Subtitlesinto

Subtitlesinto is a modular open-source toolset for managing subtitle streams in digital video. It provides utilities to convert between subtitle formats, extract subtitles from video containers, synchronize timing, and either multiplex soft subtitles into a container or burn them into the video frames.

Core capabilities include format support (SRT, VTT, ASS/SSA, SUB), timing adjustments, styling options for display fonts, size, color, and alignment, and multi-track handling for videos with several subtitle streams. Subtitlesinto focuses on interoperability with common video tooling and can operate as a standalone CLI or be integrated via libraries in other software.

Architecture and workflow: Subtitlesinto consists of a core processing library, a command-line interface, and language bindings. It relies on established video processing backends (for example FFmpeg) to perform encoding, decoding, muxing, and rendering when burning subtitles. It emphasizes accurate timing, frame-precise offsets, and compatibility with container formats such as MKV and MP4.

Usage examples: To convert a subtitle file from SRT to VTT: subtitlesinto convert -i subs.srt -o subs.vtt -f vtt. To add soft subtitles: subtitlesinto embed -i video.mp4 -s subs.vtt -o video_with_subs.mp4. To burn subtitles into video: subtitlesinto burn -i video.mp4 -s subs.srt -o video_burned.mp4. To extract: subtitlesinto extract -i video_with_subs.mkv -o subs.srt.

History and licensing: Subtitlesinto originated as a community project and has since been maintained by an open-source community. The software is distributed under a permissive license and welcomes contributions from developers and content creators.

See also: Subtitle formats, Video encoding, Subtitling, FFmpeg.