Video Editing

1. Don't have the money to buy Adobe Premiere Pro but want to learn professional editing!

Solution: DaVinci Resolve

Big Hollywood movies are using this software for color grading. It's free version is so powerful that it does not require to go for paid version.

2. Don't know how to edit videos at all, want to learn easily?

Solution: CapCut for PC

It is as good  on PC  as it is on mobile and transitions are all ready, just drag and drop and the video is ready. 

৩. Want to create motion graphics or animation like After Effects?

Solution: Jitter Video

You can animate text and element in btowser. Output is just like Figma and Canava.

4. Need to purchase plugins for removing background noise or sound of fan!

Solution: Adobe Podcast Enhance

(This AI tool will automatically turn your audio into studio quality. Totally free.)

5. Want to remove background of your video without green screen?

Solution: CapCut Remove BG অথবা Unscreen

(There's no need for expensive tools to separate people or objects from videos, the background can be removed with one click.)

6. Can't find copyright-free music or sound effects to use in videos?

Solution: YouTube Audio Library

(There is a fear of copyright infringement when taking music from other sites, but this is YouTube's own free library and there are thousands of sounds here.)

৭. Video requires stock footage or royalty free video (Storyblocks Paid)!

Solution: Mixkit বা Pexels

8. Slow PC, Computer hangs during software installation?

Solution: Clipchamp

(It comes with Windows as free. It can be used in browser also । Basic Editing, Trim or voiceover -- it is fast.)

৯. Do you screen-record for making tutorial video?

Solution: OBS Studio

(World's best open source based screen recorder. Gamer and Streamer,  all use it.)

১০. Video size is huge, can't send to anyone?

Solution: HandBrake

(This is the best software to reduce the size of the video while maintaining its quality.)

Roman Number

Roman number was introduced and used by Roman people.

There is no zero(0) symbol in roman number.

The chart of roman numerals :

I -1        II -2 III - 3 IV - 4 V - 5 VI - 6 VII - 7 VIII - 8 IX - 9 X - 10

XI - 11 XII - 12 XIII - 13 XIV - 14 XV - 15 XVI - 16 XVII - 17 XVIII - 18 XIX - 19 XX - 20

XXX - 30

XL - 40

L - 50

LX - 60

LXX - 70

LXXX - 80

XC - 90

C - 100

D - 500

M - 1000

Variables in C

In programming, we actually work with some data. Suppose we are going to add two numbers 3 and 5. So, where are we going to store this value and do addition? Here, we use variable. 

So, variable is an identifier that is used to store some value. Values are actually stored in memory location and variable is the name of that storage location or memory location. 

A variable represents a single data item. By variables or variable name, we can access the data item anywhere in the program. Different data item can be stored at any place of the program.

Variable is an identifier, so rules of identifier should be used here. 

-- Variables are constructed with digits, letters.

-- But variable name must begin with letter (underscore is also allowed at the beginning).

-- Variables are case sensitive.

-- Special symbols are not allowed(i.e. ",',% or blank space etc. ).

We can declare variable in following way:

data_type  variable_name 

We will discuss about data_type in another section. Example of some valid variables are as follows:

First_tag

max_number;

C Data type

The word data type tells that it describes the type of data.  We haven't yet studied variables, functions etc. Data type is used there to describe the type of data. C supports several different types of data, each of which may be represented differently within the computer’s memory. Below are 4 basic data types.

Data type	Description	Memory requirement	Value range
char	single character	1 byte	-128 to 127
int	integer quantity	2 bytes	-32,768 to 32,767
float	floating-point number	4 bytes	-2,147,483,648 to +2,147,483,647
double	double precision floating-point number	8 bytes	2.3E-308 to 1.7E+308

The above data types can be used in an extensive way by using qualifiers like signed,unsigned, short, long.

For example, int data type can be used as signed int or long int and char data type can be used as signed char or long char.
Signed int means it will consider the sign bit and it is same as normal int but in case of unsigned int the value range will be from 0 to 65,535.

