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 E S S T R E A M I N G W O R K ?
The big three streaming architectures and their native fi le formats
Architecture Native Formats
QuickTime QuickTime Format .mov (sometimes .qt or .qti)
RealMedia RealMedia Format .rm
Windows Media Advanced Streaming Format or .asf, .wmv, .wma
Windows Media Video/Audio
MPEG (denoted by .mpg and several other fi le extensions) is a standard fi le format for video, and it
is also a codec that is used to create formats, but it is not a complete architecture. MPEG 1, originally
designed for multimedia formats on CD ROM, does not support true streaming but only progressive
download. MPEG 4 is a brand new, international open standard for Web video, based around the
QuickTime format. Windows Media Video v1 is a derivative of the MPEG 4 codec, which has been
renamed to avoid confusion. QuickTime 5, just released as of the fi nalization of this Primer, is the fi rst
full implementation of MPEG 4 for streaming media.
WHAT ALL DO I NEED TO MAKE MY PRODUCTIONS STREAM?
This section merely outlines the tools and techniques involved in streaming media you'll fi nd more
detailed explanations in the section of this primer entitled How Do I Make (Good) Streaming Media.
The process from planning and shooting your video, through outputting the appropriate fi le formats for
the selected medium are, essentially, the same steps you would go through for developing any kind
of digital video project: pre production (planning), production (shooting video and recording audio),
and post production (editing, adding effects and titles, mixing and synchronizing audio, and outputting
for your medium of choice). But for streaming media, the process doesn't end there you still have
to publish your streams.
First, you'll need some media you want to share
Whether it's a live live Webcast from a Web cam trained on your baby's fi rst steps or a scheduled
Webcast of your CEO giving a keynote speech that's pushed to the extended enterprise or an effects
heavy movie trailer that audiences can stream on demand to build anticipation for the next big
summer blockbuster if you can capture it, you can stream it.
The term video capture may be used to refer to the digitization of analog video, from a connected
camcorder (video camera) or from a connected tape deck, as it is saved onto a computer hard drive
via a video capture card installed in the computer. The captured video clips, once digitized, can then be
manipulated (edited and/or encoded) with computer software.
The very same term capture is also used to refer to the simple transfer of DV (a video format
typically shot with a digital camcorder and, therefore, already in digital form), from a camcorder or tape
deck, onto a computer via an IEEE 1394 connection (also known as FireWire or iLink). For Webcasting,
analog video and DV can both be captured live while fi lming, to be streamed live i.e., in real time
(although a specialized video capture card designed to handle streaming is necessary for the live capture
namic Medianamic Media
and streaming of analog video).
Similarly, audio, whether recorded live or transferred from a CD or other sound storage medium is also
said to be captured, when it is saved onto a computer.
You'll probably want some video editing and visual effects software
obe Dobe D
If you are not doing a live feed, you have the opportunity to edit and develop your video story with
titles, motion graphics, transitions, and visual effects, as well as with music, voice overs, sound effects,
and other audio enhancements. Or, you may be repurposing content that was produced for other