USB/Firewire "Branching" -- Is it Possible? 55
Shaze asks: "I have been doing a lot of overseas web conferencing lately and have been playing around with my two webcams. I was suddenly intrigued by the idea of being able to 'span' or 'branch' both webcams together to create one device pulling signals from both. I did some quick research on the topic to no avail, however many of my colleagues believe this to be possible. Some even going so far as to say they have seen software or drivers that will turn your webcams into one Twain device. Aside from my own meanderings, I can't seem to find any information on anyone or anything even suggesting this is possible. What do you say Slashdot readers: Is this a new application waiting to be marketed or am I just seeing double?"
To what end? (Score:2)
What do you hope to acomplish by doing this? Stereovision?
Does it have to be real time?
In short, why?
-- MarkusQ
Re:To what end? (Score:1)
Sounds like he wants a camera aggregator driver which glues together 'n' webcams into a single, larger (or PiP style) image.
I can't see that this is likely to be supported by anything. Most likely he'll want a piece of software which reads 'n' webcams in realtime and pastes them together (solving any refresh, synchronisation, resolution and format problems) a
Re:To what end? (Score:1)
You forgot free, by tomorrow, and with as little work from himself as possible.
Re:To what end? (Score:1)
To an end TWAIN was not designed for. (Score:2)
After all, TWAIN is not SANE [mostang.com].
depth (Score:2)
Uh, what? (Score:1, Redundant)
Likewise "One device pulling signals from both" is equally nondescript. I have plugged two USB cameras into one machine before. There is no problem doing this. If you want them to both work at the same time, you'll have to use seperate host controllers or USB 1.1 cameras on a USB 2.0 bus.
Shouldn't need separate controllers for USB2.0 (Score:2)
Perhaps he's hoping to glue together enough webcams to get decent resolution? (-:
Re:Shouldn't need separate controllers for USB2.0 (Score:3, Informative)
USB1.1 devices on a USB2.0 controller can be difficult.. If you didn't put them on seperate controllers you'd have to put them on a USB hub with multiple USB1.1 USB2.0 TT's. The Transaction Translator is the device responsible for translating the USB1.1 data to USB2.0 and vice versa. There is typically only one TT per USB controller in the chipset. Webcams are especially nasty si
Possible, but pointless (Score:2, Informative)
However, this would probably require a total software rewrite to enable. I don't imagine drivers would need major revisions, fortunately.
My main question, though, is why? Unless you plan to red/blue shift the objects based on apparent depth and require people to wear stupid glasses, you won't see any interesting effects.
I think we should be more concerned with bringi
Re:Not pointless (Score:4, Informative)
Hooking two cameras to a computer is standard practise in computer vision (not what my current employer does, just another example). It's a really good way to get binocular views of a scene for passive stereo systems.
Besides, you don't need goofy red/blue glasses to look at stereo pairs of images. Just cross your eyes, for goodness sakes!
Re:Not pointless (Score:2)
Re:Not pointless (Score:2)
You forgot 'hairy palms'. What have AC's come to?
Re:Not pointless (Score:2)
Re:Not pointless (Score:2)
Re:Not pointless (Score:1)
Did this happen starting in your twenties? I find this a more plausible explanation, unless somehow you found occasion to "freeview" at stereograms for hours a day??
Re:Not pointless (Score:2)
You can buy a cheap stereoscope for general use for between $2 and $6, is yo
Re:Not pointless (Score:1)
Re:Not pointless (Score:2)
Re:Not pointless (Score:1)
So since I'm naturally nearsighted, I should do it more so that my vision becomes normal?
Re:Not pointless (Score:1)
Re:Not pointless (Score:1)
So I'm curious--do you use a Mac for that? If so, are you willing to describe more about what you do/where you work? I know that Macs aren't the only things with FW, but they're most of what I see actually using it...
You're welcome to reply off-list if you prefer.
