Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Streaming Media at Penn State Kaspar Stromme Kim Winck Center for Education Technology Services Web 2001 Conference, June26, 2001 What is Streaming A technique for transferring data over a network such that it can be processed as a steady and continuous stream stream SERVER CLIENT A Fixed Data Rate Network Bandwidth Stream What is Streaming (continued) Unicasting – one to one Multicasting – one to many Streaming Media Video Audio PowerPoint Flash/Shockwave VR 3D Formats at PSU QuickTime Real Media Windows Media IBM VideoCharger Not all media on the web streams Download Any server. Any file. Plays when done. Not all media on the web streams Download Any server. Any file. Plays when done. Fast start/progressive download Any server. Some files. Plays after a while. Not all media on the web streams Download Fast start/progressive download Any server. Any file. Plays when done. Any server. Some files. Plays after a while. Streaming Some servers. Some files. Plays right away. Streaming Media Files Media files are HUGE What’s the size of your pipe? • Modem (89%) • ISDN • Cable/DSL • LAN Source: Internet.com April 2001 http://cyberatlas.internet.com/big_picture/geographics A Few Basics HUGE Media files are Processing makes them SMALL Reduce the Screen Size 160x120 320x240 Reduce the Frame Rate TV = 29.97 fps Film = 24 fps Computer = ? fps Reduce the Frame Rate (continued) Low Motion High Motion 5-15 fps 15-25 fps Compression JPEG TIFF 34K 237K Compression (continued) Non-lossy compression (GIF) Lossy compression (JPEG) Compression DECompression CODECs are the algorithms that compress and decompress the media Popular Codecs Real Advanced Streaming Format Cinepak Sorenson MPEG 1, 2, 4, 7, MP3 PureVoice Qdesign Music ETC How video compression works Frame 1 Frame 2 ? Preparing Media for Compression Shoot tighter shots Minimize camera movements such as zooms and pans Try to shoot against plain backgrounds with little activity Always use a tripod for steady shots Turn auto focus off, this avoids unintended focusing Preparing Media (continued) Try to use a high-quality tape format such as MiniDV, SVHS or Hi8 Use new tapes to avoid glitches, dropouts, and other image degradation Record in a quiet environment with little or no background noise if possible Use high-quality recording equipment to minimize noise Creating Video for Streaming at PSU Prepare video DV Cameras at Media Tech: www.libraries.psu.edu/mtss/ Digitize and edit video CAC/CETS Digital Video Editing Seminars: cac.psu.edu/training Software: iMovie, Adobe Premiere, Media Cleaner Creating Video (continued) Where to digitize and edit video CAC Multimedia Labs- Pollock Library, 302 Patterson, 107 Rackley Faculty appointment in the Faculty Multimedia Center : cac.psu.edu/fmc Encode video for CAC/CETS Streaming Server: cac.psu.edu/streaming/specs.htm Creating Video (continued) Upload video Serve video Save to Firewire, Web/FTP site, JAZ, Zip Sign FMC Copyright Waiver Web page Play video QuickTime Player Examples: cac.psu.edu/streaming/examples.htm Streaming Service CAC/CETS Streaming Services Website ets.cac.psu.edu/projects/streaming/www/index.htm