Rudimentary streaming of raw MIDI over multicast UDP

1 files changed, 33 insertions, 0 deletions

diff --git a/midimcast.c b/midimcast.c
new file mode 100644
index 0000000..6ad047f
--- /dev/null
+++ b/midimcast.c
@@ -0,0 +1,33 @@
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "midimcast.h"
+
+void env_read_common(const char **const mcast_group, uint16_t *const mcast_port)
+{
+	midimcast_debug = getenv("DEBUG") != NULL;
+
+	*mcast_group = getenv("MCAST_GROUP");
+	if (!*mcast_group)
+		*mcast_group = "224.212.21.175";
+	debug("Using multicast group %s", *mcast_group);
+
+	const char *const mcast_port_str = getenv("MCAST_PORT");
+	if (mcast_port_str) {
+		const long mcast_port_untrunc = strtol(mcast_port_str, NULL, 0);
+		if (mcast_port_untrunc < 0 || mcast_port_untrunc > UINT16_MAX)
+			err("Port %ld does not exist", mcast_port_untrunc);
+		*mcast_port = mcast_port_untrunc;
+	} else {
+		*mcast_port = 8000;
+	}
+	debug("Using multicast port %" PRIu16, *mcast_port);
+}
+
+uint64_t now() {
+	struct timespec ts;
+	err_std(clock_gettime, CLOCK_REALTIME, &ts);
+	return ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
+}