linux/include/sound/seq_midi_event.h
Takashi Iwai ef965ad5a7 ALSA: seq: Minor cleanup of MIDI event parser helpers
snd_midi_event_encode_byte() can never fail, and it can return rather
true/false.  Change the return type to bool, adjust the argument to
receive a MIDI byte as unsigned char, and adjust the comment
accordingly.  This allows callers to drop error checks, which
simplifies the code.

Meanwhile, snd_midi_event_encode() helper is used only in seq_midi.c,
and it can be better folded into it.  This will reduce the total
amount of lines in the end.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-08-01 22:54:35 +02:00

53 lines
2.0 KiB
C

#ifndef __SOUND_SEQ_MIDI_EVENT_H
#define __SOUND_SEQ_MIDI_EVENT_H
/*
* MIDI byte <-> sequencer event coder
*
* Copyright (C) 1998,99 Takashi Iwai <tiwai@suse.de>,
* Jaroslav Kysela <perex@perex.cz>
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <sound/asequencer.h>
#define MAX_MIDI_EVENT_BUF 256
/* midi status */
struct snd_midi_event {
int qlen; /* queue length */
int read; /* chars read */
int type; /* current event type */
unsigned char lastcmd; /* last command (for MIDI state handling) */
unsigned char nostat; /* no state flag */
int bufsize; /* allocated buffer size */
unsigned char *buf; /* input buffer */
spinlock_t lock;
};
int snd_midi_event_new(int bufsize, struct snd_midi_event **rdev);
void snd_midi_event_free(struct snd_midi_event *dev);
void snd_midi_event_reset_encode(struct snd_midi_event *dev);
void snd_midi_event_reset_decode(struct snd_midi_event *dev);
void snd_midi_event_no_status(struct snd_midi_event *dev, int on);
bool snd_midi_event_encode_byte(struct snd_midi_event *dev, unsigned char c,
struct snd_seq_event *ev);
/* decode from event to bytes - return number of written bytes if success */
long snd_midi_event_decode(struct snd_midi_event *dev, unsigned char *buf, long count,
struct snd_seq_event *ev);
#endif /* __SOUND_SEQ_MIDI_EVENT_H */