Re: USBVision device defaults

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On Wed, 1 Jul 2009, Andy Walls wrote:

> It's unclear to me if the PowerOnAtOpen module parameter works properly
> when set to 0.  It might actually prevent the automatic shutoff in 3
> seconds if set to zero.

I hadn't spotted that option, it does seem to work and enables the device 
to stay active after the programme using it has exited, preserving the 
settings. With PowerOnAtOpen=0, using the normal unmodified driver, I can't 
get a picture using either flash or kdetv. However, using my bodged driver 
which forces use of the SVideo input, I can now get a colour picture in 
flash by starting and exiting kdetv first. Odd, but it does at least 
provide a workable solution to my problem.

> Also, by inspection I think the driver has a bug you may be able to
> exploit.  If you already have the driver open with an application,
> trying to open it with another application will fail, but not before
> reseting the poweroff timer back to three seconds.  So if you have an
> app that attempts to open() and close() the usbvision device node every
> 1 second, I think you can keep it from powering down and losing it's
> settings.
> Here's a useless little program to do just that.  Compile it and invoke
> it as 'program-name /dev/video0'

I gave the code a try, it works up to a point, I get a colour picture in 
flash, but the picture is frozen. I suspect your programme is grabbing 
the video device back from flash before I can kill it.

Thankyou for your help ! If anybody on this list decides to try and neaten 
up the code for the usbvision driver, I'm happy to do a bit of testing 
work (contant me on tmw@xxxxxxxxxxxxx, I may not stay subscribed to this 
email list permanantly).

Tim W

Tim Williams BSc MSc MBCS
Euromotor Autotrain LLP
58 Jacoby Place
Priory Road
B5 7UW
United Kingdom

Web :
Tel : +44 (0)121 414 2214

EuroMotor-AutoTrain is a company registered in the UK, Registration
number: OC317070.

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