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Fix MIDI Clock slave

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* take port latency into account
* fix DLL initialization, and initial speed calculation
* igonre out of bounds BPM

the DLL bandwidth still needs to be tweaked, likewise the
hardcoded 1st order LPF to track BPM (vs speed).
This commit is contained in:
Robin Gareus 2020-05-27 23:13:19 +02:00
parent 16f6e62249
commit 3e6295f538
Signed by: rgareus
GPG Key ID: A090BCE02CF57F04
1 changed files with 38 additions and 34 deletions
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72
libs/ardour/midi_clock_slave.cc
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@ -126,13 +126,13 @@ MIDIClock_TransportMaster::pre_process (MIDI::pframes_t nframes, samplepos_t now
/* no clock messages ever, or no clock messages for 1/4 second ? conclude that its stopped */
if (!current.timestamp || (now > current.timestamp && ((now - current.timestamp) > (ENGINE->sample_rate() / 4)))) {
if (!current.timestamp || one_ppqn_in_samples == 0 || (now > current.timestamp && ((now - current.timestamp) > (ENGINE->sample_rate() / 4)))) {
_bpm = 0.0;
_running = false;
_current_delta = 0;
midi_clock_count = 0;
DEBUG_TRACE (DEBUG::MidiClock, "No MIDI Clock messages received for some time, stopping!\n");
DEBUG_TRACE (DEBUG::MidiClock, string_compose ("No MIDI Clock messages received for some time, stopping! ts = %1 @ %2 ppqn = %3\n", current.timestamp, now, one_ppqn_in_samples));
return;
}
@ -152,7 +152,7 @@ MIDIClock_TransportMaster::calculate_one_ppqn_in_samples_at(samplepos_t time)
const double samples_per_quarter_note = _session->tempo_map().samples_per_quarter_note_at (time, ENGINE->sample_rate());
one_ppqn_in_samples = samples_per_quarter_note / double (ppqn);
// DEBUG_TRACE (DEBUG::MidiClock, string_compose ("at %1, one ppqn = %2\n", time, one_ppqn_in_samples));
// DEBUG_TRACE (DEBUG::MidiClock, string_compose ("at %1, one ppqn = %2 [spl] spqn = %3, ppqn = %4\n", time, one_ppqn_in_samples, samples_per_quarter_note, ppqn));
}
ARDOUR::samplepos_t
@ -190,7 +190,6 @@ void
MIDIClock_TransportMaster::update_midi_clock (Parser& /*parser*/, samplepos_t timestamp)
{
samplepos_t elapsed_since_start = timestamp - first_timestamp;
double e = 0;
calculate_one_ppqn_in_samples_at (current.position);
@ -206,29 +205,34 @@ MIDIClock_TransportMaster::update_midi_clock (Parser& /*parser*/, samplepos_t ti
midi_clock_count++;
current.position += one_ppqn_in_samples;
} else if (midi_clock_count == 1) {
/* second 0xf8 message has arrived. we can now estimate QPM
* (quarters per minute, and fully initialize the DLL
*/
e = timestamp - current.timestamp;
e2 = timestamp - current.timestamp;
const samplecnt_t samples_per_quarter = e * 24;
_bpm = (ENGINE->sample_rate() * 60.0) / samples_per_quarter;
const samplecnt_t samples_per_quarter = e2 * 24;
double bpm = (ENGINE->sample_rate() * 60.0) / samples_per_quarter;
calculate_filter_coefficients (_bpm);
if (bpm < 1 || bpm > 999) {
current.update (0, timestamp, 0);
midi_clock_count = 1; /* start over */
DEBUG_TRACE (DEBUG::MidiClock, string_compose ("BPM is out of bounds (%1)\n", timestamp, current.timestamp));
} else {
_bpm = bpm;
/* finish DLL initialization */
calculate_filter_coefficients (_bpm);
t0 = timestamp;
e2 = e;
t1 = t0 + e2; /* timestamp we predict for the next 0xf8 clock message */
/* finish DLL initialization */
midi_clock_count++;
current.update (one_ppqn_in_samples, timestamp, 0);
t0 = timestamp;
t1 = t0 + e2; /* timestamp we predict for the next 0xf8 clock message */
midi_clock_count++;
current.update (one_ppqn_in_samples + midi_port_latency.max, timestamp, 0);
}
} else {
@ -236,7 +240,7 @@ MIDIClock_TransportMaster::update_midi_clock (Parser& /*parser*/, samplepos_t ti
* speed (and tempo) with the DLL
*/
e = timestamp - t1; // error between actual time of arrival of clock message and our predicted time
double e = timestamp - t1; // error between actual time of arrival of clock message and our predicted time
t0 = t1;
t1 += b * e + e2;
e2 += c * e;
@ -281,22 +285,22 @@ MIDIClock_TransportMaster::update_midi_clock (Parser& /*parser*/, samplepos_t ti
}
}
DEBUG_TRACE (DEBUG::MidiClock, string_compose ("clock #%1 @ %2 should-be %3 transport %4 error %5 appspeed %6 "
"read-delta %7 should-be delta %8 t1-t0 %9 t0 %10 t1 %11 framerate %12 engine %13 running %14\n",
midi_clock_count, // #
elapsed_since_start, // @
current.position, // should-be
_session->transport_sample(), // transport
e, // error
(t1 - t0) / one_ppqn_in_samples, // appspeed
timestamp - current.timestamp, // read delta
one_ppqn_in_samples, // should-be delta
(t1 - t0), // t1-t0
t0, // t0
t1, // t1
ENGINE->sample_rate(), // framerate
ENGINE->sample_time(),
_running
DEBUG_TRACE (DEBUG::MidiClock, string_compose (
"clock #%1 @ %2 should-be %3 transport %4 appspeed %6 "
"read-delta %7 should-be-delta %8 t1-t0 %9 t0 %10 t1 %11 sample-rate %12 engine %13 running %14\n",
midi_clock_count, // #
elapsed_since_start, // @
current.position, // should-be
_session->transport_sample(), // transport
(t1 - t0) / one_ppqn_in_samples, // appspeed
timestamp - current.timestamp, // read delta
one_ppqn_in_samples, // should-be delta
(t1 - t0), // t1-t0
t0, // t0 (current position)
t1, // t1 (expected next pos)
ENGINE->sample_rate(), // framerate
ENGINE->sample_time(),
_running
));
}
@ -377,7 +381,7 @@ MIDIClock_TransportMaster::position (Parser& /*parser*/, MIDI::byte* message, si
DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Song Position: %1 samples: %2\n", position_in_sixteenth_notes, position_in_samples));
current.update (position_in_samples, timestamp, current.speed);
current.update (position_in_samples + midi_port_latency.max, timestamp, current.speed);
}
bool