GoKawiilNew open-source tool Overtone cuts video captions separately for each screen aspect ratio
A developer released Overtone, an open-source captioning system that stores transcribed words with timing and speaker data once, then generates separate caption cuts optimized for different screen shapes like 16:9 and 9:16 from a single file. It ships as a CLI for creating or re-cutting caption files from subtitles, audio, or video, plus a video.js player plugin that displays the caption version matching the player's shape. The tool supports offline re-cutting of existing subtitles, and can transcribe audio using OpenAI or Azure APIs, or run fully offline via whisper.cpp and Ollama.