this variation... 
$s = time;
$out4 = (pack 'v*', unpack 'C*', $buf) | ("\x00$filler" x length $buf)
+;
print time() - $s, "\n";

[download]
... introduces very low overhead.

In reply to Re^4: Interleaving bytes in a string quickly by salva
in thread Interleaving bytes in a string quickly by BrowserUk

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