include/vlc_common.h

   1 /*****************************************************************************
   2  * vlc_common.h: common definitions
   3  * Collection of useful common types and macros definitions
   4  *****************************************************************************
   5  * Copyright (C) 1998-2011 VLC authors and VideoLAN
   6  *
   7  * Authors: Samuel Hocevar <sam@via.ecp.fr>
   8  *          Vincent Seguin <seguin@via.ecp.fr>
   9  *          Gildas Bazin <gbazin@videolan.org>
  10  *          Rémi Denis-Courmont
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU Lesser General Public License as published by
  14  * the Free Software Foundation; either version 2.1 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20  * GNU Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public License
  23  * along with this program; if not, write to the Free Software Foundation,
  24  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /**
  28  * \file
  29  * This file is a collection of common definitions and types
  30  */
  31
  32 #ifndef VLC_COMMON_H
  33 # define VLC_COMMON_H 1
  34
  35 /*****************************************************************************
  36  * Required vlc headers
  37  *****************************************************************************/
  38 #include "vlc_config.h"
  39
  40 /*****************************************************************************
  41  * Required system headers
  42  *****************************************************************************/
  43 #include <stdlib.h>
  44 #include <stdarg.h>
  45
  46 #include <string.h>
  47 #include <stdio.h>
  48 #include <inttypes.h>
  49 #include <stddef.h>
  50
  51 #ifndef __cplusplus
  52 # include <stdbool.h>
  53 #endif
  54
  55 /*****************************************************************************
  56  * Compilers definitions
  57  *****************************************************************************/
  58 /* Helper for GCC version checks */
  59 #ifdef __GNUC__
  60 # define VLC_GCC_VERSION(maj,min) \
  61     ((__GNUC__ > (maj)) || (__GNUC__ == (maj) && __GNUC_MINOR__ >= (min)))
  62 #else
  63 # define VLC_GCC_VERSION(maj,min) (0)
  64 #endif
  65
  66 /* Try to fix format strings for all versions of mingw and mingw64 */
  67 #if defined( _WIN32 ) && defined( __USE_MINGW_ANSI_STDIO )
  68  #undef PRId64
  69  #define PRId64 "lld"
  70  #undef PRIi64
  71  #define PRIi64 "lli"
  72  #undef PRIu64
  73  #define PRIu64 "llu"
  74  #undef PRIo64
  75  #define PRIo64 "llo"
  76  #undef PRIx64
  77  #define PRIx64 "llx"
  78  #define snprintf __mingw_snprintf
  79  #define vsnprintf __mingw_vsnprintf
  80  #define swprintf _snwprintf
  81 #endif
  82
  83 /* Function attributes for compiler warnings */
  84 #ifdef __GNUC__
  85 # define VLC_DEPRECATED __attribute__((deprecated))
  86 # if VLC_GCC_VERSION(6,0)
  87 #  define VLC_DEPRECATED_ENUM __attribute__((deprecated))
  88 # else
  89 #  define VLC_DEPRECATED_ENUM
  90 # endif
  91
  92 # if defined( _WIN32 )
  93 #  define VLC_FORMAT(x,y) __attribute__ ((format(gnu_printf,x,y)))
  94 # else
  95 #  define VLC_FORMAT(x,y) __attribute__ ((format(printf,x,y)))
  96 # endif
  97 # define VLC_FORMAT_ARG(x) __attribute__ ((format_arg(x)))
  98 # define VLC_MALLOC __attribute__ ((malloc))
  99 # define VLC_USED __attribute__ ((warn_unused_result))
 100
 101 #else
 102 # define VLC_DEPRECATED
 103 # define VLC_DEPRECATED_ENUM
 104 # define VLC_FORMAT(x,y)
 105 # define VLC_FORMAT_ARG(x)
 106 # define VLC_MALLOC
 107 # define VLC_USED
 108 #endif
 109
 110
 111 /* Branch prediction */
 112 #ifdef __GNUC__
 113 # define likely(p)     __builtin_expect(!!(p), 1)
 114 # define unlikely(p)   __builtin_expect(!!(p), 0)
 115 # define unreachable() __builtin_unreachable()
 116 #else
 117 # define likely(p)     (!!(p))
 118 # define unlikely(p)   (!!(p))
 119 # define unreachable() ((void)0)
 120 #endif
 121
 122 #define vlc_assert_unreachable() (assert(!"unreachable"), unreachable())
 123
 124 /* Linkage */
 125 #ifdef __cplusplus
 126 # define VLC_EXTERN extern "C"
 127 #else
 128 # define VLC_EXTERN
 129 #endif
 130
 131 #if defined (_WIN32) && defined (DLL_EXPORT)
 132 # define VLC_EXPORT __declspec(dllexport)
 133 #elif defined (__GNUC__)
 134 # define VLC_EXPORT __attribute__((visibility("default")))
 135 #else
 136 # define VLC_EXPORT
 137 #endif
 138
 139 #define VLC_API VLC_EXTERN VLC_EXPORT
 140
 141
 142 /*****************************************************************************
 143  * Basic types definitions
 144  *****************************************************************************/
 145 /**
 146  * High precision date or time interval
 147  *
 148  * Store a high precision date or time interval. The maximum precision is the
 149  * microsecond, and a 64 bits integer is used to avoid overflows (maximum
 150  * time interval is then 292271 years, which should be long enough for any
 151  * video). Dates are stored as microseconds since a common date (usually the
 152  * epoch). Note that date and time intervals can be manipulated using regular
 153  * arithmetic operators, and that no special functions are required.
