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livetrax/libs/ardour/mididm.cc

89 lines
2.5 KiB
C++

/*
* Copyright (C) 2013-2014 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.
*/
#include "ardour/mididm.h"
#include "ardour/port_engine.h"
using namespace ARDOUR;
MIDIDM::MIDIDM (framecnt_t sample_rate)
: _sample_rate (sample_rate)
, _monotonic_cnt (sample_rate)
, _last_signal_tme (0)
, _cnt_total (0)
, _dly_total (0)
, _min_delay (INT32_MAX)
, _max_delay (0)
, _avg_delay (0)
, _var_m (0)
, _var_s (0)
{
}
int MIDIDM::process (pframes_t nframes, PortEngine &pe, void *midi_in, void *midi_out)
{
/* send midi event */
uint8_t obuf[3];
obuf[0] = 0xf2;
obuf[1] = (_monotonic_cnt) & 0x7f;
obuf[2] = (_monotonic_cnt >> 7) & 0x7f;
pe.midi_clear(midi_out);
pe.midi_event_put (midi_out, 0, obuf, 3);
/* process incoming */
const pframes_t nevents = pe.get_midi_event_count (midi_in);
for (pframes_t n = 0; n < nevents; ++n) {
pframes_t timestamp;
size_t size;
uint8_t* buf;
pe.midi_event_get (timestamp, size, &buf, midi_in, n);
if (size != 3 || buf[0] != 0xf2 ) continue;
_last_signal_tme = _monotonic_cnt;
/* calculate time difference */
#define MODX (16384) // 1<<(2*7)
#define MASK (0x3fff) // MODX - 1
const int64_t tc = (_monotonic_cnt + timestamp) & MASK;
const int64_t ti = (buf[2] << 7) | buf[1];
const int64_t tdiff = (MODX + tc - ti) % MODX;
/* running variance */
if (_cnt_total == 0) {
_var_m = tdiff;
} else {
const double var_m1 = _var_m;
_var_m = _var_m + ((double)tdiff - _var_m) / (double)(_cnt_total + 1);
_var_s = _var_s + ((double)tdiff - _var_m) * ((double)tdiff - var_m1);
}
/* average and mix/max */
++_cnt_total;
_dly_total += tdiff;
_avg_delay = _dly_total / _cnt_total;
if (tdiff < _min_delay) _min_delay = tdiff;
if (tdiff > _max_delay) _max_delay = tdiff;
}
_monotonic_cnt += nframes;
return 0;
}