research.m1stereo.tv/gitweb/ - melted/blob - src/framework/mlt_property.c

   1 /**
   2  * \file mlt_property.c
   3  * \brief Property class definition
   4  * \see mlt_property_s
   5  *
   6  * Copyright (C) 2003-2009 Ushodaya Enterprises Limited
   7  * \author Charles Yates <charles.yates@pandora.be>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include "mlt_property.h"
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30
  31 /** Bit pattern used internally to indicated representations available.
  32 */
  33
  34 typedef enum
  35 {
  36         mlt_prop_none = 0,    //!< not set
  37         mlt_prop_int = 1,     //!< set as an integer
  38         mlt_prop_string = 2,  //!< set as string or already converted to string
  39         mlt_prop_position = 4,//!< set as a position
  40         mlt_prop_double = 8,  //!< set as a floating point
  41         mlt_prop_data = 16,   //!< set as opaque binary
  42         mlt_prop_int64 = 32   //!< set as a 64-bit integer
  43 }
  44 mlt_property_type;
  45
  46 /** \brief Property class
  47  *
  48  * A property is like a variant or dynamic type. They are used for many things
  49  * in MLT, but in particular they are the parameter mechanism for the plugins.
  50  */
  51
  52 struct mlt_property_s
  53 {
  54         /// Stores a bit pattern of types available for this property
  55         mlt_property_type types;
  56
  57         /// Atomic type handling
  58         int prop_int;
  59         mlt_position prop_position;
  60         double prop_double;
  61         int64_t prop_int64;
  62
  63         /// String handling
  64         char *prop_string;
  65
  66         /// Generic type handling
  67         void *data;
  68         int length;
  69         mlt_destructor destructor;
  70         mlt_serialiser serialiser;
  71 };
  72
  73 /** Construct a property and initialize it
  74  * \public \memberof mlt_property_s
  75  */
  76
  77 mlt_property mlt_property_init( )
  78 {
  79         mlt_property this = malloc( sizeof( struct mlt_property_s ) );
  80         if ( this != NULL )
  81         {
  82                 this->types = 0;
  83                 this->prop_int = 0;
  84                 this->prop_position = 0;
  85                 this->prop_double = 0;
  86                 this->prop_int64 = 0;
  87                 this->prop_string = NULL;
  88                 this->data = NULL;
  89                 this->length = 0;
  90                 this->destructor = NULL;
  91                 this->serialiser = NULL;
  92         }
  93         return this;
  94 }
  95
  96 /** Clear (0/null) a property.
  97  *
  98  * Frees up any associated resources in the process.
  99  * \private \memberof mlt_property_s
 100  * \param this a property
 101  */
 102
 103 static inline void mlt_property_clear( mlt_property this )
 104 {
 105         // Special case data handling
 106         if ( this->types & mlt_prop_data && this->destructor != NULL )
 107                 this->destructor( this->data );
 108
 109         // Special case string handling
 110         if ( this->types & mlt_prop_string )
 111                 free( this->prop_string );
 112
 113         // Wipe stuff
 114         this->types = 0;
 115         this->prop_int = 0;
 116         this->prop_position = 0;
 117         this->prop_double = 0;
 118         this->prop_int64 = 0;
 119         this->prop_string = NULL;
 120         this->data = NULL;
 121         this->length = 0;
 122         this->destructor = NULL;
 123         this->serialiser = NULL;
 124 }
 125
 126 /** Set the property to an integer value.
 127  *
 128  * \public \memberof mlt_property_s
 129  * \param this a property
 130  * \param value an integer
 131  * \return false
 132  */
 133
 134 int mlt_property_set_int( mlt_property this, int value )
 135 {
 136         mlt_property_clear( this );
 137         this->types = mlt_prop_int;
 138         this->prop_int = value;
 139         return 0;
 140 }
 141
 142 /** Set the property to a floating point value.
 143  *
 144  * \public \memberof mlt_property_s
 145  * \param this a property
 146  * \param value a double precision floating point value
 147  * \return false
 148  */
 149
 150 int mlt_property_set_double( mlt_property this, double value )
 151 {
 152         mlt_property_clear( this );
 153         this->types = mlt_prop_double;
 154         this->prop_double = value;
 155         return 0;
 156 }
 157
 158 /** Set the property to a position value.
