I agree with runrig that your 1st @cmd should work. Take a few steps back; maybe in all your hacking, things have gotten confused. Just try this simple code and show your exact error output: 
use warnings;
use strict;
use IPC::Run qw(run timeout);

my @cmd = ('/usr/bin/ffmpeg', '-y', '-i', 'long_input.mov', 'long_outp
+ut.wav');
run \@cmd, timeout(3);

[download]

If that's still broken try something even simpler: 

use warnings;
use strict;
use IPC::Run qw(run timeout);

my @cmd = qw(ls /tmp);
run \@cmd, timeout(3);

[download]

Are you using a recent version of IPC::Run?

In reply to Re: Using IPC::Run to kill stuck process by toolic
in thread Using IPC::Run to kill stuck process by filmotheklown

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