<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Arial; font-size: 12pt; color: #000000'>Yiliang,<br>I found a great example using the V4L2_CID_EXPOSURE control.  My problem is, I can't find any info on what headers to include that would define the V4L2_CID_ZOOM_RELATIVE, ABSOLUTE & CONTINUOUS controls.<br><br>Does anyone know where those CIDs are defined?<br>-Thanks in advance,<br>John Buckley<br><br>----- "Yiliang Bao" <yiliangb@gmail.com> wrote: <br>> Hi John, Yes, you can do this. You can open another file on the same device using following<br>> function, even if the device is already streaming video.<br>> fd = open (videoDevName, O_RDWR /* required */ | O_NONBLOCK, 0);<br><br>> Usually it is allowed by the v4l2 driver, as long as you are not trying to stream video in the<br>> second opened instance.<br>>  -Yiliang<br><br><buckleyassoc@comcast.net><br></buckleyassoc@comcast.net></div></body></html>