Re: First Film To Be Sent Via Satellite
Not to take this off the subject, but I'm pretty sure that the commercial
projectors don't use the DLP (digital light processing) chips, but are D-ILA
projectors built by Hughes-JVC. These projectors use LCDs with a direct
radiating lamp that reflects off the LCD. The DLP is a very good technology for
home theaters, but doesn't provide the resolution for a theater size
presentation (limited to about 1024x768 grids at this point).
Alteon WebSystems, Inc.
a Nortel Company
and sometime Home Theater nut
Jugnu Ojha wrote:
> Cool stuff, all this. But the REALLY cool part is the TI projection
> technology used to display these movies - large arrays of MEMS mirrors that
> are binary toggled to achieve intensity variations. 3 arrays are used - one
> for each primary color. The images are combined optically. The mirrors are
> reliable enough to project for something like 20 years nonstop before
> expected failure.
> Jugnu J. Ojha, Ph.D.
> Technical Advisor, Optical Networking
> Caspian Networks Inc.
> (408) 382-5213
> fax: (408) 382-5588
> -----Original Message-----
> From: Bill Nowicki [mailto:BNowicki@xxxxxxxxxx]
> Sent: Friday, November 17, 2000 9:07 AM
> To: 'Rogers, Shawn'; '802.3ae'
> Subject: RE: First Film To Be Sent Via Satellite
> Been lurking for some time, now something we know about:
> The press release mentions that this used the QuVIS products, which use a
> proprietary wavelet encoding. So speculations about the MPEG-2 used on DVDs
> or miniDV underestimate the compression ratio (a modern proprietary scheme
> should do much better than venerable old MPEG-2). On the other hand, they
> start with 24 frames per second at over a thosand lines and more than twice
> that many horizontal samples, at twelve bits per component sample.
> Now sending this uncompressed stream would use 10 Gbps links as noted. But
> after the compression, my guess is that the rate is a few hundred megabits
> per second. A similar encoding our products handle is HDCAM, which is
> intra-frame compressed high definition down to about the rate of an
> uncompressed Standard Definition. Encryption would not expand but of course
> error correcting codes for the sattelite links would. And no reason for the
> transfer to be real time (the press release says it is about four times
> slower than real time). The QuVIS people have estimated a movie in their
> format would take about 8 DVD-ROMS (using their encoding of course, NOT DVD
> MPEG-2!) or a few tens of gigabytes.
> Bill Nowicki, Omneon Video Networks