WebCam Options for Linux? 40
Doesn't_Comment_Code asks: "I am working on a motion capture system, and I plan to implement it with several webcams viewing the same space from different angles. I have looked into some webcams and drivers for Linux, but I'm not sure which are best. Specifically, I need to connect three, four, or five cameras to a single machine. Can any current Linux drivers accommodate this? Also, I'm looking for basic, no-frills cameras, as automatic gain control and other features may amplify dark parts of the image that I need to stay dark."
Linux USB Camera Support (Score:2, Informative)
You'll probably find this page/list useful as a starting point
- Gef
Philips (Score:2)
Remember you'll have to choose the camera based on the 'chipset', not the brand name.
camera... (Score:2)
Can be easily modified to use v4l
Creative Video Webcam Plus (Score:2, Informative)
brooktree / motion (Score:2)
However, there are many different cards based on the bt878 chipset which support two or more inputs and if I was mad enough to do it all again I would probably use two or three such cards in a dedicated (and slightly faster, perhaps 400MHz) camera server, and scan them using motion [sourceforge.net] That should give me up to 9 cameras scanned at
USB 2.0 (Score:2)
Now, The Philips is a USB 1 device, but USB 2 has MUCH more bandwidth than 1. Try sticking an external CDROM into a USB 1 port one day and you will see what I mean.
So a USB 2.0 camera would probably be better, but I do not know if there is any such thing. A USB 2.0 PCI card is quite cheap though, although on my Suse 8.2 box the !"! machine does not boot completely if there is nothing stuck into the US
USB 2.0 != High Speed (Score:2)
Re:USB 2.0 (Score:2)
Re:USB 2.0 (Score:2)
Re:USB 2.0 (Score:2)
I'm running SuSE 8.2 and the same thing happens. I'm willing to bet you have an ASUS board. Anyhow, I get around this by appending "noapic" to my boot string but YMMV. I can confirm that everything "just works" using 2.6-test5 so I'm hoping the 2.6 kernel in SuSE 9.0 allows me to run without the apic kludge.
Re:USB 2.0 (Score:2)
Video4Linux (Score:4, Informative)
Video4Linux (Score:2)
QuickCam Web (Score:2)
You can't do anything wrong (Score:1)
Just to be sure if a specific driver is multi-device capable ask the developer if it's not specified on the website.
I suggest you go find the cheapest three webcams, look them up in the USB devices database [www.qbik.ch] if they work with Linux, and then use motion [sourceforge.net] to get the images.
Use cameras made for the task (Score:2)
se401 (Score:2)
Some of this has been done (Score:1)
The camera I use... (Score:1)
"Webcam" no good for motion... (Score:3, Informative)
As another person stated above, get some capture cards with BrookTree chips. The Bt848 and Bt878 are very well supported in Linux, and have been for many years (used to use one on a 486).
The cards can be had around $50-$75 usually, sometimes as cheap as $20-$25 at local computer shows.
According to the docs for the bttv driver, the PCI bus doesn't get saturated with 4 cards, so this is probably the way to go.
Another plus is the fact that not only are these capable of much higher resolution than any USB camera out there, the signals you can pipe into these cards can be much higher quality and from a variety of sources (old camcorder, mail-order pinhole camera, DVD-player via S-video, etc.).
In other words, you can use a high-quality CCD rather than a low-res/low-quality/low-light-sensitivity CMOS imager (that nearly all USB "webcams" have).
Another possible option is ieee1394 ("firewire") cameras.
Anyone know if any firewire webcams (not camcorders) are supported in Linux? (I've only seen two brands, years ago)
BTW: I have an IBM and a Labtec USB webcam. While both work with Linux, both suck horribly in every category compared to my Sun Camera connected to my Bt878 card (which also contains TV and FM tuners).
