Merge pull request #385 from makaveli10/add_srt_download_opt_browser_ext

Add srt download opt browser ext

Audio-Transcription-Chrome/README.md

@@ -27,6 +27,7 @@ To capture the audio in the current tab, we used the chrome `tabCapture` API to
 When using the Audio Transcription extension, you have the following options:
  - **Use Collabora Server**: We provide a demo server which runs the whisper small model.
  - **Language**: Select the target language for transcription or translation. You can choose from a variety of languages supported by OpenAI-whisper.
+ - **Download SRT file at Stop Capture**: Select if you want to download the srt file for the session at stop capture.
  - **Task:** Choose the specific task to perform on the audio. You can select either "transcribe" for transcription or "translate" to translate the audio to English.
  - **Model Size**: Select the whisper model size to run the server with.
 

Audio-Transcription-Chrome/audiopreprocessor.js

@@ -0,0 +1,77 @@
+class AudioPreProcessor extends AudioWorkletProcessor {
+  constructor() {
+    super();
+    this.sampleRate = sampleRate || 48000;
+    this.targetSampleRate = 16000;
+    this.inputSamplesNeeded = this.sampleRate * 0.5; // 0.5s
+    this.inputBuffer = new Float32Array(this.inputSamplesNeeded);
+    this.inputWriteOffset = 0;
+    this.processCount = 0;
+    this.audioDetectedCount = 0;
+  }
+
+  process(inputs, outputs) {
+    this.processCount++;
+    
+    const input = inputs[0];
+    const output = outputs[0];
+   
+    if (!input || input.length === 0) {
+      return true;
+    }
+
+    for (let channel = 0; channel < Math.min(input.length, output.length); channel++) {
+      if (input[channel] && output[channel]) {
+        output[channel].set(input[channel]);
+      }
+    }
+
+    let monoInput;
+    if (input.length === 1) {
+      monoInput = input[0];
+    } else if (input.length >= 2) {
+      monoInput = new Float32Array(input[0].length);
+      for (let i = 0; i < input[0].length; i++) {
+        monoInput[i] = (input[0][i] + (input[1] ? input[1][i] : 0)) * 0.5;
+      }
+    } else {
+      return true;
+    }
+
+    if (!monoInput || monoInput.length === 0) {
+      return true;
+    }
+
+    let inputOffset = 0;
+    while (inputOffset < monoInput.length) {
+      const remainingBuffer = this.inputSamplesNeeded - this.inputWriteOffset;
+      const toCopy = Math.min(remainingBuffer, monoInput.length - inputOffset);
+      this.inputBuffer.set(monoInput.subarray(inputOffset, inputOffset + toCopy), this.inputWriteOffset);
+
+      this.inputWriteOffset += toCopy;
+      inputOffset += toCopy;
+
+      if (this.inputWriteOffset === this.inputSamplesNeeded) {
+        const downsampled = this.downsampleTo16kHz(this.inputBuffer);
+        this.port.postMessage(downsampled);
+
+        this.inputWriteOffset = 0;
+      }
+    }
+
+    return true;
+  }
+
+  downsampleTo16kHz(inputBuffer) {
+    const ratio = this.sampleRate / this.targetSampleRate;
+    const length = Math.floor(inputBuffer.length / ratio);
+    const result = new Float32Array(length);
+    for (let i = 0; i < length; i++) {
+      const idx = Math.floor(i * ratio);
+      result[i] = inputBuffer[idx];
+    }
+    return result;
+  }
+}
+
+registerProcessor('audiopreprocessor', AudioPreProcessor);

Audio-Transcription-Chrome/background.js

@@ -159,6 +159,7 @@ async function startCapture(options) {
           task: options.task,
           modelSize: options.modelSize,
           useVad: options.useVad,
+          saveCaptions: options.saveCaptions,
         },
       });
     } else {
@@ -174,14 +175,14 @@ async function startCapture(options) {
  * Stops the capture process and performs cleanup.
  * @returns {Promise<void>} - A Promise that resolves when the capture process is stopped successfully.
  */
-async function stopCapture() {
+async function stopCapture(options) {
   const optionTabId = await getLocalStorageValue("optionTabId");
   const currentTabId = await getLocalStorageValue("currentTabId");
 
   if (optionTabId) {
     res = await sendMessageToTab(currentTabId, {
       type: "STOP",
-      data: { currentTabId: currentTabId },
+      data: { currentTabId: currentTabId, saveCaptions: options.saveCaptions },
     });
     await removeChromeTab(optionTabId);
   }
@@ -196,7 +197,7 @@ chrome.runtime.onMessage.addListener(async (message) => {
   if (message.action === "startCapture") {
     startCapture(message);
   } else if (message.action === "stopCapture") {
-    stopCapture();
+    stopCapture(message);
   } else if (message.action === "updateSelectedLanguage") {
     const detectedLanguage = message.detectedLanguage;
     chrome.runtime.sendMessage({ action: "updateSelectedLanguage", detectedLanguage });
@@ -204,7 +205,7 @@ chrome.runtime.onMessage.addListener(async (message) => {
   } else if (message.action === "toggleCaptureButtons") {
     chrome.runtime.sendMessage({ action: "toggleCaptureButtons", data: false });
     chrome.storage.local.set({ capturingState: { isCapturing: false } })
-    stopCapture();
+    stopCapture({saveCaptions: message.saveCaptions});
   }
 });
 

