Fix mute of MIDI tracks with channel forcing.

This moves MIDI channel filtering into a reusable class and moves filtering to
the source, rather than modifying the buffer afterwards.  This is necessary so
that the playlist trackers reflect the emitted notes (and thus are able to stop
them in situations like mute).

As a perk, this is also faster because events are just dropped on read, rather
than pushed into a buffer then later removed (which is very slow).

Really hammering on mute or solo still seems to produce stuck notes
occasionally (perhaps related to multiple-on warnings).  I am not yet sure why,
but occasional beats always.

1 files changed, 12 insertions, 3 deletions

diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index 47cfb1b0a0..ab972fabd8 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -38,10 +38,11 @@
 #include "evoral/EventSink.hpp"
 
 #include "ardour/debug.h"
+#include "ardour/file_source.h"
+#include "ardour/midi_channel_filter.h"
 #include "ardour/midi_model.h"
-#include "ardour/midi_state_tracker.h"
 #include "ardour/midi_source.h"
-#include "ardour/file_source.h"
+#include "ardour/midi_state_tracker.h"
 #include "ardour/session.h"
 #include "ardour/session_directory.h"
 #include "ardour/source_factory.h"
@@ -190,6 +191,7 @@ MidiSource::midi_read (const Lock&                        lm,
                        framepos_t                         start,
                        framecnt_t                         cnt,
                        MidiStateTracker*                  tracker,
+                       MidiChannelFilter*                 filter,
                        const std::set<Evoral::Parameter>& filtered) const
 {
 	BeatsFramesConverter converter(_session.tempo_map(), source_start);
@@ -218,6 +220,13 @@ MidiSource::midi_read (const Lock&                        lm,
 		for (; i != _model->end(); ++i) {
 			const framecnt_t time_frames = converter.to(i->time());
 			if (time_frames < start + cnt) {
+				if (filter && filter->filter(i->buffer(), i->size())) {
+					DEBUG_TRACE (DEBUG::MidiSourceIO,
+					             string_compose ("%1: filter event @ %2 type %3 size %4\n",
+					                             _name, time_frames + source_start, i->event_type(), i->size()));
+					continue;
+				}
+
 				// Offset by source start to convert event time to session time
 				dst.write (time_frames + source_start, i->event_type(), i->size(), i->buffer());
 
@@ -237,7 +246,7 @@ MidiSource::midi_read (const Lock&                        lm,
 		}
 		return cnt;
 	} else {
-		return read_unlocked (lm, dst, source_start, start, cnt, tracker);
+		return read_unlocked (lm, dst, source_start, start, cnt, tracker, filter);
 	}
 }