include/vlc_mtime.h

   1 /*****************************************************************************
   2  * vlc_mtime.h: high resolution time management functions
   3  *****************************************************************************
   4  * This header provides portable high precision time management functions,
   5  * which should be the only ones used in other segments of the program, since
   6  * functions like gettimeofday() and ftime() are not always supported.
   7  * Most functions are declared as inline or as macros since they are only
   8  * interfaces to system calls and have to be called frequently.
   9  * 'm' stands for 'micro', since maximum resolution is the microsecond.
  10  * Functions prototyped are implemented in interface/mtime.c.
  11  *****************************************************************************
  12  * Copyright (C) 1996, 1997, 1998, 1999, 2000 VLC authors and VideoLAN
  13  * $Id$
  14  *
  15  * Authors: Vincent Seguin <seguin@via.ecp.fr>
  16  *
  17  * This program is free software; you can redistribute it and/or modify it
  18  * under the terms of the GNU Lesser General Public License as published by
  19  * the Free Software Foundation; either version 2.1 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  25  * GNU Lesser General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU Lesser General Public License
  28  * along with this program; if not, write to the Free Software Foundation,
  29  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  30  *****************************************************************************/
  31
  32 #ifndef __VLC_MTIME_H
  33 # define __VLC_MTIME_H 1
  34
  35 /*****************************************************************************
  36  * LAST_MDATE: date which will never happen
  37  *****************************************************************************
  38  * This date can be used as a 'never' date, to mark missing events in a function
  39  * supposed to return a date, such as nothing to display in a function
  40  * returning the date of the first image to be displayed. It can be used in
  41  * comparaison with other values: all existing dates will be earlier.
  42  *****************************************************************************/
  43 #define LAST_MDATE ((mtime_t)((uint64_t)(-1)/2))
  44
  45 /*****************************************************************************
  46  * MSTRTIME_MAX_SIZE: maximum possible size of mstrtime
  47  *****************************************************************************
  48  * This values is the maximal possible size of the string returned by the
  49  * mstrtime() function, including '-' and the final '\0'. It should be used to
  50  * allocate the buffer.
  51  *****************************************************************************/
  52 #define MSTRTIME_MAX_SIZE 22
  53
  54 /*****************************************************************************
  55  * Prototypes
  56  *****************************************************************************/
  57 VLC_API char * mstrtime( char *psz_buffer, mtime_t date );
  58 VLC_API char * secstotimestr( char *psz_buffer, int32_t secs );
  59
  60 /*****************************************************************************
  61  * date_t: date incrementation without long-term rounding errors
  62  *****************************************************************************/
  63 struct date_t
  64 {
  65     mtime_t  date;
  66     uint32_t i_divider_num;
  67     uint32_t i_divider_den;
  68     uint32_t i_remainder;
  69 };
  70
  71 VLC_API void date_Init( date_t *, uint32_t, uint32_t );
  72 VLC_API void date_Change( date_t *, uint32_t, uint32_t );
  73 VLC_API void date_Set( date_t *, mtime_t );
  74 VLC_API mtime_t date_Get( const date_t * );
  75 VLC_API void date_Move( date_t *, mtime_t );
  76 VLC_API mtime_t date_Increment( date_t *, uint32_t );
  77 VLC_API mtime_t date_Decrement( date_t *, uint32_t );
  78 VLC_API uint64_t NTPtime64( void );
  79 #endif /* !__VLC_MTIME_ */