Case Study - Formats

Compression -

Lossy compression can lead to lost data and lost quality. It is typically used for JPEGs and MP3 files. These files can sometimes be recognised by jagged edges and pixelated areas. With audio files the lossy compression can cause a watery sound and a low audio range.

Lossless compression is used to reduce the file size without lowering the quality. It can be used on both audio and image files. These are large files, but are the original quality and at a small file size.

Video files -

MPG -
This is also known as MPEG, which stands for Moving Picture Experts Group. These files are commonly movies that are used for the internet. They are compressed video files so that they can be used over the internet quickly and can be downloaded at a good speed. But the picture quality is not decreased too much.

MP4 -
An MP4 file is often used by websites to store digital audio and video streams. This file type is seen as an evolution of the MP3 file because it provides more flexibility and functionality. MP4 is often favoured over MP3. This file type is commonly used on mobile devices, computers and remote hard drives. Many portable devices use MP4 to play movies on the go.

MOV -
This is a quicktime movie file commonly used for making films; short films and the likely file to be edited using Final Cut Pro. (Another Apple product) It is commonly used to save movie files and clips to a hard drive or media device. They are compressed files that make is easy to download and stream the video from the internet to a portable media device or to a computer. The file type was created by Apple but is now compatible with Windows and Mac.

AVI -
This stands for Audio Video Interleave. It is a container file format that was created by Microsoft in 1992. They are a shell file that can contain multiple files within the container file. These file types often contain audio and video data.  These files can use less compression that other video files. These file types have a 2GB size limit. But even though the format is over 20 years old, it's still commonly used.

WMV -
This stands for Windows Media Video. This is a compressed video format created by Microsoft for internet streaming applications. This file type can allow large files to be converted into smaller files. But the picture quality is protected. This keeps the file manageable but still of a good quality. These type of files can be read by most media players and can be converted into other formats, but there is a risk of losing picture quality.

FLV -
This stands for Flash Live Video. This is used to send videos over the internet to another computer. File formats allows high file compression but keeps high video quality. This format was created for Adobe but can be used by non-Adobe applications. This file type is used a lot on YouTube and Google Video.

SWF -
This stands for Small Web Format. It was designed to send graphics and animations over the internet. Animations and graphics created in Adobe Flash software are saved in this format. It is the end file format for all Flash content. They are read-only files that can't be edited.

3GP -
This stands for 3rd Generation Partnership Project. It is a format often used for mobile phones with 3G. It is a smaller version of an MP4. It is like a mobile version whereas the MP4 is often used on computers. It was made to use less bandwidth by using a smaller size; which makes it easier to stream videos and music on phones. 3G is not needed to view 3GP files. They can also be used on a computer but the quality will not be to the standard of MP4.

ASF -
This stands for Advanced Streaming Format. It was created by Microsoft for streaming media files. It itself is not a file but is actually a file container format. Files of this type can contain 3 objects: a header file, a data object and an optional index object. The header file contains the information about the media data. The data object is the media stream. The optional index object allows access to data within the ASF. They also allow for the media files to be compressed which makes it easier to download and stream over the web.

File sizes -

Resolution -
The resolution determines the detail and quality of a still or moving image.


Aspect Ratio -
The aspect ratio is defined by the ratio of width and height.

4:3 -
This means that for every 4 inches of width in an image, you will have 3 inches of height. It is 33% wider than it is high. It has been used since the early days of TV in the 40s and 50s. It has been commonly used by analog channels and still is now. It produces a box-like picture.

16:9 -
This means that for every 16 inches of width in an image, you will have 9 inches of height. It is 78% wider than it is high. It has been commonly used by movie producers, it allows viewers to see a bigger picture compared to 4:3. It increases the quality of the image and allows for bolder backdrops and scenery. It is not as wide as cinema aspect ratio, but it's similar. It produces a widescreen picture and is used for HD TV.

Media players -

Flash Player -
Flash is a software used for viewing multimedia and streaming video and audio. It can run from a web browser or on some mobile devices, but some versions do run on an operating system. It runs SWF files. It was created by Macromedia and is now distributed by Adobe. It is commonly used to run games and animations that are on webpages. It is free to download and the plug-in version is available for all recent versions of web browsers such as Internet Explorer, Firefox, Chrome, Opera and Safari.

QuickTime player -
It's simply a media player created by Apple that plays QuickTime files. You can convert files to different formats using Pro; and also record and edit. You can also stream across media across the internet. It plays videos in HD and uses less bandwidth and storage. You can watch videos from a camera, mobile phone, Mac or PC, online etc.

Windows Media Player -
It is a media played created by Microsoft that can be used for playing audio, video and viewing images. It is used on computers that run on a Windows operating system, Pocket PC and Windows Mobiles. It can also be used to rip music from discs, copy to discs and burn audio CDs. The latest version was released in 2009 alongside Windows 7. But Windows 8 and Windows RT does not run this program.

RealMedia -
It is a cross-platform software that is used to play recorded media. It is compatible with many formats. It runs MP3, MPEG-4, QuickTime, Windows Media and their own RealVideo and RealAudio formats.