Q+ Player, an UPnP DLNA DMR

This media player supports UPnP DLNA, can be played as a DMR (digital media renderer). Accessing files via SAF (Storage Access Framework) which moderated by users. 

It supports full-featured SSA/ASS subtitles. Users can add or manage font files by themselves. SSA/ASS subtitles can be dimmed, to fit HDR and DV higher contrast and brightness playback. The font size is resizable.
Subtitles in SUP (Blu-ray) and VobSub (DVD) format are supported as well (start from version 5.1). All subtitles can be either MKV embedded or side-loaded. Users can pick and apply single subtitle file, or package in Zip/7Z/RAR format during playback.

This player supports HDR/DV content, digital audio passthrough, MKV chapters navigation, frame by frame stepping, audio track selection and delay, subtitles selection and time offset. Also frame rate displaying and refresh rate auto adjusting. 

Dolby Vision playback on NVidia Shield TV 2019 succeeded. Videos can be rotated on demand, as well as full screen zooming by pinch.

It was originally designed for segmented files playback. They are presented in m3u8 (HLS media list) format, which is originally designed for TS only, but they can be mp4 or flv files now.