The pricing for high speed ADCs is very high. However, since video decoders are used in just about every flat panel display, and these generally contain a couple of ADCs, their prices are very low. So, the obvious question arises. Is it possible to use a video decoder as a multichanneled general purpose ADC....and even interleaving the channels to increase the bandwidth further. I've been scouring the web and haven't been able to find any papers or DIY projects doing this. If anyone reading this is aware of any such projects, then please point me towards them. I'd love to see if this is possible (both using them channel by channel and interleaving the channels to get an even higher sampling rate). In terms of pricing, a video speed general purpose ADC would cost in the order of $30 per chip, whereas the video decoder would be priced at about $3 per chip, a pricing order of 10:1 !!!! So, if you know of a project or paper related to this, please pass on the link. Many thanks in advance.
I like this idea. You may find that the level clamping and line buffer xcircuitry may prevent you from using it as a general purpose ADC device.
Check as many data sheets as you can find, some chip might have a debug, or level aquisition mode that streams raw samples.
I would see if there is any information relating to the opensource Software Defined Radios that makes use of commodity interfaces. Something in this line may be able to serve your purposes. Also there are some DIY digital scopes that may serve but this may be exactly what you are trying to replace.