Audio-Transcription-Chrome/content.js

@@ -1,10 +1,45 @@
-
-
 var elem_container = null;
 var elem_text = null;
 
 var segments = [];
 var text_segments = [];
+var allSegments = [];
+var lastIncompleteSegment = null;
+
+function formatTime(seconds) {
+  const date = new Date(seconds * 1000);
+  const hh = String(date.getUTCHours()).padStart(2, '0');
+  const mm = String(date.getUTCMinutes()).padStart(2, '0');
+  const ss = String(date.getUTCSeconds()).padStart(2, '0');
+  const mmm = String(date.getUTCMilliseconds()).padStart(3, '0');
+  return `${hh}:${mm}:${ss},${mmm}`;
+}
+
+function generateSRT() {
+    return allSegments
+    .map((seg, i) => {
+    const start = formatTime(seg.start);
+    const end   = formatTime(seg.end);
+    const text  = seg.text.trim().replace(/[\r\n]+/g, ' ');
+    return `${i + 1}\n${start} --> ${end}\n${text}`;
+    })
+    .join('\n\n');
+}
+
+function downloadSRT() {
+    console.log("downloadSRT called");
+    console.log("Total segments for SRT:", allSegments.length);
+    const srtBlob = new Blob([generateSRT()], { type: 'text/srt;charset=utf-8' });
+    const url = URL.createObjectURL(srtBlob);
+    const a = document.createElement('a');
+    a.href = url;
+    a.download = 'captions.srt';
+    a.style.display = 'none';
+    document.body.appendChild(a);
+    a.click();
+    URL.revokeObjectURL(url);
+    document.body.removeChild(a);
+}
 
 function initPopupElement() {
   if (document.getElementById('popupElement')) {
@@ -32,7 +67,7 @@ function initPopupElement() {
   closePopupButton.style.cursor = 'pointer';
   closePopupButton.addEventListener('click', async () => {
     popupContainer.style.display = 'none';
-    await browser.runtime.sendMessage({ action: 'toggleCaptureButtons', data: false });
+    await chrome.runtime.sendMessage({ action: 'toggleCaptureButtons', data: false });
   });
   buttonContainer.appendChild(closePopupButton);
   popupContainer.appendChild(buttonContainer);
@@ -169,8 +204,25 @@ function remove_element() {
 
 chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
     const { type, data } = request;
-    
+    const saveCaptions = data.saveCaptions;
-    if (type === "STOP") {
+
+    if (type === "STOP") {        
+        if (saveCaptions === true) {
+            // If there is a last incomplete segment, push it to allSegments
+            if (lastIncompleteSegment && lastIncompleteSegment.text && lastIncompleteSegment.text.trim() !== "") {
+                // Apply same Python logic: check if transcript is empty OR start >= last end
+                if (allSegments.length === 0 || parseFloat(lastIncompleteSegment.start) >= parseFloat(allSegments[allSegments.length - 1].end)) {
+                    allSegments.push({
+                        start: lastIncompleteSegment.start,
+                        end: lastIncompleteSegment.end,
+                        text: lastIncompleteSegment.text
+                    });
+                    console.log("Added final incomplete segment");
+                }
+            }
+        
+            downloadSRT();
+        }
         remove_element();
         sendResponse({data: "STOPPED"});
         return true;
@@ -184,53 +236,77 @@ chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
 
     init_element();
 
-    message = JSON.parse(data);
+    try {
-    message = message["segments"];
+        const message = JSON.parse(data.data);
-
+        const segments = message["segments"];
-    var text = '';
+        
-    for (var i = 0; i < message.length; i++) {
+        if (saveCaptions === true) {
-        text += message[i].text + ' ';
+            segments.forEach(seg => {
-    }
+                if (seg.completed === true && 
-    text = text.replace(/(\r\n|\n|\r)/gm, "");
+                    (allSegments.length === 0 || parseFloat(seg.start) >= parseFloat(allSegments[allSegments.length - 1].end))) {
-    
+                    allSegments.push({
-    var elem = document.getElementById('t3');
+                        start: seg.start,
-    elem.innerHTML = text;
+                        end: seg.end,
-
+                        text: seg.text
-    var line_height_style = getStyle('t3', 'line-height');
+                    });
-    var line_height = parseInt(line_height_style.substring(0, line_height_style.length - 2));
+                    
-    var divHeight = elem.offsetHeight;
+                    lastIncompleteSegment = null;
-    var lines = divHeight / line_height;
+                } else if (seg.completed !== true) {
-
+                    lastIncompleteSegment = seg;
-    text_segments = [];
+                }
-    text_segments = get_lines(elem, line_height);
+            });
-    
-    elem.innerHTML = '';
-
-    if (text_segments.length > 2) {
-        for (var i = 0; i < 3; i++) {
-            document.getElementById('t' + i).innerHTML = text_segments[text_segments.length - 3 + i];
         }
-    } else {
+        var text = '';
-        for (var i = 0; i < 3; i++) {
+        for (var i = 0; i < segments.length; i++) {
-            document.getElementById('t' + i).innerHTML = '';
+            text += segments[i].text + ' ';
         }
-    }
+        text = text.replace(/(\r\n|\n|\r)/gm, "");
+        
+        var elem = document.getElementById('t3');
+        if (elem) {
+            elem.innerHTML = text;
 