 159  *
 160  * Position is a relative time value in frame units.
 161  * \public \memberof mlt_property_s
 162  * \param this a property
 163  * \param value a position value
 164  * \return false
 165  */
 166
 167 int mlt_property_set_position( mlt_property this, mlt_position value )
 168 {
 169         mlt_property_clear( this );
 170         this->types = mlt_prop_position;
 171         this->prop_position = value;
 172         return 0;
 173 }
 174
 175 /** Set the property to a string value.
 176  *
 177  * This makes a copy of the string you supply so you do not need to track
 178  * a new reference to it.
 179  * \public \memberof mlt_property_s
 180  * \param this a property
 181  * \param value the string to copy to the property
 182  * \return true if it failed
 183  */
 184
 185 int mlt_property_set_string( mlt_property this, const char *value )
 186 {
 187         if ( value != this->prop_string )
 188         {
 189                 mlt_property_clear( this );
 190                 this->types = mlt_prop_string;
 191                 if ( value != NULL )
 192                         this->prop_string = strdup( value );
 193         }
 194         else
 195         {
 196                 this->types = mlt_prop_string;
 197         }
 198         return this->prop_string == NULL;
 199 }
 200
 201 /** Set the property to a 64-bit integer value.
 202  *
 203  * \public \memberof mlt_property_s
 204  * \param this a property
 205  * \param value a 64-bit integer
 206  * \return false
 207  */
 208
 209 int mlt_property_set_int64( mlt_property this, int64_t value )
 210 {
 211         mlt_property_clear( this );
 212         this->types = mlt_prop_int64;
 213         this->prop_int64 = value;
 214         return 0;
 215 }
 216
 217 /** Set a property to an opaque binary value.
 218  *
 219  * This does not make a copy of the data. You can use a Properties object
 220  * with its reference tracking and the destructor function to control
 221  * the lifetime of the data. Otherwise, pass NULL for the destructor
 222  * function and control the lifetime yourself.
 223  * \public \memberof mlt_property_s
 224  * \param this a property
 225  * \param value an opaque pointer
 226  * \param length the number of bytes pointed to by value (optional)
 227  * \param destructor a function to use to destroy this binary data (optional, assuming you manage the resource)
 228  * \param serialiser a function to use to convert this binary data to a string (optional)
 229  * \return false
 230  */
 231
 232 int mlt_property_set_data( mlt_property this, void *value, int length, mlt_destructor destructor, mlt_serialiser serialiser )
 233 {
 234         if ( this->data == value )
 235                 this->destructor = NULL;
 236         mlt_property_clear( this );
 237         this->types = mlt_prop_data;
 238         this->data = value;
 239         this->length = length;
 240         this->destructor = destructor;
 241         this->serialiser = serialiser;
 242         return 0;
 243 }
 244
 245 /** Convert a base 10 or base 16 string to an integer.
 246  *
 247  * The string must begin with '0x' to be interpreted as hexadecimal.
 248  * Otherwise, it is interpreted as base 10.
 249  * If the string begins with '#' it is interpreted as a hexadecimal color value
 250  * in the form RRGGBB or AARRGGBB. Color values that begin with '0x' are
 251  * always in the form RRGGBBAA where the alpha components are not optional.
 252  * Applications and services should expect the binary color value in bytes to
 253  * be in the following order: RGBA. This means they will have to cast the int
 254  * to an unsigned int. This is especially important when they need to shift
 255  * right to obtain RGB without alpha in order to make it do a logical instead
 256  * of arithmetic shift.
 257  *
 258  * \private \memberof mlt_property_s
 259  * \param value a string to convert
 260  * \return the resultant integer
 261  */
 262 static inline int mlt_property_atoi( const char *value )
 263 {
 264         if ( value == NULL )
 265                 return 0;
 266         // Parse a hex color value as #RRGGBB or #AARRGGBB.
 267         if ( value[0] == '#' )
 268         {
 269                 unsigned int rgb = strtoul( value + 1, NULL, 16 );
 270                 unsigned int alpha = ( strlen( value ) > 7 ) ? ( rgb >> 24 ) : 0xff;
 271                 return ( rgb << 8 ) | alpha;
 272         }
 273         // Do hex and decimal explicitly to avoid decimal value with leading zeros
 274         // interpreted as octal.
