Adventures in Information

Adding Video to Your Web Site

February 24, 1999Eileen Flick

Information Services Division

Today’s Overview

Why ?What ?

How ?

The goal for today is that you leave here with enough knowledge to be able to start adding video to your website.

• Only one reason . . .

Why Add Video?

–MOTION!MOTION!

Why Motion?

• Visual information / learning

• Sense of “being there”

• Create a mood

• Excite the viewer!

• Hold interest

Types of Use

• Video Programs

• Distance Learning

• Archives

Examples PageExamples Page

What is the Technology?

• Digitizing

• Compressing

• Streaming

Digitizing

• “Regular” video is an analog signal

• Computers use digital data

• Use a ‘digitizing’ or ‘capture’ card to convert the signal into data

• Just like digitizing audio

• Except it’s video :)

Compression

– Uncompressed video is approximately:• 640 x 480 resolution

• 24 bit color

• 7,372,800 bits per frame

• 30 frames per second

Compression

• Occurs while digitizing and when preparing clips for streaming

• Reducing the quality reduces the amount of information that must be compressed– 320x240, 24 bit, 15fps = 26.37 Mbps

• Want to recompress as few as times as possible

• Most used compressed sizes:– 320x240 and 160x120

Codecs (Types of Compression)• Intel Indeo

– PC platform, not compatible w/Quicktime

– doesn’t maintain video quality well

• MPEG– best compression

– only use if end result will be an MPEG file

• Sorenson– good compression & quality

– requires Quicktime 3

• Animation– okay if source is computer-generated, not good with

videotape source

Video File Formats• Quicktime 3 - Mac standard

– Cross-platform, good compression (Sorenson)

– Must flatten movie for the Web (default Quicktime has two forks, data & resource)

– movies can stream

• AVI - PC (Windows) standard– Audio & video interleaved for better quality

– Macs need special apps to play or convert to QT

• MPEG - UNIX standard– very high compression, good quality

– special encoding tools needed for max use

– more info: http://www.mpeg.org/

Streaming

• Data is played back as it arrives

• Non streamed clips must download completely before playing back

• The Analogy …– Streaming is like watching television– Non-Streaming is like renting a movie

Streaming is Good

• Faster time to initial start of playback

• Almost no storage space is needed on client computer

• Random access to stream

• Capability to send live streams

Streaming is bad

• Generally lower quality

• Can be more susceptible to the quality of the network connection

• Requires more time to encode to get the best quality

• Requires a special server to get all the benefits of streaming video

True Streaming

RealPlayerRealPlayer

Web BrowserWeb BrowserWeb ServerWeb Server

RealServerRealServer

Request for meta fileRequest for meta file

pnm meta filepnm meta filepnmpnmmetametafilefile

Request for streamRequest for stream

StreamStream

Pseudo-Streaming

RealPlayerRealPlayer

Web BrowserWeb Browser

Web ServerWeb Server

Request for meta fileRequest for meta file

http meta filehttp meta filehttphttpmetametafilefile

Request for media fileRequest for media file

media filemedia file

How Does One Do All This?

• Step 1 - Capture/Digitize the Video

• Step 2 - Encode/Compress it

• Step 3 - Publish it on the web

Step 1a - Capture the Video- The Hardware -

On a PC:• First - Video capture card

• Recommend Osprey 100 or 1000

• Miro DC30 is a poor choice for most users

• Video cards recommended by Real Networks:http://www.real.com/devzone/library/stream/vidcard.html

• Second - Enough disk space • Recommend 4+ GB drive

• Third - The Computer• As fast as possible

• 200+ MHz Processor

Capturing the Video - cont’dOn a Mac:• AV-capable Mac (7600+ or an AV model)• 4GB+ hard drive• Fast processor (pre-Power PC okay, but verrrry

slow)• Lots of RAM (at least 64MB, more better)• Note on Firewire:

– New technology for using peripheral devices, including digitizing video, new G3s use this method

– For more info: http://www.apple.com/firewire/

Step 1b - Capture the Video- The Software -

• Only basic functionality is needed• Most bundled software is fine• On the Mac, that means Apple Video Player:

Capturing Video - software cont’d• Use Adobe Premiere if more capabilities are

needed (editing, filters, etc)– Available in user rooms for PCs and Macs

• Other software possibilities: Avid Cinema, Strata VideoShop

• For real media, can also encode directly (live, as in webcasts)

• More on capturing video: – Real Media:

http://www.real.com/devzone/library/stream/videohints.html– Quicktime 3:

http://www.apple.com/quicktime/authors/auth-docs.html

Step 2 - Encode the video

• Must make the Stream vs. Non-Stream decision

• Non-Stream– QuickTime vs. AVI– QuickTime is more universal– Use Premiere if it’s necessary to re-encode the

clip

Step 2 - Encode the Video

• Streaming Video– RealMedia is recommended solution– Use RealEncoder to encode

http://www.real.com/products/tools/producer/

– One or multiple versions?• Who is your audience?

– Use Premiere to prepare clips as necessary• Add titles, soundtrack, filters

Step 3 - Publish to the Web

• Non-Streaming– Almost identical to publishing any other

document • Upload to server then link it in HTML

– QuickTime 3 now cross-platform, can be streaming or non-streaming

http://www.apple.com/quicktime

Step 3 - Publish to the WebLinking the Clip

• Simple link– File downloads, then plays– <A HREF=“movie.mov”>link the clip</A> – Let people know format and size: (1.3MB, QT)

• Embedded link– <EMBED SRC=“movie.mov” autoplay=false

width=160 height=120></EMBED>– Controller & window appear in page– Clip plays while downloading

Step 3 - Publish to the WebReal Media

• True Streaming– Requires access to RealServer

– Move files to content directory• At USC, that means the CWIS server

– Create meta-files using pnm URL’s

– Embed or link to meta-files

Step 3 - Publish to the WebLinking Real Media

• Reference file in local directory points to a metafile:– <A HREF=“movie.ram”>real video clip</A>

• Movie.ram file contain actual clip location:– pnm://www.usc.edu/dept/real/movie.rm– .ram file is simple text, contains no HTML tags

CWIS Issues

• RealServer is only available on CWIS

• Open to any CWIS user/dept

• Fill out agreement formhttp://www.usc.edu/uscweb/authoring/RealMedia – Agree to 200 MB limit– Agree to not hog streams

• HTTP Pseudo-streaming available from any web server

How to Get Setup

• HTTP Pseudo Stream has no setup!

• Create content directory

• Turn in agreement form

• Link is created to your directory

• Start streaming!

Use video on your website ...

… not because it is hard ...

… but because it is easy!

–For more information, and an excellent tutorial, For more information, and an excellent tutorial, check out:check out:–http://builder.com/Graphics/Video/ss02.html