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_factory.h"
  24 #include "mlt_frame.h"
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28 #include <math.h>
  29
  30 /** Forward references.
  31 */
  32
  33 static int producer_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
  34
  35 /** Constructor
  36 */
  37
  38 int mlt_producer_init( mlt_producer this, void *child )
  39 {
  40         // Check that we haven't received NULL
  41         int error = this == NULL;
  42
  43         // Continue if no error
  44         if ( error == 0 )
  45         {
  46                 // Initialise the producer
  47                 memset( this, 0, sizeof( struct mlt_producer_s ) );
  48
  49                 // Associate with the child
  50                 this->child = child;
  51
  52                 // Initialise the service
  53                 if ( mlt_service_init( &this->parent, this ) == 0 )
  54                 {
  55                         // Get the normalisation preference
  56                         char *normalisation = mlt_environment( "MLT_NORMALISATION" );
  57
  58                         // The parent is the service
  59                         mlt_service parent = &this->parent;
  60
  61                         // Get the properties of the parent
  62                         mlt_properties properties = mlt_service_properties( parent );
  63
  64                         // Set the default properties
  65                         mlt_properties_set( properties, "mlt_type", "mlt_producer" );
  66                         mlt_properties_set_position( properties, "_position", 0.0 );
  67                         mlt_properties_set_double( properties, "_frame", 0 );
  68                         if ( normalisation == NULL || strcmp( normalisation, "NTSC" ) )
  69                                 mlt_properties_set_double( properties, "fps", 25.0 );
  70                         else
  71                                 mlt_properties_set_double( properties, "fps", 30000.0 / 1001.0 );
  72                         mlt_properties_set_double( properties, "_speed", 1.0 );
  73                         mlt_properties_set_position( properties, "in", 0 );
  74                         mlt_properties_set_position( properties, "out", 14999 );
  75                         mlt_properties_set_position( properties, "length", 15000 );
  76                         mlt_properties_set_double( properties, "aspect_ratio", 128.0 / 117.0 );
  77                         mlt_properties_set( properties, "eof", "pause" );
  78                         mlt_properties_set( properties, "resource", "<producer>" );
  79
  80                         // Override service get_frame
  81                         parent->get_frame = producer_get_frame;
  82                 }
  83         }
  84
  85         return error;
  86 }
  87
  88 /** Get the parent service object.
  89 */
  90
  91 mlt_service mlt_producer_service( mlt_producer this )
  92 {
  93         return &this->parent;
  94 }
  95
  96 /** Get the producer properties.
  97 */
  98
  99 mlt_properties mlt_producer_properties( mlt_producer this )
 100 {
 101         return mlt_service_properties( &this->parent );
 102 }
 103
 104 /** Seek to a specified position.
 105 */
 106
 107 int mlt_producer_seek( mlt_producer this, mlt_position position )
 108 {
 109         // Determine eof handling
 110         char *eof = mlt_properties_get( mlt_producer_properties( this ), "eof" );
 111
 112         // Check bounds
 113         if ( position < 0 )
 114         {
 115                 position = 0;
 116         }
 117         else if ( !strcmp( eof, "pause" ) && position >= mlt_producer_get_playtime( this ) )
 118         {
 119                 mlt_producer_set_speed( this, 0 );
 120                 position = mlt_producer_get_playtime( this ) - 1;
 121         }
 122         else if ( !strcmp( eof, "loop" ) && position >= mlt_producer_get_playtime( this ) )
 123         {
 124                 position = position % mlt_producer_get_playtime( this );
 125         }
 126
 127         // Set the position
 128         mlt_properties_set_position( mlt_producer_properties( this ), "_position", position );
 129
 130         // Calculate the absolute frame
 131         mlt_properties_set_position( mlt_producer_properties( this ), "_frame", mlt_producer_get_in( this ) + position );
 132
 133         return 0;
 134 }
 135
 136 /** Get the current position (relative to in point).
 137 */
 138
 139 mlt_position mlt_producer_position( mlt_producer this )
 140 {
 141         return mlt_properties_get_position( mlt_producer_properties( this ), "_position" );
 142 }
 143
 144 /** Get the current position (relative to start of producer).
 145 */
 146
 147 mlt_position mlt_producer_frame( mlt_producer this )
 148 {
 149         return mlt_properties_get_position( mlt_producer_properties( this ), "_frame" );
 150 }
 151
 152 /** Set the playing speed.
