On Thu, Dec 2, 2010 at 9:21 PM, Jack O'Quin wrote: > On Thu, Dec 2, 2010 at 11:48 AM, Blaise Gassend wrote: >>> Just to make things clear: it will still not be a good solution for >>> firewire camera users >>> as images will still be unsynchronized. Only one process grabbing two >>> cameras will solve >>> this issue with high end firewire cameras such as the Flea2 which send >>> automatically synchronized frames >>> when the acquisition is done atomically. > > What DC1394 command triggers this acquisition? > > Or, is it something device-specific? Yes, this is done by the device. >From the Flea2 documentation: « Automatic Synchronization Multiple Flea2 cameras networked on the same IEEE-1394 bus are automatically synchronized to within 125µs (maximum deviation) of each other, and can synchronize across buses using Point Grey MultiSyncTM software. » http://www.ptgrey.com/products/flea2/index.asp There is nothing in the userland which has to be used to enable the synchronization, it is automatic as long as the acquisition of the two images is done fast enough (which separate process cannot achieve). >> OK, I agree with you here. If a combined driver can easily cause the >> cameras to be triggered simultaneously then there is value in adding >> support for this to the camera driver itself. -- Thomas Moulard http://www.linkedin.com/in/moulard