feat: Added wait method on FfmpegChild

src/child.rs

@@ -1,6 +1,6 @@
 use std::{
   io::{self, Write},
-  process::{Child, ChildStderr, ChildStdin, ChildStdout},
+  process::{Child, ChildStderr, ChildStdin, ChildStdout, ExitStatus},
 };
 
 use crate::error::{Error, Result};
@@ -97,6 +97,13 @@ impl FfmpegChild {
     self.inner.kill()
   }
 
+  /// Waits for the inner child process to finish execution.
+  ///
+  /// Identical to `wait` in [`std::process::Child`].
+  pub fn wait(&mut self) -> io::Result<ExitStatus> {
+    self.inner.wait()
+  }
+
   /// Wrap a [`std::process::Child`] in a `FfmpegChild`. Should typically only
   /// be called by `FfmpegCommand::spawn`.
   ///

src/command.rs

@@ -554,6 +554,10 @@ impl FfmpegCommand {
   /// Spawn the ffmpeg command as a child process, wrapping it in a
   /// `FfmpegChild` interface.
   ///
+  /// Please note that if the result is not used with [wait()](FfmpegChild::wait)
+  /// the process is not cleaned up correctly resulting in a zombie process
+  /// until your main thread exits.
+  ///
   /// Identical to `spawn` in [`std::process::Command`].
   pub fn spawn(&mut self) -> io::Result<FfmpegChild> {
     self.inner.spawn().map(FfmpegChild::from_inner)