aboutsummaryrefslogtreecommitdiff
path: root/midialsa.cpp
blob: 03d5699450f6c917af20cfd7631f2095849745a6 (plain)
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
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
/*
 * Copyright (C) 2022 Javier S. Pedro
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#define LOG_ENABLED 1
#define LOG_ENABLE_FLOW 1
#define LOG_GROUP LOG_GROUP_DEV_SB16

#include <VBox/err.h>
#include <VBox/log.h>
#include <alsa/asoundlib.h>
#include "midialsa.h"

#define MAX_POLL_FDS 4

static ssize_t rawmidi_avail(snd_rawmidi_t *rmidi)
{
    struct pollfd pfds[MAX_POLL_FDS];

    int nfds = snd_rawmidi_poll_descriptors(rmidi, pfds, MAX_POLL_FDS);
    if (nfds <= 0) {
        LogWarn(("ALSA rawmidi avail: no descriptors to poll!"));
        return VERR_AUDIO_ENUMERATION_FAILED;
    }

    int ready = poll(pfds, nfds, 0);
    if (ready < 0) {
        if (errno != EAGAIN && errno != EINTR) {
            LogWarnFunc(("Cannot poll, errno=%d", errno));
            return VERR_AUDIO_STREAM_NOT_READY;
        }
        return 0;
    } else if (ready == 0) {
        return 0;
    } else /* ready > 0 */ {
        unsigned short revents;
        int err = snd_rawmidi_poll_descriptors_revents(rmidi, pfds, nfds, &revents);
        if (err != 0) {
            LogWarnFunc(("Cannot call revents, err=%d", err));
            return VERR_AUDIO_STREAM_NOT_READY;
        }

        if (revents & POLLNVAL) {
            LogWarnFunc(("POLLNVAL"));
        }
        if (revents & POLLERR) {
            LogWarnFunc(("POLLERR"));
        }

        return revents & (POLLIN | POLLOUT);
    }
}

MIDIAlsa::MIDIAlsa() : _out(NULL)
{

}

MIDIAlsa::~MIDIAlsa()
{
}

int MIDIAlsa::open(const char *dev)
{
    int err;

    if ((err = snd_rawmidi_open(&_in, &_out, "virtual", SND_RAWMIDI_NONBLOCK))) {
        LogWarn(("ALSA rawmidi open error: %s\n", snd_strerror(err)));
        return VERR_AUDIO_STREAM_COULD_NOT_CREATE;
    }

    // TODO: Connect somewhere
    NOREF(dev);

    return VINF_SUCCESS;
}

int MIDIAlsa::close()
{
    if (_in) {
        snd_rawmidi_close(_in);
        _in = NULL;
    }
    if (_out) {
        snd_rawmidi_close(_out);
        _out = NULL;
    }
    return VINF_SUCCESS;
}

ssize_t MIDIAlsa::writeAvail()
{
    return _out ? rawmidi_avail(_out) : 0;
}


ssize_t MIDIAlsa::write(uint8_t *data, size_t len)
{
    ssize_t result = snd_rawmidi_write(_out, data, len);
    if (result < 0) {
        LogWarn(("ALSA midi write error: %s", snd_strerror(result)));
        return VERR_AUDIO_STREAM_NOT_READY;
    }
    return result;
}

ssize_t MIDIAlsa::readAvail()
{
    return _in ? rawmidi_avail(_in) : 0;
}

ssize_t MIDIAlsa::read(uint8_t *buf, size_t len)
{
    ssize_t result = snd_rawmidi_read(_out, buf, len);
    if (result < 0) {
        LogWarn(("ALSA midi read error: %s", snd_strerror(result)));
        return VERR_AUDIO_STREAM_NOT_READY;
    }
    return result;
}