 154  */
 155 typedef int64_t mtime_t;
 156
 157 /**
 158  * The vlc_fourcc_t type.
 159  *
 160  * See http://www.webartz.com/fourcc/ for a very detailed list.
 161  */
 162 typedef uint32_t vlc_fourcc_t;
 163
 164 #ifdef WORDS_BIGENDIAN
 165 #   define VLC_FOURCC( a, b, c, d ) \
 166         ( ((uint32_t)d) | ( ((uint32_t)c) << 8 ) \
 167            | ( ((uint32_t)b) << 16 ) | ( ((uint32_t)a) << 24 ) )
 168 #   define VLC_TWOCC( a, b ) \
 169         ( (uint16_t)(b) | ( (uint16_t)(a) << 8 ) )
 170
 171 #else
 172 #   define VLC_FOURCC( a, b, c, d ) \
 173         ( ((uint32_t)a) | ( ((uint32_t)b) << 8 ) \
 174            | ( ((uint32_t)c) << 16 ) | ( ((uint32_t)d) << 24 ) )
 175 #   define VLC_TWOCC( a, b ) \
 176         ( (uint16_t)(a) | ( (uint16_t)(b) << 8 ) )
 177
 178 #endif
 179
 180 /**
 181  * Translate a vlc_fourcc into its string representation. This function
 182  * assumes there is enough room in psz_fourcc to store 4 characters in.
 183  *
 184  * \param fcc a vlc_fourcc_t
 185  * \param psz_fourcc string to store string representation of vlc_fourcc in
 186  */
 187 static inline void vlc_fourcc_to_char( vlc_fourcc_t fcc, char *psz_fourcc )
 188 {
 189     memcpy( psz_fourcc, &fcc, 4 );
 190 }
 191
 192 /*****************************************************************************
 193  * Classes declaration
 194  *****************************************************************************/
 195
 196 /* Internal types */
 197 typedef struct vlc_list_t vlc_list_t;
 198 typedef struct vlc_object_t vlc_object_t;
 199 typedef struct libvlc_int_t libvlc_int_t;
 200 typedef struct date_t date_t;
 201
 202 /* Playlist */
 203
 204 typedef struct playlist_t playlist_t;
 205 typedef struct playlist_item_t playlist_item_t;
 206 typedef struct services_discovery_t services_discovery_t;
 207 typedef struct services_discovery_sys_t services_discovery_sys_t;
 208 typedef struct vlc_renderer_discovery_t vlc_renderer_discovery_t;
 209 typedef struct vlc_renderer_item_t vlc_renderer_item_t;
 210
 211 /* Modules */
 212 typedef struct module_t module_t;
 213 typedef struct module_config_t module_config_t;
 214
 215 typedef struct config_category_t config_category_t;
 216
 217 /* Input */
 218 typedef struct input_thread_t input_thread_t;
 219 typedef struct input_item_t input_item_t;
 220 typedef struct input_item_node_t input_item_node_t;
 221 typedef struct access_sys_t access_sys_t;
 222 typedef struct stream_t     stream_t;
 223 typedef struct stream_sys_t stream_sys_t;
 224 typedef struct demux_t  demux_t;
 225 typedef struct demux_sys_t demux_sys_t;
 226 typedef struct es_out_t     es_out_t;
 227 typedef struct es_out_id_t  es_out_id_t;
 228 typedef struct es_out_sys_t es_out_sys_t;
 229 typedef struct seekpoint_t seekpoint_t;
 230 typedef struct info_t info_t;
 231 typedef struct info_category_t info_category_t;
 232 typedef struct input_attachment_t input_attachment_t;
 233
 234 /* Format */
 235 typedef struct audio_format_t audio_format_t;
 236 typedef struct video_format_t video_format_t;
 237 typedef struct subs_format_t subs_format_t;
 238 typedef struct es_format_t es_format_t;
 239 typedef struct video_palette_t video_palette_t;
 240
 241 /* Audio */
 242 typedef struct audio_output audio_output_t;
 243 typedef struct aout_sys_t aout_sys_t;
 244 typedef audio_format_t audio_sample_format_t;
 245
 246 /* Video */
 247 typedef struct vout_thread_t vout_thread_t;
 248 typedef struct vlc_viewpoint_t vlc_viewpoint_t;
 249
 250 typedef video_format_t video_frame_format_t;
