Extract Strings from an HTML file

I need an sh script will get text from an html file I download the file with

wget website.com/link_123456789 -O 'testfile.txt'

the full contents of that file are located at this pastebin

But you don't need all of that just the important lines

<br>
            <IFRAME style="max-width: 850px;" SRC="http://vodlocker.com/embed-wrdlm4dbigu4-850x450.html" FRAMEBORDER=0 MARGINWIDTH=0 MARGINHEIGHT=0 SCROLLING=NO width="100%" HEIGHT=450></IFRAME>
            <br><br>
            <p>

I need the texthttp://vodlocker.com/embed-wrdlm4dbigu4-850x450.html from the file.

Is there a simple answer to work with other strings to?