Linux

Mandelbrot Set Viewer using wxPython

In previous post, I benchmarked several implementation of Mandelbrot Set in Python. To make it more complete, I port a Mandelbrot Set Viewer written in Ruby posted at Codenone using OpenGL to Python and wxPython.

Mandelbrot Set in Python

I found a good homework and posted at Codenone since last week. The first question is about Mandelbrot Set. Actually, this problem could be categorized in compute intensive which should be solved in low-level language to let it run as fast as possible. However, we are talking about alternative languages aka scripting languages like Python and Ruby so I will try to solve this problem in Python. For the solution in Ruby, please go to another post.

How to forward port in user space using socat

I was asked to help setting up a kind of traffic redirection through VPN. In particular, the VPN server is Cisco VPN so the client should be Cisco VPN client too. Since the client is Ubuntu Edgy, it is very easy to install and run cvpnd. Then I tried to forward a TCP port to another host on the same port using IPTables and DNAT. Unfortunately, it failed. Incoming TCP connection through this port always get "connection refused". I guess that the problem might involve the module cisco_ipsec. This module may hook packet routing somewhere in the kernel so DNAT will not work correctly through its network interface. However, I don't have enough to investigate deeper for more detail since the service must be available tonight. In other words, I have 15 minutes left. So I decided to use port forwarding tool running on user space instead. After searching for a while, I found socat. socat looks like an extension of netcat which provides extremely flexibility to all of us for forwarding anything and then redirect to anything.

How to convert video to FLV using Mencoder

One of the most popular video format in recent years is Flash Video or so called FLV because it supports streaming over the web architecture using normal http protocol. In another point of view, 3GP is widely used in mobile phone because it is very small and efficient for small screen like mobile phone. The technology is going to emerge someday. 3GP would be available on the web for massive distribution. The best approach for publishing video on the web is to use FLV. I will give an example of unattended command for converting any video files including 3GP to FLV using Mencoder.

How to setup fglrx for Ubuntu Feisty

It took me so long to setup fglrx driver for ATI Mobility X300 in my laptop, IBM Thinkpad T43. Actually, the ATI open source driver comes with Xorg 7.2 works very well except only 3D acceleration. The open source driver does not support 3D acceleration for ATI Mobility X300. As a result, Google Earth is useless because I can't even drag the earth to see my home. There are so many howto but none of them worked for me even this one. Now I found the exact problem and its solution to make fglrx 8.35.5 work perfectly on Ubuntu Feisty.

My son's first program

I am a programmer and I also would like to teach all I know for years to my son. He is 5 years old and know a little bit English. Actually, I want to try teaching Python but it might be too difficult for a kids who are not familiar to English language. I don't know which the best language for kid but my first programming language is Logo so I decied to give it a try.