ardour/libs/midi++2/mtc.cc

355 lines
8.0 KiB
C++

/*
Copyright (C) 2004 Paul Barton-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 <cstdlib>
#include <unistd.h>
#include <cstring>
#include <iostream>
#include "midi++/types.h"
#include "midi++/parser.h"
#include "midi++/port.h"
#include "midi++/mmc.h"
#include "pbd/transmitter.h"
using namespace std;
using namespace sigc;
using namespace MIDI;
#undef DEBUG_MTC
bool
Parser::possible_mtc (MIDI::byte *sysex_buf, size_t msglen)
{
byte fake_mtc_time[5];
if (msglen != 10 || sysex_buf[0] != 0xf0 || sysex_buf[1] != 0x7f || sysex_buf[3] != 0x01 || sysex_buf[4] != 0x01) {
return false;
}
/* full MTC */
fake_mtc_time[0] = sysex_buf[8]; // frames
fake_mtc_time[1] = sysex_buf[7]; // minutes
fake_mtc_time[2] = sysex_buf[6]; // seconds
fake_mtc_time[3] = (sysex_buf[5] & 0x1f); // hours
_mtc_fps = MTC_FPS ((sysex_buf[5] & 0x60) >> 5); // fps
fake_mtc_time[4] = (byte) _mtc_fps;
/* wait for first quarter frame, which could indicate forwards
or backwards ...
*/
reset_mtc_state ();
/* emit signals */
mtc (*this, &sysex_buf[1], msglen - 1);
mtc_time (fake_mtc_time, true, _timestamp);
#ifdef DEBUG_MTC
cerr << "New full-MTC message marks state stopped" << endl;
#endif
mtc_status (MTC_Stopped);
return true;
}
void
Parser::reset_mtc_state ()
{
#ifdef DEBUG_MTC
cerr << "MTC state reset" << endl;
#endif
/* MUST REMAIN RT-SAFE */
_mtc_forward = false;
_mtc_running = MTC_Stopped;
_mtc_locked = false;
expected_mtc_quarter_frame_code = 0;
memset (_mtc_time, 0, sizeof (_mtc_time));
memset (_qtr_mtc_time, 0, sizeof (_mtc_time));
consecutive_qtr_frame_cnt = 0;
last_qtr_frame = 0;
}
void
Parser::process_mtc_quarter_frame (MIDI::byte *msg)
{
int which_quarter_frame = (msg[1] & 0xf0) >> 4;
/* Is it an expected frame?
Remember, the first can be frame 7 or frame 0,
depending on the direction of the MTC generator ...
*/
#ifdef DEBUG_MTC
cerr << "MTC: (state = " << _mtc_running << ") "
<< which_quarter_frame << " vs. " << expected_mtc_quarter_frame_code
<< " consecutive ? " << consecutive_qtr_frame_cnt
<< endl;
#endif
if (_mtc_running == MTC_Stopped) {
/* we are stopped but are seeing qtr frame messages */
if (consecutive_qtr_frame_cnt == 0) {
/* first quarter frame */
if (which_quarter_frame != 0 && which_quarter_frame != 7) {
last_qtr_frame = which_quarter_frame;
consecutive_qtr_frame_cnt++;
}
// cerr << "first seen qframe = " << (int) last_qtr_frame << endl;
return;
} else if (consecutive_qtr_frame_cnt == 1) {
/* third quarter frame */
#ifdef DEBUG_MTC
cerr << "second seen qframe = " << (int) which_quarter_frame << endl;
#endif
if (last_qtr_frame < which_quarter_frame) {
_mtc_running = MTC_Forward;
} else if (last_qtr_frame > which_quarter_frame) {
_mtc_running = MTC_Backward;
}
#ifdef DEBUG_MTC
cerr << "Send MTC status as " << _mtc_running << endl;
#endif
mtc_status (_mtc_running);
}
switch (_mtc_running) {
case MTC_Forward:
if (which_quarter_frame == 7) {
expected_mtc_quarter_frame_code = 0;
} else {
expected_mtc_quarter_frame_code = which_quarter_frame + 1;
}
break;
case MTC_Backward:
if (which_quarter_frame == 0) {
expected_mtc_quarter_frame_code = 7;
} else {
expected_mtc_quarter_frame_code = which_quarter_frame - 1;
}
break;
case MTC_Stopped:
break;
}
} else {
/* already running */
// for testing bad MIDI connections etc.
