From: Paul Davis <paul@linuxaudiosystems.com>
Date: Mon, 6 Feb 2012 15:05:18 +0000 (+0000)
Subject: fix bug in MidiClock that sent MIDI Clock messages with negative offsets after a... 
X-Git-Tag: 3.0-beta3~14
X-Git-Url: https://main.carlh.net/gitweb/?p=ardour.git;a=commitdiff_plain;h=f4f2a9a111c32d4761308eb94a8c7cfa214b7116

fix bug in MidiClock that sent MIDI Clock messages with negative offsets after a loop point

git-svn-id: svn://localhost/ardour2/branches/3.0@11456 d708f5d6-7413-0410-9779-e7cbd77b26cf
---

diff --git a/libs/ardour/ticker.cc b/libs/ardour/ticker.cc
index 5152568022..734b401356 100644
--- a/libs/ardour/ticker.cc
+++ b/libs/ardour/ticker.cc
@@ -24,6 +24,7 @@
 
 #include "evoral/midi_events.h"
 
+#include "ardour/audioengine.h"
 #include "ardour/ticker.h"
 #include "ardour/session.h"
 #include "ardour/tempo.h"
@@ -69,6 +70,11 @@ void MidiClockTicker::transport_state_changed()
 		return;
 	}
 
+	if (!_session->engine().running()) {
+		/* Engine stopped, we can't do anything */
+		return;
+	}
+
 	float      speed    = _session->transport_speed();
 	framepos_t position = _session->transport_frame();
 
@@ -126,22 +132,29 @@ void MidiClockTicker::transport_looped()
 
 	// adjust _last_tick, so that the next MIDI clock message is sent
 	// in due time (and the tick interval is still constant)
+
 	framecnt_t elapsed_since_last_tick = loop_location->end() - _last_tick;
-	_last_tick = loop_location->start() - elapsed_since_last_tick;
+
+	if (loop_location->start() > elapsed_since_last_tick) {
+		_last_tick = loop_location->start() - elapsed_since_last_tick;
+	} else {
+		_last_tick = 0;
+	}
 }
 
-void MidiClockTicker::tick (const framepos_t& transport_frames)
+void MidiClockTicker::tick (const framepos_t& transport_frame)
 {
-	if (!Config->get_send_midi_clock() || _session == 0 || _session->transport_speed() != 1.0f || _midi_port == 0)
+	if (!Config->get_send_midi_clock() || _session == 0 || _session->transport_speed() != 1.0f || _midi_port == 0) {
 		return;
+	}
 
 	while (true) {
-		double next_tick = _last_tick + one_ppqn_in_frames(transport_frames);
-		frameoffset_t next_tick_offset = llrint (next_tick) - transport_frames;
+		double next_tick = _last_tick + one_ppqn_in_frames (transport_frame);
+		frameoffset_t next_tick_offset = llrint (next_tick) - transport_frame;
 
 		DEBUG_TRACE (PBD::DEBUG::MidiClock,
 			     string_compose ("Transport: %1, last tick time: %2, next tick time: %3, offset: %4, cycle length: %5\n",
-					     transport_frames, _last_tick, next_tick, next_tick_offset, _midi_port->nframes_this_cycle()
+					     transport_frame, _last_tick, next_tick, next_tick_offset, _midi_port->nframes_this_cycle()
 				     )
 			);
 
@@ -149,15 +162,18 @@ void MidiClockTicker::tick (const framepos_t& transport_frames)
 			break;
 		}
 
-		send_midi_clock_event (next_tick_offset);
+		if (next_tick_offset >= 0) {
+			send_midi_clock_event (next_tick_offset);
+		}
+
 		_last_tick = next_tick;
 	}
 }
 
 double MidiClockTicker::one_ppqn_in_frames (framepos_t transport_position)
 {
-	const Tempo& current_tempo = _session->tempo_map().tempo_at(transport_position);
-	double frames_per_beat = current_tempo.frames_per_beat(_session->nominal_frame_rate());
+	const Tempo& current_tempo = _session->tempo_map().tempo_at (transport_position);
+	double frames_per_beat = current_tempo.frames_per_beat (_session->nominal_frame_rate());
 
 	double quarter_notes_per_beat = 4.0 / current_tempo.note_type();
 	double frames_per_quarter_note = frames_per_beat / quarter_notes_per_beat;
diff --git a/libs/midi++2/port.cc b/libs/midi++2/port.cc
index 213f55aa19..378548ca03 100644
--- a/libs/midi++2/port.cc
+++ b/libs/midi++2/port.cc
@@ -30,6 +30,7 @@
 #include "pbd/failed_constructor.h"
 #include "pbd/convert.h"
 #include "pbd/strsplit.h"
+#include "pbd/stacktrace.h"
 
 #include "midi++/types.h"
 #include "midi++/port.h"
@@ -306,7 +307,10 @@ Port::write(byte * msg, size_t msglen, timestamp_t timestamp)
 
 		// XXX This had to be temporarily commented out to make export work again
 		if (!(timestamp < _nframes_this_cycle)) {
-			std::cerr << "assertion timestamp < _nframes_this_cycle failed!" << std::endl;
+			std::cerr << "attempting to write MIDI event of " << msglen << " bytes at time "
+				  << timestamp << " of " << _nframes_this_cycle
+				  << " (this will not work - needs a code fix)"
+				  << std::endl;
 		}
 
 		if (_currently_in_cycle) {
@@ -327,6 +331,7 @@ Port::write(byte * msg, size_t msglen, timestamp_t timestamp)
 			}
 		} else {
 			cerr << "write to JACK midi port failed: not currently in a process cycle." << endl;
+			PBD::stacktrace (cerr, 20);
 		}
 	}