| konnichiwa said: Well I am not an expert I just feel their is more going on when a blu ray movie is 50 GB in size (with almost no extra content) but you only use 14 GB to stream it on netflix =p. |
Heavier compression, with many more visible compression artifacts on the Netflix version. Plus Blu-ray uses 5 to 6 mbps for DTS HD-MA 7.1 sound, besides having all other soundtracks on the disk, while Netflix only streams one soundtrack to you at a time and uses at most lossy Dolby digital plus between 0.6 and 1.7 mbps.
4K movies on Netflix use less bandwidth than 1080p movies on blu-ray. In quiet scenes Netflix will resolve better detail in 4K, in heavy action scenes blu-ray stays more consistent in 1080p than Netflix in 4K. Netflix 4K uses a new compression algorithm that is near twice as efficient than blu-ray, yet blu-ray can dial up the bandwidth to 40mbps in action scenes for video alone. Even with the more efficient compression algorithm Netflix 4K can't match that.
The 2K movies you watch in the cinema are compressed as well, but are read from hdd at a max data rate of 250 mbps, 500mbps for HFR3D and no chroma subsampling. (full color info) I don't know the numbers for 4K digital cinema, likely over 1 gbps.
Uncompressed video output only exists in video games, anything else you see has some form of lossy compression.
HD Cable TV (7 mbps mpeg-2) < Netflix (5 mbps h.264 / 18 mbps h.265 4K) < Blu-ray (15 to 40 mbps h.264) < 4K UHD (30 to 80 mbps h.265) < 2K cinema (250 mbps) < 4K cinema (1gbps)