 251 typedef struct picture_t picture_t;
 252 typedef struct picture_sys_t picture_sys_t;
 253
 254 /* Subpictures */
 255 typedef struct spu_t spu_t;
 256 typedef struct subpicture_t subpicture_t;
 257 typedef struct subpicture_region_t subpicture_region_t;
 258
 259 typedef struct image_handler_t image_handler_t;
 260
 261 /* Stream output */
 262 typedef struct sout_instance_t sout_instance_t;
 263
 264 typedef struct sout_input_t sout_input_t;
 265 typedef struct sout_packetizer_input_t sout_packetizer_input_t;
 266
 267 typedef struct sout_access_out_t sout_access_out_t;
 268 typedef struct sout_access_out_sys_t   sout_access_out_sys_t;
 269
 270 typedef struct sout_mux_t sout_mux_t;
 271 typedef struct sout_mux_sys_t sout_mux_sys_t;
 272
 273 typedef struct sout_stream_t    sout_stream_t;
 274 typedef struct sout_stream_sys_t sout_stream_sys_t;
 275
 276 typedef struct config_chain_t       config_chain_t;
 277 typedef struct session_descriptor_t session_descriptor_t;
 278
 279 /* Decoders */
 280 typedef struct decoder_t         decoder_t;
 281 typedef struct decoder_sys_t     decoder_sys_t;
 282 typedef struct decoder_synchro_t decoder_synchro_t;
 283
 284 /* Encoders */
 285 typedef struct encoder_t      encoder_t;
 286 typedef struct encoder_sys_t  encoder_sys_t;
 287
 288 /* Filters */
 289 typedef struct filter_t filter_t;
 290 typedef struct filter_sys_t filter_sys_t;
 291
 292 /* Network */
 293 typedef struct vlc_url_t vlc_url_t;
 294
 295 /* Misc */
 296 typedef struct iso639_lang_t iso639_lang_t;
 297
 298 /* block */
 299 typedef struct block_t      block_t;
 300 typedef struct block_fifo_t block_fifo_t;
 301
 302 /* Hashing */
 303 typedef struct md5_s md5_t;
 304
 305 /* XML */
 306 typedef struct xml_t xml_t;
 307 typedef struct xml_sys_t xml_sys_t;
 308 typedef struct xml_reader_t xml_reader_t;
 309 typedef struct xml_reader_sys_t xml_reader_sys_t;
 310
 311 /* vod server */
 312 typedef struct vod_t     vod_t;
 313 typedef struct vod_sys_t vod_sys_t;
 314 typedef struct vod_media_t vod_media_t;
 315
 316 /* VLM */
 317 typedef struct vlm_t         vlm_t;
 318 typedef struct vlm_message_t vlm_message_t;
 319
 320 /* misc */
 321 typedef struct vlc_meta_t    vlc_meta_t;
 322 typedef struct input_stats_t input_stats_t;
 323 typedef struct addon_entry_t addon_entry_t;
 324
 325 /* Update */
 326 typedef struct update_t update_t;
 327
 328 /**
 329  * VLC value structure
 330  */
 331 typedef union
 332 {
 333     int64_t         i_int;
 334     bool            b_bool;
 335     float           f_float;
 336     char *          psz_string;
 337     void *          p_address;
 338     vlc_list_t *    p_list;
 339     struct { int32_t x; int32_t y; } coords;
 340
 341 } vlc_value_t;
 342
 343 /**
 344  * VLC list structure
 345  */
 346 struct vlc_list_t
 347 {
 348     int          i_type;
 349     int          i_count;
 350     vlc_value_t *p_values;
 351 };
 352
 353 /*****************************************************************************
 354  * Error values (shouldn't be exposed)
 355  *****************************************************************************/
 356 #define VLC_SUCCESS        (-0) /**< No error */
 357 #define VLC_EGENERIC       (-1) /**< Unspecified error */
 358 #define VLC_ENOMEM         (-2) /**< Not enough memory */
 359 #define VLC_ETIMEOUT       (-3) /**< Timeout */
 360 #define VLC_ENOMOD         (-4) /**< Module not found */
 361 #define VLC_ENOOBJ         (-5) /**< Object not found */
 362 #define VLC_ENOVAR         (-6) /**< Variable not found */
