avoid use of Port::port_offset() everywhere except Port::flush_buffers() and Port::get_buffer()

Split cycles are run as if they are an entire self-contained cycle, starting at zero and running for "nframes".

We adjust the timing and position of data only when retrieving and writing it to Port buffers.

8 files changed, 37 insertions, 48 deletions

diff --git a/libs/ardour/delivery.cc b/libs/ardour/delivery.cc
index 463bfce88b..b27aded421 100644
--- a/libs/ardour/delivery.cc
+++ b/libs/ardour/delivery.cc
@@ -309,7 +309,7 @@ Delivery::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample
 
 		for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
 			if (*t != DataType::AUDIO && bufs.count().get(*t) > 0) {
-				_output->copy_to_outputs (bufs, *t, nframes, Port::port_offset());
+				_output->copy_to_outputs (bufs, *t, nframes, 0);
 			}
 		}
 
@@ -328,7 +328,7 @@ Delivery::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample
 
 		for (DataType::iterator t = DataType::begin(); t != DataType::end(); ++t) {
 			if (*t != DataType::AUDIO && bufs.count().get(*t) > 0) {
-				_output->copy_to_outputs (bufs, *t, nframes, Port::port_offset());
+				_output->copy_to_outputs (bufs, *t, nframes, 0);
 			}
 		}
 	}
@@ -349,7 +349,7 @@ Delivery::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample
 				if (outs.count ().get (*t) <= n) {
 					continue;
 				}
-				b->read_from (outs.get_available (*t, n++), nframes, (*t == DataType::AUDIO ? 0 : -Port::port_offset()));
+				b->read_from (outs.get_available (*t, n++), nframes, 0);
 			}
 		}
 	}
diff --git a/libs/ardour/disk_reader.cc b/libs/ardour/disk_reader.cc
index bb1717c8d7..c5e2256aa6 100644
--- a/libs/ardour/disk_reader.cc
+++ b/libs/ardour/disk_reader.cc
@@ -1100,8 +1100,8 @@ DiskReader::get_midi_playback (MidiBuffer& dst, samplepos_t start_sample, sample
 			 * loop end.
 			 */
 
-			DEBUG_TRACE (DEBUG::MidiDiskIO, string_compose ("playback buffer read, from %1 to %2 (%3)", start_sample, end_sample, nframes));
-			size_t events_read = rtmb->read (*target, start_sample, end_sample, _tracker, Port::port_offset ());
+			DEBUG_TRACE (DEBUG::MidiDiskIO, string_compose ("playback buffer read, from %1 to %2 (%3)\n", start_sample, end_sample, nframes));
+			size_t events_read = rtmb->read (*target, start_sample, end_sample, _tracker);
 			DEBUG_TRACE (DEBUG::MidiDiskIO, string_compose ("%1 MDS events read %2 range %3 .. %4\n", _name, events_read, playback_sample, playback_sample + nframes));
 		}
 
diff --git a/libs/ardour/midi_buffer.cc b/libs/ardour/midi_buffer.cc
index 0a36c84e49..f447ef59f8 100644
--- a/libs/ardour/midi_buffer.cc
+++ b/libs/ardour/midi_buffer.cc
@@ -96,11 +96,6 @@ MidiBuffer::copy(MidiBuffer const * const copy)
 }
 
 
-/** Read events from @a src starting at time @a offset into the START of this buffer, for
- * time duration @a nframes.  Relative time, where 0 = start of buffer.
- *
- * Note that offset and nframes refer to sample time, NOT buffer offsets or event counts.
- */
 void
 MidiBuffer::read_from (const Buffer& src, samplecnt_t nframes, sampleoffset_t dst_offset, sampleoffset_t /* src_offset*/)
 {
@@ -110,11 +105,10 @@ MidiBuffer::read_from (const Buffer& src, samplecnt_t nframes, sampleoffset_t ds
 	const MidiBuffer& msrc = (const MidiBuffer&) src;
 
 	assert (_capacity >= msrc.size());
+	assert (dst_offset == 0); /* there is no known scenario in Nov 2019 where this should be false */
 
