Dieter wrote:
Well, some basic questions to ask ourselves:
1) What will it do? I personally think that a reasonable aim is decoding
video, hopefully even 720p/i or possibly 1080p/i, in real time (30+
fps),
while also providing a simple framebuffer and possibly audio. If
video is
the way to go, what formats?
1080p
Mpeg 1, 2 up to 80 Mbps
Mpeg 4 up to 20 Mbps ( Is this really the worst case? Seems low. )
H.264 up to 40 Mbps
H.264 is the killer. :-(
It is worse than just H.264, it has to be H.264 HiP 1080p/30! Only
dedicated hardware is a viable solution for that. Look at the size and
price of the first HD-DVD and Blu-Ray players. They probably are not
using a single chip solution for decode.
What is "HiP"? I searched a bit and didn't find anything that looked relevant.
Check WikiPedia.
Any sort of DSP should also work.
This seems very promising if we can find a suitable one. The TI ones look
great except they aren't fast enough. Anyone know if/when TI is coming
out with a newer faster model? I think a couple recent posts had pointers
to other brands?
The DSPs for video decode are fixed point. For OpenGL, we need a
floating point
Does video decode have to be done in fixed point, or could a floating point
unit be useful? Perhaps a fixed point unit and a floating point unit
working together somehow?
A DSP based card isn't going to decode H.264 HiP 1080p/30
If TI can speed theirs up it might.
I should have made that clear: a floating point DSP isn't going to do it.
OGD1 and OGC are going PCI-X/PCIe, so this project could go the other way
and use Ethernet. The TI chips have it built in, I'm not sure about the
other brands.
I think that most users will expect a PC expansion card.
Most users buy a Gateway/Dell/HP with virus server preinstalled.
There are lots of people clammering for a good small quiet Ethernet-to-TV box.
4) What sort of output? DVI, s-video, S/P-DIF, etc.
DVI plus s-video.
New TVs aren't going to need S-Video.
You want to throw all the old TVs into the landfill? Not very green.
When transmission goes to all digital, a lot of them are going to the
land fill. :-) If we have a box, this would be OK, but if it is a PC
card, it is going to take another card or a break out box.
What is S/P-DIF ?
Digital audio single cable.
We'll also need creaky old RCA analog audio out for all the prehistoric
TVs we want to avoid throwing into the landfill.
Sound cards usually have mini-phone stereo (3 conductor).
It would be good to support component if we can.
Are there new TVs or monitors that have component (analog) that don't
have DVI or HDMI?
I read a lot of complaints from people with $$$$ HDTV with component-in
and no digital-in. Should they throw their recent $$$$ TVs into the landfill
also?
No, they should probably keep them. My relatively inexpensive HDTV has
HDMI. I think that most current products have HDMI. Component video is
going to take a lot of hardware to produce.
Question is, do we require DVI dual link? DVI single link is good
for 1080, but only up to 60 Hz. There is a strong possibility that
we will need to support 1080 at higher than 60 Hz. And there are the
3 or 4 people that have the spendy 30" displays that require dual link.
Most current wide screen monitors are 768 lines but higher resolution
ones will be coming. Currently, 1080 is only common on screens larger
than 32 inches. This issue might or might not be determined by the
chips we use.
This makes it sound like you only care about TVs sold today, not TVs
sold 2 years ago or 2 years in the future.
No, I think that 2 channel would be good and would hope that we could
find a chip that supports it. It is a fact that we need to consider the
current and future market when designing a product. Too much of
"caring" about past TVs is going to run the price up and we will sell
less rather than more of them.
The 23-24" LCD computer monitors are 1920x1200. Just right for 1080 plus
a letterbox area for subtitles / closed caption / clock / frame counter /
editor GUI buttons / whatever.
Yes, they are here and they cost as much as my HDTV, or more -- to me
$$$$ means not very common. But, next year they will be less expensive.
If they need 2 channel DVI/HDMI, then we need it.
--
JRT
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