Video encoding and editing is not wisely done on a laptop anyhow. Aside from the fact that mobile systems generally have lower performance CPUs, memory and drives, they tend to die early deaths when used consistently for such purposes, much like regular, even high end, non-gaming laptops do when used for demanding gaming.
They simply do not have good enough cooling to last under the rigors of such processes for a long time if this is something you are doing, or will do, on a fairly regular basis. Certainly they CAN do it, but I'd want a fairly high end model and I'd make certain that there are absolutely no indications of thermal issues on any specific unit I was looking at both in professional reviews and as a general consensus on...