Add English to Katakana and Romaji conversion support

services/tts.ts

@@ -2,6 +2,7 @@ import fs from "fs";
 import path from "path";
 import ffmpegPath from "ffmpeg-static";
 import { config } from "./config.js";
+import { convertEnglishWordsOnly, initializeTextConverter } from "./text-converter.js";
 
 /**
  * Split text into natural chunks for TTS processing
@@ -108,12 +109,26 @@ async function generateAudioForChunk(
   chunkIndex: number,
   itemId: string,
 ): Promise<string> {
-  const encodedText = encodeURIComponent(chunkText);
+  // Convert English words to katakana before TTS processing
+  let processedText: string;
+  try {
+    processedText = await convertEnglishWordsOnly(chunkText);
+    if (processedText !== chunkText) {
+      console.log(`チャンク${chunkIndex + 1}で英語をカタカナに変換: ${itemId}`);
+      console.log(`変換前: "${chunkText}"`);
+      console.log(`変換後: "${processedText}"`);
+    }
+  } catch (error) {
+    console.warn(`チャンク${chunkIndex + 1}の英語変換に失敗、元のテキストを使用: ${itemId}`, error);
+    processedText = chunkText;
+  }
+
+  const encodedText = encodeURIComponent(processedText);
   const queryUrl = `${config.voicevox.host}/audio_query?text=${encodedText}&speaker=${defaultVoiceStyle.styleId}`;
   const synthesisUrl = `${config.voicevox.host}/synthesis?speaker=${defaultVoiceStyle.styleId}`;
 
   console.log(
-    `チャンク${chunkIndex + 1}の音声クエリ開始: ${itemId} (${chunkText.length}文字)`,
+    `チャンク${chunkIndex + 1}の音声クエリ開始: ${itemId} (${processedText.length}文字)`,
   );
 
   const queryResponse = await fetch(queryUrl, {
@@ -252,6 +267,13 @@ export async function generateTTSWithoutQueue(
     throw new Error("Script text is required for TTS generation");
   }
 
+  // Initialize text converter if not already initialized
+  try {
+    await initializeTextConverter();
+  } catch (error) {
+    console.warn("テキストコンバーターの初期化に失敗しました。英語変換をスキップします:", error);
+  }
+
   console.log(
     `TTS生成開始: ${itemId} (試行回数: ${retryCount + 1}, ${scriptText.length}文字)`,
   );