// if ((random() % 500) < 10) {
if (which_quarter_frame != expected_mtc_quarter_frame_code) {
consecutive_qtr_frame_cnt = 0;
#ifdef DEBUG_MTC
cerr << "MTC: (state = " << _mtc_running << ") "
<< which_quarter_frame << " vs. " << expected_mtc_quarter_frame_code << endl;
#endif
/* tell listener(s) that we skipped. if they return
true, just ignore this in terms of it being an error.
*/
boost::optional<bool> res = mtc_skipped ();
if (res.get_value_or (false)) {
/* no error, reset next expected frame */
switch (_mtc_running) {
case MTC_Forward:
if (which_quarter_frame == 7) {
expected_mtc_quarter_frame_code = 0;
} else {
expected_mtc_quarter_frame_code = which_quarter_frame + 1;
}
break;
case MTC_Backward:
if (which_quarter_frame == 0) {
expected_mtc_quarter_frame_code = 7;
} else {
expected_mtc_quarter_frame_code = which_quarter_frame - 1;
}
break;
case MTC_Stopped:
break;
}
#ifdef DEBUG_MTC
cerr << "SKIPPED, next expected = " << expected_mtc_quarter_frame_code << endl;
#endif
return;
}
/* skip counts as an error ... go back to waiting for the first frame */
#ifdef DEBUG_MTC
cerr << "Skipped MTC qtr frame, return to stopped state" << endl;
#endif
reset_mtc_state ();
mtc_status (MTC_Stopped);
return;
} else {
/* received qtr frame matched expected */
consecutive_qtr_frame_cnt++;
}
}
/* time code is looking good */
#ifdef DEBUG_MTC
cerr << "for quarter frame " << which_quarter_frame << " byte = " << hex << (int) msg[1] << dec << endl;
#endif
switch (which_quarter_frame) {
case 0: // frames LS nibble
_qtr_mtc_time[0] |= msg[1] & 0xf;
break;
case 1: // frames MS nibble
_qtr_mtc_time[0] |= (msg[1] & 0xf)<<4;
break;
case 2: // seconds LS nibble
_qtr_mtc_time[1] |= msg[1] & 0xf;
break;
case 3: // seconds MS nibble
_qtr_mtc_time[1] |= (msg[1] & 0xf)<<4;
break;
case 4: // minutes LS nibble
_qtr_mtc_time[2] |= msg[1] & 0xf;
break;
case 5: // minutes MS nibble
_qtr_mtc_time[2] |= (msg[1] & 0xf)<<4;
break;
case 6: // hours LS nibble
_qtr_mtc_time[3] |= msg[1] & 0xf;
break;
case 7:
/* last quarter frame msg has the MS bit of
the hour in bit 0, and the SMPTE FPS type
in bits 5 and 6
*/
_qtr_mtc_time[3] |= ((msg[1] & 0x1) << 4);
_mtc_fps = MTC_FPS ((msg[1] & 0x6) >> 1);
_qtr_mtc_time[4] = _mtc_fps;
break;
default:
abort(); /*NOTREACHED*/
break;
}
#ifdef DEBUG_MTC
cerr << "Emit MTC Qtr\n";
#endif
mtc_qtr (*this, which_quarter_frame, _timestamp); /* EMIT_SIGNAL */
// mtc (*this, &msg[1], msglen - 1);
switch (_mtc_running) {
case MTC_Forward:
if (which_quarter_frame == 7) {
/* we've reached the final of 8 quarter frame messages.
store the time, reset the pending time holder,
and signal anyone who wants to know the time.
*/
if (consecutive_qtr_frame_cnt >= 8) {
memcpy (_mtc_time, _qtr_mtc_time, sizeof (_mtc_time));
memset (_qtr_mtc_time, 0, sizeof (_qtr_mtc_time));
if (!_mtc_locked) {
_mtc_locked = true;
}
mtc_time (_mtc_time, false, _timestamp);
}
expected_mtc_quarter_frame_code = 0;
} else {
expected_mtc_quarter_frame_code = which_quarter_frame + 1;
}
break;
case MTC_Backward:
if (which_quarter_frame == 0) {
/* we've reached the final of 8 quarter frame messages.
store the time, reset the pending time holder,
and signal anyone who wants to know the time.
*/
if (consecutive_qtr_frame_cnt >= 8) {
memcpy (_mtc_time, _qtr_mtc_time, sizeof (_mtc_time));
memset (_qtr_mtc_time, 0, sizeof (_qtr_mtc_time));
if (!_mtc_locked) {
_mtc_locked = true;
}
mtc_time (_mtc_time, false, _timestamp);
}
expected_mtc_quarter_frame_code = 7;
} else {
expected_mtc_quarter_frame_code = which_quarter_frame - 1;
}
break;
default:
break;
}
}