Generate screenshot without downloading entire video

I'm parsing some podcasts in a back-end application and I need to generate some screenshots for them. How开发者_如何学Goever, downloading the entire videos is not an option.

Is there a way to download just a small part of the file to extract the screenshot from? Ideally, it would be the middle part.

Thanks!

Is an application that parses xmls to get screenshots in the middle part, on a web app using django and python. I'll hope to be platform independent. It will get podcasts from the place where are hosted and only get the screenshot automatically. The podcasts can have big size (500 Mb) so that's why downloading is not an option.

It is possible if the video hosting server support "Range" http request header which you can find out by seeing the "Accept-Ranges" header value, if it is true then it supports the "Range" header. Then you can ask for the middle 5-10 MB of video using "Range" request header. You can get the content length via "content-length" http response header.