R093 - Files and Formats - Compression

Do Now:

1. What does it mean to 'compress' something?
2. What is meant by the following three units when saving something on your computer?
1. KB
2. MB
3. GB
3. What is meant by the term ‘audio’?
4. What is meant by the term ‘visual’?

File Types - Key Terms:

Compression – An algorithm designed to reduce the size of a file. There are two types of compression: Lossy and Lossless.

Q. In your own words, try to explain which form of compression you believe seems like the better option and why you believe that.

But how does compression effect the size of a file?

And how is this size change reflected in the quality?

File Types - Key Terms:

Audio - Can be in the form of music, dialogue and sound effects.

Sample Rate - The number of samples per second that are taken of a waveform to create a digital signal. The higher the sample rate, the more snapshots you capture of the audio signal. The audio sample rate is measured in kilohertz (kHz) and it determines the range of frequencies captured in digital audio.

Bit Depth – The number of bits available for each sample . If the bit depth increases, it can increase the dynamic range of volume (this affects how loud the sound will be). This will also contribute to the quality of the sound file improving.

We need an understanding of the above terms when considering how sound goes from being made to being digitised.

When looking at audio file types, we will largely be considering the 4 outlined below:

Task: 

1. Read over all of the information provided in the post above.
2. Turn all of the important information into a well-designed/laid-out PowerPoint that you can refer back to in the future to revise this topic.
3. Once your PowerPoint is complete, email it to your Media teacher - Character points will be given to the overall best Presentations.