How to use ffmpeg when I call avconv

rename_binary.nix

{ pkgs ? import <nixpkgs> {} }:
with pkgs;
let 
  avconv = runCommand "avconv" {
    buildInputs = [ makeWrapper ];
  } ''
    mkdir $out
    ln -s ${ffmpeg}/* $out
    rm $out/bin
    mkdir $out/bin
    ln -s ${ffmpeg}/bin/* $out/bin
    rm $out/bin/ffmpeg
    makeWrapper ${ffmpeg}/bin/ffmpeg $out/bin/avconv
  '';
in mkShell {
  name = "hmm";
  buildInputs = with pkgs; [
    avconv
  ];
}