[justinlaster]

> it would seem to be easy to have multiple threads, starting at key frames to decode the content.

It's a resource issue (memory, cpu, etc; and meeting latency requirements between those constraints), versus the subtly different standards "H.264" hardware and software follow, as well as a few other intricacies with how the whole standard works anyways. Again, it's not that it can't be done, but as the article says it can't be done easily or at least in certain situations done consistently.

Key frames are a good anchor around anything you're doing with H264 (and other formats), but it's not the end all and be all -- and they may even cause you trouble if you "trust" them too much. It is perhaps a bit like date time programming. You can create something fairly easily that works for a decent amount of time, and even if it ends up being incorrect your clients may not even notice... or it may breakdown in a catastrophic manner in the future. But doing the latter is certainly not correct and it's certainly not professional. Quite honestly, I'd say date time programming looks like a dream compared to the inconsistent nightmare that is video programming. Date/time logic needs to be sound because many programs rely on consistent and sane output from a program perspective, where as video programming gets to slide as long as the output is generally correct from a human visual perspective.

It's been a few years since I've dived into this stuff, so some things may have changed/gotten cleaned up. But the article seems to indicate that the ecosystem hasn't really changed.