Add keyfinder: musical key detection gui

pkgs/applications/audio/keyfinder/default.nix

@@ -0,0 +1,42 @@
+{ stdenv, fetchFromGitHub, libav_0_8, libkeyfinder, qt5, taglib }:
+
+stdenv.mkDerivation rec {
+  version = "1.25-17-gf670607";
+  name = "keyfinder-${version}";
+
+  src = fetchFromGitHub {
+    repo = "is_KeyFinder";
+    owner = "ibsh";
+    rev = "f6706074435ac14c5238ee3f0dd22ac22d72af9c";
+    sha256 = "1sfnywc6jdpm03344i6i4pz13mqa4i5agagj4k6252m63cqmjkrc";
+  };
+
+  meta = with stdenv.lib; {
+    description = "Musical key detection for digital audio (graphical UI)";
+    longDescription = ''
+      KeyFinder is an open source key detection tool, for DJs interested in
+      harmonic and tonal mixing. Designed primarily for electronic and dance
+      music, it is highly configurable and can be applied to many genres. It
+      supports a huge range of codecs thanks to LibAV, and writes to metadata
+      tags using TagLib. It's intended to be very focused: no library
+      management, no track suggestions, no media player. Just a fast,
+      efficient workflow tool.
+    '';
+    homepage = http://www.ibrahimshaath.co.uk/keyfinder/;
+    license = with licenses; gpl3Plus;
+    platforms = with platforms; linux;
+    maintainers = with maintainers; [ nckx ];
+  };
+
+  # TODO: upgrade libav when "Audio sample format conversion failed" is fixed
+  buildInputs = [ libav_0_8 libkeyfinder qt5 taglib ];
+
+  configurePhase = ''
+    substituteInPlace is_KeyFinder.pro \
+       --replace "keyfinder.0" "keyfinder" \
+       --replace '$$[QT_INSTALL_PREFIX]' "$out"
+    qmake
+  '';
+
+  enableParallelBuilding = true;
+}

pkgs/top-level/all-packages.nix

@@ -10344,6 +10344,8 @@ let
 
   kermit = callPackage ../tools/misc/kermit { };
 
+  keyfinder = callPackage ../applications/audio/keyfinder { };
+
   keymon = callPackage ../applications/video/key-mon { };
 
   kid3 = callPackage ../applications/audio/kid3 {