Audio and VideoOverviewThe MediumStreaming MediaUDP and RTSPCodecsPopular FormatsRealMediaQuickTimeVarious FormatsGeneral Design GuidelinesVideo GuidelinesAudio GuidelinesLibrary of CongressVideo ContentAudio ContentIA and Audio / VideoReferencesAudio and VideoCurtis Thomas385E Information Architecture and Design IOverview•The Medium•Popular Formats•Design Guidelines•Library of Congress Analysis•IA and Audio / VideoThe Medium•Streaming Media•CodecsStreaming 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 feedCodecs•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 streamPopular Formats•RealMedia•Apple’s QuickTime•MPEG, MP3, WAVRealMedia RealMedia is a streaming audio and video format•Useful for slower Internet connections•Reduced audio quality•Slower video playback (3 to 6 fps)•Heavily affected by Internet trafficQuickTime 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 demandsVarious FormatsMPEG (Video)•High quality•9 megs per minute of videoMP3 (Audio)•High quality, fast downloadsWAV (Audio)•Highest audio quality•Longer download times•Must wait for download to finish completelyGeneral Design Guidelines•Inform users of technological demands•Provide clear access to software•Avoid gratuitous “eye candy”•Stick with standard formats•Provide controlsVideo Guidelines•Plain page summary•Screenshots from video content•Segment long clips •Choose clips with minimal motionAudio Guidelines•Summarize content•Give users control•Provide estimated download timesLibrary of CongressAmerican Memory WebsiteVideo ContentAudio ContentIA and Audio / VideoThe 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.htmlBeggs, 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.htmlNielsen, J. (1999). Video and Streaming Media. Retrieved on October 22, 2004 from:http://www.useit.com/alertbox/990808.htmlStreaming media – Wikipedia, Retrieved on October 22, 2004 from:http://en.wikipedia.org/wiki/Streaming_mediaCodec – Wikipedia, Retrieved on October 20, 2004 from:http://en.wikipedia.org/wiki/CodecQuickTime – Wikipedia, Retrieved on October 20, 2004 from:http://en.wikipedia.org/wiki/QuickTimeWindows Media – Wikipedia, Retrieved on October 20, 2004 from:http://en.wikipedia.org/wiki/Windows_MediaWindows Media Audio – Wikipedia, Retrieved on October 20, 2004 from:http://en.wikipedia.org/wiki/Windows_Media_AudioWindows Media Video – Wikipedia, Retrieved on October 20, 2004
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