Am 08.07.2012 23:35, schrieb Laurent Pinchart:
> Hi Oleksij,
>
> On Sunday 08 July 2012 10:45:45 Oleksij Rempel wrote:
>> On 08.07.2012 09:22, Eric Ding wrote:
>>> On 07/08/2012 02:52 PM, Oleksij Rempel (fishor) wrote:
>>>> Hi, can you please do one more test.
>>>> Try to reproduce it with MJPEG stream. Use this command:
>>>> luvcview -f jpg -C
>>>>
>>>> it will force jpeg (i think your cam support it) and store each frame
>>>> separately. If you can reproduce it, please send me one of this frames.
>>>
>>> Sure, I reproduced it fairly easily (with the kernel corresponding to
>>> commit e1620d5). I've attached the first frame dumped by luvcview (I
>>> already converted it from raw MJPEG to JPEG w/ Huffman tables to save
>>> you the trouble).
>>>
>>> Eric
>>>
>>> P.S. I actually attached a video showing another example of this problem
>>> to my original bug report on Launchpad:
>>>
>>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1017072/+attachment/3
>>> 202254/+files/SecondTime.avi
>> Ok,
>>
>> i have no more doubt about quirk.
>> The image should have fallowing path inside of the cam:
>> - sensor
>> - demosaicking processor
>> - jpeg compressor
>> - uvc packer
>>
>> since correct jpeg and uvc headers are produced, then the problem is on
>> first two steps.
>
> We could speculate on where the problem is inside the webcam, but that won't
> make much of a difference :-) Logitech webcams have been known in the past to
> have pretty serious race conditions in their firmware. Some of them have been
> fixed, but I wouldn't be surprised if several other similar bugs remained.
Hi Laurent,
i do this description for my self. First of all i wont to understand how
it work, to make better diagnosis. Then if i'm wrong, some body can
correct me. It also should help find cam with same symptoms. Indeed
there are non logitech cams with same symptoms. The problem, i thought
there are irreparably defect :(
> I can try contacting Logitech about this, but I'm not sure whether they will
> even be interested in investigating the problem. Their Linux support track
> record isn't as good as it was a couple of years ago :-/
>
>> I also tested my cam with USB_QUIRK_RESET_RESUME without any
>> regressions, in case you wont all_logitech_quirk. My cam is:
>> + /* Logitech Quickcam Notebook Pro */
>> + { USB_DEVICE(0x046d, 0x0991), .driver_info =
>> USB_QUIRK_RESET_RESUME },
>
--
Regards,
Oleksij
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