main.js

Author: da-wa33

code/main.js

@@ -0,0 +1,281 @@
+const STTalk = (() => {
+  let mediaRecorder;
+  let audioChunks = [];
+  let audioBlob = null;
+  let recognition;
+  let finalTranscript = "";
+  let textCallback = () => {};
+  let startTime = null;
+  let timerId = null;
+  let audioContext;
+  let analyser;
+  let sourceNode;
+  let volumeCallback = () => {};
+  let volumeLevel = 0;
+  let volumeMeterId;
+  var ST_error_level = 0;
+  var ST_alert_enabled = true;
+  const DB_NAME = "STTalkDB";
+  const STORE_NAME = "sessions";
+  let db;
+
+  function openDB() {
+    return new Promise((resolve, reject) => {
+      if (db) return resolve(db);
+      const request = indexedDB.open(DB_NAME, 1);
+      request.onerror = e => reject(e.target.error);
+      request.onsuccess = e => {
+        db = e.target.result;
+        resolve(db);
+      };
+      request.onupgradeneeded = e => {
+        const db = e.target.result;
+        if (!db.objectStoreNames.contains(STORE_NAME)) {
+          db.createObjectStore(STORE_NAME, { keyPath: "id", autoIncrement: true });
+        }
+      };
+    });
+  }
+
+  async function addSession(audioBlob, text) {
+    if (!audioBlob) throw new Error("録音音声がありません");
+    const db = await openDB();
+    return new Promise((resolve, reject) => {
+      const tx = db.transaction(STORE_NAME, "readwrite");
+      const store = tx.objectStore(STORE_NAME);
+      const data = {
+        audio: audioBlob,
+        text: text || "",
+        date: new Date().toISOString()
+      };
+      const request = store.add(data);
+      request.onsuccess = () => resolve(request.result);
+      request.onerror = e => reject(e.target.error);
+    });
+  }
+
+  async function getSessions() {
+    const db = await openDB();
+    return new Promise((resolve, reject) => {
+      const tx = db.transaction(STORE_NAME, "readonly");
+      const store = tx.objectStore(STORE_NAME);
+      const request = store.getAll();
+      request.onsuccess = () => resolve(request.result);
+      request.onerror = e => reject(e.target.error);
+    });
+  }
+
+  async function deleteSession(id) {
+    const db = await openDB();
+    return new Promise((resolve, reject) => {
+      const tx = db.transaction(STORE_NAME, "readwrite");
+      const store = tx.objectStore(STORE_NAME);
+      const request = store.delete(id);
+      request.onsuccess = () => resolve();
+      request.onerror = e => reject(e.target.error);
+    });
+  }
+
+  async function playSessionAudio(id) {
+    const db = await openDB();
+    const session = await new Promise((resolve, reject) => {
+      const tx = db.transaction(STORE_NAME, "readonly");
+      const store = tx.objectStore(STORE_NAME);
+      const request = store.get(id);
+      request.onsuccess = () => resolve(request.result);
+      request.onerror = e => reject(e.target.error);
+    });
+    if (!session || !session.audio) {
+      showAlert("音声が見つかりません");
+      ST_error_level = 1;
+      return;
+    }
+    const audio = new Audio(URL.createObjectURL(session.audio));
+    audio.play();
+  }
+
+  async function getSessionText(id) {
+    const db = await openDB();
+    const session = await new Promise((resolve, reject) => {
+      const tx = db.transaction(STORE_NAME, "readonly");
+      const store = tx.objectStore(STORE_NAME);
+      const request = store.get(id);
+      request.onsuccess = () => resolve(request.result);
+      request.onerror = e => reject(e.target.error);
+    });
+    return session ? session.text : null;
+  }
+
+  function startVolumeMeter(stream) {
+    audioContext = new AudioContext();
+    sourceNode = audioContext.createMediaStreamSource(stream);
+    analyser = audioContext.createAnalyser();
+    analyser.fftSize = 256;
+    sourceNode.connect(analyser);
+    const dataArray = new Uint8Array(analyser.frequencyBinCount);
+    function update() {
+      analyser.getByteFrequencyData(dataArray);
+      const avg = dataArray.reduce((a, b) => a + b, 0) / dataArray.length;
+      volumeLevel = avg / 255;
+      volumeCallback(volumeLevel);
+      volumeMeterId = requestAnimationFrame(update);
+    }
+    update();
+  }
