On Sun, 20 Jul 2003, Ryan Ayers wrote: > > From: Christian Hack > > I still stand by my statement. Does the windows version capture full motion > > on all 4 channels. The only simultaneous capture cards I have seen have a > > different capture chip or have more than one capture chip fitted. > > > > Feel free to prove me wrong though. ;-) > > > > CH > > I've spoken with Gerd about this previously. The only way todo this with > the current linux bttv driver, is to switch inputs (very slowly). > Generally, this means, grab 1 frame, switch and skip 5 frames (waiting for > the video device to settle down). This gives a realistic throughput of > about 2 fps switching between 2 inputs. This is totally unacceptable for a > surveillance solution. There is some trickery going on in the windows > driver, because the exact same card with the windows driver can capture > around 10-15fps across 2 inputs. I have successfully used the package at http://motion.sourceforge.net to get much better switching between ports on bttv based cards. It uses the vloopback device to attach different inputs to virtual /dev/video devices. I had no problems getting 13-15fps from two inputs, and 8-10fps from three inputs. Ed Okerson
