Does Hydrus have any support for multiple audio/video streams in one file?
Say I have 4 videos with the same audio, just slightly different video (say different levels of clothing). You can use ffmpeg or what have you to combine them into one file with multiple video streams and one audio stream, which mpv can play (at least externally, cycling with the _ keybind).
You could do similar things for multiple videos which only differ in audio, say language (keybind #). You could even have both multiple video and audio streams in one file, if you really wanted.
I could have each video+audio stored separately in Hydrus, but to me they're the same video, just different variants. Being able to combine them would help reduce clutter in the search and lets you be sure just from the thumbnail that the variant you want is available.
I think it would be cool if Hydrus could switch video/audio streams without having to launch in an external program. Don't know the technical details on whether a keybind or right click menu or both would work, though.