1 files changed, 37 insertions, 1 deletions
diff --git a/drivers/alsamidi/midi_driver_alsamidi.h b/drivers/alsamidi/midi_driver_alsamidi.h
index ac3530b1b2..9265dede3d 100644
--- a/drivers/alsamidi/midi_driver_alsamidi.h
+++ b/drivers/alsamidi/midi_driver_alsamidi.h
@@ -46,12 +46,48 @@ class MIDIDriverALSAMidi : public MIDIDriver {
 	Thread thread;
 	Mutex mutex;
 
-	Vector<snd_rawmidi_t *> connected_inputs;
+	class InputConnection {
+	public:
+		InputConnection() = default;
+		InputConnection(snd_rawmidi_t *midi_in) :
+				rawmidi_ptr{ midi_in } {}
+
+		// Read in and parse available data, forwarding any complete messages through the driver.
+		int read_in(MIDIDriverALSAMidi &driver, uint64_t timestamp);
+
+		snd_rawmidi_t *rawmidi_ptr = nullptr;
+
+	private:
+		static const size_t MSG_BUFFER_SIZE = 3;
+		uint8_t buffer[MSG_BUFFER_SIZE] = { 0 };
+		size_t expected_data = 0;
+		size_t received_data = 0;
+		bool skipping_sys_ex = false;
+		void parse_byte(uint8_t byte, MIDIDriverALSAMidi &driver, uint64_t timestamp);
+	};
+
+	Vector<InputConnection> connected_inputs;
 
 	SafeFlag exit_thread;
 
 	static void thread_func(void *p_udata);
 
+	enum class MessageCategory {
+		Data,
+		Voice,
+		SysExBegin,
+		SystemCommon, // excluding System Exclusive Begin/End
+		SysExEnd,
+		RealTime,
+	};
+
+	// If the passed byte is a status byte, return the associated message category,
+	// else return MessageCategory::Data.
+	static MessageCategory msg_category(uint8_t msg_part);
+
+	// Return the number of data bytes expected for the provided status byte.
+	static size_t msg_expected_data(uint8_t status_byte);
+
 	void lock() const;
 	void unlock() const;