-    if (text_segments.length <= 2) {
+            var line_height_style = getStyle('t3', 'line-height');
-        for (var i = 0; i < text_segments.length; i++) {
+            var line_height = parseInt(line_height_style.substring(0, line_height_style.length - 2));
-            document.getElementById('t' + i).innerHTML = text_segments[i];
+            var divHeight = elem.offsetHeight;
-        }
+            var lines = divHeight / line_height;
-    } else {
-        for (var i = 0; i < 3; i++) {
-            document.getElementById('t' + i).innerHTML = text_segments[text_segments.length - 3 + i];
-        }
-    }
 
-    for (var i = 1; i < 3; i++)
+            text_segments = [];
-    {
+            text_segments = get_lines(elem, line_height);
-        var parent_elem = document.getElementById('t' + (i - 1));
+            
-        var elem = document.getElementById('t' + i);
+            elem.innerHTML = '';
-        elem.style.top = parent_elem.offsetHeight + parent_elem.offsetTop + 'px';
+
+            if (text_segments.length > 2) {
+                for (var i = 0; i < 3; i++) {
+                    document.getElementById('t' + i).innerHTML = text_segments[text_segments.length - 3 + i];
+                }
+            } else {
+                for (var i = 0; i < 3; i++) {
+                    document.getElementById('t' + i).innerHTML = '';
+                }
+            }
+
+            if (text_segments.length <= 2) {
+                for (var i = 0; i < text_segments.length; i++) {
+                    document.getElementById('t' + i).innerHTML = text_segments[i];
+                }
+            } else {
+                for (var i = 0; i < 3; i++) {
+                    document.getElementById('t' + i).innerHTML = text_segments[text_segments.length - 3 + i];
+                }
+            }
+
+            for (var i = 1; i < 3; i++)
+            {
+                var parent_elem = document.getElementById('t' + (i - 1));
+                var elem = document.getElementById('t' + i);
+                if (parent_elem && elem) {
+                    elem.style.top = parent_elem.offsetHeight + parent_elem.offsetTop + 'px';
+                }
+            }
+        }
+    } catch (error) {
+        console.error("Error processing message:", error);
     }
 
     sendResponse({});

Audio-Transcription-Chrome/manifest.json

@@ -1,14 +1,20 @@
-  {
+{
     "manifest_version": 3,
 
     "name": "Audio Transcription",
     "version": "1.0.0",
     "description": "This extension captures the audio on the current tab, sends it to a server for transcription and shows the transcription in Real-time.",
-    
+
     "options_page": "options.html",
     "background": {
         "service_worker": "background.js"
     },
+    "web_accessible_resources": [
+        {
+        "resources": ["audiopreprocessor.js"],
+        "matches": ["<all_urls>"]
+        }
+    ],
     "permissions": [
         "storage",
         "activeTab",

Audio-Transcription-Chrome/options.js

@@ -31,41 +31,6 @@ function sendMessageToTab(tabId, data) {
   });
 }
 
-
-/**
- * Resamples the audio data to a target sample rate of 16kHz.
- * @param {Array|ArrayBuffer|TypedArray} audioData - The input audio data.
- * @param {number} [origSampleRate=44100] - The original sample rate of the audio data.
- * @returns {Float32Array} The resampled audio data at 16kHz.
- */
-function resampleTo16kHZ(audioData, origSampleRate = 44100) {
-  // Convert the audio data to a Float32Array
-  const data = new Float32Array(audioData);
-
-  // Calculate the desired length of the resampled data
-  const targetLength = Math.round(data.length * (16000 / origSampleRate));
-
-  // Create a new Float32Array for the resampled data
-  const resampledData = new Float32Array(targetLength);
-
-  // Calculate the spring factor and initialize the first and last values
-  const springFactor = (data.length - 1) / (targetLength - 1);
-  resampledData[0] = data[0];
-  resampledData[targetLength - 1] = data[data.length - 1];
-
-  // Resample the audio data
-  for (let i = 1; i < targetLength - 1; i++) {
-    const index = i * springFactor;
-    const leftIndex = Math.floor(index).toFixed();
-    const rightIndex = Math.ceil(index).toFixed();
-    const fraction = index - leftIndex;
-    resampledData[i] = data[leftIndex] + (data[rightIndex] - data[leftIndex]) * fraction;
-  }
-
-  // Return the resampled data
-  return resampledData;
-}
-
 function generateUUID() {
   let dt = new Date().getTime();
   const uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
@@ -76,24 +41,99 @@ function generateUUID() {
   return uuid;
 }
 