 275         else if ( value[0] == '0' && value[1] == 'x' )
 276         {
 277                 return strtoul( value + 2, NULL, 16 );
 278         }
 279         else
 280         {
 281                 return strtol( value, NULL, 10 );
 282         }
 283 }
 284
 285 /** Get the property as an integer.
 286  *
 287  * \public \memberof mlt_property_s
 288  * \param this a property
 289  * \return an integer value
 290  */
 291
 292 int mlt_property_get_int( mlt_property this )
 293 {
 294         if ( this->types & mlt_prop_int )
 295                 return this->prop_int;
 296         else if ( this->types & mlt_prop_double )
 297                 return ( int )this->prop_double;
 298         else if ( this->types & mlt_prop_position )
 299                 return ( int )this->prop_position;
 300         else if ( this->types & mlt_prop_int64 )
 301                 return ( int )this->prop_int64;
 302         else if ( this->types & mlt_prop_string )
 303                 return mlt_property_atoi( this->prop_string );
 304         return 0;
 305 }
 306
 307 /** Get the property as a floating point.
 308  *
 309  * \public \memberof mlt_property_s
 310  * \param this a property
 311  * \return a floating point value
 312  */
 313
 314 double mlt_property_get_double( mlt_property this )
 315 {
 316         if ( this->types & mlt_prop_double )
 317                 return this->prop_double;
 318         else if ( this->types & mlt_prop_int )
 319                 return ( double )this->prop_int;
 320         else if ( this->types & mlt_prop_position )
 321                 return ( double )this->prop_position;
 322         else if ( this->types & mlt_prop_int64 )
 323                 return ( double )this->prop_int64;
 324         else if ( this->types & mlt_prop_string )
 325                 return atof( this->prop_string );
 326         return 0;
 327 }
 328
 329 /** Get the property as a position.
 330  *
 331  * A position is an offset time in terms of frame units.
 332  * \public \memberof mlt_property_s
 333  * \param this a property
 334  * \return the position in frames
 335  */
 336
 337 mlt_position mlt_property_get_position( mlt_property this )
 338 {
 339         if ( this->types & mlt_prop_position )
 340                 return this->prop_position;
 341         else if ( this->types & mlt_prop_int )
 342                 return ( mlt_position )this->prop_int;
 343         else if ( this->types & mlt_prop_double )
 344                 return ( mlt_position )this->prop_double;
 345         else if ( this->types & mlt_prop_int64 )
 346                 return ( mlt_position )this->prop_int64;
 347         else if ( this->types & mlt_prop_string )
 348                 return ( mlt_position )atol( this->prop_string );
 349         return 0;
 350 }
 351
 352 /** Convert a string to a 64-bit integer.
 353  *
 354  * If the string begins with '0x' it is interpreted as a hexadecimal value.
 355  * \private \memberof mlt_property_s
 356  * \param value a string
 357  * \return a 64-bit integer
 358  */
 359
 360 static inline int64_t mlt_property_atoll( const char *value )
 361 {
 362         if ( value == NULL )
 363                 return 0;
 364         else if ( value[0] == '0' && value[1] == 'x' )
 365                 return strtoll( value + 2, NULL, 16 );
 366         else
 367                 return strtoll( value, NULL, 10 );
 368 }
 369
 370 /** Get the property as a signed integer.
 371  *
 372  * \public \memberof mlt_property_s
 373  * \param this a property
 374  * \return a 64-bit integer
 375  */
 376
 377 int64_t mlt_property_get_int64( mlt_property this )
 378 {
 379         if ( this->types & mlt_prop_int64 )
 380                 return this->prop_int64;
 381         else if ( this->types & mlt_prop_int )
 382                 return ( int64_t )this->prop_int;
 383         else if ( this->types & mlt_prop_double )
 384                 return ( int64_t )this->prop_double;
 385         else if ( this->types & mlt_prop_position )
 386                 return ( int64_t )this->prop_position;
 387         else if ( this->types & mlt_prop_string )
 388                 return mlt_property_atoll( this->prop_string );
 389         return 0;
 390 }
 391
 392 /** Get the property as a string.
 393  *
 394  * The caller is not responsible for deallocating the returned string!
 395  * The string is deallocated when the Property is closed.
