for a project i needed to take in and send out realtime analog (composite) video. analog video input has always been a problem, but on recent laptops apple even removed the video output via dvi adapter option (i.e. there is no displayport to video/s-video adapter).
so after experimenting and going through some old hardware i had laying around, i found a solution using two devices that i last used around 10years ago.
* dfg1394 bus powered s-video/composite video to uncompressed firewire converter from imagingsource (firewire version not longer available).
* mac osx drivers for the dfg1394 from outcastsoft. works with max/jitter etc.
* an old TView Gold scanconverter from Focus enhancements. used in combo with a 5v power from usb hack and a displayport to vga adapter.