The char data type represents individual characters. Hence, the char type will generally require only one byte of memory. Actually char type is of integer type.

With most compilers, a char data type will permit a range of values extending from 0 to 255. Some compilers represent the char data type as having a range of values extending from -128 to +127. There may also be unsigned char data (with typical values ranging from 0 to 255), or signed char data (with values ranging from -128 to +127).

Keywords and Identifiers of C Language

Identifiers: 
Identifiers are names that are given to various program elements, such as variables, functions and arrays. These are user-defined. Identifiers consist of letters, digits and some characters but the first letter must be a letter. Generally lowercase letter is used but uppercase letter can also be used. Uppercase and lowercase letters are not interchangeable.

Identifiers can be of any length but typically it accepts 31 characters.

The following names are valid identifiers.

a   x   xy   firstname  lastName  area_of_circle   _length  test18

The followings are not valid identifiers.
         18test                   The first character must be a letter
         "xx"                      Illegal character "
         first name             Blank space
         last-name              Illegal character -

Keywords:

In C programming language, there are some certain reserve words. These reserve words are called Keyword. Keywords can be used only in particular purpose that is defined in language. So, keywords cannot be used as identifiers. Keywords have standard predefined meanings.

C keyword list is below:

      

Keywords in C Language

auto	double	int	struct
break	else	long	switch
case	enum	register	typedef
char	extern	return	union
continue	for	signed	void
do	if	static	while
default	goto	sizeof	volatile
const	float	short	unsigned

Note that the keywords are all lowercase. Since uppercase and lowercase characters are not equivalent, it is possible to utilize an uppercase keyword as an identifier. Normally, however, this is not done, as it is considered a poor programming practice.

C Character Set

Character set is important for any computer languages because this character is understood by the compiler. To write a program, we code, but the code has to be meaningful to the compiler. To write statement, expression, variable or custom function name, this are formed from this computer set.

C character sets are belows:

• Uppercase letter A to Z
• Lowercase letter a to z
• The digit 0 to 9
• And some special character sets
  +    -      *    /    =    %   &    # 
  !     ?     ^    "      '   ~      \      |
  <     >   (      )      {    }     [      ]
  :      ;     .     ,       _

Most versions of the language also allow certain other characters, such as @ and $, to be included within strings and comments. It also allow some White space characters. These are;

• \b blank space
• \t horizontal tab
• \v vertical tab
• \r carriage return
• \f form feed
• \n new line 
• \\ Back slash
• \’ Single quote
• \" Double quote
• \? Question mark
• \0 Null
• \a Alarm (Audible Note)

C Program Structure

C is structured. So, it is modular and the modules are function, i.e. the modules are called function. One of the functions must be called main. The program will always begin by executing the main function, which may access other functions.

To run a c program, you must include something at the beginning of the code, which will ensure your smooth compiling. It is sort of mandatory because this loads some initial code to run a program. For example;

#include <stdio.h>

The #include is a "preprocessor" directive that loads a file called stdio.h (stdio.h is a header file). Header files are collection of some build-in codes that does a lot of task to run a program.

Now look at the below program;


#include <stdio.h>
int main()
{
  printf("Hello,World"); 

  return 0; 

  //end of code(this is a comment)

}


So the whole program is enclosed by a function and this function is called 'main()'.

In later tutorial, you will learn about details of functions, how to write function, how to use it, what are required to write a function.  

Codes are written in an enclosed pair of braces, i.e., { }

Inside braces expression statements are written, i.e., printf("Hello,World");

Each expression statement must end with a semicolon (;). 

Comments (remarks) may appear anywhere within a program, as long as they are placed within the delimiters  /* and */ (e.g., /* this is for multiple comment */). Single line comment can be written after two forward slashes //.

The program is typed in lowercase. Either upper- or lowercase can be used, though it is customary to type ordinary instructions in lowercase.

