Building FrameTrellis: My Journey Toward an Open-Source C++ Video Editor

FrameTrellis is a project aiming to create an open-source, local-first desktop video editor built using C++20, Qt 6/QML, MLT, and FFmpeg. The developer behind the project is working towards a first stable v1.0.0 release, and they are sharing their development journey rather than waiting for completion. Video editing applications combine several challenging areas of software engineering, and FrameTrellis aims to bring these together in a desktop application with a local-first approach, without requiring an account or using cloud processing, telemetry, or advertising.

The technology behind FrameTrellis includes C++20 for native application development, Qt 6/QML for desktop interface and interactive components, MLT for multimedia editing and processing workflows, and FFmpeg for media handling and video export support. The current development version features a foundation for creating, opening, and saving projects, importing various media formats, multi-track timeline editing, clip manipulation, preview playback, audio waveforms, basic picture adjustments, transitions, and audio crossfades.

Undo/redo, autosave, and crash recovery are also included, along with MP4 video exporting with H.264 and AAC.

The project documentation outlines these implemented workflows and their automated tests, but the developer acknowledges that not every professional editing feature is available, and not every platform has a stable packaged release. The roadmap includes plans for improvements such as titles, subtitles, keyframes, proxy media, additional export formats, and packaged releases.

The developer intends to share progress as features are implemented, tested, and improved, including the engineering challenges that arise during the journey. FrameTrellis is open-source under the GPL-3.0-or-later license, and the community is encouraged to explore the source code, provide feedback, report bugs, test, and contribute documentation.