Just to note that I managed to find a project which helps filling that immense lack in video playing on Android, the lack of video filtering:
the
ExoPlayerFilter library from MasayukiSuda.
One can build a media player from the ExoPlayer library, and integrate it with the ExoPlayerFilter to modify the video output (e.g. sepia, negative, contrast, edge, bump etc.) as needed, through OpenGL Shaders.
I assume OpenGL Shaders work on recent Onyx devices (Rockchip based, not i.MX 6 based). A video player based on that library and good filters (I am thinking e.g. of "posterize" effects) may reduce the battery inefficiency caused by the random placement of black and white dots on the screen every frame, owing to dithering.