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 ?

Compared to the fi nal fi les you would output for other mediums, such as 

SOME CAPTURE POINTERS 

DVD ROM or VHS tape, the fi nal fi les you'll output for the Web will be 

FOR STREAMING MEDIA

small a smaller frame size, a lower frame rate, and more heavily compressed. 

However, it is recommended that you capture your source material (both video 

Use AV hard drives

 SCSI or RAID 

and audio) at the highest quality settings your system can handle 30 fps is 

Research your video capture card

 Test it, if 

recommended for video; 16 bit for audio. You'll be using up lots of hard disk 

possible, before making a fi nal decision. 

space, but it's better to start with high quality (i.e., more data) and, therefore, 

Conserve CPU power

 Disable all anti virus 

have more choices about what information to discard when you reach the 

programs, screen savers, and extensions during the 

encoding stage, than to start with low quality (less data) and potentially 

capture process.

regret having fewer options down the road. 

 Optimize your hard drive

 Defragment your 

hard drive before capturing.

Window size

Frames per second

Color depth

Data rate

Capture high quality

 Capture your source 

(resolution)

(fps)

(bits)

per second

material (both video and audio) at the highest 

640 x 480

30

24

27.65 MB

quality settings your system can handle 30 fps 

is recommended for video; 16 bit for audio. 

640 x 480

15

24

13.83 MB

 Avoid dropped frames

 Test and improve your 

320 x 240

15

24

  3.46 MB

system until you reach a zero dropped frames 

standard. 

160 x 120

15

24

   865 KB

Capture mono audio

 Unless you really, truly 

Make sure your system has adequate capacity. A 3.46 MB per second data 

need stereo output.  

rate is standard for DV. In terms of disk space, you'll probably want at least 

Keep an archive of your raw video fi le

 For 

a 30 GB hard drive. The larger your resolution (video window size), the 

future use, and because  accidents  happen.

more colors, and the higher the frame rate captured  the bigger your 

captured fi le will be.

Dropped frames, during capture, are something you want to avoid. You can't recover dropped frames 

after capture, so you'll want to test and improve your system until you reach a zero dropped frames 

standard. If you are using Adobe Premiere to control capture, make sure to select the  Report Dropped 

Frames  option, so you'll know when frames are dropped. You can also set Adobe Premiere to auto 

matically abort capture when frames are dropped. Dropped frames are usually the result of a 

confi guration problem, or are caused by trying to capture video that exceeds the capture rate for 

your system. DV requires a hard disk capable of sustaining a 3.6 MB per second data rate.

Capture cards for streaming

You'll fi nd there are capture cards designed specifi cally for streaming media. Your decisions will depend 

on your needs and your budget. But the industry is now mature enough that there is, indeed, something 

that's right for every requirement.

The most basic capture cards are for input only. Some popular, inexpensive ones (under $200) let 

you hook up a variety of sources at once (although only one of those devices can be used at a time) 

including S video and full duplex audio input. Such cards provide basic capture software.  But in order 

to stream, you'll need a solid video editing package, such as Adobe Premiere, and streaming software like 

Real Producer Plus, to refi ne and process the video before broadcasting from a site,  reports Joel Strauch 

in his article for Streaming Media.com,  Video Capture on a Shoestring. 

34

More expensive capture cards may have input and output capabilities, and may perform a variety of 

ancillary tasks such as scaling (resizing), color conversion, de interlacing, closed captioning and more. 

namic Medianamic Media

One popular capture card priced under $2,500 has such on board pre processing capabilities, leaving 

yy

the bulk of your CPU power for creating higher quality video streams. These specialized streaming 

cards enable real time (live) streaming from a DV source, with the ability to transfer the digital video 

directly to the host.  

obe Dobe D

dd

AA

26

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41   Video Capture on a Shoestring,  by Joel Strauch, Streaming Media.com, http://www.streamingmedia.com/article.asp?id=6794