 168 double mlt_producer_get_speed( mlt_producer this )
 169 {
 170         return mlt_properties_get_double( mlt_producer_properties( this ), "speed" );
 171 }
 172
 173 /** Get the frames per second.
 174 */
 175
 176 double mlt_producer_get_fps( mlt_producer this )
 177 {
 178         return mlt_properties_get_double( mlt_producer_properties( this ), "fps" );
 179 }
 180
 181 /** Set the in and out points.
 182 */
 183
 184 int mlt_producer_set_in_and_out( mlt_producer this, mlt_timecode in, mlt_timecode out )
 185 {
 186         // Correct ins and outs if necessary
 187         if ( in < 0 )
 188                 in = 0;
 189         if ( in > mlt_producer_get_length( this ) )
 190                 in = mlt_producer_get_length( this );
 191         if ( out < 0 )
 192                 out = 0;
 193         if ( out > mlt_producer_get_length( this ) )
 194                 out = mlt_producer_get_length( this );
 195
 196         // Swap ins and outs if wrong
 197         if ( out < in )
 198         {
 199                 mlt_timecode t = in;
 200                 in = out;
 201                 out = t;
 202         }
 203
 204         // Set the values
 205         mlt_properties_set_timecode( mlt_producer_properties( this ), "in", in );
 206         mlt_properties_set_timecode( mlt_producer_properties( this ), "out", out );
 207
 208         // Seek to the in point
 209         mlt_producer_seek( this, 0 );
 210
 211         return 0;
 212 }
 213
 214 /** Get the in point.
 215 */
 216
 217 mlt_timecode mlt_producer_get_in( mlt_producer this )
 218 {
 219         return mlt_properties_get_timecode( mlt_producer_properties( this ), "in" );
 220 }
 221
 222 /** Get the out point.
 223 */
 224
 225 mlt_timecode mlt_producer_get_out( mlt_producer this )
 226 {
 227         return mlt_properties_get_timecode( mlt_producer_properties( this ), "out" );
 228 }
 229
 230 /** Get the total play time.
 231 */
 232
 233 mlt_timecode mlt_producer_get_playtime( mlt_producer this )
 234 {
 235         return mlt_producer_get_out( this ) - mlt_producer_get_in( this );
 236 }
 237
 238 /** Get the total length of the producer.
 239 */
 240
 241 mlt_timecode mlt_producer_get_length( mlt_producer this )
 242 {
 243         return mlt_properties_get_timecode( mlt_producer_properties( this ), "length" );
 244 }
 245
 246 /** Prepare for next frame.
 247 */
 248
 249 void mlt_producer_prepare_next( mlt_producer this )
 250 {
 251         mlt_producer_seek_frame( this, mlt_producer_frame( this ) + mlt_producer_get_speed( this ) );
 252 }
 253
 254 /** Get a frame.
 255 */
 256
 257 static int producer_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 258 {
 259         int result = 1;
 260         mlt_producer this = service->child;
 261
 262         // A properly instatiated producer will have a get_frame method...
 263         if ( this->get_frame != NULL )
 264         {
 265                 // Get the frame from the implementation
 266                 result = this->get_frame( this, frame, index );
 267         }
 268         else
 269         {
 270                 // Generate a test frame
 271                 *frame = mlt_frame_init( );
 272
 273                 // Set the timecode
 274                 result = mlt_frame_set_timecode( *frame, mlt_producer_position( this ) );
 275
 276                 // Calculate the next timecode
 277                 mlt_producer_prepare_next( this );
 278         }
 279
 280         // Copy the fps of the producer onto the frame
 281         mlt_properties properties = mlt_frame_properties( *frame );
 282         mlt_properties_set_double( properties, "fps", mlt_producer_get_fps( this ) );
 283
 284         return 0;
 285 }
 286
 287 /** Close the producer.
 288 */
 289
 290 void mlt_producer_close( mlt_producer this )
 291 {
 292         if ( this->close != NULL )
 293                 this->close( this );
 294         else
 295                 mlt_service_close( &this->parent );
 296 }