@pr0gramm/fluester/dist/webvtt.js

Node.js bindings for OpenAI's Whisper. Optimized for CPU.

/**
 * Creates a WebVTT string from a transcript which can be used for <track> elements of a <video> or <audio> tag.
 *
 * References:
 * - https://en.wikipedia.org/wiki/WebVTT
 * - https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API
 *
 * @throws If a timestamp has an invalid length
 * @throws If start > end
 */
export function createWebVttString(transcript) {
    const builder = ["WEBVTT", ""];
    for (const { start, end, speech } of transcript) {
        if (start > end) {
            throw new Error("start > end");
        }
        if ("00:00:00.000".length !== start.length) {
            throw new Error("00:00:00.000.length !== start.length");
        }
        if ("00:00:00.000".length !== end.length) {
            throw new Error("00:00:00.000.length !== end.length");
        }
        builder.push(`${start} --> ${end}`);
        for (const split of speech.split("\n")) {
            builder.push(`${split}`);
            builder.push("");
        }
    }
    return builder.join("\n").trim();
}