Post on 16-Jul-2015
Lesson Goals
Must know file formats used for images, audio and video
Should understand pre-production and final product file formats
Could be able to describe properties and limitations of file formats
Digital Media
Because there are so many different platforms which we can view images, video and audio we need different file formats depending on the device:
Know image, audio and video files
Be able to describe file formats
Digital Media
Digital media devices are required to be able to play back thefollowing:
There are various different types of audio, image and video file and each one is used for a specific reason or type of job.
These different files will also vary in their quality, file size and the way that the file is compressed.
Know image, audio and video files
Be able to describe file formats
Image File Formats
Watch the video and identify the good and bad features of five image file types:
GIF PNG EPS
File Type Good Points Bad Points
GIF
PNG
EPS
Zooming in is good qualityMillions of coloursCompresses well
Not good for sharp edgesNot great for textSome colour detail is lost when compressed
Features millions coloursNo colours are lostNo or little compression
Not compatiable with all applicationsLarge file sizes
Compresses wellVery small file size
Only has 256 coloursDoesn't show all colours
Millions of coloursCompresess wellSharp edges
Not compatiable with all applicationsCan only use in a few particular places
Doesn't lose colour or detailScalable to any size
Does not lose any colour qualityCan only open in certain software
Image Formats
Different image file formats are used depending on the way in which you want to use or display the image files but the quality varies greatly:
Know image, audio and video files
Be able to describe file formats
JPEG GIF
Compression
Digital media files can be either uncompressed or compressed:
Know image, audio and video files
Be able to describe file formats
This is the original file which is at the bestquality it could ever be. These files areusually used just for storage because theyhave massive file sizes.
This is a file that has been made smaller tostore on things like portable devices. Theyare poorer quality than uncompressed filesbut have a much smaller file size.
Compression
There are two main methods for compressing files:
Know image, audio and video files
Be able to describe file formats
This technique uses a formula which doesn’tlose any of the original data so the quality oflossless compression files is good.
This technique gets rid of any data it thinksis unnecessary. File sizes are much smallerbut the quality is poor compared to lossless.
Your Task
Create a table showing properties and limitations of each image file:
Big or small file size?
Common file or not?
Where is it used?
State if the file is compressed or uncompressed.
Know image, audio and video files
Be able to describe file formats
File Properties Limitations Compression
The following website may help:www.file-extensions.org
File Formats
Because there are so many different audio and video playback devices and different ways to distribute files various file formats are required.
Some people will sacrifice quality for smaller file sizes while others may required top quality files regardless of file size.
Audio file formats can vary in:
File Size
Quality
DRM
Compression
Know image, audio and video files
Be able to describe file formats
Video file formats can vary in:
File Size
Quality
Resolution
Compression
Audio Files
When comparing the file size of a 3 minute music track saved in different file formats you can clearly see the effect of audio compression:
Know image, audio and video files
Be able to describe file formats
WAV 30.4mb
WMA 15.6mb
MP3 4.2MB
MP3 1.4mb
192kbps
64kbps
Video Files
Different file formats render videos in different ways showing a variation:
The OGG file tends to look a little bit dark compared to an MP4 but has the benefit of being a much smaller file size.
Know image, audio and video files
Be able to describe file formats
File Formats
When researching file formats remember the following points:
Compression may have good and bad consequences:
Properties – Small file sizes would upload quickly.
Limitations – File would be a lower quality.
Know image, audio and video files
Be able to describe file formats
More Compression
Lower Quality Files
Smaller File Sizes
Quicker Upload Speed