1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
/*
* ALSA sequencer Timer
* Copyright (c) 1998 by Frank van de Pol <F.K.W.van.de.Pol@inter.nl.net>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#ifndef __SND_SEQ_TIMER_H
#define __SND_SEQ_TIMER_H
#include "seq.h"
typedef struct {
/* ... tempo / offset / running state */
//
//
// Different sync types (for slave operation):
//
// midi <- seq. clock
// " <- midi clock (adjust tempo)
//
// seq. clock <- hw timer
// " <- MTC
// " <- SMPTE
//
int running:1; /* running state of queue */
unsigned int tempo; /* current tempo, us/tick */
int ppq; /* time resolution, ticks/quarter */
snd_seq_tick_time_t tempo_tick; /* tick of last tempo change */
snd_seq_real_time_t tempo_time; /* time of last tempo change */
snd_seq_tick_time_t cur_tick; /* current tick */
snd_seq_real_time_t cur_time; /* current time */
snd_seq_tick_time_t sync_tmp; /* tmp var for sync */
} timer_t;
/* create new timer (constructor) */
extern timer_t *snd_seq_timer_new(void);
/* delete timer (destructor) */
extern void snd_seq_timer_delete(timer_t **tmr);
/* compare timestamp between events */
/* return 1 if a >= b; otherwise return 0 */
static inline int snd_seq_compare_tick_time(snd_seq_tick_time_t *a, snd_seq_tick_time_t *b)
{
/* compare ticks */
return (*a >= *b);
}
static inline int snd_seq_compare_real_time(snd_seq_real_time_t *a, snd_seq_real_time_t *b)
{
/* compare real time */
if (a->tv_sec > b->tv_sec)
return 1;
if ((a->tv_sec == b->tv_sec) && (a->tv_nsec >= b->tv_nsec))
return 1;
return 0;
}
/* increment timestamp */
static inline void snd_seq_inc_real_time(snd_seq_real_time_t *tm, snd_seq_real_time_t *inc)
{
tm->tv_sec += inc->tv_sec;
tm->tv_nsec += inc->tv_nsec;
while (tm->tv_nsec >= 1E9) {
/* roll-over */
tm->tv_nsec -= 1E9;
tm->tv_sec ++;
}
}
/* called by timer isr */
extern int snd_seq_timer_interrupt(snd_seq_real_time_t *period);
extern void snd_seq_timer_stop(timer_t *tmr);
extern void snd_seq_timer_start(timer_t *tmr);
extern void snd_seq_timer_continue(timer_t *tmr);
extern void snd_seq_timer_set_tempo(timer_t *tmr, int tempo);
extern void snd_seq_timer_set_ppq(timer_t *tmr, int ppq);
#endif
|
