Thanks Paulo, I've using only YUYV ... I don't use MJPEG because I have an own library to capture and I have not yet implemented that. Probably I should work on it now.
Thanks again and best wishes On Fri, 29 May 2009 22:40:58 +0100, Paulo Assis wrote > Javier, > I've done some more testing and this is what I found when capturing > 640x...@25fps video from 2 uvc cameras on the same controler, both from > logitech a QC5000pro and another camera I've been testing: > - I can capture video from both of them when streaming MJPEG data on > the two cameras. - I can capture video from both of them when > streaming MJPEG data from one and YUYV data from the other one. - > when using a YUYV stream on both I can only capture from the first > camera, from the second I get a error of no space left, basically > the USB bandwith is not enought. > > Best regards, > Paulo > > 2009/5/29 Javier Martinez Baena <[email protected]> > > > > > Thanks Paulo, not only Logitech fails, but also Creative (Optia AF at > > least). > > I will get a new Philips soon ... I hope this will work better. > > > > > > On Fri, 29 May 2009 13:49:55 +0100, Paulo Assis wrote > > > Javier Hi, > > > You should know that at least logitech cameras don't handle well usb > > > hubs, logitech is very clear on this, if you want you can get more > > > info on the quickcamteam site and forums, it has something to do > > > with the way data is handled by most usb hubs. Anyway I have been > > > able to connect up to 3 uvc cameras simultaneously in my pc, and I > > > believe two of them were on the same host (I mounted the pc myself > > > so I should know this for sure, but my memory has seen better days :) > > > ), all of them use the ehci driver. Some drivers are in fact buggy, > > > just check the following link for a example > > > (in this case the musb driver): > > http://forums.quickcamteam.net/showthread.php?tid=821 > > > > > > Best regards, > > > Paulo > > > > > > 2009/5/29 Javier Martínez Baena <[email protected]> > > > > > > > >Hi Javier, > > > > > > > > > >On Friday 22 May 2009 09:36:32 J. Martínez Baena wrote: > > > > >> Hello, > > > > > > > > > >> I have a problem with 2 webcams I'm trying to get work > > simultaneously. I > > > > >> have several models (Logitech P3000, Logitech P9000, Creative > > LiveCAM > > > > Optia > > > > >> AF, Philips). When I plug two of them on different USB ports, then > > > > >> everything works ok: I can see both simultaneously with, for > > example, > > > > >> luvcview. > > > > >> > > > > >> The problem exists when I plug two of them on the same USB (for > > example > > > > on > > > > >> frontal USB or in a USB hub). I've got the problem for combinations > > in > > > > wich > > > > >> UVC driver is used by both cameras. I can get frames for one of them > > > > (the > > > > >> first that I try), but for the second one I get a "noisy/green" > > screen > > > > ... > > > > >> it seems as if the image is corrupted. > > > > >> > > > > >> However, if I put the philips and the logitech P9000/Optia it works > > > > fine. > > > > >> The Philips (and logitech P3000) use a different driver than UVC. > > Also, > > > > I > > > > >> can plug two philips webcam and they works fine. > > > > >> > > > > >> ¿Is this a bug or an unresolved problem of the UVC driver? ¿Is it a > > USB > > > > >> problem? > > > > > > > > > >My guess is that you're having USB bandwidth issues. As the uvcvideo > > > > driver > > > > >starts capturing video on both cameras, you're not exceeding the > > > > theoretical > > > > >USB bandwidth limit. However, bugs in the USB host controller, the USB > > > > host > > > > >controller driver or the camera can result in corrupted data. Could > > you > > > > >perform the same test on another computer ? > > > > > > > > > >Best regards, > > > > > > > > > >Laurent Pinchart > > > > > > > > > > > > Hi Laurent, > > > > > > > > Sorry for the delay ... I make some tests on several computers and the > > > > problem > > > > persists. My guess is that is a problem of UVC driver (but I'm not an > > > > expert > > > > ... so it's only a guess!). When I connect different webcams (using > > other > > > > driver than UVC) it works. > > > > > > > > I tried with different resolutions (320x240, 640x480, ...) and > > different > > > > framerates. > > > > > > > > Sometimes, when a cam is running (capturing), I can't even initialice > > the > > > > other one (neither consult for allowed resolutions, etc). > > > > > > > > But I don't know how USB driver works, so, maybe an USB problem. > > > > > > > > Best regards > > > > > > > > > > > > _______________________________________________ > > > > Linux-uvc-devel mailing list > > > > [email protected] > > > > https://lists.berlios.de/mailman/listinfo/linux-uvc-devel > > > > -- DEpartment of Computer Science and A.I. http://decsai.ugr.es _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
