There is rtmpdumphelper 64 bit and it does not work very well with my main browser ( portable )
http://www.opera.com/computer/portable
Opera is faster than firefox. I dumped firefox and don't bother looking at other 64 bit browsers.
Something might work in 64 bit setup and I don't need to look at that for now.
There are fewer and fewever rtmp streams on the internet and I'll look more at html and streamlink
http://htmldog.com/guides/