+// Global variables for audio processing
+let audioContext = null;
+let preNode = null;
+let socket = null;
+let isServerReady = false;
+let currentStream = null;
+let currentOptions = null;
+
+// AudioWorklet URL - make sure this path matches your manifest.json
+const WORKLET_URL = chrome.runtime.getURL('audiopreprocessor.js');
+
+async function initAudioWorklet(stream) {
+  audioContext = new AudioContext();
+  if (audioContext.state === 'suspended') {
+    await audioContext.resume();
+  }
+
+  try {
+    await audioContext.audioWorklet.addModule(WORKLET_URL);
+    preNode = new AudioWorkletNode(audioContext, 'audiopreprocessor');
+    const mediaStream = audioContext.createMediaStreamSource(stream);
+    
+    mediaStream.connect(preNode);
+    preNode.connect(audioContext.destination);
+    preNode.port.onmessage = (event) => {
+      const data = event.data;
+      
+      
+      const audio16k = data; // Float32Array @ 16 kHz
+      
+      if (socket && socket.readyState === WebSocket.OPEN && isServerReady) {
+        socket.send(audio16k);
+      }
+    };
+        
+    // Test if we can hear audio (this will help verify the audio path)
+    
+  } catch (error) {
+    console.error("Error initializing AudioWorklet:", error);
+    throw error;
+  }
+}
+
+function cleanupAudio() {
+  
+  if (preNode) {
+    preNode.port.onmessage = null;
+    preNode.disconnect();
+    preNode = null;
+  }
+  
+  if (audioContext) {
+    audioContext.close();
+    audioContext = null;
+  }
+
+  if (currentStream) {
+    currentStream.getTracks().forEach(track => {
+      track.stop();
+      console.log("Stopped track:", track.kind);
+    });
+    currentStream = null;
+  }
+}
 
 /**
  * Starts recording audio from the captured tab.
  * @param {Object} option - The options object containing the currentTabId.
  */
 async function startRecord(option) {
+  currentOptions = option;
   const stream = await captureTabAudio();
   const uuid = generateUUID();
 
   if (stream) {
-    // call when the stream inactive
+    currentStream = stream;
     stream.oninactive = () => {
+      cleanupAudio();
       window.close();
     };
-    const socket = new WebSocket(`ws://${option.host}:${option.port}/`);
+
-    let isServerReady = false;
+    try {
+      await initAudioWorklet(stream);
+    } catch (error) {
+      console.error("Failed to initialize AudioWorklet:", error);
+      return;
+    }
+
+    socket = new WebSocket(`ws://${option.host}:${option.port}/`);
+    isServerReady = false;
     let language = option.language;
-    socket.onopen = function(e) { 
+
+    socket.onopen = function(e) {
       socket.send(
         JSON.stringify({
           uid: uuid,
@@ -129,7 +169,6 @@ async function startRecord(option) {
         language = data["language"];
         
         // send message to popup.js to update dropdown
-        // console.log(language);
         chrome.runtime.sendMessage({
           action: "updateSelectedLanguage",
           detectedLanguage: language,
@@ -139,43 +178,33 @@ async function startRecord(option) {
       }
 
       if (data["message"] === "DISCONNECT"){
-        chrome.runtime.sendMessage({ action: "toggleCaptureButtons", data: false })        
+        chrome.runtime.sendMessage({ action: "toggleCaptureButtons", data: false, saveCaptions: option.saveCaptions });        
         return;
       }
 
-      res = await sendMessageToTab(option.currentTabId, {
+      const res = await sendMessageToTab(option.currentTabId, {
         type: "transcript",
-        data: event.data,
+        data: {
+          data: event.data,
+          saveCaptions: option.saveCaptions,
+        },
       });
     };
 
-    
+    socket.onclose = () => {
-    const audioDataCache = [];
+      cleanupAudio();
-    const context = new AudioContext();
+    };
-    const mediaStream = context.createMediaStreamSource(stream);
+
-    const recorder = context.createScriptProcessor(4096, 1, 1);
+    socket.onerror = (error) => {
-
+      cleanupAudio();
-    recorder.onaudioprocess = async (event) => {
-      if (!context || !isServerReady) return;
-
-      const inputData = event.inputBuffer.getChannelData(0);
-      const audioData16kHz = resampleTo16kHZ(inputData, context.sampleRate);
-
-      audioDataCache.push(inputData);
-
-      socket.send(audioData16kHz);
     };
 
-    // Prevent page mute
-    mediaStream.connect(recorder);
-    recorder.connect(context.destination);
-    mediaStream.connect(context.destination);
-    // }
   } else {
     window.close();
   }
 }
 
+
 /**
  * Listener for incoming messages from the extension's background script.
  * @param {Object} request - The message request object.

Audio-Transcription-Chrome/popup.html

@@ -19,6 +19,10 @@
     <input type="checkbox" id="useVadCheckbox">
     <label for="useVadCheckbox">Use Voice Activity Detection</label>
   </div>
+  <div class="checkbox-container">
+    <input type="checkbox" id="saveCaptionsCheckbox">
+    <label for="saveCaptions">Download SRT file at Stop Capture</label>
+  </div>
   <div class="dropdown-container">
     <label for="languageDropdown">Select Language:</label>
     <select id="languageDropdown">

Audio-Transcription-Chrome/popup.js

@@ -5,6 +5,7 @@ document.addEventListener("DOMContentLoaded", function () {
 
   const useServerCheckbox = document.getElementById("useServerCheckbox");
   const useVadCheckbox = document.getElementById("useVadCheckbox");
+  const saveCaptionsCheckbox = document.getElementById("saveCaptionsCheckbox");
   const languageDropdown = document.getElementById('languageDropdown');
   const taskDropdown = document.getElementById('taskDropdown');
   const modelSizeDropdown = document.getElementById('modelSizeDropdown');
@@ -38,6 +39,12 @@ document.addEventListener("DOMContentLoaded", function () {
     }
   });
 