+
+  function stopVolumeMeter() {
+    if (volumeMeterId) cancelAnimationFrame(volumeMeterId);
+    if (audioContext) audioContext.close();
+  }
+
+  function getRecordingTime() {
+    if (!startTime) return 0;
+    return Math.floor((Date.now() - startTime) / 1000);
+  }
+
+  function startRecording() {
+    return navigator.mediaDevices.getUserMedia({ audio: true }).then(stream => {
+      mediaRecorder = new MediaRecorder(stream);
+      audioChunks = [];
+      audioBlob = null;
+      mediaRecorder.ondataavailable = e => {
+        if (e.data.size > 0) audioChunks.push(e.data);
+      };
+      mediaRecorder.onstop = () => {
+        audioBlob = new Blob(audioChunks, { type: "audio/webm" });
+        stopVolumeMeter();
+      };
+      mediaRecorder.start();
+      startTime = Date.now();
+      startVolumeMeter(stream);
+    });
+  }
+
+  function startRecognition() {
+    const SR = window.SpeechRecognition || window.webkitSpeechRecognition;
+    if (!SR) {
+      showAlert("このブラウザは音声認識に対応していません");
+      ST_error_level = -1;
+      return;
+    }
+    recognition = new SR();
+    recognition.lang = "ja-JP";
+    recognition.interimResults = true;
+    recognition.continuous = true;
+    recognition.onresult = event => {
+      let interim = "";
+      for (let i = event.resultIndex; i < event.results.length; i++) {
+        const transcript = event.results[i][0].transcript;
+        if (event.results[i].isFinal) {
+          finalTranscript += transcript + "\n";
+        } else {
+          interim += transcript;
+        }
+      }
+      textCallback(finalTranscript + interim);
+    };
+    recognition.start();
+  }
+
+  async function stopAll() {
+    if (mediaRecorder && mediaRecorder.state !== "inactive") {
+      mediaRecorder.stop();
+    }
+    if (recognition) recognition.stop();
+    clearInterval(timerId);
+    stopVolumeMeter();
+    setTimeout(async () => {
+      if (audioBlob) {
+        try {
+          await addSession(audioBlob, finalTranscript);
+          console.log("録音セッションを履歴に保存しました");
+          ST_error_level = 2;
+        } catch (e) {
+          console.error("履歴保存エラー", e);
+          ST_error_level = 3;
+        }
+      }
+    }, 300);
+  }
+
+  function saveAudio(filename = "録音音声.webm") {
+    if (!audioBlob) {
+      showAlert("保存できる録音データがありません");
+      ST_error_level = 4;
+      return;
+    }
+    const url = URL.createObjectURL(audioBlob);
+    const a = document.createElement("a");
+    a.href = url;
+    a.download = filename;
+    a.click();
+    URL.revokeObjectURL(url);
+  }
+
+  function saveText(filename = "文字起こし.txt") {
+    const blob = new Blob([finalTranscript], { type: "text/plain" });
+    const url = URL.createObjectURL(blob);
+    const a = document.createElement("a");
+    a.href = url;
+    a.download = filename;
+    a.click();
+    URL.revokeObjectURL(url);
+  }
+
+  function playAudio() {
+    if (!audioBlob) {
+      showAlert("再生できる音声がありません");
+      ST_error_level = 5;
+      return;
+    }
+    const audio = new Audio(URL.createObjectURL(audioBlob));
+    audio.play();
+  }
+
+  function setAlertEnabled(enabled) {
+    ST_alert_enabled = !!enabled;
+  }
+  function getAlertEnabled() {
+    return ST_alert_enabled;
+  }
+  function showAlert(msg) {
+    if (ST_alert_enabled) alert(msg);
+  }
+
+  async function stopAndSaveAudio() {
+    await stopAll();
+    saveAudio();
+  }
+
+  async function stopAndSaveText() {
+    await stopAll();
+    saveText();
+  }
+
+  return {
+    start: () => {
+      finalTranscript = "";
+      return startRecording().then(() => startRecognition());
+    },
+    stop: stopAll,
+    stopAndSaveAudio,
+    stopAndSaveText,
+    saveAudio,
+    saveText,
+    playAudio,
+    onText: callback => (textCallback = callback),
+    getFinalText: () => finalTranscript,
+    setFinalText: text => (finalTranscript = text),
+    getRecordingTime,
+    getVolume: () => volumeLevel,
+    onVolume: callback => (volumeCallback = callback),
+    addSession,
+    getSessions,
+    deleteSession,
+    playSessionAudio,
+    getSessionText,
+    setAlertEnabled,
+    getAlertEnabled,
+  };
+})();
+