 363 #define VLC_EBADVAR        (-7) /**< Bad variable value */
 364 #define VLC_ENOITEM        (-8) /**< Item not found */
 365
 366 /*****************************************************************************
 367  * Variable callbacks: called when the value is modified
 368  *****************************************************************************/
 369 typedef int ( * vlc_callback_t ) ( vlc_object_t *,      /* variable's object */
 370                                    char const *,            /* variable name */
 371                                    vlc_value_t,                 /* old value */
 372                                    vlc_value_t,                 /* new value */
 373                                    void * );                /* callback data */
 374
 375 /*****************************************************************************
 376  * List callbacks: called when elements are added/removed from the list
 377  *****************************************************************************/
 378 typedef int ( * vlc_list_callback_t ) ( vlc_object_t *,      /* variable's object */
 379                                         char const *,            /* variable name */
 380                                         int,                  /* VLC_VAR_* action */
 381                                         vlc_value_t *,      /* new/deleted value  */
 382                                         void *);                 /* callback data */
 383
 384 /*****************************************************************************
 385  * OS-specific headers and thread types
 386  *****************************************************************************/
 387 #if defined( _WIN32 )
 388 #   include <malloc.h>
 389 #   ifndef PATH_MAX
 390 #       define PATH_MAX MAX_PATH
 391 #   endif
 392 #   include <windows.h>
 393 #endif
 394
 395 #ifdef __APPLE__
 396 #include <sys/syslimits.h>
 397 #include <AvailabilityMacros.h>
 398 #endif
 399
 400 #ifdef __OS2__
 401 #   define OS2EMX_PLAIN_CHAR
 402 #   define INCL_BASE
 403 #   define INCL_PM
 404 #   include <os2safe.h>
 405 #   include <os2.h>
 406 #endif
 407
 408 #include "vlc_mtime.h"
 409 #include "vlc_threads.h"
 410
 411 /**
 412  * Common structure members
 413  *****************************************************************************/
 414
 415 /**
 416  * VLC object common members
 417  *
 418  * Common public properties for all VLC objects.
 419  * Object also have private properties maintained by the core, see
 420  * \ref vlc_object_internals_t
 421  */
 422 struct vlc_common_members
 423 {
 424     /** Object type name
 425      *
 426      * A constant string identifying the type of the object (for logging)
 427      */
 428     const char *object_type;
 429
 430     /** Log messages header
 431      *
 432      * Human-readable header for log messages. This is not thread-safe and
 433      * only used by VLM and Lua interfaces.
 434      */
 435     char *header;
 436
 437     int  flags;
 438
 439     /** Module probe flag
 440      *
 441      * A boolean during module probing when the probe is "forced".
 442      * See \ref module_need().
 443      */
 444     bool force;
 445
 446     /** LibVLC instance
 447      *
 448      * Root VLC object of the objects tree that this object belongs in.
 449      */
 450     libvlc_int_t *libvlc;
 451
 452     /** Parent object
 453      *
 454      * The parent VLC object in the objects tree. For the root (the LibVLC
 455      * instance) object, this is NULL.
