strange problem with KMC-4400R

strange problem with KMC-4400R

[Ming Liu]

Hi,

I am working on KMC-4400R card. I tried to write a program to use two 
channels from the card by following the example program of V4l2. 
However, I met a very strange problem.

When I kept capturing image, there were several lines following the 
moving objects like a ghost (sometimes more than one ghost) on the 
collected image. I can not figure out what causes this problem and how 
to fix it. The standard xawtv does not have this problem when only one 
channel is displayed.

Any comments will be helpful and many thanks in advance.

Sincerely yours
Ming

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Re: strange problem with KMC-4400R

[William M. Brack]

Hi Ming,

Ming Liu wrote:
> Hi,
>
> I am working on KMC-4400R card. I tried to write a program to use two
> channels from the card by following the example program of V4l2.
> However, I met a very strange problem.
>
> When I kept capturing image, there were several lines following the
> moving objects like a ghost (sometimes more than one ghost) on the
> collected image. I can not figure out what causes this problem and how
> to fix it. The standard xawtv does not have this problem when only one
> channel is displayed.
>
> Any comments will be helpful and many thanks in advance.
>
The 4400R is a rather strange beast.  There are, basically, four
controllers (e.g. /dev/video[0..3]) and 16 inputs; each input can go
to any of the four controllers, and the driver will also allow the
same input to go to more than one controller.  Each controller,
however, can display only one input at a time.

Your description sounds as if you are trying to use only one
controller, and switch it's input back and forth between the two
cameras.  Assuming you have no more than four cameras (and you said,
in this case, two), you should assure that each camera goes to a
separate controller (i.e. instead of using "/dev/video0 channel 1" and
"dev/video0 channel 2", for the second use "/dev/video1 channel 2". 
Hopefully that should give a "clean" image for both.

> Sincerely yours
> Ming
>

Regards,

Bill


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Re: strange problem with KMC-4400R

[Ming Liu]

Hi, Bill,

Thank you for the reply. Yes, I put one camera to "/dev/video0 channel2" 
and one to "/dev/video1 channel3" in my program.

I tested in two computers: one xubuntu (8.04) and one fedora 6. The 
problem only happens in the xubuntu system. Even I replaced the capture 
card with another KMC-4400R, the problem reappeared on the xubuntu system.

Any comments will be more than helpful.

Sincerely yours
Ming


William M. Brack wrote:
> Hi Ming,
>
> Ming Liu wrote:
>   
>> Hi,
>>
>> I am working on KMC-4400R card. I tried to write a program to use two
>> channels from the card by following the example program of V4l2.
>> However, I met a very strange problem.
>>
>> When I kept capturing image, there were several lines following the
>> moving objects like a ghost (sometimes more than one ghost) on the
>> collected image. I can not figure out what causes this problem and how
>> to fix it. The standard xawtv does not have this problem when only one
>> channel is displayed.
>>
>> Any comments will be helpful and many thanks in advance.
>>
>>     
> The 4400R is a rather strange beast.  There are, basically, four
> controllers (e.g. /dev/video[0..3]) and 16 inputs; each input can go
> to any of the four controllers, and the driver will also allow the
> same input to go to more than one controller.  Each controller,
> however, can display only one input at a time.
>
> Your description sounds as if you are trying to use only one
> controller, and switch it's input back and forth between the two
> cameras.  Assuming you have no more than four cameras (and you said,
> in this case, two), you should assure that each camera goes to a
> separate controller (i.e. instead of using "/dev/video0 channel 1" and
> "dev/video0 channel 2", for the second use "/dev/video1 channel 2". 
> Hopefully that should give a "clean" image for both.
>
>   
>> Sincerely yours
>> Ming
>>
>>     
>
> Regards,
>
> Bill
>
>
>
>   

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