Passing a nested shortcode as an argument of another shortcode?

Question

A partial solution I’ve found so far is to escape the brackets in the initial call, then replace the escaped characters in the do_foo_shortcode function.

function do_foo_shortcode($atts, $content = null) {
    extract(shortcode_atts(array(
        'bar' => '',
    ), $atts, 'foo'));

    $bar = str_replace("&#091;", "[", $bar);
    $bar = str_replace("&#093;", "]", $bar);
    $bar = do_shortcode($bar);
    $content = do_shortcode($content);

    return "$bar - $content";
}

And calling it as

[foo bar="&#91;video src=video-source.mp4&#93;"]Hello world![/foo]

Of course, this is an incomplete solution since it doesn’t allow more than 1-level nesting, and quote marks cannot be used in the inner shortcode. Not to mention how complicate is to write it.