 456      */
 457     vlc_object_t *parent;
 458 };
 459
 460 /**
 461  * Backward compatibility macro
 462  */
 463 #define VLC_COMMON_MEMBERS struct vlc_common_members obj;
 464
 465 /**
 466  * Type-safe vlc_object_t cast
 467  *
 468  * This macro attempts to cast a pointer to a compound type to a
 469  * \ref vlc_object_t pointer in a type-safe manner.
 470  * It checks if the compound type actually starts with an embedded
 471  * \ref vlc_object_t structure.
 472  */
 473 #if !defined(__cplusplus) && (__STDC_VERSION__ >= 201112L)
 474 # define VLC_OBJECT(x) \
 475     _Generic((x)->obj, \
 476         struct vlc_common_members: (vlc_object_t *)(&(x)->obj), \
 477         const struct vlc_common_members: (const vlc_object_t *)(&(x)->obj) \
 478     )
 479 #elif defined (__GNUC__)
 480 # ifndef __cplusplus
 481 #  define VLC_OBJECT( x ) \
 482     __builtin_choose_expr( \
 483         __builtin_types_compatible_p(__typeof__((x)->obj), struct vlc_common_members), \
 484         (vlc_object_t *)(x), (void)0)
 485 # else
 486 #  define VLC_OBJECT( x ) \
 487     ((vlc_object_t *)(&((x)->obj)) \
 488       + 0 * __builtin_offsetof(__typeof__(*(x)), obj.object_type))
 489 # endif
 490 #else
 491 # define VLC_OBJECT( x ) ((vlc_object_t *)&(x)->obj)
 492 #endif
 493
 494 /*****************************************************************************
 495  * Macros and inline functions
 496  *****************************************************************************/
 497
 498 /* CEIL: division with round to nearest greater integer */
 499 #define CEIL(n, d)  ( ((n) / (d)) + ( ((n) % (d)) ? 1 : 0) )
 500
 501 /* PAD: PAD(n, d) = CEIL(n ,d) * d */
 502 #define PAD(n, d)   ( ((n) % (d)) ? ((((n) / (d)) + 1) * (d)) : (n) )
 503
 504 /* __MAX and __MIN: self explanatory */
 505 #ifndef __MAX
 506 #   define __MAX(a, b)   ( ((a) > (b)) ? (a) : (b) )
 507 #endif
 508 #ifndef __MIN
 509 #   define __MIN(a, b)   ( ((a) < (b)) ? (a) : (b) )
 510 #endif
 511
 512 /* clip v in [min, max] */
 513 #define VLC_CLIP(v, min, max)    __MIN(__MAX((v), (min)), (max))
 514
 515 VLC_USED
 516 static inline int64_t GCD ( int64_t a, int64_t b )
 517 {
 518     while( b )
 519     {
 520         int64_t c = a % b;
 521         a = b;
 522         b = c;
 523     }
 524     return a;
 525 }
 526
 527 /* function imported from libavutil/common.h */
 528 VLC_USED
 529 static inline uint8_t clip_uint8_vlc( int32_t a )
 530 {
 531     if( a&(~255) ) return (-a)>>31;
 532     else           return a;
 533 }
 534
 535 /** Count leading zeroes */
 536 VLC_USED
 537 static inline unsigned (clz)(unsigned x)
 538 {
 539 #ifdef __GNUC__
 540     return __builtin_clz (x);
 541 #else
 542     unsigned i = sizeof (x) * 8;
 543
 544     while (x)
 545     {
 546         x >>= 1;
 547         i--;
 548     }
 549     return i;
 550 #endif
 551 }
 552
 553 #define clz8( x ) (clz(x) - ((sizeof(unsigned) - sizeof (uint8_t)) * 8))
 554 #define clz16( x ) (clz(x) - ((sizeof(unsigned) - sizeof (uint16_t)) * 8))
 555 /* XXX: this assumes that int is 32-bits or more */
 556 #define clz32( x ) (clz(x) - ((sizeof(unsigned) - sizeof (uint32_t)) * 8))
 557
 558 /** Count trailing zeroes */
 559 VLC_USED
 560 static inline unsigned (ctz)(unsigned x)
 561 {
 562 #ifdef __GNUC__
 563     return __builtin_ctz (x);
 564 #else
 565     unsigned i = sizeof (x) * 8;
 566
 567     while (x)
 568     {
 569         x <<= 1;
 570         i--;
 571     }
