A   S t r e a m i n g   M e d i a   P r i m e r :  

H O W   D O   I   M A K E   ( G O O D )   S T R E A M I N G   M E D I A ?

and Windows providing fewer options. Because streaming is an  emerging  technol 

ogy, codecs are continually being improved. It is important to keep up with the latest 

 [...after applying our basic settings...] 

developments, so check the Web sites for the dominant architectures, as well as trade 

Then we start tinkering... Usually, there 

publications and other resources on a regular basis.

are some parts of the movie that 

Multiple bit rate encoding

don't compress well in each [bandwidth] 

When media is encoded as individual fi les for multiple bandwidths, end users must 

version. We make a clip of the part that 

select which fi le they wanted to stream, often from among nine or more choices 

looks the worst, including about 5 10 sec 

if you encode for all three of the dominant architectures. Multiple bit rate (MBR) 

encoding solutions alleviate such confusion for the end user, and can also make the 

onds before and 5 10 seconds after the 

process of encoding easier. There are, however, some trade offs. 

problem area, taking the clip from the 

With the MBR approach, several different streams are encoded at different bit rates 

uncompressed version. We recompress this 

and combined into a single fi le. This is called SureStream in the RealMedia architec 

section as many times as necessary, adjust 

ture and Intelligent Streaming in Windows Media. In the QuickTime architecture, 

the strategy is slightly different separate fi les called  alternate data rate  movies 

ing the settings each time until we get 

are stored in the same folder or directory. When the client calls for the media fi le, 

it right. Sometimes we have to go to a 

a negotiation between client and server determines the available bandwidth, the 

higher data rate. When the clip of the 

appropriate bit rate stream is automatically transmitted and, if the network becomes 

congested, the transmission will automatically switch to a lower bit rate stream. 

worst part looks right, we recompress the 

Critics of this  adaptive  streaming approach say that servers are sometimes over 

whole movie with those settings... We use 

sensitive to network congestion, often streaming a lower bandwidth and, therefore, 

half a dozen computers at a time for tin 

poorer quality fi le than necessary. 

kering, each one with slightly different set 

Multiple bit rate (MBR) encoding vs. individual streaming fi les

tings. That saves a lot of time... We keep 

our default settings on one machine, so 

Issue

MBR Encoding

Individual Encoding

they don't get overwritten, and drag them 

Deployment

Requires the appropriate 

Files can be hosted on either a 

streaming media server software

streaming server or Web server

onto the others for tinkering... 

Network congestion

Server software monitors each 

May cause temporary disruptions 

  Secrets of the Apple Compressionist 

connection, automatically switch 

to playback

QuickTime Book

49

ing to a lower bandwidth stream 

to prevent media player from 

pausing to re buffer.

Storage

MBR fi les often require more space 

Files require less storage space

than the sum of the individual fi les

Web page 

Only one  Play  button graphic or 

Multiple  Play  button graphics or 

integration

link needed on Web page

links are required

Frame size

Video frame size must be the same 

Individual fi les can be optimized 

for all bandwidth streams so, while 

to take full advantage of higher 

quality can be better, size can't be 

bandwidths, e.g. larger frame sizes

larger to take advantage of higher 

Save for Web in Adobe Premiere features a 

bandwidth capacity

special edition of Terran Interactive's Media 

Cleaner EZ, making it easy to encode your 

Audio

Audio settings must be the same 

Individual fi les can be optimized to 

productions for streaming in QuickTime, 

for all bandwidth streams to avoid 

take full advantage of higher band 

RealMedia, and/or Windows Media formats.

disruptions to the soundtrack as the 

widths, e.g. higher quality audio

stream is adapted to conditions

namic Medianamic Media

How do I encode my media productions?

yy

While all of the choices make encoding sound complicated, it can be very, very easy to output your 

productions for streaming. The  one step Web output  Save for Web feature in Adobe Premiere, and 

wizards available in other post production tools, deliver simple to use solutions. And, like most fi lm 

and video techniques, advanced tools are available which can, when combined with experience and 

obe Dobe D

expertise, dramatically improve the quality of the fi nal production. You can also look to a growing 

dd

AA

number of specialists to outsource encoding. Your decision to encode your own video projects for 

streaming or to call upon the services of a specialized outsource depends on your objectives, your 

33

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ambitions and, of course, your budget.

49  QuickTime for the Web, by Steven W. Gulie, May 1, 2000, Morgan Kaufmann Publishers