ardour/libs/backends/alsa/alsa_rawmidi.h

157 lines
3.5 KiB
C++

/*
* 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_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"
namespace ARDOUR {
class AlsaRawMidiIO {
public:
AlsaRawMidiIO (const char *device, const bool input);
virtual ~AlsaRawMidiIO ();
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_rawmidi_t *_device;
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 AlsaRawMidiOut : public AlsaRawMidiIO
{
public:
AlsaRawMidiOut (const char *device);
void* main_process_thread ();
int send_event (const pframes_t, const uint8_t *, const size_t);
};
class AlsaRawMidiIn : public AlsaRawMidiIO
{
public:
AlsaRawMidiIn (const char *device);
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);
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;
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