Add resumable thumbnail extraction Also improves initial import by skipping any already existing thumbnails.

Author: cal2195

main-support.ts

@@ -302,6 +302,28 @@ export function superDangerousDelete(imageLocation: string, numberOfImage: numbe
 
 // GENERATE INDEXES FOR ARRAY
 
+export function hasAllThumbs(fileHash: string, screenshotFolder: string) : boolean {
+  // Check in reverse order for efficiency
+  return fs.existsSync(screenshotFolder + '/' + fileHash + '-first.jpg')
+         && fs.existsSync(screenshotFolder + '/' + fileHash + '.mp4')
+         && fs.existsSync(screenshotFolder + '/' + fileHash + '.jpg');
+}
+
+/**
+ * Generate indexes for any files missing thumbnails
+ */
+export function missingThumbsIndex(fullArray: ImageElement[], screenshotFolder: string): number[] {
+  const indexes: number[] = [];
+  const total: number = fullArray.length;
+  for (let i = 0; i < total; i++) {
+    if (!hasAllThumbs(fullArray[i][3], screenshotFolder)) {
+      indexes.push(i);
+    }
+  }
+
+  return indexes;
+}
+
 /**
  * Generate indexes for each element in finalArray, e.g.
  * [0, 1, 2, 3, ..., n] where n = finalArray.length

main.ts

@@ -198,6 +198,7 @@ ffmpeg.setFfmpegPath(ffmpegPath);
 import {
   alphabetizeFinalArray,
   countFoldersInFinalArray,
+  missingThumbsIndex,
   everyIndex,
   extractAllMetadata,
   finalArrayWithoutDeleted,
@@ -253,6 +254,19 @@ function openThisDamnFile(pathToVhaFile: string) {
       console.log(globals.selectedSourceFolder + ' - videos location');
       console.log(globals.selectedOutputFolder + ' - output location');
 
+      // resume extracting any missing thumbnails
+      const screenshotOutputFolder: string = path.join(globals.selectedOutputFolder, 'vha-' + globals.hubName);
+
+      const indexesToScan: number[] = missingThumbsIndex(lastSavedFinalObject.images, screenshotOutputFolder);
+
+      extractAllScreenshots(
+        lastSavedFinalObject.images,
+        globals.selectedSourceFolder,
+        screenshotOutputFolder,
+        globals.screenShotSize,
+        indexesToScan
+      );
+
       globals.angularApp.sender.send(
         'finalObjectReturning',
         JSON.parse(data),
@@ -625,7 +639,7 @@ function sendFinalResultHome(
 
     const screenshotOutputFolder: string = path.join(globals.selectedOutputFolder, 'vha-' + globals.hubName);
 
-    const indexesToScan: number[] = everyIndex(myFinalArray);
+    const indexesToScan: number[] = missingThumbsIndex(myFinalArray, screenshotOutputFolder);
 
     extractAllScreenshots(
       myFinalArray,