Even at 300MB, a file sourced from a BluRay will look significantly better than one sourced from a "CAM" (camera recording) or "HDRip."
While it sounds like a tall order, this specific niche of the internet caters to people who want a cinematic experience without burning through their data or storage space. Here is everything you need to know about how these files work and how to find the best quality. What are 300MB Dual-Audio Movies?
Even on slower internet connections, a 300MB file can be downloaded in minutes. The Myth of "All Size Free"
This is the gold standard for small files. It provides better color depth and clarity than the older x264 codec at the same file size.