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", 0.0 );
  61                 mlt_properties_set_position( properties, "out", 179999 );
  62                 mlt_properties_set_position( properties, "length", 180000 );
  63                 mlt_properties_set_double( properties, "aspect_ratio", 4.0 / 3.0 );
  64                 mlt_properties_set( properties, "log_id", "multitrack" );
  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 /** Convert frame position to position.
  90 */
  91
  92 /*
  93 mlt_position mlt_producer_time( mlt_producer this, int64_t frame )
  94 {
  95         if ( frame < 0 )
  96                 return -1;
  97         else
  98                 return ( mlt_position )frame / mlt_producer_get_fps( this );
  99 }
 100 */
 101
 102 /** Convert position to frame position.
 103 */
 104
 105 /*
 106 int64_t mlt_producer_frame_position( mlt_producer this, mlt_position position )
 107 {
 108         if ( position < 0 )
 109                 return -1;
 110         else
 111                 return ( int64_t )( floor( position * mlt_producer_get_fps( this ) + 0.5 ) );
 112 }
 113 */
 114
 115 /** Seek to a specified position.
 116 */
 117
 118 int mlt_producer_seek( mlt_producer this, mlt_position position )
 119 {
 120         // Check bounds
 121         if ( position < 0 )
 122                 position = 0;
 123         else if ( position > mlt_producer_get_playtime( this ) )
 124                 position = mlt_producer_get_playtime( this ) - 1;
 125
 126         // Set the position
 127         mlt_properties_set_position( mlt_producer_properties( this ), "position", position );
 128
 129         // Calculate the absolute frame
 130         mlt_properties_set_position( mlt_producer_properties( this ), "frame", mlt_producer_get_in( this ) + position );
 131
 132         return 0;
 133 }
 134
 135 /** Get the current position (relative to in point).
 136 */
 137
 138 mlt_position mlt_producer_position( mlt_producer this )
 139 {
 140         return mlt_properties_get_position( mlt_producer_properties( this ), "position" );
 141 }
 142
 143 /** Get the current position (relative to start of producer).
 144 */
 145
 146 mlt_position mlt_producer_frame( mlt_producer this )
 147 {
 148         return mlt_properties_get_double( mlt_producer_properties( this ), "frame" );
 149 }
 150
 151 /** Set the playing speed.
 152 */
 153
 154 int mlt_producer_set_speed( mlt_producer this, double speed )
 155 {
 156         return mlt_properties_set_double( mlt_producer_properties( this ), "speed", speed );
 157 }
 158
 159 /** Get the playing speed.
 160 */
 161
 162 double mlt_producer_get_speed( mlt_producer this )
 163 {
 164         return mlt_properties_get_double( mlt_producer_properties( this ), "speed" );
 165 }
 166
 167 /** Get the frames per second.
 168 */
 169
 170 double mlt_producer_get_fps( mlt_producer this )
 171 {
 172         return mlt_properties_get_double( mlt_producer_properties( this ), "fps" );
 173 }
 174
 175 /** Set the in and out points.
 176 */
 177
 178 int mlt_producer_set_in_and_out( mlt_producer this, mlt_position in, mlt_position out )
 179 {
 180         // Correct ins and outs if necessary
 181         if ( in < 0 )
 182                 in = 0;
 183         else if ( in > mlt_producer_get_length( this ) )
 184                 in = mlt_producer_get_length( this );
 185
 186         if ( out < 0 )
 187                 out = 0;
 188         else if ( out > mlt_producer_get_length( this ) )
 189                 out = mlt_producer_get_length( this );
 190
 191         // Swap ins and outs if wrong
 192         if ( out < in )
 193         {
 194                 mlt_position t = in;
 195                 in = out;
 196                 out = t;
 197         }
 198
 199         // Set the values
 200         mlt_properties_set_position( mlt_producer_properties( this ), "in", in );
 201         mlt_properties_set_position( mlt_producer_properties( this ), "out", out );
 202
 203         return 0;
 204 }
 205
 206 /** Get the in point.
 207 */
 208
 209 mlt_position mlt_producer_get_in( mlt_producer this )
 210 {
 211         return mlt_properties_get_position( mlt_producer_properties( this ), "in" );
 212 }
 213
 214 /** Get the out point.
 215 */
 216
 217 mlt_position mlt_producer_get_out( mlt_producer this )
 218 {
 219         return mlt_properties_get_position( mlt_producer_properties( this ), "out" );
 220 }
 221
 222 /** Get the total play time.
 223 */
 224
 225 mlt_position mlt_producer_get_playtime( mlt_producer this )
 226 {
 227         return mlt_producer_get_out( this ) - mlt_producer_get_in( this ) + 1;
 228 }
 229
 230 /** Get the total length of the producer.
 231 */
 232
 233 mlt_position mlt_producer_get_length( mlt_producer this )
 234 {
 235         return mlt_properties_get_position( mlt_producer_properties( this ), "length" );
 236 }
 237
 238 /** Prepare for next frame.
 239 */
 240
 241 void mlt_producer_prepare_next( mlt_producer this )
 242 {
 243         mlt_producer_seek( this, mlt_producer_frame( this ) + mlt_producer_get_speed( this ) );
 244 }
 245
 246 /** Get a frame.
 247 */
 248
 249 static int producer_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 250 {
 251         int result = 1;
 252         mlt_producer this = service->child;
 253
 254         // A properly instatiated producer will have a get_frame method...
 255         if ( this->get_frame != NULL )
 256         {
 257                 // Get the frame from the implementation
 258                 result = this->get_frame( this, frame, index );
 259         }
 260         else
 261         {
 262                 // Generate a test frame
 263                 *frame = mlt_frame_init( );
 264
 265                 // Set the position
 266                 result = mlt_frame_set_position( *frame, mlt_producer_position( this ) );
 267
 268                 // Calculate the next position
 269                 mlt_producer_prepare_next( this );
 270         }
 271
 272         // Copy the fps and speed of the producer onto the frame
 273         mlt_properties properties = mlt_frame_properties( *frame );
 274         mlt_properties_set_double( properties, "fps", mlt_producer_get_fps( this ) );
 275         double speed = mlt_producer_get_speed( this );
 276         mlt_properties_set_double( properties, "speed", speed );
 277
 278         return 0;
 279 }
 280
 281 /** Close the producer.
 282 */
 283
 284 void mlt_producer_close( mlt_producer this )
 285 {
 286         if ( this->close != NULL )
 287                 this->close( this );
 288         else
 289                 mlt_service_close( &this->parent );
 290 }