Linux

Advanced Recording X Window and Audio via VNC

Now I know about ffmpeg with x11grab patch, xvidcap, and ScreenKast. From all these three alternatives, ScreenKast is the best one in feature comparison. By the way, it is totally based on KDE while my desktop is GNOME. I don't want to run KDE application in GNOME environment because I have to waste lots of main memory to hold 2 low-level desktop interface.

Open Source YouTube

Everyone knows what YouTube or Google Video is. Most of them might use to waste a period of time in this kind of service. I'm one of them. I also wonder how it works. Technically, upload video service like YouTube and Google Video is very similar in underlying technology. In particular, all uploaded videos are automatically converted to Flash Video or FLV. The FLVs are stored in the file server. However, the FLVs is nevered shown directly on your browser. Instead, the FLVs are played inside Flash Video Player written in Flash itself. As a result, you can view a video immediately after getting only some part of the full-length video. In other words, Flash Video Player and FLV are the best couple for on-demand video streaming.

If you think it is too complex and too difficult to implement XXXTube by yourself, I will summarize everything you need to know and to have.

  1. You need a Flash Video Player,
  2. Uploading system,
  3. Video conversion system,
  4. Big storage and
  5. Bandwidth

Web Application and SELinux

One of my friend would like to set up a personal web for controlling BTQueue backend through web interface using PHPBTque. It is a good idea in case of you don't like ssh and command line. Unfortunately, he got some weird problem like "permission denied (13)". This error message was not ejected by BTQueue for sure. So where it came from is the key to fix this problem. Since the system he is running is Fedora Core 5, I guessed it should be SELinux and it is. SELinux is great in security but it is very difficult and too complicate to configure in general purpose server. Usually, I disabled SELinux in my all FC instances. By the way, other may like SELinux enough to configure SELinux for maximum security.

Let's markdown

If you have read my blog for a half year, you might notice that the update rate has slowed down for a month. The main reason is I switched to Ubuntu and I don't have [Post2Blog][1]. Post2Blog is very powerful and it helped me to blog as fast as I expect. In Ubuntu, I have [Performancing for Firefox][2] which is a cool stuff but not comparable to Post2Blog in any criteria. Today, I have just decided to

Local DNS Cache in Ubuntu

If you have been to be a Windows user, you might notice about DNS cache feature in Windows platform. This is one of the key to speedup the whole system while surfing the internet especially when you are home. In case of you are an ADSL subscriber, average query time for popular domainnames is about 35 msecs while unpopular domainnames is about 300 msecs or more depending on number of hops to your origin name server. If caching enabled, the second try will be 1 or 2 msec constantly!

Parallel Filesystem: another review

Once in a life time, you might want to have big, big, big storage such that no more remove operations are required. I don't know other but I really want to have one. Cluster is a good approach to make my dream come true. There are so many solution out there. I will not talk about commercial product since I don't have enough money support to buy one so this post only focuses on open source solutions.