# ffmpeg -i filename.flv -acodec libmp3lame filename.mp3
Monthly Archives: December 2010
taking movie screenshots with mplayer
Start mplayer with following options
# mplayer -vf screenshot filename.avi
The movie will start as usual, press “s” to take screenshot.
It will save a file named ‘shot0001.png’ and so on, incrementing number every time you press “s”
using denyhosts
I came across this service called denyhosts…
It basically keeps your server from the unwanted ssh attempts and brute force attacks. For denyhosts
to work, you need to have sshd
with tcp_wrappers
support and python
.
The IPs from which unwanted ssh attacks come are listed in /etc/hosts.deny
file by denyhosts
If you want to whitelist any of them, then you can put them in /etc/hosts.allow
file.
For e.g. putting sshd: 192.16.20.3
line in /etc/hosts.deny
file will disable all ssh attempts from that host and putting it in /etc/hosts.allow
will allow them.
Additionally what I do on my systems is … I keep only one system accessible from internet (sshd listens on both private and public interface) and on other systems I configure sshd to listen only on private interfaces. This can be achieved by putting
ListenAddress private_ip_here
line in /etc/ssh/sshd_config
The other security measure is to disable root user to access ssh at all. put PermitRootLogin no
line in /etc/ssh/sshd_config
file, then access system with a normal user (not a sudoer) through ssh and then use su -
to gain root access.