-	if (dst_offset == 0) {
-		clear ();
-		assert (_size == 0);
-	}
+	clear ();
+	assert (_size == 0);
 
 	for (MidiBuffer::const_iterator i = msrc.begin(); i != msrc.end(); ++i) {
 		const Evoral::Event<TimeType> ev(*i, false);
@@ -129,9 +123,10 @@ MidiBuffer::read_from (const Buffer& src, samplecnt_t nframes, sampleoffset_t ds
 			   Check it is within range of this (split) cycle, then shift.
 			*/
 			if (ev.time() >= 0 && ev.time() < nframes) {
-				push_back (ev.time() + dst_offset, ev.size(), ev.buffer());
+				push_back (ev.time(), ev.size(), ev.buffer());
 			} else {
-				cerr << "\t!!!! MIDI event @ " <<  ev.time() << " skipped, not within range 0 .. " << nframes << ": ";
+				cerr << "\t!!!! MIDI event @ " <<  ev.time() << " skipped, not within range 0 .. " << nframes << endl;
+				PBD::stacktrace (cerr, 30);
 			}
 		} else {
 			/* Negative offset: shifting events from global/port
@@ -143,12 +138,12 @@ MidiBuffer::read_from (const Buffer& src, samplecnt_t nframes, sampleoffset_t ds
 			   Shift first, then check it is within range of this
 			   (split) cycle.
 			*/
-			const samplepos_t evtime = ev.time() + dst_offset;
+			const samplepos_t evtime = ev.time();
 
 			if (evtime >= 0 && evtime < nframes) {
 				push_back (evtime, ev.size(), ev.buffer());
 			} else {
-				cerr << "\t!!!! MIDI event @ " <<  evtime << " (based on " << ev.time() << " + " << dst_offset << ") skipped, not within range 0 .. " << nframes << ": ";
+				cerr << "\t!!!! MIDI event @ " <<  evtime << " (based on " << ev.time() << ") skipped, not within range 0 .. " << nframes << ": ";
 			}
 		}
 	}
diff --git a/libs/ardour/midi_port.cc b/libs/ardour/midi_port.cc
index 7eed2ef468..2e0d8c2e44 100644
--- a/libs/ardour/midi_port.cc
+++ b/libs/ardour/midi_port.cc
@@ -273,12 +273,13 @@ MidiPort::flush_buffers (pframes_t nframes)
 
 			const Evoral::Event<MidiBuffer::TimeType> ev (*i, false);
 
+			const samplepos_t adjusted_time = ev.time() + _global_port_buffer_offset;
 
 			if (sends_output() && _trace_parser) {
 				uint8_t const * const buf = ev.buffer();
 				const samplepos_t now = AudioEngine::instance()->sample_time_at_cycle_start();
 
-				_trace_parser->set_timestamp (now + ev.time());
+				_trace_parser->set_timestamp (now + adjusted_time);
 
 				uint32_t limit = ev.size();
 
