On Wed, 2001-10-17 at 12:13, Almond Wong wrote: > > Besides, I brought a card with BT878 on board and 4 composite input. Is > BT878 can support 4 camera at the same time, what is the frame rate per > second ? Any limitation ? > You can capture video just from one input at the same time. The only way you can capture from N cameras with just one video card is to switch inputs periodically. This method has, however, limitations. When you switch from one video input to another, the bt878 takes some time to resync to the new analog input stream (unless you are using phase-syncronised cameras). This leads to the fact that a number of fields captured after input switching are invalid (a mixture of both inputs, black stripes across the images...). To avoid this, you would have to discard those invalid fields. This will all make the capture speed turn to less (quite less) than the theoretical 50 fps PAL (60 fps for NTSC). Miguel
