rtmpsrv allows you to get all parameters that are required by rtmpdump. You don't need packet sniffers or complex analysis to use rtmpdump when using rtmpsrv. The only problem you may have is when a video consists of several segments (chapters). In such cases just skip to the next chapter.

How to compile rtmpdump with rtmpsrv and rtmpsuck in Linux:
Code:

svn checkout svn://svn.mplayerhq.hu/rtmpdump/trunk rtmpdump
cd rtmpdump
make linux

How to use rtmpsrv in Linux:
Configure your firewall to redirect RTMP traffic through a local port:
Code:

sudo iptables -t nat -A OUTPUT -p tcp --dport 1935 -j REDIRECT

Then just start rtmpsrv:
Code:

./rtmpsrv

rtmpsrv will be analyzing data from your local port. It will output an rtmpdump command that can be used to download videos.

When you get the rtmpdump command, press CTRL+C. This will stop rtmpsrv.

You may also delete the firewall redirect created above:
Code:

sudo iptables -t nat -D OUTPUT -p tcp --dport 1935 -j REDIRECT

Since rtmpsrv produces rtmpdump command, the only thing you need to do is copy-paste it to download the video. Simple as it is