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Full-Screen Video Over 28.8k: The Claims Continue
gwernol writes "Over at Screen Daily they are claiming that an Australian company has demonstrated a high quality, full-screen video-on-demand service that is delivered over a 28.8k modem. They claim this will 'eliminate the need for broadband.' If this is true, then they'll change the world. Of course, the basic technology has been around for a while, see this article from 1998 or this one from earlier this year. I remain extremely sceptical. If this is real, why won't they allow proper independent testing? But it is interesting that they're getting funding. Could this be the last great Internet scam?"
Several readers also pointed out this brief report at imdb.com as well. We've mentioned this before, but the news here is the reportedly successful demo. It would be a lot easier to swallow if he'd let people test it independently, but video-over-28.8 sure is tantalizing.
I'm just as skeptical as the next geek, but remember: MP3 changed everything in audio. Compressing a 60M song to ~6M?!? 10-12X compression with only minor quality loss? No one believed it when they were told, but once we started hearing it ourselves, we couldnt believe our ears. I hope they have made the next quantum leap in compression. I doubt it, but I hope.
For anyone who's ever heard of Pixelon, we'll believe it when we can test it ourselves.
The new article as well as the earlier one both say that the technology is "backed by a report from Monash University" {in Melbourne}, but back in April, Monash vigorously disputed claims of their support. They conducted an independent review but the compression algorithm was black-boxed. The company may be misrepresenting the purpose and parameters of the review, from the university's point of view.
lake effect weblog
{Network engineer in Chicago--looking for work!}
Here we go again, Americans assuming that everyone lives in their country.
:). The USA is AFAIK one of the only countries with unmetered local calls.
Well some of us live in the poor, deprived, third-world old United Kingdom, where speed cameras and CCTV monitor our every move, and dialup access is (mostly) metered! Broadband only covers about 10% of the population (thankfully me
In many cases, broadband is the only unmeterted access.
--Russ
The current state of the art in compression technology is benchmarked by Jeff Gilchrist at his site which includes current benchmarks in image compression technology too.
This was a real question from a job interview! Q: What area of programming do you consider yourself not to be good in?
Last year I did some work on image compression
using wavelet transforms. We were able to get
50:1 compression on scientific image data, with
12-bit dynamic range. That compression ratio was
without any use of interframe similarities --
a movie compression algorithm could probably
get another 20:1 compression without much trouble.
At 30 fps, 0.33 MB per frame, that's 10 MB of
image data per second. Compressed 1000 to one,
you're only talking about 10 kilobytes
per second. If you're willing to suffer with
less dynamic range around spike bits of data,
it's not unreasonable to think that another
factor of four could come out of that, giving 2.5
kB/sec or 20 kbps -- leaving 8kbps for the sound.
80% (factor of five) compression is unreasonably
inefficient. Even without frame-to-frame similarities, wavelet image compression schemes can achieve 50x compression with no visible degradation (I know, I did experiments last year as part of a spacecraft proposal effort). That's a factor of 10 from your figures -- 1.9 seconds per frame. Using the similarities between frames, it's not unreasonable to think that another factor-of-10 applies (MPEG achieves factor-of-100
compression where JPEG only gets factor-of-10), bringing the frame count up to 10/second.
Suppose, for example that the camera is slowly panning across a static image. MPEG would see that as the *whole frame* differing from its predecessor, where a location-independent approach like fractal compression would still be able to take advantage of the redundancy.
No, MPEG would not. Do you think it was designed by a group of monkeys? MPEG would see this as a simple translation and code the correct motion vectors into the B-frames of the stream. There is more to MPEG than simple DCT blocks. You're talking about MJPEG.
A witty
Do Psuedo video on demand then.
/sec bandwidth no matter how many people are viewing - even 100,000 viewers! That is MUCH cheaper than serving up video on demand to even only 100 viewers!
Your show is 1 hour long. Have 12 multi-cast streams of the same show, each offset by 5 minutes. If each video stream is 256 Kbps, then you need 3 megabits
Of course, the trade off is that a viewer might have to wait 5 minutes to watch the beginning of the show.
Unfortunately, we can't even do this scheme yet anyways since there is no 'Standard' router protocol for efficient multicasting... Or is there one that doesn't require tunnels everywhere?
I experimented with this last year. I was trying to prototype a client-server system on which graphics were rendered on a central server then compressed and piped to clients.
:) I wrote a software wavelet codec which I then tried to integrate with MPEG2 interframe compression. This turned out to be very tricky because a lot of the interframe motion vector compression relies on the DCT blocks from the JPEG-style intraframe stage (you've probably seen the obvious 'boxes' of pixels when viewing a very highly compressed JPEG image).
I played with some wavelet video compression/decompression cards based on the analog devices ADV601 chip (you can google it). It can achieve high compression ratios on grayscale images working on a frame by frame basis (kinda like MJPEG but with wavelets).
After playing with the server a bit (it was a Beowulf cluster
Anyway, the results I was getting (for grayscale) *sound* impressive. 200:1 was possible for most images but only pictures with smooth contrast changes looked any good after decompression. Any sharp edges (e.g. graphical overlays) were completely destroyed at any compression rate over 10:1. Throwing the MPEG interframe stuff into the mix didn't really help much (partly due to the problem outlined above), although I can't say I explored all the possibilities along this route.
After becoming more interested in coding proper parallel apps for Beowulves rather than hacking the MPEG's source I let the project drop. Code available if you'd like a look.
My personal opinion on this fullscreen video with CD-quality sound over 28.8 is that it's complete tosh. It's absolutely impossible to compress that much information into such a small pipe. Unless this guy has discovered something that makes an awful lot of our current mathematical thinking invalid then this claim is nonsense.
I pay about $7 for my broadband connections.
I have 2 x 100Mbit FullDuplex switched Ethernet to my appartment (currently only using one).
The Area of (about) 100 connected users is connected through a Gigabit connection to our local ISP that has ha (today) 96Mbit connection to the internet, 155Mbit connection to the Swedish University Network and 100-1000Mbit connections to the other networks in our Town.
Fot, Fotare, Fotast...
http://www.screendaily.com/cgi/process_template_my sql.pl?template=../html_templates/section.ttml&and _clause=stories.STORY_NUMBER=5733&redirect=../shtm l_files/search_redirect.shtml