I am trying to continuously capture and digitise raw composite video signals with sufficient bit depth and sample rate to be able to decode it including the colour channels. I am not looking for a video capture board as i'd like to have the raw signal and decode it in software myself.
So my question: What is the most cost effective way of doing this? i've already looked at digital oscilloscopes (pico etc) which offer capture functionality. but i am not sure if this is the best / cheapest option. it seems to me that capture of analogue signals would be a fairly common requirement but haven't found many easy to use products that do this. Ideally i am looking for a USB connected device with an interface to C++ or similar. any advice greatly appreciated!