1 /*****************************************************************************
2 * mtime.c: high resolution time management functions
3 * Functions are prototyped in vlc_mtime.h.
4 *****************************************************************************
5 * Copyright (C) 1998-2007 VLC authors and VideoLAN
6 * Copyright © 2006-2007 Rémi Denis-Courmont
9 * Authors: Vincent Seguin <seguin@via.ecp.fr>
10 * Rémi Denis-Courmont <rem$videolan,org>
13 * This program is free software; you can redistribute it and/or modify it
14 * under the terms of the GNU Lesser General Public License as published by
15 * the Free Software Foundation; either version 2.1 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU Lesser General Public License for more details.
23 * You should have received a copy of the GNU Lesser General Public License
24 * along with this program; if not, write to the Free Software Foundation,
25 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
26 *****************************************************************************/
28 /*****************************************************************************
30 *****************************************************************************/
36 #include <vlc_common.h>
40 #if !defined (_POSIX_TIMERS) || defined (_WIN32)
41 # define _POSIX_TIMERS (-1)
43 #if (_POSIX_TIMERS > 0)
44 # include <time.h> /* clock_gettime() */
46 # include <sys/time.h>
50 * Return a date in a readable format
52 * This function converts a mtime date into a string.
53 * psz_buffer should be a buffer long enough to store the formatted
55 * \param date to be converted
56 * \param psz_buffer should be a buffer at least MSTRTIME_MAX_SIZE characters
57 * \return psz_buffer is returned so this can be used as printf parameter.
59 char *mstrtime( char *psz_buffer, mtime_t date )
61 static const mtime_t ll1000 = 1000, ll60 = 60, ll24 = 24;
63 snprintf( psz_buffer, MSTRTIME_MAX_SIZE, "%02d:%02d:%02d-%03d.%03d",
64 (int) (date / (ll1000 * ll1000 * ll60 * ll60) % ll24),
65 (int) (date / (ll1000 * ll1000 * ll60) % ll60),
66 (int) (date / (ll1000 * ll1000) % ll60),
67 (int) (date / ll1000 % ll1000),
68 (int) (date % ll1000) );
73 * Convert seconds to a time in the format h:mm:ss.
75 * This function is provided for any interface function which need to print a
76 * time string in the format h:mm:ss
78 * \param secs the date to be converted
79 * \param psz_buffer should be a buffer at least MSTRTIME_MAX_SIZE characters
80 * \return psz_buffer is returned so this can be used as printf parameter.
82 char *secstotimestr( char *psz_buffer, int32_t i_seconds )
84 if( unlikely(i_seconds < 0) )
86 secstotimestr( psz_buffer + 1, -i_seconds );
93 d = div( i_seconds, 60 );
95 d = div( d.quot, 60 );
98 snprintf( psz_buffer, MSTRTIME_MAX_SIZE, "%u:%02u:%02u",
99 d.quot, d.rem, i_seconds );
101 snprintf( psz_buffer, MSTRTIME_MAX_SIZE, "%02u:%02u",
107 * Date management (internal and external)
111 * Initialize a date_t.
113 * \param date to initialize
114 * \param divider (sample rate) numerator
115 * \param divider (sample rate) denominator
118 void date_Init( date_t *p_date, uint32_t i_divider_n, uint32_t i_divider_d )
121 p_date->i_divider_num = i_divider_n;
122 p_date->i_divider_den = i_divider_d;
123 p_date->i_remainder = 0;
129 * \param date to change
130 * \param divider (sample rate) numerator
131 * \param divider (sample rate) denominator
134 void date_Change( date_t *p_date, uint32_t i_divider_n, uint32_t i_divider_d )
136 /* change time scale of remainder */
137 p_date->i_remainder = p_date->i_remainder * i_divider_n / p_date->i_divider_num;
138 p_date->i_divider_num = i_divider_n;
139 p_date->i_divider_den = i_divider_d;
143 * Set the date value of a date_t.
148 void date_Set( date_t *p_date, mtime_t i_new_date )
150 p_date->date = i_new_date;
151 p_date->i_remainder = 0;
155 * Get the date of a date_t
160 mtime_t date_Get( const date_t *p_date )
166 * Move forwards or backwards the date of a date_t.
168 * \param date to move
169 * \param difference value
171 void date_Move( date_t *p_date, mtime_t i_difference )
173 p_date->date += i_difference;
177 * Increment the date and return the result, taking into account
180 * \param date to increment
181 * \param incrementation in number of samples
184 mtime_t date_Increment( date_t *p_date, uint32_t i_nb_samples )
186 mtime_t i_dividend = i_nb_samples * CLOCK_FREQ * p_date->i_divider_den;
187 lldiv_t d = lldiv( i_dividend, p_date->i_divider_num );
189 p_date->date += d.quot;
190 p_date->i_remainder += (int)d.rem;
192 if( p_date->i_remainder >= p_date->i_divider_num )
194 /* This is Bresenham algorithm. */
195 assert( p_date->i_remainder < 2*p_date->i_divider_num);
197 p_date->i_remainder -= p_date->i_divider_num;
204 * Decrement the date and return the result, taking into account
207 * \param date to decrement
208 * \param decrementation in number of samples
211 mtime_t date_Decrement( date_t *p_date, uint32_t i_nb_samples )
213 mtime_t i_dividend = (mtime_t)i_nb_samples * CLOCK_FREQ * p_date->i_divider_den;
214 p_date->date -= i_dividend / p_date->i_divider_num;
215 unsigned i_rem_adjust = i_dividend % p_date->i_divider_num;
217 if( p_date->i_remainder < i_rem_adjust )
219 /* This is Bresenham algorithm. */
220 assert( p_date->i_remainder < p_date->i_divider_num);
222 p_date->i_remainder += p_date->i_divider_num;
225 p_date->i_remainder -= i_rem_adjust;
231 * @return NTP 64-bits timestamp in host byte order.
233 uint64_t NTPtime64 (void)
235 #if (_POSIX_TIMERS > 0)
238 clock_gettime (CLOCK_REALTIME, &ts);
247 gettimeofday (&tv, NULL);
248 ts.tv_sec = tv.tv_sec;
249 ts.tv_nsec = tv.tv_usec * 1000;
252 /* Convert nanoseconds to 32-bits fraction (232 picosecond units) */
253 uint64_t t = (uint64_t)(ts.tv_nsec) << 32;
257 /* There is 70 years (incl. 17 leap ones) offset to the Unix Epoch.
258 * No leap seconds during that period since they were not invented yet.
260 assert (t < 0x100000000);
261 t |= ((70LL * 365 + 17) * 24 * 60 * 60 + ts.tv_sec) << 32;