30536a - Learning Activity 03

Introduction. What is Multimedia? In everyday life, multimedia is everything you hear or see, e.g. text in books, sound in music, and graphics in pictures. - ppt download

I am now up to Study Period 6 with my course and this is part of my research for learning activity 3:

30536a - Learning Activity 3

Research

Do an internet search to find the various file formats that are used on the web. Record their file extension abbreviation (e.g. .swf) and what it means. List how the type of file is used. Find examples of image, video, audio and coding formats in your research. List 10 file types. Record your findings in your resource kit.

Answer

I found this link (a slideshow presentation) c/o Slide player via a Google Search: http://slideplayer.com/slide/6417666/; the author of this slideshow is Erik Parks and he uploaded (or modified it) a year ago (2015).

In Slides 21-26, this is what he had to say about file types:

Multimedia– File Types File Types 

There are many different ways to store files but choosing the correct file type can dramatically reduce the amount of backing storage required. Some file types compress the data, which makes the storage requirements smaller and therefore faster to download.

Multimedia – File Types Text:

Text files may have one of the following file extensions:

1.     .txt (text),

2.     .doc (document),

3.     .rtf (rich text format).

Doc and txt are versions of saving word-processed documents. However, if the file is open in another application the original formatting (bold, italic etc) of the text may be lost. RTF files are saved with all the formatting information. RTF files can be opened using many packages and the format will still be there. 

Multimedia – File Types Graphics:

1.     files may have one of the following file extensions:

2.    .bmp (bitmap),

3.     .gif (graphics interchange format) – a bit-mapped graphics file  format,

4.     .jpeg (Joint Photographic Experts Group – used for photos and graphics Bitmapped graphics

A bitmapped graphic is a picture made up of a grid of dots called pixels. A pixel can be stored in 1 bit
of the computer’s memory. A black pixel is stored as a 1 and a white pixel as a 0. The bitmap picture stores data about each pixel, which means bitmap pictures, have a large storage requirement. File compression makes the file size smaller Compressing using GIF files reduce storage requirements of a bitmap graphic. Compressing using JPEG file compression reduces the file size by about eighty percent. This is done by cutting out parts of the graphic that won’t be noticed by the human eye.

Multimedia – File Types Moving images

Moving images come in two formats, video or animation images. Animations are created using animation software, whereas video images are captured from a video camera. Video files may have one of the following file extensions:

1.     .mpeg - Moving Picture Experts Group.

2.     Avi -Audio Video Interleave (Microsoft’s Video for Windows standard)

Files saved as MPEG are compressed by cutting out any unchanged data from the various frames in the video. MPEG files are therefore easier to store. Files saved as .AVI store the audio and video data in a single file and this is not compressed. This limits the quality and size of the video to be stored. 

Multimedia – File Types Animation software 

Animations are a series of still pictures that have a slight change in each picture. They are played very fast so they give the impression of a moving picture, like a flick book. Text, graphs and buttons on web pages as well as pictures can all be animated. 

Multimedia – File Types capturing and storing audio

The vibration of air creates the sounds we hear. Your eardrum changes these vibrations of air into sound that we recognise. Sound files may have the file extension:

1.     .wav sound file

2.     .mp3 MPEG-1 Audio Layer-3

Files saved as .WAV are compressed but still have a high storage requirement. Files saved as.MP3

compress the file smaller than a .wav file. Audio compression of audio files is necessary due to the size of raw audio data. Compressing the sound file means that, because the file is smaller, it will be quicker to download it.