js-tts-wrapper/esm/markdown/converter.js

A JavaScript/TypeScript library that provides a unified API for working with multiple cloud-based Text-to-Speech (TTS) services

import { isNode } from "../utils/environment.js";
/**
 * Speech Markdown converter using the official speechmarkdown-js library
 *
 * This module provides functions to convert Speech Markdown to SSML
 * using the speechmarkdown-js library (https://github.com/speechmarkdown/speechmarkdown-js)
 */
// Dynamic import for speechmarkdown-js
let SpeechMarkdown = null;
let speechMarkdownLoaded = false;
async function loadSpeechMarkdown() {
    if (speechMarkdownLoaded)
        return SpeechMarkdown;
    try {
        if (isNode) {
            // In Node.js, try to import speechmarkdown-js
            const module = await import("speechmarkdown-js");
            SpeechMarkdown = module.SpeechMarkdown;
            speechMarkdownLoaded = true;
            return SpeechMarkdown;
        }
        // In browser, speechmarkdown-js is not available
        console.warn("speechmarkdown-js is not available in browser environments. Speech Markdown features will be limited.");
        return null;
    }
    catch (_error) {
        console.warn("speechmarkdown-js not found. Speech Markdown features will be limited. Install with: npm install speechmarkdown-js");
        return null;
    }
}
/**
 * SpeechMarkdownConverter class for converting Speech Markdown to SSML
 */
export class SpeechMarkdownConverter {
    constructor() {
        Object.defineProperty(this, "speechMarkdownInstance", {
            enumerable: true,
            configurable: true,
            writable: true,
            value: null
        });
    }
    async ensureInitialized() {
        if (!this.speechMarkdownInstance) {
            const SpeechMarkdownClass = await loadSpeechMarkdown();
            if (SpeechMarkdownClass) {
                this.speechMarkdownInstance = new SpeechMarkdownClass();
            }
        }
        return this.speechMarkdownInstance;
    }
    /**
     * Convert Speech Markdown to SSML
     *
     * @param markdown Speech Markdown text
     * @param platform Target platform (amazon-alexa, google-assistant, microsoft-azure, etc.)
     * @returns SSML text
     */
    async toSSML(markdown, platform = "amazon-alexa") {
        const instance = await this.ensureInitialized();
        if (!instance) {
            // Fallback: return the text wrapped in basic SSML
            return `<speak>${markdown}</speak>`;
        }
        return instance.toSSML(markdown, { platform });
    }
    /**
     * Check if text is Speech Markdown
     *
     * @param text Text to check
     * @returns True if the text contains Speech Markdown syntax
     */
    isSpeechMarkdown(text) {
        return isSpeechMarkdown(text);
    }
    /**
     * Get the available platforms supported by the Speech Markdown library
     *
     * @returns Array of platform names
     */
    getAvailablePlatforms() {
        return getAvailablePlatforms();
    }
}
// Create a default converter instance
const defaultConverter = new SpeechMarkdownConverter();
/**
 * Convert Speech Markdown to SSML
 *
 * This function uses the speechmarkdown-js library to convert Speech Markdown syntax to SSML.
 * The library supports various Speech Markdown features including:
 * - Breaks: [500ms] or [break:"500ms"]
 * - Emphasis: *emphasized text*
 * - Rate, pitch, volume: (rate:slow), (pitch:high), (volume:loud)
 * - And many more (see the speechmarkdown-js documentation)
 *
 * @param markdown Speech Markdown text
 * @param platform Target platform (amazon-alexa, google-assistant, microsoft-azure, etc.)
 * @returns SSML text
 */
export async function toSSML(markdown, platform = "amazon-alexa") {
    return await defaultConverter.toSSML(markdown, platform);
}
/**
 * Check if text is Speech Markdown
 *
 * This function checks if the text contains Speech Markdown syntax patterns.
 * It uses regular expressions to detect common Speech Markdown patterns such as:
 * - Breaks: [500ms] or [break:"500ms"]
 * - Emphasis: *emphasized text*
 * - Rate, pitch, volume: (rate:slow), (pitch:high), (volume:loud)
 *
 * @param text Text to check
 * @returns True if the text contains Speech Markdown syntax
 */
export function isSpeechMarkdown(text) {
    // Use a simple heuristic to check for common Speech Markdown patterns
    // This is a simplified version as the library doesn't provide a direct way to check
    const patterns = [
        /\[\d+m?s\]/, // Breaks: [500ms]
        /\[break:"\w+"\]/, // Breaks with quotes: [break:"weak"]
        /\+\+.*?\+\+/, // Strong emphasis: ++text++
        /\+.*?\+/, // Moderate emphasis: +text+
        /~.*?~/, // No emphasis: ~text~
        /-.*?-/, // Reduced emphasis: -text-
        /\(.*?\)\[emphasis(:"(strong|moderate|reduced|none)")?\]/, // Standard emphasis: (text)[emphasis:"strong"]
        /\(.*?\)\[rate:"(x-slow|slow|medium|fast|x-fast)"\]/, // Rate: (text)[rate:"slow"]
        /\(.*?\)\[pitch:"(x-low|low|medium|high|x-high)"\]/, // Pitch: (text)[pitch:"high"]
        /\(.*?\)\[volume:"(silent|x-soft|soft|medium|loud|x-loud)"\]/, // Volume: (text)[volume:"loud"]
        /\(.*?\)\[voice:".*?"\]/, // Voice: (text)[voice:"Brian"]
        /\(.*?\)\[lang:".*?"\]/, // Language: (text)[lang:"en-US"]
        /\(.*?\)\[\w+:"?.*?"?\]/, // Any other Speech Markdown modifier: (text)[modifier:"value"]
    ];
    return patterns.some((pattern) => pattern.test(text));
}
/**
 * Get the available platforms supported by the Speech Markdown library
 *
 * This function returns the list of platforms supported by the speechmarkdown-js library.
 * These platforms have different SSML dialects, and the library will generate
 * SSML appropriate for the specified platform.
 *
 * @returns Array of platform names (amazon-alexa, google-assistant, microsoft-azure)
 */
export function getAvailablePlatforms() {
    // The library doesn't expose a direct way to get platforms, so we hardcode them
    // These are the platforms supported by speechmarkdown-js as of version 1.x
    return ["amazon-alexa", "google-assistant", "microsoft-azure"];
}