Re: image quality of Labtec Webcam 2200

["Németh Márton" <nm127@freemail.hu>]

Jean-Francois Moine wrote:
> On Fri, 11 Sep 2009 09:09:20 +0200
> Németh Márton <nm127@freemail.hu> wrote:
> 
>> You can find my results at
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html
>> There are three types of problems: a) Sometimes the picture contains
>> a 8x8 pixel error, like in image #9
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00009
>> b) Sometimes the brightness of the half picture is changed, like in
>> images #7, #36 and #37
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00007
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00036
>> http://v4l-test.sourceforge.net/results/test-20090911/index.html#img00037
>> c) Sometimes the libv4l cannot convert the raw image and the errno is
>> set to EAGAIN (11), for example image #1, #2 and #3
>>
>> Do you know how can I fix these problems?
> 
> The error EAGAIN is normal when decoding pac7311 images, because they
> are rotated 90°. But this error should occur one time only.

I have the feeling that the Labtec Webcam 2200 is not based on the PAC7311
but on PAC7312. The PAC7312 also contains a microphone input and the
Labtec Webcam 2200 also have a built-in microphone.
See http://www.pixart.com.tw/productsditel.asp?ToPage=1&productclassify_id=12&productclassify2_id=33
for the datasheets. See also http://labtec.com/index.cfm/gear/details/EUR/EN,crid=30,contentid=761 .

> I looked at the raw image #1, and it seems that there are JPEG errors
> inside (sequences ff ff). There should be a problem in the pac7311
> driver. Hans, may you confirm?
>