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Showing posts from January, 2011

Video file manipulation

Many times I have downloaded a movie and when opened it is in French or Russian or any other language I do not know. Most people outright delete the file. I thought no. In most of the cases the video quality is superb while it is difficult to find  the same movie in english with the same quality. The reason is obvious. However, as it turns out that the big uncle does not care about the prints in English which are very low quality. So, I thought that I can download them, extract their audio and plug the mp3 into the audio track of the high quality print in different language. And here's how to do it. These methods work only in Linux (sorry Windows users).

To extract audio from avi(or mpg) file :

ffmpeg -i file.avi -acodec copy output.mp3

acodec does a direct copy of the audio track without involving any encoding into mp3.

To add the audio to avi file :

Open avidemux and load the video file (with nn-english audio). Say yes to all pop-ups. Then goto the menu Audio-> Main track ->…

when "cannot talk to klauncher" happens

Sometimes things go bad, for example if you had to press Ctrl+Alt+Backspace to restart the X, some services can misbehave after you log in anew. If KDE apps point messages at you saying "cannot talk to klauncher", and system tray icons appear in windows, instead of appearing on the system tray, then instead of rebooting or reinstalling Linux (as some may suggest) simple type in a console:

$ dcopserver_shutdown
$ kdeinit

That's all.

NIce utilities to have in Linux distro

Meld - File comparison. Very good. Also, can try out Kompare. Text based mode would be to use vimdiff.

F.lux  - Adjust the screen color and hue so that the glare is reduced during the night when tehre is less ambient light.

Flpsed - Pdf annotator. Very accurate. But limited in that it can only add text to pdf's.

Ipe - A spline based vector graphics drawing tool. Very very good for scientific/mathematical drawing. For example, a surface with vectors on it is easily drawn. Much better at drawing curves than xfig. The best feature is its Latex friendliness. Any graphic object could be labeled by a expression writtten in LaTeX. If I want to label the normal vector to my surface na then all I have to do is click and type $n^a$ and then run latex and it directly comes onto the screen. For xfig it is only ouputed in the file and not visible on-screen.