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Video on the web - stepping up the rate
28k streams
28k
windows-media stream
15 frames per sec, 21kbps
Try
it now |
Over a modem, streaming video barely works. Everyone has seen the typical postage stamp sized, pixellated videos, with sound burbling out as if from the bottom of the ocean?
Now that you've got broadband, you probably want to be blown away by streaming video! Here are the steps on the quality ladder..
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56k streams
56k
windows-media stream
15 frames per sec, 36kps
Try it now |
The next step up from 28k streams are 56k streams.. these are hardly much better.. with little or no audible improvement, and only a slightly larger image.. Designed to just fit to a 56k modem, still a very unsatisfying experience.
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100k stream
Now comes the territory of dual channel ISDN users -- the 100k streams. 
100k windows
media stream
20 frames per sec, 100kpbs
Try it now |
Now at least you can make out sufficiently large
writing on the video, and the sound is a leap above the previous effort.. still
not even FM radio quality though.
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300k stream
300k
windows media stream
30 frames per sec, 300kbps
Try it |
The 300k stream is getting more interesting. The native size for a 300k video stream is 320 pixels by 240 -- this about one quarter regular TV resolution, although not quite! resolution isnt the only measure of quality: NTSC is 525 lines, at 60 frames per second (interlaced), whereas a 300k windows/Real video stream is running at more like 15-30, with lossy compression. |
Compression artifacts
300k windows stream
Jaggies example |
One of the visible problems with streaming media is the amount of compression artifacts that show up when the scenes move quickly. These can be seen in the picture to the right.. this was snapped within a few frames of a switch to split screen in the video: looking at the colored patterns in the lower left you can clearly seen the blockiness and color bleed.. 300k windows or real video streams look best when the picture is not moving around quickly!
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State of the streaming art for now : On2.com .. 350 to 650kbps
On2.com has its own video codec, its own windows video player, and is producing its own video content. Lets check what they can do...
On2 stream
best case |
Pretty clear! That is 320x240, almost no compression artifacts visible.. and it
doubles up to 640x480 quite
well, which is the size On2 want you to watch in. Unfortunately, this stream requires about 650kbs/sec of steady throughput! the fallback stream is about 350kbs/sec, and the result is shown below.. where Ms Hitower has a slightly blurry face, and you can see decompression artifacts around the borders of the shapes in the background, which become pronounced when in action scenes, and scene changes.
On2
stream
fallback case |
One significant improvement On2 has made over 300k windows or Real player streams is to the sound quality, and to the reduction in scene-change compression artifacts to almost zero at the optimal speed, and the frame rate looks to be faster as well! possibly 24fps, adding significant smoothness to the final clips. On2 also offer a 1024x768 full screen mode, where the screen is either interlaced with black lines or further interpolated.
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