anchor.diff:  
   stdenv.mkDerivation rec {
     name = "ffmpeg-full-${version}";
  -  version = "2.8.1";
  -
  -  src = fetchurl {
  -    url = "https://www.ffmpeg.org/releases/ffmpeg-${version}.tar.bz2";
  -    sha256 = "1qk6g2h993i0wgs9d2p3ahdc5bqr03mp74bk6r1zj6pfinr5mvg2";
  -  };
  -
  -  patchPhase = ''patchShebangs .'';
  +
  +  inherit (ffmpeg) src version;
  +
  +  postPatch = ''
  +    patchShebangs .
  +    sed -i libavcodec/libvpxenc.c \
  +      -e '/VP8E_UPD_ENTROPY/d' \
  +      -e '/VP8E_USE_REFERENCE/d' \
  +      -e '/VP8E_UPD_REFERENCE/d' \
  +      -e '/VP8D_USE_REFERENCE/d'
  +  '';
   
     configureFlags = [
       /*
  
positive.code:     (enableFeature (fribidi != null) "libfribidi")
      (enableFeature (game-music-emu != null) "libgme")
      (enableFeature (gnutls != null) "gnutls")
      (enableFeature (gsm != null) "libgsm")
      #(enableFeature (ilbc != null) "libilbc")
      (enableFeature (ladspaH !=null) "ladspa")
      (enableFeature (lame != null) "libmp3lame")
  
negative.code: , optimizationsDeveloper ? true
  , extraWarningsDeveloper ? false
  , strippingDeveloper ? false
  
  , ffmpeg
  }:
  
  /* Maintainer notes:
  