@@ -295,8 +296,8 @@ MidiPort::flush_buffers (pframes_t nframes)
 				const Session* s = AudioEngine::instance()->session();
 				const samplepos_t now = (s ? s->transport_sample() : 0);
 				DEBUG_STR_DECL(a);
-				DEBUG_STR_APPEND(a, string_compose ("MidiPort %7 %1 pop event    @ %2 (global %4, within %5 gpbo %6 sz %3 ", _buffer, ev.time(), ev.size(),
-				                                    now + ev.time(), nframes, _global_port_buffer_offset, name()));
+				DEBUG_STR_APPEND(a, string_compose ("MidiPort %7 %1 pop event    @ %2[%7] (global %4, within %5 gpbo %6 sz %3 ", _buffer, adjusted_time, ev.size(),
+				                                    now + adjusted_time, nframes, _global_port_buffer_offset, name(), ev.time()));
 				for (size_t i=0; i < ev.size(); ++i) {
 					DEBUG_STR_APPEND(a,hex);
 					DEBUG_STR_APPEND(a,"0x");
@@ -311,14 +312,13 @@ MidiPort::flush_buffers (pframes_t nframes)
 			// XXX consider removing this check for optimized builds
 			// and just send 'em all, at cycle_end
 			// see AudioEngine::split_cycle (), PortManager::cycle_end()
-			if (   ev.time() >= _global_port_buffer_offset
-			    && ev.time() < _global_port_buffer_offset + nframes) {
-				pframes_t tme = floor (ev.time() / _speed_ratio);
+			if ((adjusted_time >= _global_port_buffer_offset) && (adjusted_time < _global_port_buffer_offset + nframes)) {
+				pframes_t tme = floor (adjusted_time / _speed_ratio);
 				if (port_engine.midi_event_put (port_buffer, tme, ev.buffer(), ev.size()) != 0) {
-					cerr << "write failed, dropped event, time " << ev.time() << endl;
+					cerr << "write failed, dropped event, time " << adjusted_time << '/' << ev.time() << endl;
 				}
 			} else {
-				cerr << "Dropped outgoing MIDI event. time " << ev.time()
+				cerr << "Dropped outgoing MIDI event. time " << adjusted_time << '/' << ev.time() 
 				     << " out of range [" << _global_port_buffer_offset
 				     << " .. " << _global_port_buffer_offset + nframes
 				     << "]";
diff --git a/libs/ardour/midi_track.cc b/libs/ardour/midi_track.cc
index 575ccdc3a5..2711f2e864 100644
--- a/libs/ardour/midi_track.cc
+++ b/libs/ardour/midi_track.cc
@@ -462,12 +462,12 @@ MidiTrack::snapshot_out_of_band_data (samplecnt_t nframes)
 	 * the last argument ("stop on overflow in destination") so that we'll
 	 * ship the rest out next time.
 	 *
-	 * the Port::port_offset() + (nframes-1) argument puts all these events at the last
+	 * the (nframes-1) argument puts all these events at the last
 	 * possible position of the output buffer, so that we do not
-	 * violate monotonicity when writing. Port::port_offset() will
-	 * be non-zero if we're in a split process cycle.
+	 * violate monotonicity when writing.
 	 */
-	_immediate_events.read (_immediate_event_buffer, 0, 1, Port::port_offset() + nframes - 1, true);
+
+	_immediate_events.read (_immediate_event_buffer, 0, 1, nframes - 1, true);
 }
 
 void
@@ -821,7 +821,7 @@ MidiTrack::act_on_mute ()
 		}
 
 		/* Resolve active notes. */
-		_disk_reader->resolve_tracker(_immediate_events, Port::port_offset());
+		_disk_reader->resolve_tracker (_immediate_events, 0);
 	}
 }
 
@@ -873,7 +873,7 @@ void
 MidiTrack::realtime_handle_transport_stopped ()
 {
 	Route::realtime_handle_transport_stopped ();
-	_disk_reader->resolve_tracker (_immediate_events, Port::port_offset());
+	_disk_reader->resolve_tracker (_immediate_events, 0);
 }
 
 void
diff --git a/libs/ardour/rt_midibuffer.cc b/libs/ardour/rt_midibuffer.cc
index ec8a2852bd..3a60c9e93f 100644
--- a/libs/ardour/rt_midibuffer.cc
+++ b/libs/ardour/rt_midibuffer.cc
@@ -223,7 +223,7 @@ RTMidiBuffer::read (MidiBuffer& dst, samplepos_t start, samplepos_t end, MidiSta
 			break;
 		}
 
-		DEBUG_TRACE (DEBUG::MidiRingBuffer, string_compose ("read event sz %1 @ %2\n", size, unadjusted_time));
+		DEBUG_TRACE (DEBUG::MidiRingBuffer, string_compose ("read event sz %1 @ %2 (=> %3 via -%4 +%5\n", size, unadjusted_time, evtime, start, offset));
 		tracker.track (addr);
 
 		++item;
diff --git a/libs/ardour/session_midi.cc b/libs/ardour/session_midi.cc
index 2e77aa6ef2..6967a1cdf5 100644
--- a/libs/ardour/session_midi.cc
+++ b/libs/ardour/session_midi.cc
@@ -456,7 +456,7 @@ Session::send_full_time_code (samplepos_t const t, MIDI::pframes_t nframes)
 	// Send message at offset 0, sent time is for the start of this cycle
 
 	MidiBuffer& mb (_midi_ports->mtc_output_port()->get_midi_buffer (nframes));
-	mb.push_back (Port::port_offset(), sizeof (msg), msg);
+	mb.push_back (0, sizeof (msg), msg);
 