 396  * This tries its hardest to convert the property to string including using
 397  * a serialization function for binary data, if supplied.
 398  * \public \memberof mlt_property_s
 399  * \param this a property
 400  * \return a string representation of the property or NULL if failed
 401  */
 402
 403 char *mlt_property_get_string( mlt_property this )
 404 {
 405         // Construct a string if need be
 406         if ( ! ( this->types & mlt_prop_string ) )
 407         {
 408                 if ( this->types & mlt_prop_int )
 409                 {
 410                         this->types |= mlt_prop_string;
 411                         this->prop_string = malloc( 32 );
 412                         sprintf( this->prop_string, "%d", this->prop_int );
 413                 }
 414                 else if ( this->types & mlt_prop_double )
 415                 {
 416                         this->types |= mlt_prop_string;
 417                         this->prop_string = malloc( 32 );
 418                         sprintf( this->prop_string, "%f", this->prop_double );
 419                 }
 420                 else if ( this->types & mlt_prop_position )
 421                 {
 422                         this->types |= mlt_prop_string;
 423                         this->prop_string = malloc( 32 );
 424                         sprintf( this->prop_string, "%d", (int)this->prop_position ); /* I don't know if this is wanted. -Zach */
 425                 }
 426                 else if ( this->types & mlt_prop_int64 )
 427                 {
 428                         this->types |= mlt_prop_string;
 429                         this->prop_string = malloc( 32 );
 430                         sprintf( this->prop_string, "%lld", this->prop_int64 );
 431                 }
 432                 else if ( this->types & mlt_prop_data && this->serialiser != NULL )
 433                 {
 434                         this->types |= mlt_prop_string;
 435                         this->prop_string = this->serialiser( this->data, this->length );
 436                 }
 437         }
 438
 439         // Return the string (may be NULL)
 440         return this->prop_string;
 441 }
 442
 443 /** Get the binary data from a property.
 444  *
 445  * This only works if you previously put binary data into the property.
 446  * This does not return a copy of the data; it returns a pointer to it.
 447  * If you supplied a destructor function when setting the binary data,
 448  * the destructor is used when the Property is closed to free the memory.
 449  * Therefore, only free the returned pointer if you did not supply a
 450  * destructor function.
 451  * \public \memberof mlt_property_s
 452  * \param this a property
 453  * \param[out] length the size of the binary object in bytes (optional)
 454  * \return an opaque data pointer or NULL if not available
 455  */
 456
 457 void *mlt_property_get_data( mlt_property this, int *length )
 458 {
 459         // Assign length if not NULL
 460         if ( length != NULL )
 461                 *length = this->length;
 462
 463         // Return the data (note: there is no conversion here)
 464         return this->data;
 465 }
 466
 467 /** Destroy a property and free all related resources.
 468  *
 469  * \public \memberof mlt_property_s
 470  * \param this a property
 471  */
 472
 473 void mlt_property_close( mlt_property this )
 474 {
 475         mlt_property_clear( this );
 476         free( this );
 477 }
 478
 479 /** Copy a property.
 480  *
 481  * A Property holding binary data only copies the data if a serialiser
 482  * function was supplied when you set the Property.
 483  * \public \memberof mlt_property_s
 484  * \author Zach <zachary.drew@gmail.com>
 485  * \param this a property
 486  * \param that another property
 487  */
 488 void mlt_property_pass( mlt_property this, mlt_property that )
 489 {
 490         mlt_property_clear( this );
 491
 492         this->types = that->types;
 493
 494         if ( this->types & mlt_prop_int64 )
 495                 this->prop_int64 = that->prop_int64;
 496         else if ( this->types & mlt_prop_int )
 497                 this->prop_int = that->prop_int;
 498         else if ( this->types & mlt_prop_double )
 499                 this->prop_double = that->prop_double;
 500         else if ( this->types & mlt_prop_position )
 501                 this->prop_position = that->prop_position;
 502         else if ( this->types & mlt_prop_string )
 503         {
 504                 if ( that->prop_string != NULL )
 505                         this->prop_string = strdup( that->prop_string );
 506         }
 507         else if ( this->types & mlt_prop_data && this->serialiser != NULL )
 508         {
 509                 this->types = mlt_prop_string;
 510                 this->prop_string = this->serialiser( this->data, this->length );
 511         }
 512 }