At the same time, how many video players have been written in pure python? Assuming the number is non-zero, how many get any use?
Using python as an example here makes little sense, since the constraints of the problem domain make it a particularly poor choice. Try choosing a language that doesn't suffer as much in performance (future Rust, maybe?).
Oh, I agree. I think that C was the right choice for FFmpeg, at least at the time, and I do not think that python would be the right choice for it today.
I'm just making a point that language is relevant when discussing the type and frequency of errors that are surfacing in a project.
Language has a lot to do with what sort of issues programmers will have to tackle.