Creating ISO images in Linux : FEDORA 19

1.  Few useful commands to create ISO images in linux :

First install mkisofs from root by typing :

yum install mkisofs

In most of the recent linux distros...this would invariably be pre-installed...the above command will work for yum installations

If u require to create an iso file from a directory containing other files and sub-directories via the terminal, you can use the following command:

mkisofs -o image.iso -R /path/to/folder/

An example is shown below : here YOURFILE is the name of the ISO image that will be created and then is the route where the data is stored.

mkisofs -o YOURFILE.iso -R /run/media/kurta/CEH\ Tools\ Vol-1/

COMPRESSION.... has a LIMIT?

1. Compression of files to me means diminution or simply reduction in size of data in order to save space or transmission time.So till recently I used to use the famous winzip which used to give an average reduction of 30-40% of the original file size.But that stood till recently before I met a file of size 716kb....even less then one MB and when I unzipped it ..it stood out to be a complete 696 MB...amazing..yes a compression beyond belief.

2. For information compression can be as simple as removing all extra space characters, inserting a single repeat character to indicate a string of repeated characters, and substituting smaller bit strings for frequently occurring characters. This kind of compression can reduce a text file to 50% of its original size and this is made possible with the help of various programs that uses various obscured formulas or algorithms.

3. This lead me to hounding for various zipping softwares available in the web world and I found one KGB....now the KGB site claims (http://kgbarchiver.net/)  that it reduces 1 GB into 1 MB......I said in my mind.....ke bhaiya this is impossible till i tried compressing one avi file of 700MB ...........and the reduced size was 726kb...........so was it!!!!!!!so I mailed it to my mail box....downloaded it in my office next day.and yes...i downloaded 700kb file and I got extracted with a 700 MB file...so theorem proved LHS =RHS.

4. So where is the discommotion?...good things never come easy........i had to wait for 135 minutes for compression and "Yes" before you try it make sure you have a good processor which can bear the load of work that would be given to the bechara processor combined with gooooooood RAM......the other problem is availability of the software at a price...where did I get it from? do u wish to know? the answer starts from T & ends with Z.........still not understood......better mail me ur email id.......will let u know!!!!!!!!!!

MPEG vs H.264

1. A not so techie person like me knows MPEG as the extension of videos also known with the extension name of .mpg,.mpeg,.mp1.We have been seeing this name since the birth of CDs in late 90s(...i m speaking in Indian gali context,thats when this term evoluted to a common man ).

2. Any one who has followed up the term MPEG would know or would have heard names of various versions that followed MPEG1,MPEG2, MPEG3, MPEG4 and lately some thing known as H.264 comes up in the context of video compression technology.So this term aroused my interest to know in some detail about what has been the change and value addition over these various versions that keep following up every 2-3 years.

3. Moving Picture Experts Group(....expanded form MPEG) also known as  ISO/IEC JTC1/SC29 WG11 evoluted from MPEG 1 to H.264 2day.

4. MPEG 1 : The earliest standard for compression of video and audio was designed to compress VHS-quality raw digital video and CD audio.This included many severe shortcomings in form of a lower resolution,less efficient audio compression system,lack of flexibility,access control issues,unsuitable for HDTV,did not support interlaced footage.

5. MPEG-2 : Successor tO MPEG 1 Standard that describes a combination of lossy video compression and lossy audio data compression methods also permitted storage and transmission of movies using currently available storage media and transmission bandwidth.This overcame the shortcomings of MPEG-1 mentioned above.

6. MPEG-3 : A coding standard designed to handle HDTV signals but it was soon discovered that MPEG-2, at high data rates, would accommodate HDTV.Thus, in 1992 HDTV was included as a separate profile in the MPEG-2 standard and MPEG-3 was rolled into MPEG-2

7. MPEG-4 : About this I will give a point wise summary in days to come.In brief otherwise it absorbs many of the features of MPEG-1 and MPEG-2 and other related standards adding new features such as support for 3D rendering.MPEG-4 is still a developing standard and is divided into a number of parts. Companies promoting MPEG-4 compatibility do not always clearly state which "part" level compatibility they are referring to. 

8. The key parts to be aware of are MPEG-4 part 2 and MPEG-4 part 10 used by the Nero Digital AVC, by Quicktime 7, and by next-gen DVD formats like HD DVD and Blu-ray Disc.

9. Now comes the talk about H.264.In short H.264 is a standard for video compression, and is equivalent to MPEG-4 Part 10, or MPEG-4 AVC (for Advanced Video Coding). It uses motion-compensation-based codec standard.Now whats motion compensation?Will speak on this in few days after I get 2 know what it is?

10. Thanks wiki for sharing this.