Using Kitty with background_opacity 0.6, Hyprland with blur enabled, and Jolteon configured to use GruvboxDarkTransparent and the beautiful wallpaper of Outset Island by Matt Vince.

• Automatic sorting
• Search for song through entire library

• Bookmarks
• When adding an entire folder, scan folder for .cue files and offer using the cue sheet rather than adding individual tracks from the folder.

Currently, files can only be added to playlists from the file browser. Support to do so from the Library is coming soon.

If any non-bug causes an issue, rather than just being ignored, it'll be communicated in a status area. For example: a file that cannot be played correctly, for whatever reason.

Same goes for performed actions ("Added X to library", for example).

Status: partially implemented; almost complete.

• There will be some way to switch themes programmatically from outside the application, for themes to be switchable by external scripts.
• Integration with OS light/dark mode will be added. Which theme is associated with each mode will be configurable, but have a sensible default.
• See assets/gruvbox_dark.toml

Status: partially implemented

• Deleted playlist are soft-deleted, not truly deleted.
• The playlist graveyard can be opened and closed with F8.
• The playlist graveyard cannot be focused or used at all, right now. Just opened to see it, and closed. In the future, it'll be properly interactive, allowing un-deleting playlists, and maybe hard-deleting.

The currently playing song and its position will be persisted too, so, rather than to start playing the next song, it'll start playing the same song at the position it was when Jolteon was closed.

Cue sheet tracks are handled as if they were individual files. If playing 2 consecutive tracks from a single Cue sheet, when track A finishes playing, Jolteon will still close the file, open it again, and seek to the starting time of track B. This basically defeats the gapless playback we get for free from Cue sheet files. In the future, this case will be handled specifically, to take advantage of it and just keep playing the same audio file.

True gapless playback between different files is a different challenge. Latency is addressed by buffering two files at once rather than just one, and, roughly speaking, chaining the decoding iterators. We may still wind up with undesired pauses or audible artifacts between songs. Ideally, for gapless playback, we should always try to have a single, big audio file for the entire album, with its Cue sheet.

Partially implemented. The app checks for new GitHub releases when launched, and detects new versions, but doesn't yet download the published binary.

Displaying music by artist, album, track number and song title is generally more desirable than navigating the file system, but, sometimes, being able to manually structure and organize music beyond its metadata is convenient.

Personally, I prefer having all soundtracks under an OST folder, rather than mixed with bands. Same goes for "classic" music, or interpreted music in general (as opposed to original compositions).

There's no real reason not to support both approaches at once, by organizing music files by metadata but allowing grouping by virtual directories, which would enable things like:

• Interpreted
  • Bach
• Modern
  • The Doors
  • Pink Floyd
    • The Piper at the Gates of Dawn
    • The Dark Side of the Moon
    • Wish You Were Here
• Soundtracks
  • Cowboy Bebop
  • Ry Cooder - Crossroads

Kitty supports full-resolution, full-color images. It shouldn't be particularly hard to add this feature.

I'll have to figure out the best UI and UX for this, and probably make it optional/configurable.

Jolteon uses Rodeo to play music, with the symphonia backend.

I mainly use flac files, and some mp3. Other formats aren't usually tested.

So far, I've only found one issue with one flac file, which fails to perform seeks, and, after a few seconds of playback, causes the cpal thread to panic, crashing Jolteon. This same file does run well with mpv. It does report errors reading it, but it still recovers well from them, and is able to seek without issues.

I tried switching the flac backend, but got even worse results. I looked into using libmpv and libavcodec, which, in my mind, are pretty much guaranteed to be more stable, but switching to them is far from trivial.

Figuring out the specific bug in the flac codecs built in pure Rust is probably an easier and more reasonable path forward.

And Jolteon shouldn't crash if the audio playback crashes, but that's a story for another day.

I don't benchmark Jolteon, but I do use it many hours, every day, and the release build always stays at .5% of my CPU, and usually 25MiB of RAM. I manually compare this to mpv (with --no-audio-display) and Jolteon usually consumes about the same CPU and significantly less RAM.

I haven't experienced any issues with the audio performance itself, but this is handled by symphonia and cpal, so there isn't a lot Jolteon can do to break it. Same goes for the UI, which is managed by Ratatui.

I keep it open for days at a time — sometimes, even over a week, and haven't seen it crash or increase memory usage.

If you do experience any sort of performance issues — be it choppy UI, keyboard input response, choppy audio, or significantly higher CPU/RAM usage than mpv or any other well-known media player for the same file, please open an issue reporting it. Being able to reproduce this with an audio file available in the public domain, or with a license that permits sharing it, would be ideal, even if hard or very unlikely.