Comment by gugagore

Yes, you don't need the machinery of learning when you already have an algorithm you're happy with. Adding a table of numbers, I don't think anyone hopes to do much better than we already do with our circuits and computer architectures.

With video compression, I think most would agree that there might be better architectures/algorithms that we haven't stumbled upon yet. Whether specifically "neural networks" will be the shape of a better architecture, I don't know. But almost surely some meta-algorithm that can try out tons of different parameters/data-pipeline-topologies for something that vaguely resembles h.264 might find something better than h.264.

Neural nets are expensive to train. But so is designing h.264.