Hi Oleksij, On Monday 09 July 2012 07:35:54 Oleksij Rempel wrote: > Am 08.07.2012 23:35, schrieb Laurent Pinchart: > > 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 > >>> /3202254/+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. It's a good idea, but don't try too hard, Logitech webcams can be *really* buggy ;-) > 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 personally consider many webcams to be broken enough to qualify for a refund. Of course vendors probably disagree... > > 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, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
