New Usb To Hdmi Adapter


fischju2000

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http://news.thomasnet.com/fullstory/551830

One of these seems a lot better than the option of analog VGA and about the same price. Also a lot easier than adding another output yourself (if that is technically possible).

Problem would of course be drivers and how much of the CPU it would take. Not much use if you can't use the Pandora for anything while it outputting an HD picture.
 
seems nice in theory but unfortunately the quality is guaranteed to not be very good
also the price is pretty steep
 
$179, lol. I somehow don't see myself spending that much on a single accessory for my pandora (or likely all of them put together, unless I get a solar array or some such to power it with).
 
Well a quick bit of maths tells me that the "34Mbps" they claim it takes over USB (I thought the maximum was WAY over that... USB is supposed to be 480Mbps isn't it?... even allowing for overhead, that's little more than USB1 was - dunno what they've buggered up there but they repeat that claim twice) is much less than a 1600x1200x16 bit display requires (each frame, uncompressed, woud require 1600x1200x2 bytes = 3.8MBytes x 60fps = 230MBytes/s). MPEG4 compression of that image would still take up about 50Mbit/s for the same video on a standard profile, still way past their 34Mbps number.

So it's sending a *highly* compressed image, so this means the brunt of the *encoding* of the video image (because this is taking an image from the computer and putting it out to an HDMI adaptor) is done by the host CPU.

So your poor Pandora will be *encoding* HD-res footage at quite high compression onto a realtime-sensitive device connected over a USB hub. That doesn't bode well. Even some modern laptop computers can struggle with *decoding* HD-movies and that's with optimisation, drivers, graphics cards, etc. Encoding always takes MUCH more resources.

Just as a hint, most ordinary 720p TV-out's (or even TV-in's) struggle on old machines if they work over USB because of the compression required. I've seen an WinTV over USB struggle to hit five FPS and even then there are artifacts on a 600MHz machine - that's with MPEG *decoding*. I would think this idea was dead in the water unless they've got something magical. However, I imagine they slapped a MPEG decoder chip tied to the HDMI interface inside the device (that hardware is probably super-cheap now given the prevelance of HDMI and MPEG decoding on the same chip) and rely on the host computer to encode and send a suitably compressed MPEG stream over USB to account for USB's unsuitable transfer rates. It's like the old WinModem days where the work done by the host CPU could bring the system to a halt if it was an old machine.

It might work, but it's a lot of work for the Pandora to do. I'm not sure how well it would work with drivers (do they exist for Linux, are they binary blobs because of MPEG encoding patents, licensing etc.?), optimisation (e.g. are the drivers optimised for ARM or, more likely, for MMX/SSE instructions to do the encoding?), battery life (probably severely limits things if it's running at 75-100% CPU all the time to display an image, and I assume you'd want to display *something* interesting like an emulator etc., which will add to the load), jerkiness (if things are scheduled incorrectly or you have a lot of stuff happening on the Pandora, it isn't going to be able to keep up with HD, refresh rates, etc.).

I would *guess* that if it did work, it would be next to useless at actual HD resolutions and all you'd end up with is a very expensive TV-Out that only worked at SD resolution.

P.S. My maths might be wrong but I'm pretty sure, given devices that I've seen, that the general feeling is correct.
 
I don't think we'll see full HD coming out of the Pandora. Something like this might be good for sending standard def images to a newish TV or monitor though. I've got a new BenQ 22" HD monitor (E2200HD), which is shared between PC and Xbox 360. It would be cool to use it for Pandora gaming as well (forgetting quality issues for the moment). Bit pricey for that though.
 
I really don't like the fact that the pandora's tvout function will be svideo. svideo is good for vga outputs, but it would be really interesting to have component-out. you could have progressive 720p with ease.
 
well something like shooting a revolver through the back of a cannon is what I originally imagined
 
It's a nice idea, but as already explained very well, the output quality is not going to be worth anything near the price. Might as well just up-convert the s-video output.
 
Gruso said:
I don't think we'll see full HD coming out of the Pandora. Something like this might be good for sending standard def images to a newish TV or monitor though. I've got a new BenQ 22" HD monitor (E2200HD), which is shared between PC and Xbox 360. It would be cool to use it for Pandora gaming as well (forgetting quality issues for the moment). Bit pricey for that though.

The OMAP3530 can output to two 1920x1200 displays via the LCD output, the other solution would be to add another hookup to this and use fancy means of turning that into a usable signal (externally).
 
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^ The OMAP3530 can perhaps, but not Pandora. Not without some serious hardware hacking anyway. You'd basically be pulling it apart and turning it into a Beagleboard. :p
 
Even if the Pandora could *output* HD, it doesn't mean it has the processing power to do anything useful with it. The difference between 800x480 (pandora default res), for example and 1920x1200 (the OMAP highest res) is a 6 times increase in the number of pixels that need to be drawn, and hence the amount of data going over the internal buses. Six times!

