Use piper-phonemize to convert text to token IDs (#453)

nodejs-examples/test-offline-tts-en.js

@@ -4,9 +4,9 @@ const sherpa_onnx = require('sherpa-onnx');
 
 function createOfflineTts() {
   const vits = new sherpa_onnx.OfflineTtsVitsModelConfig();
-  vits.model = './vits-vctk/vits-vctk.onnx';
-  vits.lexicon = './vits-vctk/lexicon.txt';
-  vits.tokens = './vits-vctk/tokens.txt';
+  vits.model = 'vits-piper-en_US-amy-low/en_US-amy-low.onnx'
+  vits.tokens = './vits-piper-en_US-amy-low/tokens.txt';
+  vits.dataDir = './vits-piper-en_US-amy-low/espeak-ng-data'
 
   const modelConfig = new sherpa_onnx.OfflineTtsModelConfig();
   modelConfig.vits = vits;
@@ -18,10 +18,11 @@ function createOfflineTts() {
 }
 
 const tts = createOfflineTts();
-const speakerId = 99;
+const speakerId = 0;
 const speed = 1.0;
-const audio =
-    tts.generate('Good morning. How are you doing?', speakerId, speed);
+const audio = tts.generate(
+    '“Today as always, men fall into two groups: slaves and free men. Whoever does not have two-thirds of his day for himself, is a slave, whatever he may be: a statesman, a businessman, an official, or a scholar.”',
+    speakerId, speed);
 audio.save('./test-en.wav');
 console.log('Saved to test-en.wav successfully.');
 tts.free();