Uses of DD Command

Linux provides a DD command which is the powerful UNIX utility. It makes use of Linux kernel makefiles to make boot images.
DD can be used to copy data from one device to another or from one location to another.
Administrator is the only person having rights to execute DD command. You can use the below DD command in Linux operating
system which will help you in various ways.

The uses of DD command are as follows:
~ If you want to take the backup data from one hard disk to another hard disk within the same system. The command is given below:
Code:

# dd if=/dev/sda of=/dev/sdb

~ In this “if” specifies input file name and “of” specifies the file where the data has to be copied. If you mention source device in target device and vice versa then you might loss all your data.
~ If you want to restore the hard disk with the image file of another hard disk then use the following command:
Code:

# dd if=hdadisk.img of=/dev/hdb

~ To copy the data from the floppy into the image format you need to type the following command:
Code:

# dd if=/dev/fd0 of=myfloppy.img

In the input file specify the name of floppy location and in output give the name of floppy image file.
~Type the below command to read data from one location and write it to another location. The command is given below:
Code:

dd if= of= bs= ("USUALLY" some power of 2, and usually not less than 512 bytes (ie, 512, 1024, 2048, 4096, 8192, 16384, but can be any reasonable whole integer value.) skip= seek= conv=< conversion >

~ If you want to remove CD, DVD or USB from the system then type the below command. This command will rescue it from the system.
Code:

ddrescue -b 2048 -d -e 20 -r 300 -v /dev/hdc /home/sam/dvd.iso log.txt

~ You can backup a partition. For taking the backup you need to specify the partition name in input file and then specify the path or image file where you want to take backup. The dd command for taking backup is given below:
Code:

# dd if=/dev/hda1 of=~/partition1.img

~You can create an iso file from the source file. So we can enter the CD or DVD and create an iso file from the data contained in them. The dd command for creating iso is given below:
Code:

# dd if=/dev/cdrom of=tgsservice.iso bs=2048

Thus dd command reads one block at time, executes it and writes to the targeted output file.

How to Add subtitles to your home made videos

You filmed your vacation and you want to add subtitles to your video to showcase places you have visited for example,
to provide additional information to sound and image, or to translate foreign dialogue.

Movie Maker software, which is built into Windows XP, Windows Vista and you can install in Windows 7 for free ,
you can easily perform the editing of your videos. It also allows you to add subtitles that are embedded directly to your video.
Thus, whatever the medium and the software with which you watch your movie, the subtitles will be displayed and legible.

You can view your subtitles between two clips in the form of a transition or directly involved in a clip.
To define the appearance of the subtitle, you need to use the timeline table. And for a perfect result, you can customize the font,
size and color of subtitles.

Importing a movie:

Open Windows Movie Maker built into Windows XP and Windows Vista. You'll find it in the Start menu.
~ Run Windows Movie Maker by clicking the Start button, click All Programs, then clicking on the shortcut Windows Movie Maker.
~ In the software window that opens, click the Task button to bring up the Task Pane.
~ Inside, drop down the list 1. Capture Video and choose Import Video.
~ Select your hard drive the movie you want to add subtitles and click the Import button.

Split the movie into clips:

Movie Maker cut your movie into smaller clips, which correspond to different sequences of the movie.
You can work more effectively on small pieces of film and arrange them in order of your choice.
~ If a video clip seems too long, click with right mouse button and choose Create clips.
~ Drag the different clips in your movie in a row in the storyboard.
~ The various clips are connected then make up your movie.
~ You can verify that your film is in the right order using the preview box on the right.

Add a subtitle:

You will now have to choose the moments when putting your subtitles.
~ Switch then to the pasteboard time by clicking the button displays the timeline.
~ Start playing your movie, and when you want to add a subtitle, press the Pause button.
~ In the task pane, scroll down the list 2. Edit Video. Click on the Create titles or generics.
~ Then click Add a title selected clip in the timeline.
~ Enter your text in the text box below to display it in the bottom of the video.
If necessary, move the text down by putting two newlines just before.
~ Then click the Modify font and text color.
~ You can then modify the font, size and color of the text. Choose a color quite readable, like yellow.
~ Then click the Add link under the video.
~ Then the operation again whenever you want to add a subtitle.
~ To adjust the appearance of a subtitle with the video, you can manually move the subtitles into the Title Overlay row.

Save Movie:

Here is how you can save your movie with subtitles.
~ After checking with the insight that all your subtitles are well placed, pull down list 3. Complete video of the left pane.
~ Then click Save to my computer.
~ Enter a name for your video and click the Next button.
~ Leave optimum quality and click the Next button. Your film is created.
~ Then click the Finish button.
~ Your film is then opened with Windows Media Player. The subtitles are embedded in the video, you can
burn your movie or send it to friends, everyone will have subtitles.