Adding avxsynth.

To add it, I also add ffms and log4cpp.

pkgs/development/libraries/ffms/default.nix

@@ -0,0 +1,20 @@
+{ stdenv, fetchurl, zlib, ffmpeg, pkgconfig }:
+
+stdenv.mkDerivation {
+  name = "ffms-2.17";
+  
+  src = fetchurl {
+    url = http://ffmpegsource.googlecode.com/files/ffms-2.17-src.tar.bz2;
+    sha256 = "0gb42hrwnldz3zjlk4llx85dvxysxlfrdf5yy3fay8r8k1vpl7wr";
+  };
+
+  NIX_CFLAGS_COMPILE = "-fPIC";
+
+  buildInputs = [ zlib ffmpeg pkgconfig ];
+
+  meta = {
+    homepage = http://code.google.com/p/ffmpegsource/;
+    description = "Libav/ffmpeg based source library for easy frame accurate access";
+    license = "MIT";
+  };
+}