/**
* Subtitle format converters
*/
import { formatSRTTime, formatVTTTime } from "./utils.js";
export interface TranscriptItem {
text: string;
offset: number;
duration: number;
}
/**
* Convert transcript to SRT format
*/
export function convertToSRT(transcript: TranscriptItem[]): string {
let srt = "";
transcript.forEach((item, index) => {
const startTime = formatSRTTime(item.offset);
const endTime = formatSRTTime(item.offset + item.duration);
srt += `${index + 1}\n`;
srt += `${startTime} --> ${endTime}\n`;
srt += `${item.text}\n\n`;
});
return srt.trim();
}
/**
* Convert transcript to VTT format
*/
export function convertToVTT(transcript: TranscriptItem[]): string {
let vtt = "WEBVTT\n\n";
transcript.forEach((item) => {
const startTime = formatVTTTime(item.offset);
const endTime = formatVTTTime(item.offset + item.duration);
vtt += `${startTime} --> ${endTime}\n`;
vtt += `${item.text}\n\n`;
});
return vtt.trim();
}
/**
* Convert transcript to plain text format
*/
export function convertToTXT(transcript: TranscriptItem[]): string {
return transcript.map((item) => item.text).join("\n");
}
/**
* Convert transcript to JSON format
*/
export function convertToJSON(transcript: TranscriptItem[]): string {
const formatted = transcript.map((item) => ({
text: item.text,
start: item.offset,
end: item.offset + item.duration,
duration: item.duration,
}));
return JSON.stringify(formatted, null, 2);
}
/**
* Format subtitles to specified format
*/
export function formatSubtitles(transcript: TranscriptItem[], format: string): string {
switch (format.toUpperCase()) {
case "SRT":
return convertToSRT(transcript);
case "VTT":
return convertToVTT(transcript);
case "TXT":
return convertToTXT(transcript);
case "JSON":
return convertToJSON(transcript);
default:
throw new Error(`Unsupported format: ${format}. Supported formats: SRT, VTT, TXT, JSON`);
}
}