Re:"Webcam" no good for motion... (Score:2)
However I do agree about the flexibility of input sources, as well as the importance of CCD versus CMOS. I have a nearly antique Connectix QuickCam VC, which was CCD until Logitech bought the line and made them CMOS. Though the resolution isn't great, it does give very clear pictures even in low light. The case broke long ago, so I built the gu
Re:"Webcam" no good for motion... (Score:2)
(since it's analog, horizontal is indeterminate).
Every USB "webcam" I've seen maxes out at 352x288 (at best).
This is a limitation of the hardware itself, they use 352x288 1/4" CMOS imagers.
USB cameras interpolate to 640x480.
BrookTree cards can handle 640x480 streaming real-time (30 real frames per second).
That data rate is impossible with USB(1).
The question was for motion capture.
Forget the misleading labels on your webcam box, try and capture at 352x288
Re:"Webcam" no good for motion... (Score:2)
The reason is that with the progression of digital camera resolutions, the high-pixel-count imaging sensors are rock-bottom priced and find their way into webcams. QCIF sensors are used only in the dirt-cheap bottom end devic
Re:"Webcam" no good for motion... (Score:2)
Brand and model please?
Please give examples of these magical webcams that can do 640x480 at 30fps over USB1.
We should use this wonderful technology to get a few orders of magnatude higher throughput over all serial data lines!
You're not going to convince anyone that you can do real-time video at any reasonable resolution with USB1.
you are forgetting something (Score:1)
That said, I still think that a capture card is the best bet because it allows you to change the camera at a later time without worying about breaking your Linux support
Re:you are forgetting something (Score:2)
I'm curious which USB webcam can do 640x480 at a reasonable frame rate, even if it does use hardware compression, that works with Linux.
Please let me know, as I know a few people who'd love to get one.
Re:"Webcam" no good for motion... (Score:3, Interesting)
That said, naturally USB 1.1 even in Full Speed won't do 640x480 at 30fps. But USB 2.0 is getting pretty common, so you could try this camera for $99 [orangemicro.com].
Re:"Webcam" no good for motion... (Score:2)
Hey, and it has experimental Linux support.
Very cool! Thanks!
(the comment about speed was due to the fact that the topic of the Ask Slashdot question, and of my posting, was motion capture)
Re:"Webcam" no good for motion... (Score:2)
Ack... I spoke too soon.
The ibot2 uses a CMOS sensor (not a CCD), which means it is horrible in low light conditions.
Re:"Webcam" no good for motion... (Score:2)
CMOS sensors do work really well in good lighting. Which means 90% of the time you'd actually need to use the camera...except the other 10% they are useless.
Re:"Webcam" no good for motion... (Score:1)
No. Not in the sense in which you are using the number. The 525 lines of NTSC includes all of that groady analogue stuff from the start of one frame to the start of the next frame: vertical blanking, synch, et al. The number of lines of picture is more like the familiar 480 (or maybe 486, depends on which standard you ask).
Not completely. There are bandwidth limits to color NTSC that are well defined
Re:"Webcam" no good for motion... (Score:2)
IIRC, NTSC bandwidth translates into a nominal 704 pixels per scan line -- non-rectangular pixels, with
Use video cameras + capture, not webcam (Score:1)
As someone else mentioned, forget it if you want motion. In that case, PCI/1394 is the only way to go.
Use industrial cams (Score:1)
LinuxMediaLabs MultiChannel PCI Boards (Score:1)
http://www.linuxmedialabs.com/
Check out the LMLBT4M card (listed under all products) 4 channel multiplexed or the LMLBT44 with 4 channel full-rate.
They have free software with motion capture.
Are there cheap cameras with exposure control? (Score:2)
I could tolerate 10 frames per second and 160x120 pixels, but I can't tolerate the motion blur. I want to do stereo vision, so I want all the cameras to capture an image at the same time.
What's the cheapest USB or firewire camera which allows control of the exposure time and timing?
My computer has USB 1.1, 2.0 and firewire ports on the motherboard. I don