add guix build file

examples/MP100.midizaprc

@@ -0,0 +1,59 @@
+
+# Minimal Mackie emulation for the Harley Benton MP-100 a.k.a. MeloAudio MIDI
+# Commander foot controller (https://meloaudio.com)
+
+# This device is rather limited in what it can do as a Mackie controller (no
+# feedback, just 4 switches, 4 toggles, and 2 continuous controllers), but it
+# may still come in handy to guitarists for basic hands-free DAW control. Note
+# that we can't make good use of the bank switches on the device (the two
+# extra switches on the right), since these always emit a PC message, which
+# interferes with our use of the PC messages for the transport controls. It
+# may be possible to do something better by configuring a custom mode on the
+# device, but here we stick to what's available in the factory settings.
+
+# Copyright (c) 2019 Albert Graef <aggraef@gmail.com>
+
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice and
+# this notice are preserved.  This file is offered as-is, without any
+# warranty.
+
+JACK_NAME "midizap-MP100"
+JACK_PORTS 1
+
+# Auto-connect to the MP-100 on the input, and Ardour's Mackie control input
+# on the output side.
+
+JACK_IN  TSMIDI.* MIDI 1
+JACK_OUT ardour:mackie control in
+
+# The following configuration assumes that the MP-100 is set to mode 1 (JAMP),
+# which is the default. Note that the controller numbers for the top row and
+# the expression pedal inputs are specific to JAMP mode, so you will have to
+# adjust these if you run the device in a different host mode. As implemented
+# below, the controls are laid out as follows:
+
+# top row:    [mute] [solo] [rec]   [select]  EXP1: volume (current channel)
+# bottom row: [stop] [play] [chan<] [chan>]   EXP2: volume (master)
+
+[MIDI]
+
+# Note that MCP expects a note-on/off pair for each activation of the
+# mure/solo/rec/select switches, while the MP-100 top switches act as toggles,
+# so we have to use suitable mod translations for the top row.
+
+# top row (mute/solo/rec/select for current channel)
+CC22[] E1{127} E1{0}   # Mute
+CC25[] G#0{127} G#0{0} # Solo
+CC24[] C0{127} C0{0}   # Rec
+CC26[] C2{127} C2{0}   # Select
+
+# bottom row (basic transport and bank controls)
+PC0 A7  # Stop
+PC1 A#7 # Play
+PC2 C4  # Channel Left
+PC3 C#4 # Channel Right
+
+# EXP-1 and EXP-2 (current channel and master volume)
+CC4[] PB[129]-1 # Volume
+CC7[] PB[129]-9 # Master

midizap.c

@@ -1428,10 +1428,10 @@ handle_event(uint8_t *msg, uint8_t portno, int depth, int recursive)
       } else if (msg[2] > 64) {
 	int step = get_cc_step(tr, portno, chan, msg[1], -1);
 	if (step) {
-	  int d = (msg[2]-64)/step;
+	  uint8_t d = (msg[2]-128)/step;
 	  while (d) {
 	    send_strokes(tr, portno, status, chan, msg[1], 0, 0, -1, depth);
-	    d--;
+	    d++;
 	  }
 	}
       }

midizap.scm

@@ -0,0 +1,51 @@
+(define-module (guixpkgs midizap)
+  #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (guix build-system gnu)
+  #:use-module (guix packages)
+  #:use-module (guix git-download)
+  #:use-module (gnu packages xorg)
+  #:use-module (gnu packages audio)
+  #:use-module (guix gexp))
+
+(define-public midizap
+  (package
+    (name "midizap")
+    (version "0.8")
+    (source
+     (local-file "." "midizap" #:recursive? #t)
+     ;; (origin
+     ;;   (method git-fetch)
+     ;;   (uri (git-reference
+     ;; 	     (url "https://github.com/agraef/midizap.git")
+     ;; 	     (commit version)))
+     ;;   (sha256
+     ;; 	(base32
+     ;; 	 "0y31fnffl31n9lpkiw1dc3q4rnpfnras30n9y2h5j6586dkmgni4")))
+     )
+    (arguments
+     `(#:tests? #f 			; no check target
+       #:make-flags
+       (list "CC=gcc"
+	     (string-append "DESTDIR=" %output)
+	     "prefix=")
+       #:phases
+       (modify-phases %standard-phases
+	 (replace 'configure
+           (lambda* (#:key inputs outputs #:allow-other-keys)
+             (substitute* "Makefile"
+               (("/usr/include/X11/")
+                (string-append (assoc-ref inputs "xorgproto") "/include/X11/"))
+	       (("-lXtst") "-lXtst -ljack"))
+             #t)))))
+    ;; (native-inputs `(("pkg-config" ,pkg-config)))
+    (inputs `(("jack" ,jack-1)
+	      ("libx11" ,libx11)
+	      ("libxtst" ,libxtst)
+	      ("xorgproto" ,xorgproto)))
+    (build-system gnu-build-system)
+    (home-page "")
+    (synopsis "")
+    (description "")
+    (license license:gpl2+)))
+
+midizap