Re:Not pointless (Score:1)
Technology's there, but driving adoption is hard. (Score:2)
Well, that's all well and good, but even though there's one-to-one Internet video conferencing technology good enough that TechWeb thought it was a satellite feed [macdailynews.com] when they saw it last week, it still needs extensions to support one-to-many, many-to-one and many-to-many conferencing.
And even then you'd still have the onerous task of convincing everyone to use iChat AV [apple.com]. After all, it's an Apple [apple.com] product, a
Well... maybe not with webcams, but... (Score:2)
The catches are:
There are probably computers out there with enough horsepow
Re:G5? sheeit. . . (Score:2)
Re:G5? sheeit. . . (Score:2)
Re:Well... maybe not with webcams, but... (Score:2)
Most modern computers today have 3D accelerators in them. Those cards are basically built to do image processing in hardware. (Naturally they are made to transform 3D -> 2D, but the math is largely the same so it doesn't matter.)
I've only seen stuff about this in academi
Well... not with storage,, but... (Score:2)
This guy was able to enjoy 24oz of carbonated refreshment instead of 12, but looked like a total ass.
What??? (Score:3, Informative)
Re:What??? (Score:3, Funny)
Yeah! I got an email today telling me they could make it twice as wide!
Something about a pill.
Come to think of it, I get one of these emails almost everyday.
Re:What??? (Score:2)
Thats what I thought (Score:1)
I've seen similar (Score:3, Informative)
I've never seen something that uses one USB and one Firewire camera, though. To me, it makes just as much sense to use two FireWire cameras or two USB 2.0 cameras since the bandwidth of USB 1.2 is so small. I did some computer vision work as an undergrad with a single Logitech Quickcam Express. The camera grabbed 24 bit 320x244 images at a rather low framerate - something like 10 or 15 fps. This took up 90% of the USB's bandwidth!
If you want to, you might be able to write a driver that allows you to treat the two as a single TWAIN device, but I imagine the possibility of such a task is highly OS-dependent. I haven't taken a good look to check, but it seems like it would be possible to do so under the Video4Linux framework. MacOS and Windows, I have no idea.
What do you want to do today? (Score:2)
The Easy Way (Score:2)
http://www.3dstereo.com/Merchant2/merchant.mvc? S cr een=PROD&Product_Code=LOR-LICeos&Category_Code=jl- ncam&Product_Count=28
Another approach that would be more universal (i.e. can put any 2 video signals together) would be to preprocess it with conventional analog TV split screen gadgets, the 2 video inputs are merged
Sure, why not? Except on Linux. (Score:3, Informative)
I have multiple cameras working quite well under QNX, but I wrote that driver. It only uses about 4% of the (1.5GHz) CPU per camera at 640x480 x 15FPS RGB, so it's a modest CPU load. I don't get the image tearing problem Windows does, so the hardware can do the job; it's a Windows problem.
The Linux FireWire driver subsystem has some major problems in the bus reset area and doesn't handle multiple bus masters properly. The last time I looked at that driver, it didn't allocate isochronous channels properly; everything went on channel 0. That limits you to one active camera. But that may have been fixed by now.
Custom Drivers (Score:2)
Custom driver == expensive (either in time... or money or both)
Application: WebcamXP (Score:3, Informative)
how about a link to something ? (Score:4, Informative)
Where I used to work (Score:3, Informative)
What FPS was it? (Score:2)
Re:What FPS was it? (Score:2)
And as for FPS... I think it was a bit jerky as it was used to record between two monitoring devices (where a little stutter is not too bad) and might not be suitable for PVR recording, but then the software (custom-made) wasn't too great either. I'm not sure the channel-swapping was at fault though.
For hom applications, you could probably get away with a standard TV-input card. The per-channel FPS woul
Re:What FPS was it? (Score:2)
two apps (Score:2)
The answer you want may be... (Score:2)
Haven't they led most of the practial/commercial advances in this area?