diff --git a/share/examples/sound/midi-kqueue.c b/share/examples/sound/midi-kqueue.c new file mode 100644 --- /dev/null +++ b/share/examples/sound/midi-kqueue.c @@ -0,0 +1,104 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2025 Goran Mekić + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include + +#include +#include +#include +#include +#include + +#define CMD_MASK 0xF0 +#define CHANNEL_MASK 0x0F +#define NOTE_ON 0x90 +#define NOTE_OFF 0x80 +#define CTL_CHANGE 0xB0 + +int +main(int argc, char *argv[]) +{ + int fd, kq; + struct kevent event = {}; + unsigned char raw, type, channel, b1, b2; + + if ((fd = open("/dev/umidi0.0", O_RDWR)) < 0) + err(1, "Error opening MIDI device"); + + if ((kq = kqueue()) < 0) + err(1, "Failed to allocate kqueue"); + EV_SET(&event, fd, EVFILT_READ, EV_ADD | EV_CLEAR, 0, 0, 0); + if (kevent(kq, &event, 1, NULL, 0, NULL) < 0) + err(1, "Failed to register kevent"); + + for (;;) { + if (kevent(kq, NULL, 0, &event, 1, NULL) < 0) { + warn("Event error"); + break; + } + if (event.flags & EV_ERROR) { + warn("Event error: %s", strerror(event.data)); + break; + } + if (read(fd, &raw, sizeof(raw)) < sizeof(raw)) + err(1, "Error reading command byte"); + if (!(raw & 0x80)) + continue; + + type = raw & CMD_MASK; + channel = raw & CHANNEL_MASK; + + if (read(fd, &b1, sizeof(b1)) < sizeof(b1)) + err(1, "Error reading byte 1"); + if (read(fd, &b2, sizeof(b2)) < sizeof(b2)) + err(1, "Error reading byte 2"); + + switch (type) { + case NOTE_ON: + printf("Channel %d, note on %d, velocity %d\n", + channel, b1, b2); + break; + case NOTE_OFF: + printf("Channel %d, note off %d, velocity %d\n", + channel, b1, b2); + break; + case CTL_CHANGE: + printf("Channel %d, controller change %d, value %d\n", + channel, b1, b2); + break; + default: + printf("Unknown event type %d\n", type); + break; + } + } + + EV_SET(&event, fd, EVFILT_READ, EV_DELETE, 0, 0, 0); + if (kevent(kq, &event, 1, NULL, 0, NULL) < 0) + err(1, "Failed to unregister kevent"); + close(kq); + return (0); +}