Audio and Video
Curtis Thomas
385E Information Architecture and
Design I
Overview
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The Medium
Popular Formats
Design Guidelines
Library of Congress Analysis
IA and Audio / Video
The Medium
• Streaming Media
• Codecs
Streaming Media
Streaming media was made possible by the
creation of two protocols:
• User Datagram Protocol (UDP)
• RealTime Streaming Protocol (RTSP)
UDP and RTSP
• Continuously send information even
when data dropout occurs
• Users get information in chunks
• Network congestion can cause a lapse
in the video or audio feed
Codecs
• Transform data streams by discarding any
unnecessary data
• Audio codecs discard frequencies that fall
outside of the range of human hearing
• Video codecs predict picture content from
previously viewed images in the stream
Popular Formats
• RealMedia
• Apple’s QuickTime
• MPEG, MP3, WAV
RealMedia
RealMedia is a streaming audio and video
format
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Useful for slower Internet connections
Reduced audio quality
Slower video playback (3 to 6 fps)
Heavily affected by Internet traffic
QuickTime
Offers a streaming format as well as
smaller downloadable files
• Higher quality streaming format than
RealMedia
• Average file size is 5 to 6 megs per minute
of video
• Greater bandwidth demands
Various Formats
MPEG (Video)
• High quality
• 9 megs per minute of video
MP3 (Audio)
• High quality, fast downloads
WAV (Audio)
• Highest audio quality
• Longer download times
• Must wait for download to finish completely
General Design Guidelines
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Inform users of technological demands
Provide clear access to software
Avoid gratuitous “eye candy”
Stick with standard formats
Provide controls
Video Guidelines
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Plain page summary
Screenshots from video content
Segment long clips
Choose clips with minimal motion
Audio Guidelines
• Summarize content
• Give users control
• Provide estimated download times
Library of Congress
American Memory Website
Video Content
Audio Content
IA and Audio / Video
The key to successful Web multimedia
is to tailor your content for Web
delivery.
Do not simply translate video and
audio content to the computer screen.
Employ design guidelines and use the
strength of computers to make
content exciting and approachable.
References
American Memory from the Library of Congress, Retrieved on October 20, 2004 from:
http://memory.loc.gov/ammem/index.html
Beggs, J. and Thede D. (2001). Designing Web Audio: Chapter 5: Introduction to Streaming Media.
Retrieved October on 22, 2004 from:
http://www.oreilly.com/catalog/sound/chapter/ch05.html
Nielsen, J. (1999). Video and Streaming Media. Retrieved on October 22, 2004 from:
http://www.useit.com/alertbox/990808.html
Streaming media – Wikipedia, Retrieved on October 22, 2004 from:
http://en.wikipedia.org/wiki/Streaming_media
Codec – Wikipedia, Retrieved on October 20, 2004 from:
http://en.wikipedia.org/wiki/Codec
QuickTime – Wikipedia, Retrieved on October 20, 2004 from:
http://en.wikipedia.org/wiki/QuickTime
Windows Media – Wikipedia, Retrieved on October 20, 2004 from:
http://en.wikipedia.org/wiki/Windows_Media
Windows Media Audio – Wikipedia, Retrieved on October 20, 2004 from:
http://en.wikipedia.org/wiki/Windows_Media_Audio
Windows Media Video – Wikipedia, Retrieved on October 20, 2004 from:
http://en.wikipedia.org/wiki/Windows_Media_Audio