Netflix halves size of 4K films
Netflix announces in its own Tech-Blog that it wants to re-encode its complete premium product range, thus halving the size of all movies and series. The range includes 4K (UHD) films/series, 10-bit color depth, HDR and HFR.
Although the bitrate is reduced, there should be no loss of quality. Up to now there were static encoder settings, but these are now to be dynamically optimized per title and scene. For this purpose, a special procedure, Video Multi-Method Assessment Fusion (VMAF), is used. With VMAF, the image is optimized for human perception rather than for technical peculiarities.
According to Netflix, the new approach provides sharper textures and higher detail at lower bit rates. It is even planned to re-encode the entire catalog with this technique, which is expected to be completed in a few months.