Many ISPs in Sri Lanka (Dialog, SLT, Hutch) offer daily fair usage policies. Streaming a 2GB Sinhala movie in H.264 burns through data. With H.265, you watch the same movie using 50% less data.
If you want to convert videos to this format for free, HandBrake is an excellent open-source tool that supports the x265 encoder. 265x sinhala free