 572     return i;
 573 #endif
 574 }
 575
 576 /** Bit weight */
 577 VLC_USED
 578 static inline unsigned (popcount)(unsigned x)
 579 {
 580 #ifdef __GNUC__
 581     return __builtin_popcount (x);
 582 #else
 583     unsigned count = 0;
 584     while (x)
 585     {
 586         count += x & 1;
 587         x = x >> 1;
 588     }
 589     return count;
 590 #endif
 591 }
 592
 593 /** Bit weight of long long */
 594 VLC_USED
 595 static inline int (popcountll)(unsigned long long x)
 596 {
 597 #ifdef __GNUC__
 598     return __builtin_popcountll(x);
 599 #else
 600     int count = 0;
 601     while (x)
 602     {
 603         count += x & 1;
 604         x = x >> 1;
 605     }
 606     return count;
 607 #endif
 608 }
 609
 610 VLC_USED
 611 static inline unsigned (parity)(unsigned x)
 612 {
 613 #ifdef __GNUC__
 614     return __builtin_parity (x);
 615 #else
 616     for (unsigned i = 4 * sizeof (x); i > 0; i /= 2)
 617         x ^= x >> i;
 618     return x & 1;
 619 #endif
 620 }
 621
 622 /** Byte swap (16 bits) */
 623 VLC_USED
 624 static inline uint16_t (bswap16)(uint16_t x)
 625 {
 626     return (x << 8) | (x >> 8);
 627 }
 628
 629 /** Byte swap (32 bits) */
 630 VLC_USED
 631 static inline uint32_t (bswap32)(uint32_t x)
 632 {
 633 #if defined (__GNUC__) || defined(__clang__)
 634     return __builtin_bswap32 (x);
 635 #else
 636     return ((x & 0x000000FF) << 24)
 637          | ((x & 0x0000FF00) <<  8)
 638          | ((x & 0x00FF0000) >>  8)
 639          | ((x & 0xFF000000) >> 24);
 640 #endif
 641 }
 642
 643 /** Byte swap (64 bits) */
 644 VLC_USED
 645 static inline uint64_t (bswap64)(uint64_t x)
 646 {
 647 #if defined (__GNUC__) || defined(__clang__)
 648     return __builtin_bswap64 (x);
 649 #elif !defined (__cplusplus)
 650     return ((x & 0x00000000000000FF) << 56)
 651          | ((x & 0x000000000000FF00) << 40)
 652          | ((x & 0x0000000000FF0000) << 24)
 653          | ((x & 0x00000000FF000000) <<  8)
 654          | ((x & 0x000000FF00000000) >>  8)
 655          | ((x & 0x0000FF0000000000) >> 24)
 656          | ((x & 0x00FF000000000000) >> 40)
 657          | ((x & 0xFF00000000000000) >> 56);
 658 #else
 659     return ((x & 0x00000000000000FFULL) << 56)
 660          | ((x & 0x000000000000FF00ULL) << 40)
 661          | ((x & 0x0000000000FF0000ULL) << 24)
 662          | ((x & 0x00000000FF000000ULL) <<  8)
 663          | ((x & 0x000000FF00000000ULL) >>  8)
 664          | ((x & 0x0000FF0000000000ULL) >> 24)
 665          | ((x & 0x00FF000000000000ULL) >> 40)
 666          | ((x & 0xFF00000000000000ULL) >> 56);
 667 #endif
 668 }
 669
 670
 671 /* Free and set set the variable to NULL */
 672 #define FREENULL(a) do { free( a ); a = NULL; } while(0)
 673
 674 #define EMPTY_STR(str) (!str || !*str)
 675
 676 VLC_API char const * vlc_error( int ) VLC_USED;
 677
 678 #include <vlc_arrays.h>
 679
 680 /* MSB (big endian)/LSB (little endian) conversions - network order is always
 681  * MSB, and should be used for both network communications and files. */
 682
 683 #ifdef WORDS_BIGENDIAN
 684 # define hton16(i) ((uint16_t)(i))
 685 # define hton32(i) ((uint32_t)(i))
 686 # define hton64(i) ((uint64_t)(i))
 687 #else
 688 # define hton16(i) bswap16(i)
 689 # define hton32(i) bswap32(i)
 690 # define hton64(i) bswap64(i)
 691 #endif
 692 #define ntoh16(i) hton16(i)
 693 #define ntoh32(i) hton32(i)
 694 #define ntoh64(i) hton64(i)
 695
