Part 2 – Distribution - File Types.

Stuart Matthews
Multimedia Technology
Part 2 – Distribution
File Types.
There are many different file types used to create and present interactive presentations. File formats for picture and image documents include .gif (graphics interchange format). GIF files are limited to 256 colours and supports up to 8 bits per pixel, as well as still images .gif files can be small animations. Transparency can also be used in .gif files. Most drawing and image applications can produce and use .gif files. Because of the limit of colours available on a .gif file the quality of the picture will not be as good as other file formats. Jpeg files are the most common file type used for pictures as they support much more colours than .gif files. Jpeg files allow adjustable compression meaning user can choose between picture quality and picture size. Jpeg files are the most commonly used in digital image capture devices like cameras and mobile phones. Jpegs are the most used file type for pictures on the web. Most drawing applications like Fireworks, Photoshop and Paint can produce and support jpeg files.
File types .swf (shockwave flash) and .fla (flash) are used by Flash to create interactive presentations and movies. Swf files use vectors in animations and are designed to keep files sizes down to allow publication on the internet. Fla files contain the source material for flash documents. Flash software can edit .fla files and export them as .swf files.
Ppt file types are Microsoft PowerPoint files for producing interactive presentations and can include text, pictures and sound files.
QuickTime files (.qt) are used by QuickTime player to display videos, animations, media clips, sound and music. .qt files contain one or more layer each of which stores a particular form of data, this can be sound, video, music or text. QuickTime player also supports other multimedia file types like .wav, .mp3 and .mpeg.
Html files (Hyper text mark-up language) are used for writing pages of the web. Html is the main language used for web pages. Html files can be written in many applications from simple text editors to custom software for writing web pages. Html files are read by web browsers to tell the browser how to place and display text, images, video and sound on a web page. CSS (Cascading style sheets) are used with html files to give more control over how the page is displayed. Using .css files allows the user greater control over the layout and look of the page or site.
Executable files (.exe) are used for running programs. Exe files contain binary information and are created in an IDE (integrated development environment). The finished program is then interpreted or complied to allow use of the program.
Mp3 (mpeg layer 3) files are generally used for music and sound. Mp3s are digital audio encoding formats using lossy data compression to reduce file size. The mp3s remove the very high peaks and low peaks of the sound without much loss of quality of the sound; this is possible as the human ear can’t hear the highest and lowest frequencies that are on a CD track. File sizes are generally 10 times smaller than that of a CD track. Many portable players have been produced to capitalise on the popularity of Mp3s.