New video and music features in Kodi 16

Version 16.0 of the Kodi free-software media center was released on February 21. Unlike some previous releases that debuted major new features (such as Android support in 13.0 or H.265 video support in 14.0), this new release appears comparatively quiet on the surface. Under the hood, though, there are several changes that will make life easier for users, particularly where user-interface issues and system maintenance are concerned.

The installation procedure is a rather cut-and-dried affair at this point. Official builds are provided by the project for several Ubuntu-based distributions, as are community-maintained builds for Fedora, Debian, and OpenELEC. There are also packages for download for Android (both ARM and x86), a variety of Raspberry-Pi–specific distributions, Windows, iOS, OS X, BSD, and for an ever-growing list of consumer hardware devices like Amazon's Fire TV. Apart from the iOS and consumer-hardware cases (which may involve jailbreaking steps), little is required to get up and running.

The Kodi user interface, likewise, has stabilized over the past few release cycles, and navigation is more streamlined and logical than it was in years past. There are still UI inconsistencies to be found, such as whether the "close" button appears on the right or the left of a pop-over window. And in some instances, multi-page blocks of text (such as the "Description" block in the Add-ons Manager) can only be scrolled by using the mouse, not with arrow or page up/down keys. But, on the whole, media sources and configuration options are reachable in only a few clicks, it is difficult if not impossible to get lost, and the interface is virtually devoid of arcane internal terminology. The latter is a considerable accomplishment indeed, given that it includes explaining video calibration and debug logging.

Speaking of logging, one of the most-highlighted new features in this release is Kodi's new event-logging framework. This is a mechanism that provides an in-application, browseable view of a wide variety of events: adding new media to the library, altering settings, installing add-ons, and so forth. The logged events include errors and warnings, which the release notes highlight as a feature that users have missed in past releases—leaving them unable to troubleshoot problems when newly-added media fails to show up in the library, for example.

An example of the subtle improvements in 16.0 is the revamped Music Library feature. Kodi has developed a reputation for admirable handling of video content (both local and remote), but has let its support for serving as a music manager languish. The 16.0 release marks the start of a renewed effort to rectify the situation. Adding new audio content is now much simpler, and Kodi automatically scans and adds the relevant metadata from the files.

There is also a new framework in place to support advanced audio processing. Though it is not active yet, in future releases it will pave the way for a number of audio features, like multi-channel equalizers, "fake surround sound," and a variety of other effects.

Deeper under the hood, the new release brings two changes to the way skins and other add-ons are stored. The first is that the file layout used within skin add-ons has been changed to match that of other add-on types; this was primarily done to make it easier to migrate settings from one skin to another. The second and perhaps more interesting change is that add-ons can now share image resources. It may take some time for add-on authors to begin taking advantage of the feature, but it will enable skins to, for example, provide a customized look to other add-ons (such as theming the icons of media sources to match the UI).

On the video front, perhaps the most obvious new addition is support for non-linear stretching of 4:3 content to fit on 16:9 displays. The technique employed tries to retain the center of the screen without visible distortion and progressively stretches out the image closer to the sides of the display. Of course, purists still might scoff at anyone deigning to watch Citizen Kane in anything other than the original aspect ratio, but there are surely instances when such elongation is necessary. Users who employ Kodi as a digital video recorder (DVR) will be pleased to note that Kodi's PVR module (from "personal" video recorder) now supports "series" recording rules, which is a staple of most other DVR applications.

Those users with 3D displays (either 3D-capable TVs or virtual-reality headsets) will get to sample a unique new UI feature: Kodi UI "skins" can now employ 3D depth effects, with the default skin ("Confluence") providing an example. The much larger group of users without 3D displays also get some UI improvements, however. Most notably, the "long press" action is now supported in Kodi's remote-control command mapping. That makes it possible to use Kodi with a number of modern, simple remotes—where the recent trend is toward directional arrow keys, a "Select" or "OK" button, and little else.

This style of remote is particularly popular with consumer hardware like the Fire TV; users who control Kodi through other means (such as a wireless keyboard) are unaffected. The long press is bound to Kodi's context-menu action by default, so it pops up a menu of additional commands. Those using Kodi on a Linux box with touchscreen support have yet another UI option, as Kodi now supports multi-touch gestures. Gesture support has been available in the Android and iOS releases for some time; there is a small set of gestures recognized by default, though it is configurable.

Finally, the Android rendering stack has been reworked to cope with 4K displays. In earlier releases, both the Kodi UI and any video content being displayed were rendered to the same surface, using libstagefright. But that made it impossible to render the UI and the video at different resolutions. Rendering the 4K version of the Kodi UI brought interactivity to a crawl on most Android devices, while limiting video playback to 720p or 1080p resolution would defeat the purpose of 4K support. Starting with the 16.0 release, the video stream and the UI are rendered to separate MediaCodec surfaces (rather than libstagefright), thus enabling 4K hardware-accelerated video while keeping the UI at its native, non-4K resolution.

As a project, Kodi relies heavily on the community of add-on and skin developers for implementing new user-facing features. So as the core application matures, there may be fewer big developments in every release cycle. Nevertheless, as the 16.0 release shows, there will always be room for improvements. Some of the new under-the-hood functionality will take time to trickle out as developers update add-ons and skins, but there is certainly enough in the new release for users to be happy with the upgrade.