anchor.diff:  , enableVmaf ? true, libvmaf
   }:
   
  +let
  +  isCross = stdenv.buildPlatform != stdenv.hostPlatform;
  +in
   stdenv.mkDerivation rec {
     pname = "libaom";
     version = "3.5.0";
  
positive.code: 
    postFixup = ''
      moveToOutput lib/libaom.a "$static"
    '';
  
    outputs = [ "out" "bin" "dev" "static" ];
  
negative.code:   ] ++ lib.optionals (stdenv.isDarwin && stdenv.isAarch64) [
      # CPU detection isn't supported on Darwin and breaks the aarch64-darwin build:
      "-DCONFIG_RUNTIME_CPU_DETECT=0"
    ] ++ lib.optionals (isCross && !stdenv.hostPlatform.isx86) [
      "-DAS_EXECUTABLE=${stdenv.cc.targetPrefix}as"
    ] ++ lib.optionals stdenv.isAarch32 [
      # armv7l-hf-multiplatform does not support NEON
  