js-tts-wrapper
Version:
A JavaScript/TypeScript library that provides a unified API for working with multiple cloud-based Text-to-Speech (TTS) services
185 lines (184 loc) • 7.79 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.SpeechMarkdownConverter = void 0;
exports.toSSML = toSSML;
exports.isSpeechMarkdown = isSpeechMarkdown;
exports.getAvailablePlatforms = getAvailablePlatforms;
const environment_1 = require("../utils/environment");
/**
* 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 {
// Enable in both environments, but gate Node via env flag to keep it opt-in on servers/CI
if (environment_1.isNode) {
const enabled = (() => {
try {
// Allow true/1/yes/on (case-insensitive)
const v = process?.env?.SPEECHMARKDOWN_ENABLE ?? "";
return /^(1|true|yes|on)$/i.test(String(v));
}
catch {
return false;
}
})();
if (!enabled) {
console.warn("speechmarkdown-js disabled in Node (set SPEECHMARKDOWN_ENABLE=true to enable). Using built-in fallback.");
return null;
}
}
// Attempt dynamic import in both Node and browser without triggering bundlers to hard-require it
const dynamicImport = new Function('m', 'return import(m)');
const module = await dynamicImport("speechmarkdown-js");
// Prefer named export, but tolerate default exports
SpeechMarkdown = module?.SpeechMarkdown ?? module?.default?.SpeechMarkdown ?? module?.default;
if (!SpeechMarkdown) {
throw new Error("speechmarkdown-js module did not expose SpeechMarkdown class");
}
speechMarkdownLoaded = true;
return SpeechMarkdown;
}
catch (_error) {
console.warn("speechmarkdown-js not available. Using built-in fallback. To enable full Speech Markdown in browsers, add 'speechmarkdown-js' to your app and it will be loaded at runtime.");
return null;
}
}
// Lightweight fallback converter for a minimal subset used in tests
function convertSpeechMarkdownFallback(markdown) {
let out = markdown;
// [break:"500ms"] -> <break time="500ms"/>
out = out.replace(/\[break:\"([^\"]+)\"\]/g, '<break time="$1"/>');
// [500ms] or [500s] -> <break time="500ms"/>
out = out.replace(/\[(\d+)m?s\]/g, '<break time="$1ms"/>');
return out;
}
/**
* SpeechMarkdownConverter class for converting Speech Markdown to SSML
*/
class SpeechMarkdownConverter {
constructor() {
Object.defineProperty(this, "speechMarkdownInstance", {
enumerable: true,
configurable: true,
writable: true,
value: null
});
}
async ensureInitialized() {
if (!this.speechMarkdownInstance) {
const SpeechMarkdownClass = await loadSpeechMarkdown();
if (SpeechMarkdownClass) {
this.speechMarkdownInstance = new SpeechMarkdownClass();
}
}
return this.speechMarkdownInstance;
}
/**
* Convert Speech Markdown to SSML
*
* @param markdown Speech Markdown text
* @param platform Target platform (amazon-alexa, google-assistant, microsoft-azure, etc.)
* @returns SSML text
*/
async toSSML(markdown, platform = "amazon-alexa") {
// Attempt to initialize the full converter (no-op if disabled/unavailable)
await this.ensureInitialized();
if (this.speechMarkdownInstance) {
return this.speechMarkdownInstance.toSSML(markdown, { platform });
}
// Fallback: minimal conversion
const converted = convertSpeechMarkdownFallback(markdown);
return `<speak>${converted}</speak>`;
}
/**
* 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();
}
}
exports.SpeechMarkdownConverter = SpeechMarkdownConverter;
// 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++ or +emphasized+
* - Rate, pitch, volume: (text)[rate:"slow"], (text)[pitch:"high"], (text)[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
*/
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: ++text++ or +text+
* - Rate, pitch, volume: (text)[rate:"slow"], (text)[pitch:"high"], (text)[volume:"loud"]
*
* @param text Text to check
* @returns True if the text contains Speech Markdown syntax
*/
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]
/\[break:"[^"\]]+"\]/, // Breaks with quotes: [break:"weak"] or [break:"500ms"]
/\+\+.*?\+\+/, // 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)
*/
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"];
}