And that's just doing simple stuff like drawing a nice 2D bitmap. Once you get into 3D games etc. you are multiplying up the amount of video RAM and processing that needs to be done on the GPU and across the buses by much more than that. Then you might well have to do lots of per-pixel testing/drawing for some games (even 2d platformers), which means that you're running code which increases in complexity, memory use, CPU use in line with the total number of pixels. So over the already-stressed main bus with it's 6x graphics data, you're trying to do loads more calculations too. Now this is a horrible simplification but things literally do scale like this. Anyone around in the early DOS days knows this... you couldn't run Doom in high res without a mean machine, you couldn't run GTA in anything other than 320x240 if you didn't have a real 3D graphics card in your machine or a powerful PC for the time.

The GP2X can run Quake perfectly in 320x240 resolution. What you're suggesting is the equivalent of running Quake at 800x600 on the same machine. It won't happen or, if it does, you'll get (at least) a six-fold reduction in framerates, everything else being equal.

Forget it. Your Pandora (or any device with limited CPU power) ain't gonna be able to look much better on your telly than it does on the Pandora screen, scaled up a bit, and if it *does* it's gonna take quite a performance hit to do so.

P.S. Personally, I think HD is a waste of time anyway unless you've got an ENORMOUS telly or you're sitting six inches from the screen. My family just got a 46" one (running, coincidentally, at a true 1920x1200 resolution) and although the picture is absolutely enormous, standard SD shows up worse than their old 32" CRT showed it. HD programming doesn't look any better on the HDTV from a certain distance than the same program in SD (or even just "trying" to show a HD channel) on the old CRT next to it (I know, because the five of us tested it). That magic distance where you can actually spot the difference in casual viewing happens to be just short of the nearest chair/sofa (we didn't move any of the chairs and the new HDTV is actually *closer* because it's so large and on a diagonally-placed table in the same corner)

Any reasonable distance from the telly and your eyes can't distinguish pixels properly anyway - don't think they can because you can spot a single white pixel on an entirely black telly, or because the HD "looks better" than SDTV because a lot of tricks and physical processes are in play that only take effect when you're not concentrating/staring/looking at realistic motion, not to mention manufacturer tricks to make SD look crappy on cheap HD TV's etc.
 
ledow said:
Even if the Pandora could *output* HD, it doesn't mean it has the processing power to do anything useful with it.
Displaying OpenOffice presentations would be a great deal of "useful", and I'm sure the Pandora processor and a USB-HDMI adapter would be up to that.

The bandwidth calculations for 1600x1200 assumed every pixel would be changed. This is fair for movies, but presentations are what 90% of folks would want HDMI output for, and that would need trivial amounts of bandwidth to the display. For my part, doing the occasional presentations is one of the main reasons I still have a laptop. If I could give them from my Pandora, I would seriously consider dispensing with a conventional laptop entirely.
 
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The USB to VGA is really going to be a big demand...

It's the only way to get any monitor hooked up... literally having a portable universal workstation.
 
Korlithiel said:
$179, lol. I somehow don't see myself spending that much on a single accessory for my pandora (or likely all of them put together, unless I get a solar array or some such to power it with).
Yikes, for that price you almost might as well buy a media center device like the apple tv or something that will be guaranteed to have better output and function as expected.
 
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Korlithiel said:
$179, lol. I somehow don't see myself spending that much on a single accessory for my pandora (or likely all of them put together, unless I get a solar array or some such to power it with).

As I already mentioned in previous thread on USB - VGA, I will buy this one:
UK (65 GBP), US (70 USD). People's experience with it: [1], [2]. The sisusb linux driver webpage.
 
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cosurgi said:
Korlithiel said:
$179, lol. I somehow don't see myself spending that much on a single accessory for my pandora (or likely all of them put together, unless I get a solar array or some such to power it with).

As I already mentioned in previous thread on USB - VGA, I will buy this one:
UK (65 GBP), US (70 USD). People's experience with it: [1], [2]. The sisusb linux driver webpage.


cool, thanks for the links! i think i'll order one of them right away :)

one (possibly stupid) question: will it work ok through a usb hub, too? i know it will take some performance hit, but that's no problem. just to make sure i can make a 'docking station' with vga, mouse and keyboard through one usb port.
 
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fischju2000 said:
http://news.thomasnet.com/fullstory/551830

One of these seems a lot better than the option of analog VGA and about the same price. Also a lot easier than adding another output yourself (if that is technically possible).

Problem would of course be drivers and how much of the CPU it would take. Not much use if you can't use the Pandora for anything while it outputting an HD picture.



thats one reason why i think firewire should of replaced usb. usb is highly dependent on the cpu speed for transfer rates due to it's controller less nature. due to this a usb drive ends up being a order of magnitude slower then one on a actual controller. this makes a system pretty slow if one has to boot from a usb drive. i though have seen firewire drives in the same situation perform about the same as a internal drive.
 
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