Re: [gphoto-devel] Gphoto2 support 4 Vupoint Pen cams (Chris Simpson>

[<ki...@ba...>]

On Sun, 24 Sep 2006, gph...@li... wrote:

>   3. Gphoto2 support 4 Vupoint Pen cams (Chris Simpson>
> Message: 3
> Date: Sat, 23 Sep 2006 22:11:42 -0500
> From: "Chris Simpson" <ch...@pa...>
> Subject: [gphoto-devel] Gphoto2 support 4 Vupoint Pen cams
> To: <gph...@li...>
> Message-ID:
> 	<GIE...@pa...>
> Content-Type: text/plain;	charset="iso-8859-1"
>
> To whom it may concern,
>
> I am trying to put a webcam on a Debian (sarge) linux server. I have had no
> success thus far with this software or any other that i have found. I know
> that the system is able to detect the device but I can't mount it or make
> any simple program work with it. Below is an output of the debugging command
> as requested for additional support. Please see if you can get support into
> the build for all VuPoint models. If you know of any other webcam software
> that would work with the Vupoint cameras that would be helpful.

Chris,

Is this a "dual mode" camera which can be used both as a webcam and as a 
stillcam? If so, then perhaps its stillcam feature should be supported 
here. If we know what its USB Vendor:Product ID comes out to be, and some 
of that other good stuff from lsusv -v (or even better, from the 
/proc/bus/usb/devices file if your distro is provides you with that) would 
be very helpful, as a first step. For, what we get from the log file is 
simply

6.632386 context(0): Could not detect any camera

*** Error ***
Could not detect any camera
*** Error (-105: 'Unknown model') ***

which means that we do not have support for it.


Now, if your camera is a pure webcam, we do not support webcams at all 
here. Why not? Well, for a rather fundamental reason. Libgphoto2 is a 
"userspace" project, which accesses all USB I/O stuff through libusb, 
which provides a standard interface to the lower-level USB stuff, which is 
handled by the Linux kernel. Thus the access to the USB ports is slowed 
down, as a consequence of the fundamental security model underlying the 
design of Linux (and, boy, we don't want to throw that away, do we?). In 
this situation, the reaction times are simply not fast enough to run most 
webcams. Thus, in general a webcam needs to have a kernel module 
supporting it in order to function.

If your camera is a pure webcam, or if it is dual-mode and you want to 
support the webcam functionality, we would thus kindly suggest that you 
look for kernel webcam support for it. One good way to see if it is 
already supported would be to search for the Vendor and Product numbers of 
your camera in the source code for the latest kernel.

Whether in this project, in the kernel, or in any other project, to rely 
upon the name and model on the outside of the camera when looking for 
support can be worse than useless. The "manufacturer" may not be putting 
anything on the camera but a decal with some writing on it and may have 
even changed the internal parts completely from the last production batch, 
without changing the outside of the case or the shrink-wrapped package. 
Case in point; The Vivitar Vivicam 55 used to use a certain chip. Someone 
has been having trouble with one of those, so I went down to the store and 
bought a Vivitar Vivicam 55 last week. Was no help, because what I bought 
has another chip in it. The only way to know for sure about what is inside 
is to hook up and get the Vendor and Product numbers. Truth must be 
present at some level, or else no operating system on God's earth could 
support a USB device. Look for those numbers. That's where the truth is.


Theodore Kilgore