There are V4L2 drivers that can't be opened more than once, extract from Section "1.1.3. Multiple Opens" from the Video for Linux Two API Specification also confirms it:
"In general, V4L2 devices can be opened more than once. When this is supported by the driver, users can for example start a "panel" application to change controls like brightness or audio volume, while another application captures video and audio." So I'm guessing Ben might have one of these V4L2 devices that don't allow multiple opens. With earlier 2.6 kernels, there were also V4L drivers that haven't been ported to V4L2 yet (note: V4L drivers can't be opened multiple times, but V4L2 drivers using the V4L compatibility layer can if the driver can). Doug > -----Original Message----- > From: [email protected] [mailto:accessgrid-l- > [email protected]] On Behalf Of Jason Bell > Sent: Thursday, 1 November 2007 8:41 AM > To: [email protected]; ag-tech; accessgrid- > [email protected] > Subject: [AG-L] RE: [AG-TECH] Dropping OSS device in Rat (Linux) > > G'day Ben > > The issue that I mentioned is in regards to OSS, you shouldn't see the > problem with ALSA. > > I am surprised that you are using ALSA, as the audio quality is > significantly better using OSS. > > I have never experienced the issue of the device not being present > straight away (which should always be the case). But I am pretty sure > there are no special scripts or anything like that which would delay > you from seeing the device. With the newer versions of Linux (using > the newer kernels), the video devices can actually be shared, unlike > the OSS device, therefore there would be no reason to do any delaying, > etc. > > Cheers, > Jason. _______________________________________________ accessgrid-l mailing list [email protected] http://lists.grangenet.net/mailman/listinfo/accessgrid-l
