File Format

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

Viewing Digital Media

What devices can we use to view digital media files?

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

What is compression?

Think of what the keyword may actually stand for…

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

Playing Audio and VideoDescribe the different devices that could be used…

Vid

eo

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

File Formats

File formats you could research for your work include:

Know image, audio and video files

Be able to describe file formats

Audio Video

Co

mp

ress

edU

nco

mp

ress

ed avi

wmv mov

mpg mp4swf

flv

aiff wav

mp3 wma

aacogg

flac