alsa_midi.h

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/*
 * Copyright (C) 2014-2017 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#ifndef __libbackend_alsa_midi_h__
#define __libbackend_alsa_midi_h__
 
#include <stdint.h>
#include <poll.h>
#include <pthread.h>
 
#include "pbd/ringbuffer.h"
#include "ardour/types.h"
 
/* max bytes per individual midi-event
 * events larger than this are ignored */
#define MaxAlsaMidiEventSize (256)
 
namespace ARDOUR {
 
class AlsaMidiIO {
public:
        AlsaMidiIO ();
        virtual ~AlsaMidiIO ();
 
        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;
 
        const std::string & name () const { return _name; }
 
protected:
        pthread_t _main_thread;
        pthread_mutex_t _notify_mutex;
        pthread_cond_t _notify_ready;
 
        int  _state;
        bool  _running;
 
        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) {}
        };
 
        PBD::RingBuffer<uint8_t>* _rb;
 
        std::string _name;
 
        virtual void init (const char *device_name, const bool input) = 0;
 
};
 
class AlsaMidiOut : virtual public AlsaMidiIO
{
public:
        AlsaMidiOut ();
 
        int send_event (const pframes_t, const uint8_t *, const size_t);
};
 
class AlsaMidiIn : virtual public AlsaMidiIO
{
public:
        AlsaMidiIn ();
 
        size_t recv_event (pframes_t &, uint8_t *, size_t &);
 
protected:
        int queue_event (const uint64_t, const uint8_t *, const size_t);
};
 
} // namespace
 
#endif