iRule redirect URI to another pool

In general, as the following recipe explains, HTTP::path is the right choice for this type of selection and case normalization is typically not desirable:

• iRule Recipe 1: Single URL Explicit Redirect

However, that doesn't answer your question. I recommend implementing this rule:

when HTTP_REQUEST { 
    log local0. "PATH = (HTTP::path)"
    if { [HTTP::path] starts_with "/video" } { 
        log local0. "  .. starts_with /video"
        pool Video_pool 
    }
}

Assuming the rule is executed at all, the first message should be logged on each request. It will also tell you what the extracted HTTP::path is. The second message should be logged only if there is a match. From here, you may be able to see what's occurring. If not, can you share which of these is ending up in the log?