+  chrome.storage.local.get("saveCaptionsState", ({ saveCaptionsState }) => {
+    if (saveCaptionsState !== undefined) {
+      saveCaptionsCheckbox.checked = saveCaptionsState;
+    }
+  });
+
   chrome.storage.local.get("selectedLanguage", ({ selectedLanguage: storedLanguage }) => {
     if (storedLanguage !== undefined) {
       languageDropdown.value = storedLanguage;
@@ -88,6 +95,7 @@ document.addEventListener("DOMContentLoaded", function () {
         task: selectedTask,
         modelSize: selectedModelSize,
         useVad: useVadCheckbox.checked,
+        saveCaptions: saveCaptionsCheckbox.checked,
       }, () => {
         // Update capturing state in storage and toggle the buttons
         chrome.storage.local.set({ capturingState: { isCapturing: true } }, () => {
@@ -105,7 +113,11 @@ document.addEventListener("DOMContentLoaded", function () {
     }
 
     // Send a message to the background script to stop capturing
-    chrome.runtime.sendMessage({ action: "stopCapture" }, () => {
+    chrome.runtime.sendMessage(
+      { 
+        action: "stopCapture",
+        saveCaptions: saveCaptionsCheckbox.checked,
+      }, () => {
       // Update capturing state in storage and toggle the buttons
       chrome.storage.local.set({ capturingState: { isCapturing: false } }, () => {
         toggleCaptureButtons(false);
@@ -128,6 +140,7 @@ document.addEventListener("DOMContentLoaded", function () {
     stopButton.disabled = !isCapturing;
     useServerCheckbox.disabled = isCapturing;
     useVadCheckbox.disabled = isCapturing;
+    saveCaptionsCheckbox.disabled = isCapturing;
     modelSizeDropdown.disabled = isCapturing;
     languageDropdown.disabled = isCapturing;
     taskDropdown.disabled = isCapturing; 
@@ -146,6 +159,11 @@ document.addEventListener("DOMContentLoaded", function () {
     chrome.storage.local.set({ useVadState });
   });
 
+  saveCaptionsCheckbox.addEventListener("change", () => {
+    const saveCaptionsState = saveCaptionsCheckbox.checked;
+    chrome.storage.local.set({ saveCaptionsState });
+  });
+
   languageDropdown.addEventListener('change', function() {
     if (languageDropdown.value === "") {
       selectedLanguage = null;

Audio-Transcription-Firefox/README.md

@@ -25,6 +25,7 @@ To capture the audio in the current tab, we used the chrome `tabCapture` API to
 When using the Audio Transcription extension, you have the following options:
  - **Use Collabora Server**: We provide a demo server which runs the whisper small model.
  - **Language**: Select the target language for transcription or translation. You can choose from a variety of languages supported by OpenAI-whisper.
+ - **Download SRT file at Stop Capture**: Select if you want to download the srt file for the session at stop capture.
  - **Task:** Choose the specific task to perform on the audio. You can select either "transcribe" for transcription or "translate" to translate the audio to English.
   - **Model Size**: Select the whisper model size to run the server with.
 

Audio-Transcription-Firefox/audiopreprocessor.js

@@ -0,0 +1,70 @@
+class AudioPreProcessor extends AudioWorkletProcessor {
+    constructor() {
+      super();
+      this.sampleRate = sampleRate || 48000;
+      this.targetSampleRate = 16000;
+      this.inputSamplesNeeded = this.sampleRate * 0.5;
+      this.inputBuffer = new Float32Array(this.inputSamplesNeeded);
+      this.inputWriteOffset = 0;
+    }
+  
+    process(inputs, outputs) {
+      const input = inputs[0]; 
+      const output = outputs[0];
+      if (!input || input.length === 0) {
+        return true;
+      }
+      for (let channel = 0; channel < Math.min(input.length, output.length); channel++) {
+        if (input[channel] && output[channel]) {
+          output[channel].set(input[channel]);
+        }
+      }
+
+      let monoInput;
+      if (input.length === 1) {
+        monoInput = input[0];
+      } else if (input.length > 1) {
+        monoInput = new Float32Array(input[0].length);
+        for (let channel = 0; channel < input.length; channel++) {
+          monoInput.set(input[channel], 0);
+        }
+      }
+
+      if (!monoInput) {
+        return true;
+      }
+  
+      let inputOffset = 0;
+      while (inputOffset < monoInput.length) {
+        const remainingBuffer = this.inputSamplesNeeded - this.inputWriteOffset;
+        const toCopy = Math.min(remainingBuffer, monoInput.length - inputOffset);
+        this.inputBuffer.set(monoInput.subarray(inputOffset, inputOffset + toCopy), this.inputWriteOffset);
+
+        this.inputWriteOffset += toCopy;
+        inputOffset += toCopy;
+
+        if (this.inputWriteOffset === this.inputSamplesNeeded) {
+          const downsampled = this.downsampleTo16kHz(this.inputBuffer);
+          this.port.postMessage(downsampled);
+
+          this.inputWriteOffset = 0;
+        }
+      }
+
+      return true;
+    }
+  
+    downsampleTo16kHz(inputBuffer) {
+      const ratio = this.sampleRate / this.targetSampleRate;
+      const length = Math.floor(inputBuffer.length / ratio); 
+      const result = new Float32Array(length);
+      for (let i = 0; i < length; i++) {
+        const idx = Math.floor(i * ratio);
+        result[i] = inputBuffer[idx];
+      }
+      return result;
+    }
+  }
+  
+  registerProcessor('audiopreprocessor', AudioPreProcessor);
+  

