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livetrax/libs/midi++2/alsa_sequencer_midiport.cc

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/*
Copyright (C) 2004 Paul Davis
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.
$Id$
*/
#include <fcntl.h>
#include <cerrno>
#include <midi++/types.h>
#include <midi++/alsa_sequencer.h>
#include <midi++/port_request.h>
//#define DOTRACE 1
#ifdef DOTRACE
#define TR_FN() (cerr << __FUNCTION__ << endl)
#define TR_VAL(v) (cerr << __FILE__ " " << __LINE__ << " " #v "=" << v << endl)
#else
#define TR_FN()
#define TR_VAL(v)
#endif
using namespace std;
using namespace MIDI;
ALSA_SequencerMidiPort::ALSA_SequencerMidiPort (PortRequest &req)
: Port (req)
, seq (0)
, decoder (0)
, encoder (0)
{
TR_FN();
int err;
if (0 <= (err = CreatePorts (req)) &&
0 <= (err = snd_midi_event_new (1024, &decoder)) && // Length taken from ARDOUR::Session::midi_read ()
0 <= (err = snd_midi_event_new (64, &encoder))) { // Length taken from ARDOUR::Session::mmc_buffer
snd_midi_event_init (decoder);
snd_midi_event_init (encoder);
_ok = true;
req.status = PortRequest::OK;
} else
req.status = PortRequest::Unknown;
}
ALSA_SequencerMidiPort::~ALSA_SequencerMidiPort ()
{
if (decoder)
snd_midi_event_free (decoder);
if (encoder)
snd_midi_event_free (encoder);
if (seq)
snd_seq_close (seq);
}
int ALSA_SequencerMidiPort::selectable () const
{
struct pollfd pfd[1];
if (0 <= snd_seq_poll_descriptors (seq, pfd, 1, POLLIN | POLLOUT)) {
return pfd[0].fd;
}
return -1;
}
int ALSA_SequencerMidiPort::write (byte *msg, size_t msglen)
{
TR_FN ();
int R;
snd_midi_event_reset_encode (encoder);
int nwritten = snd_midi_event_encode (encoder, msg, msglen, &SEv);
TR_VAL (nwritten);
if (0 < nwritten) {
if (0 <= (R = snd_seq_event_output (seq, &SEv)) &&
0 <= (R = snd_seq_drain_output (seq))) {
bytes_written += nwritten;
if (output_parser) {
output_parser->raw_preparse (*output_parser, msg, nwritten);
for (int i = 0; i < nwritten; i++) {
output_parser->scanner (msg[i]);
}
output_parser->raw_postparse (*output_parser, msg, nwritten);
}
return nwritten;
} else {
TR_VAL(R);
return R;
}
} else
return nwritten;
}
int ALSA_SequencerMidiPort::read (byte *buf, size_t max)
{
TR_FN();
int err;
snd_seq_event_t *ev;
if (0 <= (err = snd_seq_event_input (seq, &ev))) {
TR_VAL(err);
err = snd_midi_event_decode (decoder, buf, max, ev);
}
if (err > 0) {
bytes_read += err;
if (input_parser) {
input_parser->raw_preparse (*input_parser, buf, err);
for (int i = 0; i < err; i++) {
input_parser->scanner (buf[i]);
}
input_parser->raw_postparse (*input_parser, buf, err);
}
}
return -ENOENT == err ? 0 : err;
}
int ALSA_SequencerMidiPort::CreatePorts (PortRequest &req)
{
int err;
if (0 <= (err = snd_seq_open(&seq, "default", SND_SEQ_OPEN_DUPLEX,
(req.mode & O_NONBLOCK) ? SND_SEQ_NONBLOCK : 0))) {
snd_seq_set_client_name (seq, req.devname);
unsigned int caps = 0;
if (req.mode == O_WRONLY || req.mode == O_RDWR)
caps |= SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE;
if (req.mode == O_RDONLY || req.mode == O_RDWR)
caps |= SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ;
err = snd_seq_create_simple_port (seq, req.tagname, caps, SND_SEQ_PORT_TYPE_MIDI_GENERIC);
if (err >= 0) {
port_id = err;
snd_seq_ev_clear (&SEv);
snd_seq_ev_set_source (&SEv, port_id);
snd_seq_ev_set_subs (&SEv);
snd_seq_ev_set_direct (&SEv);
} else
snd_seq_close (seq);
}
return err;
}