git: 0ca4d5d8209c - main - sound examples: Simplify MIDI example

From: Christos Margiolis <christos_at_FreeBSD.org>
Date: Sat, 24 Aug 2024 12:09:14 UTC
The branch main has been updated by christos:

URL: https://cgit.FreeBSD.org/src/commit/?id=0ca4d5d8209cf4d2d0bb37d7f20d95ac3457026d

commit 0ca4d5d8209cf4d2d0bb37d7f20d95ac3457026d
Author:     Christos Margiolis <christos@FreeBSD.org>
AuthorDate: 2024-08-24 12:07:40 +0000
Commit:     Christos Margiolis <christos@FreeBSD.org>
CommitDate: 2024-08-24 12:07:40 +0000

    sound examples: Simplify MIDI example
    
    Sponsored by:   The FreeBSD Foundation
    MFC after:      2 days
    Reviewed by:    dev_submerge.ch, emaste
    Differential Revision:  https://reviews.freebsd.org/D46306
---
 share/examples/Makefile            |  3 +-
 share/examples/sound/oss/midi.c    | 77 ++++++++++++++++++++++----------------
 share/examples/sound/oss/ossmidi.h | 63 -------------------------------
 3 files changed, 46 insertions(+), 97 deletions(-)

diff --git a/share/examples/Makefile b/share/examples/Makefile
index 211ec2272c05..d57416112226 100644
--- a/share/examples/Makefile
+++ b/share/examples/Makefile
@@ -322,8 +322,7 @@ SE_SOUND_OSS= \
 	README \
 	basic.c \
 	midi.c \
-	ossinit.h \
-	ossmidi.h
+	ossinit.h
 
 SE_DIRS+=	sunrpc
 SE_SUNRPC=	Makefile
diff --git a/share/examples/sound/oss/midi.c b/share/examples/sound/oss/midi.c
index 6d6ac9aa0fcd..5b001ba537e5 100644
--- a/share/examples/sound/oss/midi.c
+++ b/share/examples/sound/oss/midi.c
@@ -2,6 +2,10 @@
  * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2022 Goran Mekić
+ * Copyright (c) 2024 The FreeBSD Foundation
+ *
+ * Portions of this software were developed by Christos Margiolis
+ * <christos@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -25,52 +29,61 @@
  * SUCH DAMAGE.
  */
 
+#include <err.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
 #include <unistd.h>
 
-#include "ossmidi.h"
+#define CMD_MASK	0xF0
+#define CHANNEL_MASK	0x0F
+#define NOTE_ON		0x90
+#define NOTE_OFF	0x80
+#define CTL_CHANGE	0xB0
 
 int
-main()
+main(int argc, char *argv[])
 {
-	midi_event_t event;
-	midi_config_t midi_config;
-	int l = -1;
-	unsigned char raw;
+	int fd;
+	unsigned char raw, type, channel, b1, b2;
 
-	midi_config.device = "/dev/umidi1.0";
-	oss_midi_init(&midi_config);
+	if ((fd = open("/dev/umidi0.0", O_RDWR)) < 0)
+		err(1, "Error opening MIDI device");
 
-	while ((l = read(midi_config.fd, &raw, sizeof(raw))) != -1) {
-		if (!(raw & 0x80)) {
+	for (;;) {
+		if (read(fd, &raw, sizeof(raw)) < sizeof(raw))
+			err(1, "Error reading command byte");
+		if (!(raw & 0x80))
 			continue;
-		}
-		event.type = raw & CMD_MASK;
-		event.channel = raw & CHANNEL_MASK;
-		switch (event.type) {
+
+		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:
-		case NOTE_OFF:
-		case CONTROLLER_ON:
-			if ((l = read(midi_config.fd, &(event.note), sizeof(event.note))) == -1) {
-				perror("Error reading MIDI note");
-				exit(1);
-			}
-			if ((l = read(midi_config.fd, &(event.velocity), sizeof(event.velocity))) == -1) {
-				perror("Error reading MIDI velocity");
-				exit(1);
-			}
+			printf("Channel %d, note on %d, velocity %d\n",
+			    channel, b1, b2);
 			break;
-		}
-		switch (event.type) {
-		case NOTE_ON:
 		case NOTE_OFF:
-			printf("Channel %d, note %d, velocity %d\n", event.channel, event.note, event.velocity);
+			printf("Channel %d, note off %d, velocity %d\n",
+			    channel, b1, b2);
 			break;
-		case CONTROLLER_ON:
-			printf("Channel %d, controller %d, value %d\n", event.channel, event.controller, event.value);
+		case CTL_CHANGE:
+			printf("Channel %d, controller change %d, value %d\n",
+			    channel, b1, b2);
 			break;
 		default:
-			printf("Unknown event type %d\n", event.type);
+			printf("Unknown event type %d\n", type);
+			break;
 		}
 	}
-	return 0;
+	
+	close(fd);
+
+	return (0);
 }
diff --git a/share/examples/sound/oss/ossmidi.h b/share/examples/sound/oss/ossmidi.h
deleted file mode 100644
index 99a6bacffe73..000000000000
--- a/share/examples/sound/oss/ossmidi.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * SPDX-License-Identifier: BSD-2-Clause
- *
- * Copyright (c) 2022 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 <stdlib.h>
-#include <stdio.h>
-#include <fcntl.h>
-
-#define CMD_MASK 0xF0
-#define NOTE_ON 0x90
-#define NOTE_OFF 0x80
-#define CHANNEL_MASK 0xF
-#define CONTROLLER_ON 0xB0
-
-typedef struct midi_event {
-	unsigned char type;
-	unsigned char channel;
-	union {
-		unsigned char note;
-		unsigned controller;
-	};
-	union {
-		unsigned char velocity;
-		unsigned char value;
-	};
-} midi_event_t;
-
-typedef struct midi_config {
-	char   *device;
-	int	fd;
-} midi_config_t;
-
-void
-oss_midi_init(midi_config_t *config)
-{
-	if ((config->fd = open(config->device, O_RDWR)) == -1) {
-		perror("Error opening MIDI device");
-		exit(1);
-	}
-}