Audio-Transcription-Firefox/content.js

@@ -1,144 +1,162 @@
 let socket = null;
 let isCapturing = false;
-let mediaStream = null;
 let audioContext = null;
-let scriptProcessor = null;
 let language = null;
-
 let isPaused = false;
+let preNode = null;
+let allSegments = [];
+let lastIncompleteSegment = null;
 
-const mediaElements = document.querySelectorAll('video, audio');
+function formatTime(seconds) {
-mediaElements.forEach((mediaElement) => {
+  const date = new Date(seconds * 1000);
-  mediaElement.addEventListener('play', handlePlaybackStateChange);
+  const hh = String(date.getUTCHours()).padStart(2, '0');
-  mediaElement.addEventListener('pause', handlePlaybackStateChange);
+  const mm = String(date.getUTCMinutes()).padStart(2, '0');
-});
+  const ss = String(date.getUTCSeconds()).padStart(2, '0');
-
+  const mmm = String(date.getUTCMilliseconds()).padStart(3, '0');
-
+  return `${hh}:${mm}:${ss},${mmm}`;
-function handlePlaybackStateChange(event) {
-  isPaused = event.target.paused;
 }
 
+function generateSRT() {
+    return allSegments
+    .map((seg, i) => {
+    const start = formatTime(seg.start);
+    const end   = formatTime(seg.end);
+    const text  = seg.text.trim().replace(/[\r\n]+/g, ' ');
+    return `${i + 1}\n${start} --> ${end}\n${text}`;
+    })
+    .join('\n\n');
+}
+
+function downloadSRT() {
+    const srtBlob = new Blob([generateSRT()], { type: 'text/srt;charset=utf-8' });
+    const url = URL.createObjectURL(srtBlob);
+    const a = document.createElement('a');
+    a.href = url;
+    a.download = 'captions.srt';
+    a.style.display = 'none';
+    document.body.appendChild(a);
+    a.click();
+    URL.revokeObjectURL(url);
+    document.body.removeChild(a);
+}
+
+
 function generateUUID() {
   let dt = new Date().getTime();
-  const uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
+  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => {
     const r = (dt + Math.random() * 16) % 16 | 0;
     dt = Math.floor(dt / 16);
     return (c === 'x' ? r : (r & 0x3 | 0x8)).toString(16);
   });
-  return uuid;
 }
 
 
-/**
+document.querySelectorAll('video, audio').forEach(el => {
- * Resamples the audio data to a target sample rate of 16kHz.
+  el.addEventListener('play', () => { isPaused = false; });
- * @param {Array|ArrayBuffer|TypedArray} audioData - The input audio data.
+  el.addEventListener('pause', () => { isPaused = true; });
- * @param {number} [origSampleRate=44100] - The original sample rate of the audio data.
+});
- * @returns {Float32Array} The resampled audio data at 16kHz.
- */
-function resampleTo16kHZ(audioData, origSampleRate = 44100) {
-  // Convert the audio data to a Float32Array
-  const data = new Float32Array(audioData);
 
-  // Calculate the desired length of the resampled data
-  const targetLength = Math.round(data.length * (16000 / origSampleRate));
 
-  // Create a new Float32Array for the resampled data
+function setupMessageHandler() {
-  const resampledData = new Float32Array(targetLength);
+  if (preNode) {
+    preNode.port.onmessage = e => {
+      const audio16k = e.data; 
+      if (isCapturing && socket && socket.readyState === WebSocket.OPEN && !isPaused) {
+        socket.send(audio16k);
+      }
+    };
+  }
+}
 
-  // Calculate the spring factor and initialize the first and last values
-  const springFactor = (data.length - 1) / (targetLength - 1);
-  resampledData[0] = data[0];
-  resampledData[targetLength - 1] = data[data.length - 1];
 
-  // Resample the audio data
+const WORKLET_URL = browser.runtime.getURL('audiopreprocessor.js');
-  for (let i = 1; i < targetLength - 1; i++) {
+
-    const index = i * springFactor;
+async function initAudioWorklet() {
-    const leftIndex = Math.floor(index).toFixed();
+  if (audioContext && preNode) {
-    const rightIndex = Math.ceil(index).toFixed();
+    setupMessageHandler();
-    const fraction = index - leftIndex;
+    return;
-    resampledData[i] = data[leftIndex] + (data[rightIndex] - data[leftIndex]) * fraction;
+  }
+  audioContext = new AudioContext();
+  await audioContext.audioWorklet.addModule(WORKLET_URL);
+
+  preNode = new AudioWorkletNode(audioContext, 'audiopreprocessor');
+  document.querySelectorAll('audio, video').forEach(el => {
+    let src;
+    try {
+      src = audioContext.createMediaElementSource(el);
+    } catch(e) {
+      console.warn('Could not create MediaElementSource for', el, e);
+      return;
+    }
+    src.connect(preNode);
+    src.connect(audioContext.destination);
+  });
+
+  preNode.connect(audioContext.destination);
+
+  setupMessageHandler();
+}
+
+async function startRecording(data) {
+  if (!audioContext) {
+    await initAudioWorklet();
   }
 
