Video Technology

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]

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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

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Sunday, May 17, 2009