Output VTT File

2 VersionsOutput

Renders each upstream [Subtitle] list to a WebVTT .vtt file under output_path, writing the WEBVTT header and formatting cue timings as HH:MM:SS.mmm, with the file named from name_template plus a 6-digit index.

How it fits

Typical backends

Web captioning. Decode audio, transcribe it into timed cues, and write a VTT track for a browser video element.

SRT-to-VTT conversion. Load SubRip cues and re-emit them in the WebVTT format browsers prefer.

Caveats

I/O contractEach call writes one complete .vtt file beginning with the WEBVTT marker; an empty subtitle list still produces a header-only file, and no per-cue identifier is emitted (any incoming cue index is ignored).
AccuracyCue start and end times that are NaN or negative are clamped to 00:00:00.000, and WebVTT uses a dot rather than a comma before the milliseconds.
State lifetimeThe filename index is a process-local counter that resets on restart, so reusing output_path with the same name_template overwrites earlier files.

Versions

ee71e6e9default
Automated release
8/1/2026