History of C Language

C was developed by Dennis Ritchie at Bell Telephone Laboratories, Inc. (now a part of AT&T) in 1972. When Dennis Ritchie was trying to rewrite the code for UNIX operating system, C was born. He was considering to rewrite the system using the B language, Thompson's( Ken Thompson invented B programming language) simplified version of BCPL. The name of C was chosen simply as the next after B. So, C is an outgrowth of two earlier languages, called BCPL and B.

Earlier days, C was basically used within Bell Laboratories. In 1978, Brian Kernighan and Ritchie published a definitive description of the language. The Kernighan and Ritchie description is commonly referred to as "K&R C." After that, further development of C was began. By the mid 1980s, the popularity of C had become widespread. Numerous C compilers and interpreters had been written for computers of all sizes, and many commercial application programs had been developed. Many commercial software applications were started to re-written in C language.

Due to availability of various C compilers, minor incompatibilities were found between different implementations of the language. To stop this problem, the American National Standards Institute (ANSI) formed a committee, X3J11, to establish a standard specification of C in 1983. In 1990, the ANSI C standard (with formatting changes) was adopted by the International Organization for Standardization (ISO). Later the different versions of C was introduced as C89, C99 etc. and the current standard for the C programming language is C18(published in June, 2018).

Introduction to C Language

C is a general-purpose, structured programming language. It is really a powerful language to write complex computer program and that's why it is really one of a popular high level language like Pascal and Fortran. It has features that allows user to write low-level programming language and it is flexible also to write system programming (i.e. operating system) and application programming. 

It's instruction set includes large number of operators, several built-in functions, control-statement keyword etc. Hence, it allows users to write additional library function. Program written in C language is very fast.

C is highly portable. So, a C program, written in one computer can be run on another with little or no modification. The reason for this is that C relegates most computer-dependent features to its library functions. 

As it said earlier that C is structured programming language which means program can be written as block in terms of function module. A proper collection of modules would make a complete program.

IMEI Number

IMEI stands for 'International Mobile Equipment Identity', is a unique (15 or 17 digit) number assigned to  mobile phone. It can also be found in 3G/4G tablets, laptops with PCMCIA wireless internet cards, and other mobile equipment. In a dual-SIM phone, you’ll see two IMEI numbers, one for each SIM slot. The IEMI is also known as 'International Mobile Station Equipment Identity'. In the case of CDMA network there is also a MEID number.

The main purpose of using this number is to trace the device. As the number is unique, it helps us to identify the device and therefore it can be used for stopping a phone from accessing that network if it is theft. We can use this number to block a mobile phone from being used by another person.

How to find this number: 

• Dial *#06# on your keypad and press call or send button, your IMEI number will be retrieved and displayed on your screen.
• On the back or bottom of the device or under, IMEI number can be found printed.
• IMEI numbers can also be printed on the original packaging of your device.

The Structure of an IMEI Number:
IMEI numbers either come in a 17 digit or 15 digit sequences of numbers. The IMEI format currently utilized is AA-BBBB-CC-XXXXXX-Z:

First 8 digits of IMEI number are TAC (Type Allocation Code) which will give you the mobile phone brand and model. Other 7 digits are defined by manufacturer (6 are serial number and 1 is check digit).

For example a IMEI number: 354230061155201 

Here TAC: 354230 | FAC: 06 | SNR: 115520 | CD: 1

CSS

According to W3C , CSS is a simple mechanism for adding style (e.g., fonts, colors, spacing) to Web documents. The elaboration of CSS is Cascading Style Sheets. It describes how the markup language will be demonstrated in the screen.

CSS separates the document content from document presentation. This separation improves to write markup language in a clean way. Moreover, it enables to use same design style in various part of the document which reduces the redundancy of writing more  style languages.

Håkon Wium Lie first proposed about CSS in 1994 when he was working with Tim Berners-Lee at CERN. Gijsbert (Bert) Bos also proposed similar type of idea at that time. W3C released first  CSS Recommendation (CSS1) in 1996 after much discussion on various mailing list.

CSS have simple syntax. A CSS rule-set consists of a Selector and a Declaration Block. Selector points to the markup language (i.e HTML element) element and  Declaration block contains a list of declaration in braces. Each declaration consists of property and value and separated by colon. Each declaration ends up with semicolon. Markup language elements are may be specified with attributes like Id or Class. 

