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_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", 36000.0 );
  62                 mlt_properties_set_timecode( properties, "length", 36000.0 );
  63                 mlt_properties_set_int( properties, "known_length", 1 );
  64                 mlt_properties_set_double( properties, "aspect_ratio", 4.0 / 3.0 );
  65                 mlt_properties_set( properties, "log_id", "multitrack" );
  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 /** Convert frame position to timecode.
  91 */
  92
  93 mlt_timecode mlt_producer_time( mlt_producer this, int64_t frame )
  94 {
  95         if ( frame < 0 )
  96                 return -1;
  97         else
  98                 return ( mlt_timecode )frame / mlt_producer_get_fps( this );
  99 }
 100
 101 /** Convert timecode to frame position.
 102 */
 103
 104 int64_t mlt_producer_frame_position( mlt_producer this, mlt_timecode position )
 105 {
 106         if ( position < 0 )
 107                 return -1;
 108         else
 109                 return ( int64_t )( floor( position * mlt_producer_get_fps( this ) + 0.5 ) );
 110 }
 111
 112 /** Seek to a specified time code.
 113 */
 114
 115 int mlt_producer_seek( mlt_producer this, mlt_timecode timecode )
 116 {
 117         // Check bounds
 118         if ( timecode < 0 )
 119                 timecode = 0;
 120         if ( timecode > mlt_producer_get_playtime( this ) )
 121                 timecode = mlt_producer_get_playtime( this );
 122
 123         // Set the position
 124         mlt_properties_set_timecode( mlt_producer_properties( this ), "position", timecode );
 125
 126         // Calculate the absolute frame
 127         double frame = ( mlt_producer_get_in( this ) + timecode ) * mlt_producer_get_fps( this );
 128         mlt_properties_set_double( mlt_producer_properties( this ), "frame", floor( frame + 0.5 ) );
 129
 130         return 0;
 131 }
 132
 133 /** Seek to a specified absolute frame.
 134 */
 135
 136 int mlt_producer_seek_frame( mlt_producer this, int64_t frame )
 137 {
 138         // Calculate the time code
 139         double timecode = ( frame / mlt_producer_get_fps( this ) ) - mlt_producer_get_in( this );
 140
 141         // If timecode is invalid, then seek on time
 142         if ( frame < 0 || timecode < 0 )
 143         {
 144                 // Seek to the in point
 145                 mlt_producer_seek( this, 0 );
 146         }
 147         else if ( timecode > mlt_producer_get_playtime( this ) )
 148         {
 149                 // Seek to the out point
 150                 mlt_producer_seek( this, mlt_producer_get_playtime( this ) );
 151         }
 152         else
 153         {
 154                 // Set the position
 155                 mlt_properties_set_timecode( mlt_producer_properties( this ), "position", timecode );
 156
 157                 // Set the absolute frame
 158                 mlt_properties_set_double( mlt_producer_properties( this ), "frame", frame );
 159         }
 160
 161         return 0;
 162 }
 163
 164 /** Get the current time code.
 165 */
 166
 167 mlt_timecode mlt_producer_position( mlt_producer this )
 168 {
 169         return mlt_properties_get_timecode( mlt_producer_properties( this ), "position" );
 170 }
 171
 172 /** Get the current frame.
 173 */
 174
 175 uint64_t mlt_producer_frame( mlt_producer this )
 176 {
 177         return mlt_properties_get_double( mlt_producer_properties( this ), "frame" );
 178 }
 179
 180 /** Set the playing speed.
 181 */
 182
 183 int mlt_producer_set_speed( mlt_producer this, double speed )
 184 {
 185         return mlt_properties_set_double( mlt_producer_properties( this ), "speed", speed );
 186 }
 187
 188 /** Get the playing speed.
 189 */
 190
 191 double mlt_producer_get_speed( mlt_producer this )
 192 {
 193         return mlt_properties_get_double( mlt_producer_properties( this ), "speed" );
 194 }
 195
 196 /** Get the frames per second.
