4K resolution
The term "2160p" could be applied to any format with a height of 2160 pixels, but it is most commonly used in reference to the 4K UHDTV resolution of 38402160 due to its association with the well-known 720p and 1080p HDTV formats. Although 38402160 is both a 4K resolution and a 2160p resolution, these terms cannot always be used interchangeably since not all 4K resolutions are 2160 pixels tall, and not all 2160p resolutions are ≈4000 pixels wide. However, some companies have begun using the term "4K" to describe devices with support for a 2160p resolution, even if it is not close to 4000 pixels wide. For example, many "4K" dash cams only support a resolution of 28802160 (4∶3); although this is a 2160p resolution, it is not a 4K resolution. Samsung also released a 51202160 (64∶27) TV, but marketed it as a "4K" TV despite its 5K-class resolution.
Vudu
Movies are encoded in MPEG-4 video and Dolby Digital Plus audio. Vudu offers movies in three formats: standard-definition (480p and 480i), high-definition (1080p and 1080i) and ultra high-definition (2160p) or commonly known as UHD or 4k. Standard-definition movies are up-scaled to higher 1080i/p resolution and high-definition movies can be output at 1080p24. Audio is sourced in Dolby Digital Plus and output in Dolby Digital 5.1, with the option of stereo output. Audio is limited to stereo playback on HTPC/PC/Mac platforms. Users are able to adjust video to display in stretched, boxed, or zoomed format as well as adjusting overscan settings depending on their television format.