-  // Return the resampled data
+  const uid = generateUUID();
-  return resampledData;
+  socket = new WebSocket(`ws://${data.host}:${data.port}/`);
+  language = data.language;
+
+  socket.onopen = () => {
+    socket.send(JSON.stringify({
+      uid,
+      language: data.language,
+      task: data.task,
+      model: data.modelSize,
+      use_vad: data.useVad
+    }));
+  };
+
+  let serverReady = false;
+  socket.onmessage = async event => {
+    const msg = JSON.parse(event.data);
+    if (msg.uid !== uid) return;
+
+    if (msg.status === 'WAIT') {
+      await browser.runtime.sendMessage({ action: 'showPopup', data: msg.message });
+      return;
+    }
+    if (!serverReady && msg.message === 'SERVER_READY') {
+      serverReady = true;
+      return;
+    }
+    if (!language && msg.language) {
+      language = msg.language;
+      await browser.runtime.sendMessage({ action: 'updateSelectedLanguage', data: language });
+      return;
+    }
+    if (msg.message === 'DISCONNECT') {
+      await browser.runtime.sendMessage({ action: 'toggleCaptureButtons' });
+      return;
+    }
+    if (msg.segments) {
+      await browser.runtime.sendMessage({ action: 'transcript', data: {data: event.data, saveCaption: data.saveCaption} });
+    }
+  };
+
+  isCapturing = true;
 }
 
-function startRecording(data) {
+function stopRecording() {
-    socket = new WebSocket(`ws://${data.host}:${data.port}/`);
+  isCapturing = false;
-    language = data.language;
+  if (socket) {
+    socket.close();
+    socket = null;
+  }
 
-    const uuid = generateUUID();
+  remove_element();
-    socket.onopen = function(e) { 
-      socket.send(
-        JSON.stringify({
-            uid: uuid,
-            language: data.language,
-            task: data.task,
-            model: data.modelSize,
-            use_vad: data.useVad
-        })
-      );
-    };
-
-    let isServerReady = false;
-    socket.onmessage = async (event) => {
-      const data = JSON.parse(event.data);
-      if (data["uid"] !== uuid)
-        return;
-      
-      if (data["status"] === "WAIT"){
-        await browser.runtime.sendMessage({ action: "showPopup", data: data["message"] })
-        return;
-      }
-      
-      if (!isServerReady && data["message"] === "SERVER_READY"){
-        isServerReady = true;
-        return;
-      }
-
-      if (language === null ){
-        language = data["language"];
-        await browser.runtime.sendMessage({ action: "updateSelectedLanguage", data: language })      
-        return
-      }
-
-      if (data["message"] === "DISCONNECT"){
-        await browser.runtime.sendMessage({ action: "toggleCaptureButtons", data: false })        
-        return
-      }
-
-      await browser.runtime.sendMessage({ action: "transcript", data: event.data })
-          .catch(function(error) {
-            console.error("Error sending message:", error);
-          });
-    };
-
-  // Access the audio stream from the current tab
-  navigator.mediaDevices.getUserMedia({ audio: true })
-    .then(function(stream) {
-      // Create a new MediaRecorder instance
-      const audioDataCache = [];
-      audioContext = new AudioContext();
-      mediaStream = audioContext.createMediaStreamSource(stream);
-      recorder = audioContext.createScriptProcessor(4096, 1, 1);
-
-      recorder.onaudioprocess = async (event) => {
-        if (!audioContext || !isCapturing || !isServerReady || isPaused) return;
-
-        const inputData = event.inputBuffer.getChannelData(0);
-        const audioData16kHz = resampleTo16kHZ(inputData, audioContext.sampleRate);
-
-        audioDataCache.push(inputData);
-        
-        socket.send(audioData16kHz);
-      };
-
-      // Prevent page mute
-      mediaStream.connect(recorder);
-      recorder.connect(audioContext.destination);
-    })
 }
 
+
 var elem_container = null;
 var elem_text = null;
 
