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