I've been writing a set of encapsulating classes for video4linux for our workplace, and the classes are finally done enough that I can see frames from my USB webcam on my development machine. The aim of the project is to provide a nice easy interface for a legacy project that uses a BT848 capture card. My problem comes in that although my testing application works fine with a USB camera on my development machine, with the BTTV card on the testing machine it wont dispaly anything. It appears that the program is stopping at the read(fd,buffer,sizeof(buffer)) command and not returning. I know that the device is opened, and have been trhough the CSPICT and CSWIN ioctls, and outputing the device class shows that all the values for those and the other structures are reasonable. My first idea was that it would be related to the video channel, and the tuner settings, however I've noticed that Xawtv seems to do the same thing. If I start up Xawtv in full screen mode then the video comes through fine on every channel (although it's all in black and white and horibly grainy). It comes throught he same on every channel, as we only have a webcam conencted directly to one of the composite ins, thats to be expected, however if I start xawtv in windowed mode, it stops responding, and can only be killed with a kill -KILL command, just like my application. I have tried a variety of differant methods, full screen, differant resolutions and palettes, and I can't get even a grainy bad image to appear to my application, does anybody have any ideas, cos I'm fresh out of them :( I can send portions of code and exmaple outputs if necessary, but don't want to clutter the list. Michael Spall ECM Systems
