CES 2007
Another exhausting week at CES in Las Vegas. We stayed at the Bellagio again thanks to Jeff’s poker prowness. It was unusally cold in Vegas, but the sun was shining…not that we saw much of it.
The social highlight was the Microsoft Vista release party at Pure in Caesars. Awesome food, open bar and a live performance by the Pussycat Dolls. Very nice event…thanks uncle Bill!
JPEG2000 and UWB
JPEG2000 had quite a bit of buzz thanks to the UWB vendors. UWB was white hot this year and several vendors were demonstrating in-home video distribution of HD content via a wireless UWB solution. Tzero seems to be taking the lead in this category and had a nice demonstration in their booth. (rumor had it that Bill Gates even made a visit…wouldn’t that be ironic)
So how is this done?
A 1080 HD video signal creates an uncompressed data rate of 1424 Mbs. Encoded in JPEG2000, you can run a 3:1 compression and still be “lossless”. Encode at 8:1 and the result is “visually lossless”. At 3:1 you can get the data rate down to 475 Mbs, at 8:1 you can get it down to 178 Mbs. The wireless UWB pipe is running around 480 Mbs, so you can comfortably get a nice J2K compressed video running within those constraints. The Tzero folks had the compression up around 20:1, so I suspect there is some additional overhead or error correction that they are accomodating.
So why JPEG2000?
There’s a few answers to this question. First is the visual quality. Side by side, the J2K compressed video signal looks more appealing then that of an MPEG compressed video. Yes, this is subjective…but to my eyes, I find the macroblock artifacts to be very unnatural and noticable…especially on an HD monitor.
Another reason is the latency. It’s non-existant with JPEG2000. Not so with MPEG compression. This is problaby not a big deal for watching TV or a movie, but for gaming…that’s big.
Lastly, error resiliency. Ever watch television and have blocks and streaks disappear from the signal? What you are seeing is the MPEG compression trying to recover from an error. Although I’m no expert on wireless communications, I suspect that lots of bits are subject to interruption in the wireless UWB world. When JPEG2000 encounters such a loss of data, the visual result is almost undetectable. There’s a lot of underlying technical reasoning to this, but the visual result is a softening or slight blurring of the area where data is lost. Unlikely you’ll not even notice that when watching a video.
So why do I care?
You might not…but if you have a nice HDTV, lots of components and a gaming module then you have lots of expensive cables running amok. Personally my living room has been taken over by my daughters’ GameCube and controllers. I would love to have a centralized content distribution center that I could access with all my TVs, computers, etc. A wireless solution makes sense provided the visual fidelity is not compromised. I like the idea, I’d buy into that!
HD Photo F.U.D.
Microsoft Vista is being released this month and the marketing machine is kicking into gear. We have already seen a lot of comparisons of HD Photo to JPEG and JPEG2000. Most of the comparisons are not particularly accurate, but to the common person…how are they going to know? I suspect that we are going to have to deal with this issue more directly in the coming weeks.
Of note, we still face the issue of “what is JPEG2000″. The naming convention has lumped it into the JPEG camp and now the HD Photo camp. Its surprising how many “video experts” that we engage who have no understanding of its use as a video format. What to do, what to do?
HD Broadcast Production
Another hot area for JPEG2000 is in HD Broadcast Production. No, we’re not talking about distribution out to your house, but for use in the production facilities. With the increasing demand for HD broadcast content, these folks need to move a lot video content around the studios. Their first requirement is that they would like to preserve content in its highest form for as long as possible, primarily for editing purposes. Second, they usually have an exisisting infrastructure of GigE throughout the studio.
Back to our calculator…HD 1080 uncompressed is 1424 Mbs. Run a “lossless” compression of 2:1 and you can push that around easily over GigE. Cool trick…and I won’t beat the visual fidelity horse yet again.