alsa_rawmidi.h

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/*
 * Copyright (C) 2014-2015 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_rawmidi_h__
#define __libbackend_alsa_rawmidi_h__
 
#include <stdint.h>
#include <poll.h>
#include <pthread.h>
 
#include <alsa/asoundlib.h>
 
#include "pbd/ringbuffer.h"
#include "ardour/types.h"
#include "alsa_midi.h"
 
namespace ARDOUR {
 
class AlsaRawMidiIO : virtual public AlsaMidiIO {
public:
        AlsaRawMidiIO (const std::string &name, const char *device, const bool input);
        virtual ~AlsaRawMidiIO ();
 
protected:
        snd_rawmidi_t *_device;
 
private:
        void init (const char *device_name, const bool input);
};
 
class AlsaRawMidiOut : public AlsaRawMidiIO, public AlsaMidiOut
{
public:
        AlsaRawMidiOut (const std::string &name, const char *device);
        void* main_process_thread ();
};
 
class AlsaRawMidiIn : public AlsaRawMidiIO, public AlsaMidiIn
{
public:
        AlsaRawMidiIn (const std::string &name, const char *device);
 
        void* main_process_thread ();
 
protected:
        int queue_event (const uint64_t, const uint8_t *, const size_t);
private:
        void parse_events (const uint64_t, const uint8_t *, const size_t);
        bool process_byte (const uint64_t, const uint8_t);
 
        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 uint64_t time, const uint8_t byte) {
                _parser_buffer[0] = byte;
                _event.prepare(time, 1);
        }
 
        bool prepare_buffered_event(const uint64_t time) {
                const bool result = _unbuffered_bytes == 0;
                if (result) {
                        _event.prepare(time, _total_bytes);
                }
                _total_bytes = 0;
                _unbuffered_bytes = 0;
                if (_status_byte >= 0xf0) {
                        _expected_bytes = 0;
                        _status_byte = 0;
                }
                return result;
        }
 
        struct ParserEvent {
                uint64_t _time;
                size_t _size;
                bool _pending;
                ParserEvent (const uint64_t time, const size_t size)
                        : _time(time)
                        , _size(size)
                        , _pending(false) {}
 
                void prepare(const uint64_t time, const size_t size) {
                        _time = time;
                        _size = size;
                        _pending = true;
                }
        } _event;
 
        bool    _first_time;
        size_t  _unbuffered_bytes;
        size_t  _total_bytes;
        size_t  _expected_bytes;
        uint8_t _status_byte;
        uint8_t _parser_buffer[1024];
};
 
} // namespace
 
#endif