Add a Raw MIDI parser (based on ALSA raw MIDI)

1 files changed, 89 insertions, 0 deletions

diff --git a/libs/ardour/ardour/raw_midi_parser.h b/libs/ardour/ardour/raw_midi_parser.h
new file mode 100644
index 0000000000..3e1e70066b
--- /dev/null
+++ b/libs/ardour/ardour/raw_midi_parser.h
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2014,2017 Robin Gareus <robin@gareus.org>
+ * Copyright (C) 2010 Devin Anderson
+ *
+ * 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.
+ */
+
+#ifndef _ardour_raw_midi_parser_h_
+#define _ardour_raw_midi_parser_h_
+
+#include "ardour/libardour_visibility.h"
+#include "ardour/types.h"
+
+namespace ARDOUR {
+
+class LIBARDOUR_API RawMidiParser
+{
+public:
+	RawMidiParser ();
+
+	void reset () {
+		_event_size = 0;
+		_unbuffered_bytes = 0;
+		_total_bytes = 0;
+		_expected_bytes = 0;
+		_status_byte = 0;
+	}
+
+	uint8_t const * midi_buffer () const { return  _parser_buffer; }
+	size_t buffer_size () const { return _event_size; }
+
+	/** parse a MIDI byte
+	 * @return true if message is complete, false if more data is needed
+	 */
+	bool process_byte (const uint8_t byte);
+
+private:
+
+	void record_byte (uint8_t byte) {
+		if (_total_bytes < sizeof (_parser_buffer)) {
+			_parser_buffer[_total_bytes] = byte;
+		} else {
+			++_unbuffered_bytes;
+		}
+		++_total_bytes;
+	}
+
+	void prepare_byte_event (const uint8_t byte) {
+		_parser_buffer[0] = byte;
+		_event_size = 1;
+	}
+
+	bool prepare_buffered_event () {
+		const bool result = _unbuffered_bytes == 0;
+		if (result) {
+			_event_size = _total_bytes;
+		}
+		_total_bytes = 0;
+		_unbuffered_bytes = 0;
+		if (_status_byte >= 0xf0) {
+			_expected_bytes = 0;
+			_status_byte = 0;
+		}
+		return result;
+	}
+
+	size_t  _event_size;
+	size_t  _unbuffered_bytes;
+	size_t  _total_bytes;
+	size_t  _expected_bytes;
+	uint8_t _status_byte;
+	uint8_t _parser_buffer[1024];
+};
+
+} // namespace ARDOUR
+
+#endif /* _ardour_raw_midi_parser_h_ */