Below The Convex Hull

Netflix replaced its one-size-fits-all bitrate ladder (for example 1080p pinned at 5800 kbps for every title) with a per-title ladder. For each title they run trial encodes at several resolutions and quantizer settings, measure quality against the source after upscaling back to display resolution, and keep only the points on the upper envelope of the resulting curves.

A complex action title measures like this:

Bitrate (kbps) 480p 720p 1080p
560 36.1 35.2 33.4
1500 38.4 39.1 37.6
3000 39.6 41.8 42.3
4500 40.1 42.9 44.8

Which resolution belongs on this title's ladder at the 1500 kbps rung?

A

1080p, since the target device is a 1080p display and the client upscales anything smaller

B

480p

C

720p

D

1080p