>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