@@ -308,6 +326,8 @@ function remove_element() {
 
 browser.runtime.onMessage.addListener((request, sender, sendResponse) => {
   const { action, data } = request;
+  const saveCaption = data.saveCaption || false;
+
   if (action === "startCapture") {
       isCapturing = true;
       startRecording(data);
@@ -318,12 +338,20 @@ browser.runtime.onMessage.addListener((request, sender, sendResponse) => {
         socket.close();
         socket = null;
     }
-    
+
-    if (audioContext) {
+
-        audioContext.close();
+    if (saveCaption === true) {
-        audioContext = null;
+      if (lastIncompleteSegment && lastIncompleteSegment.text && lastIncompleteSegment.text.trim() !== "") {
-        mediaStream = null;
+          if (allSegments.length === 0 || parseFloat(lastIncompleteSegment.start) >= parseFloat(allSegments[allSegments.length - 1].end)) {
-        recorder = null;
+              allSegments.push({
+                  start: lastIncompleteSegment.start,
+                  end: lastIncompleteSegment.end,
+                  text: lastIncompleteSegment.text
+              });
+          }
+      }
+  
+      downloadSRT();
     }
 
     remove_element();
@@ -337,8 +365,25 @@ browser.runtime.onMessage.addListener((request, sender, sendResponse) => {
   } else if (action === "show_transcript"){
     if (!isCapturing) return;
     init_element();    
-    message = JSON.parse(data);
+    message = JSON.parse(data.data);
     message = message["segments"];
+
+    if (saveCaption === true) {
+      message.forEach(seg => {
+          if (seg.completed === true && 
+              (allSegments.length === 0 || parseFloat(seg.start) >= parseFloat(allSegments[allSegments.length - 1].end))) {
+              allSegments.push({
+                  start: seg.start,
+                  end: seg.end,
+                  text: seg.text
+              });
+              
+              lastIncompleteSegment = null;
+          } else if (seg.completed !== true) {
+              lastIncompleteSegment = seg;
+          }
+      });
+    }
     
     var text = '';
     for (var i = 0; i < message.length; i++) {

Audio-Transcription-Firefox/manifest.json

@@ -8,6 +8,9 @@
       "activeTab",
       "<all_urls>"
     ],
+    "web_accessible_resources": [
+      "audiopreprocessor.js"
+    ],
     "background": {
       "scripts": ["background.js"],
       "persistent": false

Audio-Transcription-Firefox/popup.html

@@ -19,6 +19,10 @@
     <input type="checkbox" id="useVadCheckbox">
     <label for="useVadCheckbox">Use Voice Activity Detection</label>
   </div>
+  <div class="checkbox-container">
+    <input type="checkbox" id="saveCaptionCheckbox">
+    <label for="saveCaption">Download SRT file at Stop Capture</label>
+  </div>
   <textarea id="waitTextBox" style="display: none;"></textarea>
   <div class="dropdown-container">
     <label for="languageDropdown">Select Language:</label>

Audio-Transcription-Firefox/popup.js

@@ -4,6 +4,7 @@ document.addEventListener("DOMContentLoaded", function() {
 
   const useServerCheckbox = document.getElementById("useServerCheckbox");
   const useVadCheckbox = document.getElementById("useVadCheckbox");
+  const saveCaptionCheckbox = document.getElementById("saveCaptionCheckbox");
   const languageDropdown = document.getElementById('languageDropdown');
   const taskDropdown = document.getElementById('taskDropdown');
   const modelSizeDropdown = document.getElementById('modelSizeDropdown');
@@ -41,6 +42,12 @@ document.addEventListener("DOMContentLoaded", function() {
     }
   });
 
+  browser.storage.local.get("saveCaptionState", ({ saveCaptionState }) => {
+    if (saveCaptionState !== undefined) {
+      saveCaptionCheckbox.checked = saveCaptionState;
+    }
+  });
+
   browser.storage.local.get("selectedLanguage", ({ selectedLanguage: storedLanguage }) => {
     if (storedLanguage !== undefined) {
       languageDropdown.value = storedLanguage;
@@ -85,6 +92,7 @@ document.addEventListener("DOMContentLoaded", function() {
               task: selectedTask,
               modelSize: selectedModelSize,
               useVad: useVadCheckbox.checked,
+              saveCaption: saveCaptionCheckbox.checked,
             } 
           });
         toggleCaptureButtons(true);
@@ -101,7 +109,7 @@ document.addEventListener("DOMContentLoaded", function() {
   stopButton.addEventListener("click", function() {
     browser.tabs.query({ active: true, currentWindow: true })
       .then(function(tabs) {
-        browser.tabs.sendMessage(tabs[0].id, { action: "stopCapture" })
+        browser.tabs.sendMessage(tabs[0].id, { action: "stopCapture", data: {saveCaption: saveCaptionCheckbox.checked, } })
           .then(function(response) {
             toggleCaptureButtons(false);
             browser.storage.local.set({ capturingState: { isCapturing: false } })
@@ -124,6 +132,7 @@ document.addEventListener("DOMContentLoaded", function() {
     stopButton.disabled = !isCapturing;
     useServerCheckbox.disabled = isCapturing;
     useVadCheckbox.disabled = isCapturing;
+    saveCaptionCheckbox.disabled = isCapturing;
     modelSizeDropdown.disabled = isCapturing;
     languageDropdown.disabled = isCapturing;
     taskDropdown.disabled = isCapturing; 
@@ -142,6 +151,11 @@ document.addEventListener("DOMContentLoaded", function() {
     browser.storage.local.set({ useVadState });
   });
 
+  saveCaptionCheckbox.addEventListener("change", () => {
+    const saveCaptionState = saveCaptionCheckbox.checked;
+    browser.storage.local.set({ saveCaptionState });
+  });
+
   languageDropdown.addEventListener('change', function() {
     if (languageDropdown.value === "") {
       selectedLanguage = null;