Example:

Suppose H1 is a HTML tag and the document can be written as:

<h1> Sen Computing </h1> 

It can be associated with CSS ----

<h1 style="color: red; font-size: 15px;"> Sen Computing </h1> [Inline stylesheet]

or

h1{color: red; font-size:15px}   [External stylesheet]

External stylesheet can be written in file that have .css extension and can be linked up with the HTML file.

The current version of CSS is CSS3.

FREE GRAPHICS SOURCES

FREE GRAPHICS SOURCES for your purposes.

Free Public Domain Images:

http://www.sxc.hu/
http://www.stockvault.net/
http://search.creativecommons.org/
 http://www.morguefile.com/
 

Free Patterns/Textures: 

http://www.squidfingers.com/pattern
http://www.brusheezy.com/
http://www.textureking.com/
 

Free Vector Graphics: 

http://www.vecteezy.com/
http://qvectors.net/

http://www.freevectors.net/
 

Free Icons:

http://www.freeiconsweb.com 

http://www.iconfinder.com/
 

Free Fonts:

http://www.dafont.com/
 

Various Free Graphics: 

http://www.bittbox.com/category/freebies

http://blog.spoongraphics.co.uk 

http://psd.tutsplus.com/category/fr...

 

Cool Text Generator:

http://cooltext.com/

Innovator of IT

1. Sir Tim Berners-Lee – World Wide Web
2. Vint Cerf And Bob Kahn – TCP/IP
3. Larry Page and Sergey Brin – Google Inc.
4. David Filo and Jerry Yang – Yahoo! Inc.
5. Bill Gates – Microsoft
6. Steven Paul Jobs – Apple Inc.
7. Mark Zuckerberg – Facebook
8. Chad Hurley and Steve Chen – YouTube
9. Linus Torvalds – Linux
10. Jack Dorsey – Twitter
11. Kevin Rose – Digg
12. Bram Cohen – BitTorrent
13. Mike Morhaime – Blizzard Entertainment
14. Jimmy Wales – Wikipedia
15. Jeff Preston Bezos – Amazon
16. Shawn Fanning – Napster, Rupture
17. Pierre Omidyar – eBay
18. Jack Ma – Alibaba
19. Craig Newmark – Craigslist
20. Matt Mullenweg – WordPress
21. Thomas Anderson – MySpace
22. Garrett Camp – StumbleUpon
23. Jon Postel – Internet Pioneer
24. Caterina Fake – Flickr
25. Marc Andreessen – Netscape

ASCII Code

ASCII is a character code electric transmission. ASCII stands for American Standard Code for Information Interchange. American National Standards Institute (ANSI) developed this code. The first edition of the code was published in 1963.

Previously character was represented in different ways and it created problem to networking with other computer. Bob Bemer, an IBM engineer proposed ANSI to develop a single code for computer communication.

ASCII uses 7 bit for character code, that means 7 bit to represent each character. So, in total, 128 character can be represented by ASCII code.

The first 32 characters are control character. Decimal Range (0-31). These are unprintable.

The rest characters are printable characters. Decimal Range (32-127).

If Gmail Is Hacked

You have your gmail account. You are trying to login and see the password is wrong ! Timid and disgusted, you quickly click "Can't access your account?" button, trying to reset password by your alternate email address. But no, hacker has already changed your alternate email address, your phone number, address, security question, everything ! What to do?

Don't worry.Only way to get back it, is to contact Google support center. Go to link below:

https://www.google.com/accounts/recovery

You will see a text, "having trouble signing in?". Select your field and submit to continue. Google will scrutinized your account info again, if everything is perfect then you will get back your account. It may take some days.

