Live Photo Converter is a cross-platform application for processing Android Live Photos (MVIMG files). It provides a modern GTK4/LibAdwaita graphical interface, a set of command-line tools, and a shared library (`liblivephototools`) for creating, extracting, and repairing these files. The core operation involves appending an MP4 video to a JPEG image and managing the associated XMP metadata (Google's GCamera and Container namespaces). It also supports generating long exposure photos from video frames and copying metadata between images. The architecture is a well-structured monolith written in Vala and built with Meson. The core logic resides in a shared library, with CLI and GUI frontends linking against it. Video processing is handled by a clean strategy pattern, defaulting to an in-process GStreamer pipeline with an FFmpeg subprocess fallback. The build system is highly sophisticated, supporting Linux (Flatpak, Arch), Windows (MSYS2), macOS (Homebrew), and Android (experimental, via pixiewood). The codebase demonstrates strong software craftsmanship. It features clean abstractions (abstract base classes `LivePhoto`/`LiveMaker`), meticulous thread safety (GOnce, AtomicInt, AsyncQueue, Mutex), and well-encapsulated utility components. The `PipelineWatch` class for GStreamer error handling and the `Reporter` class for CLI output are particularly well-crafted and reusable. The primary weakness is the absence of a formal unit test suite, which prevents a higher quality score.