1.3 - File compression

Question 1

What are the two types of compression? [2]

Answer 1

Lossy and Lossless

Question 2

What is lossy compression? [1]

Answer 2

if you compress a file, you lose some portion of it

Question 3

What is lossless compression? [2]

Answer 3

• if you compress a file, you lose nothing
• when you decompress you get everything back

Question 4

What is the sound range that humans can hear? [2]

Answer 4

20Hz - 20,000Hz

Question 5

What are some ways to use perceptual music shaping? [3]

Answer 5

• reduce sample rate and sample resolution
• cut and throw frequencies that can’t be heard by humans
• remove software sound

Question 6

Perceptual music shaping is an example of what sort of compression? [1]

Answer 6

lossy

Question 7

What do mp3 files store? [1]

Answer 7

audio

Question 8

What do mp4 files store? [4]

Answer 8

• pictures
• music
• videos
• animations

Question 9

What is run length encoding used for? [2]

Answer 9

• lossless compression
• to reduce text size and photo file

Question 10

What type of compression can pictures have? [1]

Answer 10

both lossy and lossless