diff --git a/pkgs/mp4grep-big.nix b/pkgs/mp4grep-big.nix
new file mode 100644
index 0000000..6155fac
--- /dev/null
+++ b/pkgs/mp4grep-big.nix
@@ -0,0 +1,3 @@
+{ callPackage }:
+
+callPackage ./mp4grep.nix { model = "big"; }
diff --git a/pkgs/mp4grep.nix b/pkgs/mp4grep.nix
index 520488e..bd0f6aa 100644
--- a/pkgs/mp4grep.nix
+++ b/pkgs/mp4grep.nix
@@ -1,44 +1,69 @@
-{ lib
-, stdenv
-, fetchurl
+{ stdenv
+, autoPatchelfHook
+, fetchFromGitHub
+, fetchzip
 , gcc-unwrapped
-, jre
 , makeWrapper
-, unzip
+, ocamlPackages
+, model ? "small"
 }:
 
 let
-
-  pname = "mp4grep";
-  version = "0.1.1";
-
-  files = stdenv.mkDerivation
-    {
-      pname = "${pname}-files";
-      inherit version;
-      src = fetchurl {
-        url = "https://github.com/o-oconnell/${pname}/releases/download/v${version}/${pname}-${version}.zip";
-        sha256 = "3e63a9097ca8046eb22effee075aac71179a3c94d463049c42397a10f4087d8b";
-      };
-      nativeBuildInputs = [ makeWrapper unzip ];
-      installPhase = ''
-        cp -a . $out
-        makeWrapper $out/bin/${pname} $out/launch \
-        --set JAVA_HOME ${jre} \
-        --run 'export MP4GREP_CACHE="$HOME/.cache/mp4grep"' \
-        --suffix LD_LIBRARY_PATH : ${lib.getLib gcc-unwrapped}/lib \
-        --add-flags "--model $out/model"
-      '';
+  # https://alphacephei.com/vosk/models
+  models = {
+    big = fetchzip {
+      url = "https://alphacephei.com/vosk/models/vosk-model-en-us-0.22.zip";
+      hash = "sha256-kakOhA7hEtDM6WY3oAnb8xKZil9WTA3xePpLIxr2+yM=";
     };
+    small = fetchzip {
+      url = "https://alphacephei.com/vosk/models/vosk-model-small-en-us-0.15.zip";
+      hash = "sha256-CIoPZ/krX+UW2w7c84W3oc1n4zc9BBS/fc8rVYUthuY=";
+    };
+  };
+
+  installBin = bin: ''
+    install -D $MP4GREP_INSTALL_PREFIX/${bin} $out/share/mp4grep/${bin}
+    makeWrapper $out/share/mp4grep/${bin} $out/bin/${bin} \
+    --run 'export MP4GREP_CACHE="$HOME/.cache/mp4grep"' \
+    --run 'mkdir -p "$MP4GREP_CACHE"' \
+    --set MP4GREP_MODEL ${models.${model}}
+  '';
 
 in
-stdenv.mkDerivation
+stdenv.mkDerivation rec
 {
-  inherit pname version;
-  dontUnpack = true;
-  nativeBuildInputs = [ makeWrapper ];
+  pname = "mp4grep";
+  version = "0.1.4";
+
+  src = fetchFromGitHub {
+    owner = "o-oconnell";
+    repo = "mp4grep";
+    rev = "${version}-linux-x86";
+    sha256 = "HsZZ+KDf4bpdvJjM42vh5u1gKhGSH+g6zYS0pRM5aTU=";
+  };
+
+  buildInputs = [
+    gcc-unwrapped.lib
+  ];
+
+  nativeBuildInputs = [
+    autoPatchelfHook
+    makeWrapper
+    ocamlPackages.ocaml
+  ];
+
+  dontStrip = true;
+  OPAM_SWITCH_PREFIX = ".";
+  MP4GREP_INSTALL_PREFIX = "./bin-nix";
+
+  preBuild = ''
+    mkdir $MP4GREP_INSTALL_PREFIX
+    ln -s ${ocamlPackages.parmap}/lib/ocaml/4.14.0/site-lib/parmap $OPAM_SWITCH_PREFIX/lib/
+  '';
+
   installPhase = ''
-    mkdir -p $out/bin
-    ln -s ${files}/launch $out/bin/mp4grep
+    install -D $MP4GREP_INSTALL_PREFIX/mp4grep-libs/libvosk.so $out/share/mp4grep/libvosk.so
+    ${installBin "mp4grep"}
+    ${installBin "mp4grep-convert"}
   '';
 }