[Linuxsampler-devel] "True mono" patch for SFZ engine

[shane r. <sha...@em...>]

I have written a tiny patch that allows off_by to trigger release of samples on the *same key* even within the same group. The result is a more consistent interpretation of the SFZ API. For example, complex ride patterns will not result in tens/100's of voices at the same time. This results in a more realistic sound, less CPU usage, less voice usage, and volume levels don't go through the roof.


 --- linuxsampler/src/engines/sfz/Voice.cpp 2012-04-17 23:09:11.000000000 -0500
 +++ linuxsampler/src/engines/sfz/Voice.cpp 2012-04-17 23:35:58.000000000 -0500
 @@ -275,7 +275,7 @@
 dmsg(4,("Voice %x processGroupEvents event type=%d", this, itEvent->Type));
 if (itEvent->Type == Event::type_control_change ||
 (Type & Voice::type_controller_triggered) ||
 - itEvent->Param.Note.Key != MIDIKey) {
 + itEvent->Param.Note.Key) {
 dmsg(4,("Voice %x - kill", this));
 if (pRegion->off_mode == ::sfz::OFF_NORMAL) {
 // turn off the voice by entering release envelope stage

 Setting up SFZs to take advantage of the new feature
 ====================================================

 It works like this:

 For the purpose of an example, our group number will be 001. Of course, it can be any integer.

 1) Groups trigger groups.
 // Closed Hats on key 1, switched via MIDICC
 <group> key=1 group=001 off_by=001 locc23=64 hicc23=127
 <region> HatClosed.wav lorand=0 hirand=0.5
 <region> HatClosed2.wav lorand=0.5 hirand=0.6

 // Semi Open Hats on key 1, switched via MIDICC
 <group> key=1 group=001 off_by=001 locc23=1 hicc23=63
 <region> HatSemiOpen.wav lorand=0 hirand=0.5
 <region> HatSemiOpen2.wav lorand=0.5 hirand=0.6

 // Hi Hat Foot on key 2
 <group> key=2 group=001 off_by=001
 <region> HiHatFoot.wav lorand=0 hirand=0.5
 <region> HiHatFoot2.wav lorand=0.5 hirand=0.6

 * Regions within a group will not trigger release. Only if groups is seperate.

 2) Regions trigger regions.
 // Closed Hats on key 1, switched via MIDICC
 <group> key=1 locc23=64 hicc23=127
 <region> HatClosed.wav lorand=0 hirand=0.5 group=001 off_by=001
 <region> HatClosed2.wav lorand=0.5 hirand=0.6 group=001 off_by=001

 // Semi Open Hats on key 1, switched via MIDICC
 <group> key=1 locc23=1 hicc23=63
 <region> HatSemiOpen.wav lorand=0 hirand=0.5 group=001 off_by=001
 <region> HatSemiOpen2.wav lorand=0.5 hirand=0.6 group=001 off_by=001

 // Hi Hat Foot on key 2
 <group> key=2
 <region> HiHatFoot.wav lorand=0 hirand=0.5 group=001 off_by=001
 <region> HiHatFoot2.wav lorand=0.5 hirand=0.6 group=001 off_by=001

 3) You can define a "ghost trigger" <group> with group=NNN, and any <region> or <group> on those keys with the off_by=NNN will have their releases triggered.

 // Closed Hats on key 1, switched via MIDICC
 <group> key=1 group=001 off_by=002 locc23=64 hicc23=127
 <region> HatClosed.wav lorand=0 hirand=0.5
 <region> HatClosed2.wav lorand=0.5 hirand=0.6

 // Semi Open Hats on key 1, switched via MIDICC
 <group> key=1 group=001 off_by=002 locc23=1 hicc23=63
 <region> HatSemiOpen.wav lorand=0 hirand=0.5
 <region> HatSemiOpen2.wav lorand=0.5 hirand=0.6

 // Hi Hat Foot on key 2
 <group> key=2 group=001 off_by=002
 <region> HiHatFoot.wav lorand=0 hirand=0.5
 <region> HiHatFoot2.wav lorand=0.5 hirand=0.6


 // ghost trigger

 <group> end=-1 sample=samples\releaseTrigger_koala_silent_1.wav group=002
 <region> key=1
 <region> key=2

 Shane Richards