1. Comparison Charts and descriptions of the most
Commonly used video and image file formats
Video Streaming vs. Downloading
Video Streaming • Streaming is the transfer of data in a continuous
stream over the Web (usually audio or video) that
allows the user to play it as it arrives.
• To receive this content, you must have the right
plug-in for the application, such as RealPlayer,
QuickTime viewer, etc.
• A method for transferring data continuously.
Streaming allows you to display the data on your
browser before the entire file is transmitted.
Downloading • To transfer (data or programs) from a server or host
computer to one's own computer or device.
• Allows media to be played quicker because it is
downloaded to ones computer.
Most common Video file formats compared
Video File Format Characteristics
ASF,WMV • Can be streamed across the Internet and viewed before
(Advanced Streaming entire file has been downloaded when using a
Format) Windows Media server.
(Windows Media Video) • Requires Windows Media Player be installed on client.
• Typically placed on an internet streaming server.
AVI • Can be viewed with standard Windows Players such as
(Audio Video Interleave) Windows Media Player.
• Uncompressed yields a high quality video but uses a
lot of storage space.
• If downloading from the Internet, the entire file must
be downloaded before being played.
• Typically stored on local hard disk or CDROM or
made available as download from web server.
MOV • Requires Apples Quicktime Movie Player
(Apple Quicktime Movie) • Depending on Compression chosen can provide a very
high quality video clip, but better quality uses more
storage space.
• Can be streamed across the Internet and viewed before
entire file has been downloaded if using a Quicktime

2. streaming server.
• Can be placed both on an internet streaming server, or
local storage such as hard disk or CDROM.
MPEG • Can provide VHS quality movies or better
(Motion Pictures Experts • Mpeg1 is equal to VHS.
Group) • Mpeg2 is better than VHS and used for DVD
• Mpeg4 is being developed
• Requires an MPEG player to view
• If downloading from the Internet, the entire file must
be downloaded before being played because files sizes
are very large.
• Typically MPEG1 is used to make a one hour VCD
movie.
• Typically MPEG2 is used to make DVD movies, but
can be used to make about a 30 minute high quality
VCD.
• Can be placed on any storage media large enough to
hold the file, but at current time the internet speed will
not support streaming MPEG files. Any MPEG files
found on the Web will have to be downloaded to the
local drive and played using an MPEG player.
RM • Can be streamed across the Internet and viewed before
(Real Media) entire file has been downloaded when using a Real
Networks Streaming server.
• Has very high compression, but at a cost to quality.
• Requires Real Networks RealPlayer to view content.
Basic Picture Image file format comparison
This chart is particularly helpful when wanting to place an image file on
diskette or a website and the size needs to be small.
The table below illustrates the relative file sizes that can be achieved by the
different file formats in storing a "native" 1MB image, and also indicates the color depth
supported:
File format Image size No. of colors
BMP - RGB 1MB 16.7 million

3. BMP - RLE 83KB 256
GIF 31KB 256
JPEG - min. compression 185KB 16.7 million
JPEG - min. progressive
150KB 16.7 million
compression
JPEG - max. compression 20KB 16.7 million
JPEG - max. progressive
16KB 16.7 million
compression
PCX 189KB 16.7 million
TIFF 1MB 16.7 million
TIFF - LZW compression 83KB 16.7 million
PNG - file format will compress files at a similar ratio to jpeg,
except unlike jpeg, resaving an image will not degrade its
quality. Where possible PNG should be the file type of
choice.
Material adapted from SAMM – Students Achieving with Multimedia Class