 197 */
 198
 199 double mlt_producer_get_fps( mlt_producer this )
 200 {
 201         return mlt_properties_get_double( mlt_producer_properties( this ), "fps" );
 202 }
 203
 204 /** Set the in and out points.
 205 */
 206
 207 int mlt_producer_set_in_and_out( mlt_producer this, mlt_timecode in, mlt_timecode out )
 208 {
 209         // Correct ins and outs if necessary
 210         if ( in < 0 )
 211                 in = 0;
 212         if ( in > mlt_producer_get_length( this ) )
 213                 in = mlt_producer_get_length( this );
 214         if ( out < 0 )
 215                 out = 0;
 216         if ( out > mlt_producer_get_length( this ) )
 217                 out = mlt_producer_get_length( this );
 218
 219         // Swap ins and outs if wrong
 220         if ( out < in )
 221         {
 222                 mlt_timecode t = in;
 223                 in = out;
 224                 out = t;
 225         }
 226
 227         // Set the values
 228         mlt_properties_set_timecode( mlt_producer_properties( this ), "in", in );
 229         mlt_properties_set_timecode( mlt_producer_properties( this ), "out", out );
 230
 231         // Seek to the in point
 232         mlt_producer_seek( this, 0 );
 233
 234         return 0;
 235 }
 236
 237 /** Get the in point.
 238 */
 239
 240 mlt_timecode mlt_producer_get_in( mlt_producer this )
 241 {
 242         return mlt_properties_get_timecode( mlt_producer_properties( this ), "in" );
 243 }
 244
 245 /** Get the out point.
 246 */
 247
 248 mlt_timecode mlt_producer_get_out( mlt_producer this )
 249 {
 250         return mlt_properties_get_timecode( mlt_producer_properties( this ), "out" );
 251 }
 252
 253 /** Get the total play time.
 254 */
 255
 256 mlt_timecode mlt_producer_get_playtime( mlt_producer this )
 257 {
 258         return mlt_producer_get_out( this ) - mlt_producer_get_in( this );
 259 }
 260
 261 /** Get the total length of the producer.
 262 */
 263
 264 mlt_timecode mlt_producer_get_length( mlt_producer this )
 265 {
 266         return mlt_properties_get_timecode( mlt_producer_properties( this ), "length" );
 267 }
 268
 269 /** Prepare for next frame.
 270 */
 271
 272 void mlt_producer_prepare_next( mlt_producer this )
 273 {
 274         mlt_producer_seek_frame( this, mlt_producer_frame( this ) + mlt_producer_get_speed( this ) );
 275 }
 276
 277 /** Get a frame.
 278 */
 279
 280 static int producer_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 281 {
 282         int result = 1;
 283         mlt_producer this = service->child;
 284
 285         // A properly instatiated producer will have a get_frame method...
 286         if ( this->get_frame != NULL )
 287         {
 288                 // Get the frame from the implementation
 289                 result = this->get_frame( this, frame, index );
 290
 291                 mlt_properties frame_properties = mlt_frame_properties( *frame );
 292                 double speed = mlt_producer_get_speed( this );
 293                 mlt_properties_set_double( frame_properties, "speed", speed );
 294         }
 295         else
 296         {
 297                 // Generate a test frame
 298                 *frame = mlt_frame_init( );
 299
 300                 // Set the timecode
 301                 result = mlt_frame_set_timecode( *frame, mlt_producer_position( this ) );
 302
 303                 // Calculate the next timecode
 304                 mlt_producer_prepare_next( this );
 305         }
 306
 307         // Copy the fps of the producer onto the frame
 308         mlt_properties properties = mlt_frame_properties( *frame );
 309         mlt_properties_set_double( properties, "fps", mlt_producer_get_fps( this ) );
 310
 311         return 0;
 312 }
 313
 314 /** Close the producer.
 315 */
 316
 317 void mlt_producer_close( mlt_producer this )
 318 {
 319         if ( this->close != NULL )
 320                 this->close( this );
 321         else
 322                 mlt_service_close( &this->parent );
 323 }