 696 /** Reads 16 bits in network byte order */
 697 VLC_USED
 698 static inline uint16_t U16_AT (const void *p)
 699 {
 700     uint16_t x;
 701
 702     memcpy (&x, p, sizeof (x));
 703     return ntoh16 (x);
 704 }
 705
 706 /** Reads 32 bits in network byte order */
 707 VLC_USED
 708 static inline uint32_t U32_AT (const void *p)
 709 {
 710     uint32_t x;
 711
 712     memcpy (&x, p, sizeof (x));
 713     return ntoh32 (x);
 714 }
 715
 716 /** Reads 64 bits in network byte order */
 717 VLC_USED
 718 static inline uint64_t U64_AT (const void *p)
 719 {
 720     uint64_t x;
 721
 722     memcpy (&x, p, sizeof (x));
 723     return ntoh64 (x);
 724 }
 725
 726 #define GetWBE(p)  U16_AT(p)
 727 #define GetDWBE(p) U32_AT(p)
 728 #define GetQWBE(p) U64_AT(p)
 729
 730 /** Reads 16 bits in little-endian order */
 731 VLC_USED
 732 static inline uint16_t GetWLE (const void *p)
 733 {
 734     uint16_t x;
 735
 736     memcpy (&x, p, sizeof (x));
 737 #ifdef WORDS_BIGENDIAN
 738     x = bswap16 (x);
 739 #endif
 740     return x;
 741 }
 742
 743 /** Reads 32 bits in little-endian order */
 744 VLC_USED
 745 static inline uint32_t GetDWLE (const void *p)
 746 {
 747     uint32_t x;
 748
 749     memcpy (&x, p, sizeof (x));
 750 #ifdef WORDS_BIGENDIAN
 751     x = bswap32 (x);
 752 #endif
 753     return x;
 754 }
 755
 756 /** Reads 64 bits in little-endian order */
 757 VLC_USED
 758 static inline uint64_t GetQWLE (const void *p)
 759 {
 760     uint64_t x;
 761
 762     memcpy (&x, p, sizeof (x));
 763 #ifdef WORDS_BIGENDIAN
 764     x = bswap64 (x);
 765 #endif
 766     return x;
 767 }
 768
 769 /** Writes 16 bits in network byte order */
 770 static inline void SetWBE (void *p, uint16_t w)
 771 {
 772     w = hton16 (w);
 773     memcpy (p, &w, sizeof (w));
 774 }
 775
 776 /** Writes 32 bits in network byte order */
 777 static inline void SetDWBE (void *p, uint32_t dw)
 778 {
 779     dw = hton32 (dw);
 780     memcpy (p, &dw, sizeof (dw));
 781 }
 782
 783 /** Writes 64 bits in network byte order */
 784 static inline void SetQWBE (void *p, uint64_t qw)
 785 {
 786     qw = hton64 (qw);
 787     memcpy (p, &qw, sizeof (qw));
 788 }
 789
 790 /** Writes 16 bits in little endian order */
 791 static inline void SetWLE (void *p, uint16_t w)
 792 {
 793 #ifdef WORDS_BIGENDIAN
 794     w = bswap16 (w);
 795 #endif
 796     memcpy (p, &w, sizeof (w));
 797 }
 798
 799 /** Writes 32 bits in little endian order */
 800 static inline void SetDWLE (void *p, uint32_t dw)
 801 {
 802 #ifdef WORDS_BIGENDIAN
 803     dw = bswap32 (dw);
 804 #endif
 805     memcpy (p, &dw, sizeof (dw));
 806 }
 807
 808 /** Writes 64 bits in little endian order */
 809 static inline void SetQWLE (void *p, uint64_t qw)
 810 {
 811 #ifdef WORDS_BIGENDIAN
 812     qw = bswap64 (qw);
 813 #endif
 814     memcpy (p, &qw, sizeof (qw));
 815 }
 816
 817 /* */
 818 #define VLC_UNUSED(x) (void)(x)
 819
 820 /* Stuff defined in src/extras/libc.c */
 821
 822 #if defined(_WIN32)
 823 /* several type definitions */
 824 #   if defined( __MINGW32__ )
 825 #       if !defined( _OFF_T_ )
 826             typedef long long _off_t;
 827             typedef _off_t off_t;
 828 #           define _OFF_T_
 829 #       else
 830 #           ifdef off_t
 831 #               undef off_t
 832 #           endif
 833 #           define off_t long long
 834 #       endif
 835 #   endif
 836
 837 #   ifndef O_NONBLOCK
 838 #       define O_NONBLOCK 0
 839 #   endif
