> -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf > Of Markus Rechberger > Sent: Tuesday, April 13, 2010 2:24 PM > To: Andreas Auer > Cc: [email protected] > Subject: Re: UVC webcam problem > > On Tue, Apr 13, 2010 at 10:27 AM, Andreas Auer <[email protected]> > wrote: > > Hi, > > > > I'm trying to get a UVC webcam working with the latest khilman kernel > > (2.6.34) on a Davinci EVM like board with DM6446 processor. > > > > I'm able to request the buffers and queue them without errors. But if I > > switch on the streaming the UVC driver tells me: > > "uvcvideo: USB isochronous frame lost (-18)." > > > > Some time ago, I tried the 2.6.32 kernel from the arago project and > webcam > > capturing was working out of the box but WLAN was not working. (so, I > > switched to the khilman kernel). > > > > Maybe, someone can help me with the uvc webcam problem!!! > > > > with our tests the DM6446 only supported up to around 4.5 mbyte of > isochronous data...
DM644x USB supports only normal ISO mode hence the max ISO bandwidth achievable is limited to ~64Mbps. > Raw Analog TV 720x576x25 requires around 170 mbit, I guess webcams are > near to that level there's no chance to get such a thing work. > Maybe MJPEG or MPEG based devices can work with it. One could use BULK mode if higher throughput is needed but not may webcams support such a transport. > > Markus > _______________________________________________ > Davinci-linux-open-source mailing list > [email protected] > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
