Help with website

[Shis1947]

Hello
I am trying to download a video from the website given below using rtmpdump
I tried using rtmpdump Helper but it was in vain

Pageurl: http://live.rankerslearning.com/demo/viewdemovideos
RTMPDumphelper gave me this:

RTMP Server 2.4 git-6230845 2011-9-25
(c) 2010 Andrej Stepanchuk, Howard Chu; license: GPL

Streaming on rtmp://0.0.0.0:1935
WARNING: Trying different position for client digest!

rtmpdump -r "rtmp://182.18.162.84/VOD" -a "VOD" -f "WIN 18,0,0,160" -W "http://r
eleases.flowplayer.org/swf/flowplayer-3.2.16.swf" -p "http://live.rankerslearnin
g.com/demo/viewdemovideos" -y "mp4:DemoHigh_30042015_Eamcet_BOTANY_JANAKIRAM_FAB
ACEAE_512.mp4" -o mp4_DemoHigh_30042015_Eamcet_BOTANY_JANAKIRAM_FABACEAE_512.flv


Closing connection... done!

RTMPDump 2.4 git-6230845 2011-9-25
(c) 2010 Andrej Stepanchuk, Howard Chu, The Flvstreamer Team; license: GPL
Connecting ...
INFO: Connected...
ERROR: RTMP_ReadPacket, failed to read RTMP packet header

Can anyone tell me or suggest me what to use to record those videos? I want to do this through command line so that i can control from other apps

P.S: The video works well when i dont run rtmpdump but it fails to load even in browser when rtmpdump is running