 153 */
 154
 155 int mlt_producer_set_speed( mlt_producer this, double speed )
 156 {
 157         return mlt_properties_set_double( mlt_producer_properties( this ), "_speed", speed );
 158 }
 159
 160 /** Get the playing speed.
 161 */
 162
 163 double mlt_producer_get_speed( mlt_producer this )
 164 {
 165         return mlt_properties_get_double( mlt_producer_properties( this ), "_speed" );
 166 }
 167
 168 /** Get the frames per second.
 169 */
 170
 171 double mlt_producer_get_fps( mlt_producer this )
 172 {
 173         return mlt_properties_get_double( mlt_producer_properties( this ), "fps" );
 174 }
 175
 176 /** Set the in and out points.
 177 */
 178
 179 int mlt_producer_set_in_and_out( mlt_producer this, mlt_position in, mlt_position out )
 180 {
 181         // Correct ins and outs if necessary
 182         if ( in < 0 )
 183                 in = 0;
 184         else if ( in > mlt_producer_get_length( this ) )
 185                 in = mlt_producer_get_length( this );
 186
 187         if ( out < 0 )
 188                 out = 0;
 189         else if ( out > mlt_producer_get_length( this ) )
 190                 out = mlt_producer_get_length( this );
 191
 192         // Swap ins and outs if wrong
 193         if ( out < in )
 194         {
 195                 mlt_position t = in;
 196                 in = out;
 197                 out = t;
 198         }
 199
 200         // Set the values
 201         mlt_properties_set_position( mlt_producer_properties( this ), "in", in );
 202         mlt_properties_set_position( mlt_producer_properties( this ), "out", out );
 203
 204         return 0;
 205 }
 206
 207 /** Get the in point.
 208 */
 209
 210 mlt_position mlt_producer_get_in( mlt_producer this )
 211 {
 212         return mlt_properties_get_position( mlt_producer_properties( this ), "in" );
 213 }
 214
 215 /** Get the out point.
 216 */
 217
 218 mlt_position mlt_producer_get_out( mlt_producer this )
 219 {
 220         return mlt_properties_get_position( mlt_producer_properties( this ), "out" );
 221 }
 222
 223 /** Get the total play time.
 224 */
 225
 226 mlt_position mlt_producer_get_playtime( mlt_producer this )
 227 {
 228         return mlt_producer_get_out( this ) - mlt_producer_get_in( this ) + 1;
 229 }
 230
 231 /** Get the total length of the producer.
 232 */
 233
 234 mlt_position mlt_producer_get_length( mlt_producer this )
 235 {
 236         return mlt_properties_get_position( mlt_producer_properties( this ), "length" );
 237 }
 238
 239 /** Prepare for next frame.
 240 */
 241
 242 void mlt_producer_prepare_next( mlt_producer this )
 243 {
 244         mlt_producer_seek( this, mlt_producer_position( this ) + mlt_producer_get_speed( this ) );
 245 }
 246
 247 /** Get a frame.
 248 */
 249
 250 static int producer_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
 251 {
 252         int result = 1;
 253         mlt_producer this = service->child;
 254
 255         // Determine eof handling
 256         char *eof = mlt_properties_get( mlt_producer_properties( this ), "eof" );
 257
 258         // A properly instatiated producer will have a get_frame method...
 259         if ( this->get_frame == NULL || ( !strcmp( eof, "continue" ) && mlt_producer_position( this ) > mlt_producer_get_out( this ) ) )
 260         {
 261                 // Generate a test frame
 262                 *frame = mlt_frame_init( );
 263
 264                 // Set the position
 265                 result = mlt_frame_set_position( *frame, mlt_producer_position( this ) );
 266
 267                 // Mark as a test card
 268                 mlt_properties_set_int( mlt_frame_properties( *frame ), "test_image", 1 );
 269                 mlt_properties_set_int( mlt_frame_properties( *frame ), "test_audio", 1 );
 270
 271                 // Calculate the next position
 272                 mlt_producer_prepare_next( this );
 273         }
 274         else
 275         {
 276                 // Get the frame from the implementation
 277                 result = this->get_frame( this, frame, index );
 278         }
 279
 280         // Copy the fps and speed 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         double speed = mlt_producer_get_speed( this );
 284         mlt_properties_set_double( properties, "_speed", speed );
 285
 286         return 0;
 287 }
 288
 289 /** Close the producer.
 290 */
 291
 292 void mlt_producer_close( mlt_producer this )
 293 {
 294         if ( this->close != NULL )
 295                 this->close( this );
 296         else
 297                 mlt_service_close( &this->parent );
 298 }