anchor.diff:  { mkDerivation, lib, fetchFromGitHub, extra-cmake-modules
   , qtbase, qtmultimedia, qtquick1, qttools
   , libGL, libX11
  -, libass, openal, ffmpeg_3, libuchardet
  +, libass, openal, ffmpeg, libuchardet
   , alsaLib, libpulseaudio, libva
   }:
   
  
positive.code:     homepage = "http://www.qtav.org/";
      maintainers = [ maintainers.jraygauthier ];
      platforms = platforms.linux;
      broken = !(lib.versionOlder qtbase.version "5.13");
    };
  }
  
negative.code: 
  mkDerivation rec {
    pname = "libqtav";
    version = "git-2020-09-10";
  
    nativeBuildInputs = [ extra-cmake-modules qttools ];
    buildInputs = [
      qtbase qtmultimedia qtquick1
      libGL libX11
      libass openal ffmpeg libuchardet
      alsaLib libpulseaudio libva
    ];
  
    src = fetchFromGitHub {
      sha256 = "0qwrk40dihkbwmm7krz6qaqyn9v3qdjnd2k9b4s3a67x4403pib3";
      rev = "2a470d2a8d2fe22fae969bee5d594909a07b350a";
      repo = "QtAV";
      owner = "wang-bin";
      fetchSubmodules = true;
  