Proportion

We know that ratio is comparison of two numbers and if two ratios are equal then it is called Proportion. So, Proportion says that two ratios are equal.
Though ratio and proportion are different terms for the same mathematical concept but they are often used together as a phrase, "ratio and proportion". 8/10 = 12/15
Here, the common ratio is 4/5.
Do the ratios 18/9 and 2/1 form a proportion? (Answer it by yourself)

#Take another example of word problem so that you can understand it more.
Rob can eat 10 cakes in 60 minutes. In this way, how much time will it take to eat 35 cakes?
Let's think, it will take M minutes. Then
10/60=35/M
10M= 60 × 35
10M=2100
M= 2100/10

M=210

So, it will take 210 minutes to eat all the 35 cakes.

#You are making lemonade. The amount of sugar you need depends on the amount of lemonade mix you use. Is the amount of sugar you need proportional to the amount of lemonade mix you use?

Cups of sugar	1/3	1	3
Packets of lemonade mix	1	3	9

For each column in the table, let's write the ratio (in simplest form) of cups of sugar to packets of lemonade mix.
1/(1/3) =3 3/1=3 9/3=3
So, the answer is yes.

Ratios

We often compare two things and this comparison is called 'Ratio' in mathematics. A ratio compares two different quantities. So, it also a relation between two quantities. 

For example, there are 10 instructors and 30 girls in a hall room. So the ration between instructor and girl is 10 to 30 and in simplification it is 1 to 3 which means for every 3 girls there is one instructor.

Here are a few different ways we can describe the ratio of instructors to girls:

• There is 1 instructor for every 3 girls.
• The ratio of instructor to girls 1 to 3.
• The ratio of instructor to girls 1/3
• The ratio of instructor to girls 1:3

Ways to write ratios:

Here are several ways to describe the same ratio:

-  6 to 11

-  6:11

-  6/11

Fraction

A fraction is part of a whole. If we divide a whole thing, it will be divided into several pieces. Each piece can be seen as fractional part of the original whole thing.

In the above picture a circle is cut into 2 pieces and another circle is cut into 8 pieces. Each part can be said as fraction of the original circle and it can be represented as 1/2 and 1/8. Here 1 is called numerator and 2 and 8 is called denominator.

The numerator represents a number of equal parts while the denominator indicates how many of those parts make up a unit or a whole. For example, in the fraction 4/8, the numerator, 4, tells us that the fraction represents 4 equal parts, and the denominator, 8, tells us that 8 parts make up a whole. The denominator cannot be zero here. So, relation between can represented as :

Numerator

-------------------

Denominator

Proper Fraction and Improper Fraction:

A proper fraction is a fraction where the numerator is smaller than denominator.

Below are examples of improper fractions:
2/4, 3/5, 3/7

An improper fraction is a fraction where the numerator is greater than or equal to the denominator. Below are examples of improper fractions:
9/4, 5/5, 7/3

Mixed number:
A mixed number sometimes also called mixed fraction has a whole number and proper fraction. It is actually sum of a  whole number(not zero) and a proper fraction. This sum (+) symbol is never expressed.
3 4⁄5
It is actually  3 + 4⁄5 and is equivalent to 19/5.

Prime Number and Composite Number

What are prime numbers?
It is a whole number which has exactly two factors. The factors are 1 and the number itself. So, a prime number can be divided evenly by 1 and the number itself.

Example:
2,3,5,7 etc.
Pick a number 3 or 7. 3 can be divided by 1 and 3 itself. It is not evenly divisible by any other whole numbers.

What are composite numbers?
Composite numbers have more than two factors. A composite number has factors in addition to 1 and the itself.

Example:
4,9,18,77 etc.
Pick a number 18. it can be divided by 1,3,6,9 and 18 itself. So, it has more factors.

What is Multiple?

Multiples are numbers that result when we multiply one whole number by another whole number. The first four multiples of 3 are 3,6,9,12
3 × 1 = 3
3 × 2= 6
3 × 3= 9
3 × 4 = 12

We can write multiples of 5 as below:
5 × 1 = 5
5 × 2 = 10
5 × 3 = 15
5 × 8 = 40 

 We can never list all of the multiples of a number. In our example, 3 could be multiplied by an infinite number of numbers to find new multiples.