Bits-Data-Representation-and-Manipulation

• The left most bit (the most significant bit) is used as the sign bit. 最左位数表示正负
  • represents +
  • represents -

1. For positive number： Signed-magnitude, 1's complement, 2's complement forms are the same.正数原码反码补码一样
2. After two backcode complements, the original number can be obtained 经过两次反码，补码操作可得到原数
3. For binary odd number, the most right bit must be one.
4. For Hexadecimal number each bit represents 4bits binary number

• Scientific notation:

Represented by 16 bits

• 16 bits: 1 for sign; 5 for exponent; 10 for Mantissa
• Exponent bias (offset): 24 -1 =15; range: [-14, 15]
  • 01111 represents 0 in exponent

• 32 bits: 1 for sign; 8 for exponent; 23 for Mantissa
  

• The American Standard Code for Information Interchange

• 7 bits to represent 128 characters

  • 0~31: control characters
  • 32~127: symbols, digits and letters

• 48 represents '0'

• 65 represents 'A'

• 97 represents 'a'
  

• 16 bits
• Support unlimited characters
• To permit backward compatibility, ASCII is a subset of Unicode.

• A microphone converts sound to an analog electrical signal
• An analog-to-digital converter (ADC) converts the analog signal to a digital signal through sampling
• CD audio, for example, has a sampling rate of 44.1 kHz (44,100 samples per second)
• An digital-to-analog converter performs the reverse process, from a digital to an analog signal
• An analog signal can be amplified and send to a speaker to produce sound

• A video consists of a stream of frames, or images, displayed at n>16 frames per second
• An Image consist of a collection of pixels
• Pixels are tiny dots of color
• A pixel’s color is represented by a binary number, its RGB value
• Thus a video can be seen as a huge binary number