QtPotato is a Qt 6 / Kirigami video player for Linux. Playback is handled by libmpv, and the interface is modelled after Haruna. It can also translate a whole subtitle track with any OpenAI-compatible API and show the result in the player.

Features

Subtitle translation: sends a text subtitle track (embedded or external) to an OpenAI-compatible chat completions API in batches, with nearby lines as context. The result is cached as an .srt file, so the same video does not have to be translated twice.
mpv playback: hardware decoding and everything else libmpv supports. Your mpv.conf is loaded at startup (can be turned off in the settings).
Subtitles: track selection, a secondary subtitle, delay, font size and outline settings.
Playlist: other videos in the same folder are added automatically, with repeat and stop-after modes.
Recent files, MPRIS (media keys and Plasma's media controls), and full screen with auto-hiding controls.
Follows your Plasma style, colours and icons.

Building

Dependencies

CMake ≥ 3.25 and a C++20 compiler
Qt ≥ 6.8 (Core, Gui, Qml, Quick, QuickControls2, Widgets, Network, Concurrent, DBus)
KDE Frameworks ≥ 6.10: Extra CMake Modules, Kirigami, KI18n, KCoreAddons, KCrash, KConfig
MpvQt ≥ 1.0
QCoro ≥ 0.10 (Qt 6)
QtKeychain ≥ 0.14 (Qt 6)
FFmpeg (libavformat, libavcodec, libavutil)

On Arch Linux:

sudo pacman -S cmake ninja extra-cmake-modules qt6-base qt6-declarative \
    kirigami ki18n kcoreaddons kcrash kconfig mpvqt qcoro qtkeychain-qt6 ffmpeg

Build and run

cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build
./build/bin/qtpotato [file]

To install system-wide:

sudo cmake --install build

Tests

cmake -B build -DBUILD_TESTING=ON
cmake --build build
ctest --test-dir build

AppImage

packaging/appimage/build-appimage.sh [build-dir]

The script downloads linuxdeploy and bundles the Qt, KF6 and mpv libraries from the host. The AppImage only runs on distros whose glibc is at least as new as the build machine's.

Translating subtitles

Open Settings → Translation (Ctrl+Shift+,) and fill in:
- API base URL: the OpenAI-compatible endpoint including the version path, for example https://api.openai.com/v1 or http://localhost:11434/v1 for Ollama.
- API key: stored in your system wallet (KWallet / Secret Service), not in the config file.
- Model: type a name or click Load Models to fetch the list from the API.
- Translate into: the target language, written the way you would tell the model (default: Vietnamese).
Play a video and select the subtitle track you want to translate.
Press Ctrl+T (Subtitles → Translate Subtitle). Progress is shown in the player; when it finishes, the translated track replaces the original.

Translations are cached in ~/.cache/qtpotato/translations/ as <video>.<key>.<lang>.srt. Only text subtitles can be translated; image-based ones (PGS, VobSub) are not supported.

Keyboard shortcuts

The defaults follow Haruna.

Playback

Action	Shortcut
Play / pause	`Space`
Seek backward / forward 5 s	`Left` / `Right`
Seek backward / forward 15 s	`Shift+Left` / `Shift+Right`
Seek backward / forward 30 s	`Down` / `Up`
Previous / next chapter	`PgDown` / `PgUp`
Previous / next frame	`,` / `.`
Slower / faster	`[` / `]`
Reset speed	`Backspace`
Previous / next file	`Shift+,` / `Shift+.`
Volume down / up	`0` / `9`
Mute	`M`

Subtitles

Action	Shortcut
Translate subtitle	`Ctrl+T`
Toggle subtitles	`Ctrl+S`
Previous / next subtitle line	`Ctrl+Left` / `Ctrl+Right`
Next / previous subtitle track	`J` / `Shift+J`
Show earlier / later	`Z` / `Shift+Z`
Larger / smaller font	`Ctrl+Z` / `Ctrl+X`
Add external subtitle	`Alt+S`

Window

Action	Shortcut
Open file	`Ctrl+O`
Open URL	`Ctrl+Shift+O`
Full screen	`F`
Playlist	`P`
Screenshot	`S`
Settings	`Ctrl+Shift+,`

Seek step sizes and the volume step can be changed under Settings → Playback.

Configuration

Settings: ~/.config/qtpotatorc
mpv config: /etc/mpv/mpv.conf and ~/.config/mpv/mpv.conf
Translation cache: ~/.cache/qtpotato/translations/

License

QtPotato is licensed under the GNU General Public License v3.0 or later.