From: Han-Wen Nienhuys <hanwen@xs4all.nl>
Date: Sun, 3 Dec 2006 16:30:14 +0000 (+0100)
Subject: Fix MIDI drums: only override channel if channel was not preassigned.
X-Git-Tag: release/2.10.1-1
X-Git-Url: https://git.donarmstrong.com/?a=commitdiff_plain;h=ca90232dec411ec5346a37ba5e306378098d6558;p=lilypond.git

Fix MIDI drums: only override channel if channel was not preassigned.
(cherry picked from 7f67c831a686fff774feeb6692a4ed76294c21bc commit)
---

diff --git a/input/no-notation/midi-drums.ly b/input/no-notation/midi-drums.ly
new file mode 100644
index 0000000000..acf96b9864
--- /dev/null
+++ b/input/no-notation/midi-drums.ly
@@ -0,0 +1,14 @@
+
+\score {
+  \new DrumStaff <<
+    \drummode {
+      bd4 sn4 bd4 sn4
+      <<
+	{\voiceOne \repeat unfold 16 hh16 }
+	\new DrumVoice { \voiceTwo bd4 sn4 bd4 sn4 }
+      >> \oneVoice
+    }
+  >>
+  \layout {}
+  \midi {}
+}
diff --git a/lily/audio-staff.cc b/lily/audio-staff.cc
index 5d402febf5..1616ceb3c8 100644
--- a/lily/audio-staff.cc
+++ b/lily/audio-staff.cc
@@ -18,6 +18,11 @@ Audio_staff::add_audio_item (Audio_item *l)
   audio_items_.push_back (l);
 }
 
+Audio_staff::Audio_staff ()
+{
+  channel_ = -1; 
+}
+
 void
 Audio_staff::output (Midi_stream &midi_stream, int channel)
 {
diff --git a/lily/include/audio-staff.hh b/lily/include/audio-staff.hh
index e20fc1c4d7..fa6e1b9429 100644
--- a/lily/include/audio-staff.hh
+++ b/lily/include/audio-staff.hh
@@ -16,6 +16,8 @@ struct Audio_staff : public Audio_element
   void add_audio_item (Audio_item *l);
   void output (Midi_stream &midi_stream_r, int track_i);
 
+  Audio_staff ();
+  
   vector<Audio_item*> audio_items_;
   int channel_;
 };
diff --git a/lily/performance.cc b/lily/performance.cc
index 0bfe37ee82..59cc64a2e2 100644
--- a/lily/performance.cc
+++ b/lily/performance.cc
@@ -43,6 +43,7 @@ Performance::output (Midi_stream &midi_stream)
 
   midi_stream << Midi_header (1, tracks_, clocks_per_4);
   message (_ ("Track...") + " ");
+  
   int channel = 0;
   for (vsize i = 0; i < audio_staffs_.size (); i++)
     {
@@ -50,30 +51,37 @@ Performance::output (Midi_stream &midi_stream)
       if (be_verbose_global)
 	progress_indication ("[" + to_string (i));
 
-      /*
-	MIDI players tend to ignore instrument settings on
-	channel 10, the percussion channel by default.
-      */
-      if (channel % 16 == 9)
-	channel++;
+      int midi_channel =  s->channel_;
+
+      if (midi_channel < 0)
+	{
+	  midi_channel = channel;
+	  channel ++;
+	  /*
+	    MIDI players tend to ignore instrument settings on
+	    channel 10, the percussion channel.
+	  */
+	  if (channel % 16 == 9)
+	    channel ++;
+	}
 
       /*
 	Huh? Why does each staff also have a separate channel? We
 	should map channels to voices, not staves. --hwn.
       */
-      if (channel > 15)
+      if (midi_channel > 15)
 	{
 	  warning (_ ("MIDI channel wrapped around"));
 	  warning (_ ("remapping modulo 16"));
+
+	  midi_channel = midi_channel % 16; 
 	}
 
-      s->output (midi_stream, channel);
-      channel ++;
+      s->output (midi_stream, midi_channel);
       if (be_verbose_global)
 	progress_indication ("]");
     }
 }
-
 void
 Performance::add_element (Audio_element *p)
 {