prepare ALSA sequencer

libs/backends/alsa/alsa_sequencer.h

@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2014 Robin Gareus <robin@gareus.org>
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __libbackend_alsa_sequencer_h__
+#define __libbackend_alsa_sequencer_h__
+
+#include <stdint.h>
+#include <poll.h>
+#include <pthread.h>
+
+#include <alsa/asoundlib.h>
+
+#include "pbd/ringbuffer.h"
+#include "ardour/types.h"
+
+namespace ARDOUR {
+
+class AlsaSeqMidiIO {
+public:
+	AlsaSeqMidiIO (const char *port_name, const bool input);
+	virtual ~AlsaSeqMidiIO ();
+
+	int state (void) const { return _state; }
+	int start ();
+	int stop ();
+
+	void setup_timing (const size_t samples_per_period, const float samplerate);
+	void sync_time(uint64_t);
+
+	virtual void* main_process_thread () = 0;
+
+protected:
+	pthread_t _main_thread;
+	pthread_mutex_t _notify_mutex;
+	pthread_cond_t _notify_ready;
+
+	int  _state;
+	bool  _running;
+
+	snd_seq_t *_seq;
+	//snd_seq_addr_t _port;
+	int _port;
+
+	int _npfds;
+	struct pollfd *_pfds;
+
+	double _sample_length_us;
+	double _period_length_us;
+	size_t _samples_per_period;
+	uint64_t _clock_monotonic;
+
+	struct MidiEventHeader {
+		uint64_t time;
+		size_t size;
+		MidiEventHeader(const uint64_t t, const size_t s)
+			: time(t)
+			, size(s) {}
+	};
+
+	RingBuffer<uint8_t>* _rb;
+
+private:
+	void init (const char *device_name, const bool input);
+};
+
+class AlsaSeqMidiOut : public AlsaSeqMidiIO
+{
+public:
+	AlsaSeqMidiOut (const char *port_name);
+
+	void* main_process_thread ();
+	int send_event (const pframes_t, const uint8_t *, const size_t);
+};
+
+class AlsaSeqMidiIn : public AlsaSeqMidiIO
+{
+public:
+	AlsaSeqMidiIn (const char *port_name);
+
+	void* main_process_thread ();
+	size_t recv_event (pframes_t &, uint8_t *, size_t &);
+
+private:
+	int queue_event (const uint64_t, const uint8_t *, const size_t);
+};
+
+} // namespace
+
+#endif