Screen Video Capture using kx11grab & ffmpeg in Ubuntu 10.04.

     Suppose, you need to teach someone on how to use a particular software etc. In such cases it will be useful if you capture the video display and send to one who needs it. There are some tools that can capture the screen and save in different video formats such as avi, mpeg etc.

     In Ubuntu, there are two tools that work together to capture screen. They are
1. ffmpeg
2. kx11grab

These can be installed as,

sudo apt-get install ffmpeg
sudo apt-get install kx11grab

Usage :

Use the below sample command to capture screen,

ffmpeg -f x11grab -s 1024x768 -r 75 -i :0.0 /tmp/out.avi

Ubuntu 10.04 Linux will be released on 27th April 2010.

    The next version of Ubuntu will be Lucid Lynx and will be known as 10.04 version. The date for release of final version is on 27th April 2010. The version will be a LTS i.e. long term support.

A Solution to BUG in Desktop-switcher of Ubuntu 9.04 Netbook Remix. (Bug #370133)

Introduction:

     In NBR Ubuntu 9.04 version, there are 2 modes of Desktops.

1. Ubuntu Netbook Desktop.

2. Classic Desktop.

    Switching between these 2 modes can be done by running a command "desktop-switcher" in Terminal Window Or By selecting it from 

"Menu

->System->Preferences->Switch Desktop Mode".

Problem: There is a BUG in the desktop-switcher package that comes as a default package of Ubuntu NBR 9.04. The bug will affect the Desktop Modes as a result of which the "Classic desktop" will lose its panels, Menu, etc. You will see only a Background Image + any Icons on Desktop. No Keys will work at that stage. But you can add a Terminal LAUNCHER to Desktop and run some commands.

Note : You need a Terminal window to go for below steps. If you are in "Classic desktop" mode, you can Right Click on Desktop area and select "Create a Launcher......" from the menu. Use command "gnome-terminal".

Solution:

Steps are,

1. Remove old desktop Switcher package.

sudo dpkg -r --force-all desktop-switcher
2. Remove Configeration data of desktop switcher.

rm -rf ~/.config/desktop-switcher
3. Install desktop-switcher_0.4.6_i386.deb from the link : http://swiss.ubuntuforums.org/attachment.php?attachmentid=111829&d=1241109082

4. Try switching between Desktop Modes and finally Restart the computer if needed.

Reference : My practical Testing + Information from the site http://swiss.ubuntuforums.org/attachment.php?attachmentid=111829&d=1241109082

Recover EXT3 Partitions and Data - Ubuntu Linux.

Note : Please use this option only as final option for recovering data from Corrupted ext3 partitions. In my case, I recovered all files and folders from a corrupted ext3 partition, in which Madriva 2007 was installed. I used my ASUS eeePC with Ubuntu 9.10 (Karmic Koala) version, for this. The Hard disk was connected to eeePC through USB cable.


Steps :

1. Connect the corrupted HardDisk to your Laptop using USB cable.
2. Boot your computer with UBUNTU (preferably).
3. Make sure that Harddisk is unmounted (usually you can not mount a corrupted partitioned Harddisk).
4. Open a "Terminal" type the following command and press ENTER.

/sbin/fsck.ext3 -b 57345 /dev/sdc7

Where /dev/sdc7 was the partition to be recovered. Use "Sudo" as prefix for the above command if you get messages such as " Permission denied".


5. The above command will recover partition and will prompt for "yes". (In my case, I gave "y" to all prompts). After the execution of this command, e2fsck starts automatically.

6. Finally you will find that all files and directories are recoverd in the partition. You may check by mounting the partition and browsing.


Note : When I was usig the command I recovered A-Z files and folders as it was. But due to my mistake, I run the command once again on the recoverd partition. Finally I left with only single folder named "lost+found". I browsed the folder to see my lost files and folders and it was stored in several sub-folders. One example is, My Desktop folder was found in ""#76511" folder. When I tried to copy the folder to other folder, I could not copy the files / folders and I was getting error message that the "file or folder" does not exist. Then I used "kget" command to copy the files and folders to other folders. (i.e. Right click on files and goto "Download with kget" option and then chose the Destination folder, wher the files and folders to be copied). Please note that "kget" can be used only for files and not for folders. Hence you need to create folders manually, wherever needed.

Reference : An article on Net + My effort.

A Solution - Broken Downloads in Ubuntu Linux.

 

Suppose you are downloading a file from Internet using your web browser (Mozilla Firefox). Suddenly, Internet gets disconnected. At that moment you have no choice but to re-download, usually. Because, if you select "retry" option, download starts from the beginning and you will lose all the partial data that you have downloaded. I found a solution for this, which helps to continue the downloads from the point where it got disconnected previously.

1. Open a "Terminal" window / "Konsole" window.
2. Change directory to the Download directory. e.g. If you are downloading to a folder "/home/v", then type the command cd /home/v.
3. Then type the following command to continue downloading,

wget -c http://www.downloadpack.com/main/example.deb

Where,
http://www.downloadpack.com/main/example.deb is the Download link for the file example.deb which need to be downloaded.
-c option enables you to continue downloads.

Please note that you can get Download Link of the file in Downloads section of your browser, you can just right click on the broken download file and copy the link location.

(Note :
1. Another option is to use wget command alone in order to download bigger files.
2. Usually broken download creats a file named "example.deb.part".
3. I took help from Nanda N, KarMic for this, thanks to her.

Install NGSPICE & MAGIC - VLSI Tools for Ubuntu OS.

         Installation of VLSI design tools such as "ngspice" and "magic" is fairely easy in Ubuntu Linux OS. The simple steps are given below. Please note that Ubuntu uses "debian" packages.

Steps :

1. Go to the below sites and download the packages.

MAGIC:
http://tuxmaniac.com/work/packages/magic/magic_7.5.129-1_i386.deb

NGSPICE:
http://nchc.dl.sourceforge.net/sourceforge/ngspice/ngspice_17.0.0-1_i386.deb

XSPICE:
http://nchc.dl.sourceforge.net/sourceforge/ngspice/xspice_17.0.0-1_i386.deb

Note : XSPICE is a dependent package for NGSPICE.

2. Install packages using following command.

MAGIC:
$ dpkg -i magic_7.5.129-1_i386.deb


NGSPICE:
$ dpkg -i xspice_17.0.0-1_i386.deb ngspice_17.0.0-1_i386.deb


Note: You can not install "xspice" & "ngspice" independently. You need to install both at a time.


Happy Designing....


Note : I took help from Mr. Prassana Kalyan, KarMic for this. Thanks to him.

Useful Packages Available in Ubuntu.

        I have tried to List some of the Packages that are really helpful. These packages all come with Ubuntu Linux.


gparted - Partition Manager.
ubuntu-rescue-remix - Data Recovery Tool
brasero - CD burner tool.
openoffice.org - Presently 3.2 version has lot more features when we talk about MailMerge, Conditional Formatting and Total Number of Cells available.
otrs2 - Open Ticket Request System software.
xsane - Scanner Software.
Gimp - Graphical Editor which is almost same as Photoshop.
usb-creator - Usb Startup disk creator software.
Image-Writer - Write .img images on disks.
synaptic - Package manager software tool.
Apache2 - Web Server.
Squirrelmail - webmail server software.
mplayer - Movie Player
totem - Audio Player.
firefox - Webbrowser
evolution - email client (same as thunderbird).
gedit - Test editor for gnome
gdm - Gnome Display manager.