Assembly has never been dead in the realm of multimedia processing, or for that matter, anywhere that you have to do an enormous amount of SIMD-able number crunching.
Find a video (en|de)coder without SIMD and you've found an unusable piece of software.
There's a reason that Intel focuses so much on SIMD instructions and arithmetic units with each new chip release: if not for SIMD or dedicated hardware, it would be physically impossible to decode 1080p video on almost any modern machine.
Not a tradeoff; that's just bad input checking. Most of ffmpeg's decoders have heavy checks in them--crashes are usually bugs (missing checks). Yes, the checks have a small speed cost, but it's at most 1-2%, probably less.
Find a video (en|de)coder without SIMD and you've found an unusable piece of software.
There's a reason that Intel focuses so much on SIMD instructions and arithmetic units with each new chip release: if not for SIMD or dedicated hardware, it would be physically impossible to decode 1080p video on almost any modern machine.