Merge pull request #11707 from Snuffleupagus/issue-11694

Always prefer the PDF.js JPEG decoder for very large images, in order to reduce peak memory usage (issue 11694)

src/core/jpeg_stream.js

@@ -134,6 +134,17 @@ const JpegStream = (function JpegStreamClosure() {
             stream.pos += 2; // Skip marker length.
             stream.pos += 1; // Skip precision.
             const scanLines = stream.getUint16();
+            const samplesPerLine = stream.getUint16();
+
+            // Letting the browser handle the JPEG decoding, on the main-thread,
+            // will cause a *large* increase in peak memory usage since there's
+            // a handful of short-lived copies of the image data. For very big
+            // JPEG images, always let the PDF.js image decoder handle them to
+            // reduce overall memory usage during decoding (see issue 11694).
+            if (scanLines * samplesPerLine > 1e6) {
+              validDimensions = false;
+              break;
+            }
 
             // The "normal" case, where the image data and dictionary agrees.
             if (scanLines === dictHeight) {