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/***************************************************************************
sfx_time.h Copyright (C) 2003,04 Christoph Reichenbach
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public Licence as
published by the Free Software Foundaton; either version 2 of the
Licence, or (at your option) any later version.
It is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
merchantibility or fitness for a particular purpose. See the
GNU General Public Licence for more details.
You should have received a copy of the GNU General Public Licence
along with this program; see the file COPYING. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
Please contact the maintainer for any program-related bug reports or
inquiries.
Current Maintainer:
Christoph Reichenbach (CR) <jameson@linuxgames.com>
***************************************************************************/
#ifndef _SFX_TIME_H_
#define _SFX_TIME_H_
typedef struct {
long secs;
long usecs;
int frame_rate;
int frame_offset;
/* Total time: secs + usecs + frame_offset/frame_rate */
} sfx_timestamp_t;
sfx_timestamp_t
sfx_new_timestamp(long secs, long usecs, int frame_rate);
/* Creates a new mutable timestamp
** Parameters: (long x long) (secs, usecs): Initial timestamp
** (int) frame_rate: Frame rate, for increasing the time stamp
*/
sfx_timestamp_t
sfx_timestamp_add(sfx_timestamp_t timestamp, int frames);
/* Adds a number of frames to a timestamp
** Parameters: (sfx_timestampt_t *) timestamp: The timestamp to update
** (int) frames: Number of frames to add
** Returns : (sfx_timestamp_t) The increased timestamp
*/
sfx_timestamp_t
sfx_timestamp_renormalise(sfx_timestamp_t timestamp, int new_freq);
/* Translates a timestamp to a new base frame frequency
** Parameters: (sfx_timestamp_t *) timestamp: The timestamp to normalise
** (int) new_freq: The new frequency to normalise to
** Returns : (sfx_timestamp_t) The re-normalised timestamp
** The translation looses accuracy in the order of magnitude of milliseconds
** for "usual" sampling frequencies.
*/
int
sfx_timestamp_frame_diff(sfx_timestamp_t a, sfx_timestamp_t b);
/* Computes the difference (# of frames) between two timestamps
** Parameters: (sfx_timestamp) a: See below
** (sfx_timestamp) b: See below
** Returns : (int) a-b
*/
long
sfx_timestamp_usecs_diff(sfx_timestamp_t a, sfx_timestamp_t b);
/* Computes the difference (# of microseconds) between two timestamps
** Parameters: (sfx_timestamp) a: See below
** (sfx_timestamp) b: See below
** Returns : (long) a-b
*/
void
sfx_timestamp_gettime(sfx_timestamp_t *timestamp, long *secs, long *usecs);
/* Determines the time described by a given timestamp
** Parameters: (sfx_timestamp_t *) timestamp: Timestamp to read from
** Returns : (int * x int *) (secs, usecs): Seconds and microseconds since
** the epoch described there
*/
#endif /* !defined(_SFX_TIME_H_) */
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