 840
 841 #   include <tchar.h>
 842 #endif /* _WIN32 */
 843
 844 typedef struct {
 845     unsigned num, den;
 846 } vlc_rational_t;
 847
 848 VLC_API bool vlc_ureduce( unsigned *, unsigned *, uint64_t, uint64_t, uint64_t );
 849
 850 #define container_of(ptr, type, member) \
 851     ((type *)(((char *)(ptr)) - offsetof(type, member)))
 852
 853 /*****************************************************************************
 854  * I18n stuff
 855  *****************************************************************************/
 856 VLC_API char *vlc_gettext( const char *msgid ) VLC_FORMAT_ARG(1);
 857 VLC_API char *vlc_ngettext( const char *s, const char *p, unsigned long n ) VLC_FORMAT_ARG(1) VLC_FORMAT_ARG(2);
 858
 859 #define vlc_pgettext( ctx, id ) \
 860         vlc_pgettext_aux( ctx "\004" id, id )
 861
 862 VLC_FORMAT_ARG(2)
 863 static inline const char *vlc_pgettext_aux( const char *ctx, const char *id )
 864 {
 865     const char *tr = vlc_gettext( ctx );
 866     return (tr == ctx) ? id : tr;
 867 }
 868
 869 /*****************************************************************************
 870  * Loosy memory allocation functions. Do not use in new code.
 871  *****************************************************************************/
 872 static inline void *xmalloc (size_t len)
 873 {
 874     void *ptr = malloc (len);
 875     if (unlikely (ptr == NULL))
 876         abort ();
 877     return ptr;
 878 }
 879
 880 static inline void *xrealloc (void *ptr, size_t len)
 881 {
 882     void *nptr = realloc (ptr, len);
 883     if (unlikely (nptr == NULL))
 884         abort ();
 885     return nptr;
 886 }
 887
 888 static inline void *xcalloc (size_t n, size_t size)
 889 {
 890     void *ptr = calloc (n, size);
 891     if (unlikely (ptr == NULL))
 892         abort ();
 893     return ptr;
 894 }
 895
 896 static inline char *xstrdup (const char *str)
 897 {
 898     char *ptr = strdup (str);
 899     if (unlikely(ptr == NULL))
 900         abort ();
 901     return ptr;
 902 }
 903
 904 /*****************************************************************************
 905  * libvlc features
 906  *****************************************************************************/
 907 VLC_API const char * VLC_CompileBy( void ) VLC_USED;
 908 VLC_API const char * VLC_CompileHost( void ) VLC_USED;
 909 VLC_API const char * VLC_Compiler( void ) VLC_USED;
 910
 911 /*****************************************************************************
 912  * Additional vlc stuff
 913  *****************************************************************************/
 914 #include "vlc_messages.h"
 915 #include "vlc_objects.h"
 916 #include "vlc_variables.h"
 917 #include "vlc_main.h"
 918 #include "vlc_configuration.h"
 919
 920 #if defined( _WIN32 ) || defined( __OS2__ )
 921 #   define DIR_SEP_CHAR '\\'
 922 #   define DIR_SEP "\\"
 923 #   define PATH_SEP_CHAR ';'
 924 #   define PATH_SEP ";"
 925 #else
 926 #   define DIR_SEP_CHAR '/'
 927 #   define DIR_SEP "/"
 928 #   define PATH_SEP_CHAR ':'
 929 #   define PATH_SEP ":"
 930 #endif
 931
 932 #define LICENSE_MSG \
 933   _("This program comes with NO WARRANTY, to the extent permitted by " \
 934     "law.\nYou may redistribute it under the terms of the GNU General " \
 935     "Public License;\nsee the file named COPYING for details.\n" \
 936     "Written by the VideoLAN team; see the AUTHORS file.\n")
 937
 938 #endif /* !VLC_COMMON_H */