video technology
DESCRIPTION
A high-level look at why different video technologies behave differently at the user experience level. Prepared for education at Observer.TRANSCRIPT
Video DeliveryA High-Level Look
Sunday, May 17, 2009
Disclaimer
The following slides are meant only to describe high-level interactions. Many more variables exist in any video discussion.
Sunday, May 17, 2009
Issue at Hand
• Video Performance
• Sometimes slow, choppy - Why?
• Bandwidth
• Video Encoding and Delivery
• Receiving Video
Sunday, May 17, 2009
Bandwidth
• Bit rate = data transfer rate and/or the encoded quality of a video file
• Larger bit rates require more network and storage use
• Resolution = video display size/quality
• Larger resolutions require more network and storage use
Sunday, May 17, 2009
Video Encoding/Delivery
• Video Encoding
• Different formats, such as Windows Media or Flash, require different technologies for delivery
• Delivery from Server
• Streaming = delivers in small chunks
• Download = delivers all at once
Sunday, May 17, 2009
End Users
• Players
• Some are plug-ins only, others are plug-ins calling local applications
• Browser
• Different browsers handle plug-ins and delivery protocols differently
• Act differently depending on OS
Sunday, May 17, 2009
Use Cases
• Common
• Streaming Video - server to client
• Downloading Video - server to client
• Uncommon
• Streaming Video - server to terminal server to client (terminal services)
Sunday, May 17, 2009
Delivery - Server/Client
Streaming Server
Client
Download Server
Client
Streaming Progressive Download
vs.
connectionbegins
connectionends
connectionbegins
connectionends
Sunday, May 17, 2009
Perfect Storm (Part I)
• All variables must match for good end user experience
• Server technology, client technology, bandwidth capacity, etc.
• Now, let’s add another layer - Terminal Server, which acts like a streaming technology (delivers in small chunks)
Sunday, May 17, 2009
Delivery - Terminal
Streaming Server
Terminal Server
connectionbegins
Download Server
Terminal Server
Streaming Progressive Download
vs.
Client Client
connectionbegins
connectionends
connectionends
Sunday, May 17, 2009
Perfect Storm (Part II) • All variables still must match for good end
user experience
• Server technology, client technology, bandwidth capacity, etc.
• Terminal Server introduces conflicting technologies for downloaded video, which is main Charlotte.com delivery
• Download too heavy to transfer seamlessly
Sunday, May 17, 2009
Questions?
• Jason SilversteinInteractive | General and Product [email protected]
Sunday, May 17, 2009
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Sunday, May 17, 2009
Backup Slides
Sunday, May 17, 2009
Video Encoding
• Windows Media
• Microsoft proprietary from client to server to encoding to delivery
• Live and on-demand are high quality
• Streaming is most prevalent delivery
• Capable of Digital Rights Management (“DRM”) and HD quality
Sunday, May 17, 2009
Video Encoding (con’t)• Flash Technology
• Format created by Macromedia (now Adobe), made famous by YouTube
• Encoding more efficient than Microsoft but relies on third-party video (On2) and audio (mp3)
• Usually delivered via download
• Lacks HD and DRM capabilities
Sunday, May 17, 2009
Video Encoding (con’t)
• QuickTime
• Apple proprietary application
• Uses proprietary and/or standards for encoding content
• Capable of HD and DRM (both are industry standards)
• Download is most common delivery
Sunday, May 17, 2009
Bit Rate & Resolution
• Part of encoding process
• Bit rate rises as quality increases; dial-up video = 56 kbps, DSL = 300 kbps, e.g.
• Resolution measures pixels high and wide; larger numbers create larger file sizes
• Bit Rate and Resolution both affect playback, especially for downloads
Sunday, May 17, 2009
Client Technologies• Windows Media Player
• Plays Windows Media primarily; can do some other online formats
• Can play live or on-demand
• Plug-in calls in application from OS, meaning longer start times
• Tightly integrated into OS through delivery chain
Sunday, May 17, 2009
Client Technologies (con’t)
• Flash
• Lightweight plug-in
• Plays Flash video only (on purpose)
• Can play live or on-demand
• Considered best “web” experience by many
Sunday, May 17, 2009
Client Technologies (con’t)
• QuickTime
• QuickTime primarily; other online formats are possible
• Can play live or on-demand
• Plug-in calls in application from OS, meaning longer start times
Sunday, May 17, 2009
Video Delivery
• Progressive Download (aka “PDL”)
• Using a web server to deliver video in an on-demand capacity only
• Once request is made, entire file is delivered at once
• No further requests or communication with server
Sunday, May 17, 2009
Video Delivery (con’t)
• Streaming
• Uses a specialized server and software to deliver video in small, streamed bits to the client
• Connection between client and server is constant through delivery
• Can be used for live or on-demand
Sunday, May 17, 2009
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Sunday, May 17, 2009