use default allocator (system)

src/main.rs

@@ -1,4 +1,3 @@
-use std::alloc;
 use std::env;
 use std::path::Path;
 use std::{fs, io};
@@ -6,9 +5,6 @@ use std::{fs, io};
 use ffmpeg_next::{self as ffmpeg, codec, filter, format, frame, media};
 use rayon::prelude::*;
 
-#[global_allocator]
-static ALLOCATOR: alloc::System = alloc::System;
-
 #[derive(Debug)]
 enum Error {
     Io(io::Error),