[gst-devel] gstV4L2src: Issue with blocking VIDIOC_QBUF

Andy Wingo wingo at pobox.com
Fri Aug 24 22:51:59 CEST 2007

On Thu 23 Aug 2007 20:04, Stefan Kost <ensonic at hora-obscura.de> writes:

>> Is this a problem with the implementation of the
>> driver I am using? or is it a general V4L2 issue? Does
>> it happen due to priorities of the two threads? 
> It could be a driver issue. Unfortunately there is one detail not exactly
> defined in the specs regarding DQBUF.

Agreed; either the driver should not block during QBUF, or you should
redesign such that you memcpy() all buffers in the thread that produces
them so that you do not introduce QBUF syscalls from two threads.
Perhaps v4l2src needs a copy-mode property like v4lsrc, or otherwise a
mode to use the user ptr interface.



More information about the gstreamer-devel mailing list