 	_pframes_since_last_mtc = 0;
 	return 0;
@@ -558,7 +558,7 @@ Session::send_midi_time_code_for_cycle (samplepos_t start_sample, samplepos_t en
 		assert (out_stamp < nframes);
 
 		MidiBuffer& mb (_midi_ports->mtc_output_port()->get_midi_buffer(nframes));
-		if (!mb.push_back (Port::port_offset () + out_stamp, 2, mtc_msg)) {
+		if (!mb.push_back (out_stamp, 2, mtc_msg)) {
 			error << string_compose(_("Session: cannot send quarter-frame MTC message (%1)"), strerror (errno))
 			      << endmsg;
 			return -1;
@@ -598,12 +598,7 @@ Session::send_midi_time_code_for_cycle (samplepos_t start_sample, samplepos_t en
 void
 Session::send_immediate_mmc (MachineControlCommand c)
 {
-	if (AudioEngine::instance()->in_process_thread()) {
-		_mmc->send (c, Port::port_offset());
-	} else {
-		_mmc->send (c, 0);
-	}
-
+	_mmc->send (c, 0);
 }
 
 bool
diff --git a/libs/ardour/ticker.cc b/libs/ardour/ticker.cc
index 7e36978177..7d378d72ae 100644
--- a/libs/ardour/ticker.cc
+++ b/libs/ardour/ticker.cc
@@ -329,7 +329,7 @@ MidiClockTicker::send_midi_clock_event (pframes_t offset, pframes_t nframes)
 	static uint8_t msg = MIDI_CMD_COMMON_CLOCK;
 
 	MidiBuffer& mb (_midi_port->get_midi_buffer (nframes));
-	mb.push_back (offset + Port::port_offset(), 1, &msg);
+	mb.push_back (offset, 1, &msg);
 
 	DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Tick with offset %1\n", offset));
 }
@@ -343,7 +343,7 @@ MidiClockTicker::send_start_event (pframes_t offset, pframes_t nframes)
 
 	static uint8_t msg = { MIDI_CMD_COMMON_START };
 	MidiBuffer& mb (_midi_port->get_midi_buffer (nframes));
-	mb.push_back (offset + Port::port_offset(), 1, &msg);
+	mb.push_back (offset, 1, &msg);
 
 	DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Start %1\n", _last_tick));
 }
@@ -357,7 +357,7 @@ MidiClockTicker::send_continue_event (pframes_t offset, pframes_t nframes)
 
 	static uint8_t msg = { MIDI_CMD_COMMON_CONTINUE };
 	MidiBuffer& mb (_midi_port->get_midi_buffer (nframes));
-	mb.push_back (offset + Port::port_offset(), 1, &msg);
+	mb.push_back (offset, 1, &msg);
 
 	DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Continue %1\n", _last_tick));
 }
@@ -371,7 +371,7 @@ MidiClockTicker::send_stop_event (pframes_t offset, pframes_t nframes)
 
 	static uint8_t msg = MIDI_CMD_COMMON_STOP;
 	MidiBuffer& mb (_midi_port->get_midi_buffer (nframes));
-	mb.push_back (offset + Port::port_offset(), 1, &msg);
+	mb.push_back (offset, 1, &msg);
 
 	DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Stop %1\n", _last_tick));
 }
@@ -395,9 +395,8 @@ MidiClockTicker::send_position_event (uint32_t midi_beats, pframes_t offset, pfr
 	msg[2] = midi_beats >> 7;
 
 	MidiBuffer& mb (_midi_port->get_midi_buffer (nframes));
-	mb.push_back (offset + Port::port_offset(), 3, &msg[0]);
+	mb.push_back (offset, 3, &msg[0]);
 
-	DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Song Position Sent: %1 to %2 (events now %3, buf = %4)\n", midi_beats, _midi_port->name(),
-						       mb.size(), &mb));
+	DEBUG_TRACE (DEBUG::MidiClock, string_compose ("Song Position Sent: %1 to %2 (events now %3, buf = %4)\n", midi_beats, _midi_port->name(), mb.size(), &mb));
 
 }