Merge mozilla master

Author: atishdhu

README.md

@@ -125,7 +125,7 @@ The API documentation can be found at:
 
 + https://mozilla.github.io/pdf.js/api/
 
-## Question
+## Questions
 
 Check out our FAQs and get answers to common questions:
 

l10n/en-US/viewer.ftl

@@ -348,6 +348,7 @@ pdfjs-editor-free-highlight-thickness-input = Thickness
 pdfjs-editor-free-highlight-thickness-title =
     .title = Change thickness when highlighting items other than text
 
+# .default-content is used as a placeholder in an empty text editor.
 pdfjs-free-text2 =
     .aria-label = Text Editor
     .default-content = Start typing…

src/core/base_stream.js

@@ -68,6 +68,10 @@ class BaseStream {
     return false;
   }
 
+  async getTransferableImage() {
+    return null;
+  }
+
   peekByte() {
     const peekedByte = this.getByte();
     if (peekedByte !== -1) {

src/core/image.js

@@ -752,6 +752,10 @@ class PDFImage {
         drawWidth === originalWidth &&
         drawHeight === originalHeight
       ) {
+        const image = await this.#getImage(originalWidth, originalHeight);
+        if (image) {
+          return image;
+        }
         const data = await this.getImageBytes(originalHeight * rowBytes, {});
         if (isOffscreenCanvasSupported) {
           if (mustBeResized) {
@@ -810,6 +814,10 @@ class PDFImage {
           }
 
           if (isHandled) {
+            const image = await this.#getImage(drawWidth, drawHeight);
+            if (image) {
+              return image;
+            }
             const rgba = await this.getImageBytes(imageLength, {
               drawWidth,
               drawHeight,
@@ -1013,6 +1021,20 @@ class PDFImage {
     };
   }
 
+  async #getImage(width, height) {
+    const bitmap = await this.image.getTransferableImage();
+    if (!bitmap) {
+      return null;
+    }
+    return {
+      data: null,
+      width,
+      height,
+      bitmap,
+      interpolate: this.interpolate,
+    };
+  }
+
   async getImageBytes(
     length,
     {

src/core/jpeg_stream.js

@@ -13,10 +13,10 @@
  * limitations under the License.
  */
 
+import { shadow, warn } from "../shared/util.js";
 import { DecodeStream } from "./decode_stream.js";
 import { Dict } from "./primitives.js";
 import { JpegImage } from "./jpg.js";
-import { shadow } from "../shared/util.js";
 
 /**
  * For JPEG's we use a library to decode these images and the stream behaves
@@ -32,6 +32,18 @@ class JpegStream extends DecodeStream {
     this.params = params;
   }
 
+  static get canUseImageDecoder() {
+    return shadow(
+      this,
+      "canUseImageDecoder",
+      // eslint-disable-next-line no-undef
+      typeof ImageDecoder === "undefined"
+        ? Promise.resolve(false)
+        : // eslint-disable-next-line no-undef
+          ImageDecoder.isTypeSupported("image/jpeg")
+    );
+  }
+
   get bytes() {
     // If `this.maybeLength` is null, we'll get the entire stream.
     return shadow(this, "bytes", this.stream.getBytes(this.maybeLength));
@@ -46,22 +58,7 @@ class JpegStream extends DecodeStream {
     this.decodeImage();
   }
 
-  decodeImage(bytes) {
-    if (this.eof) {
-      return this.buffer;
-    }
-    bytes ||= this.bytes;
-
-    // Some images may contain 'junk' before the SOI (start-of-image) marker.
-    // Note: this seems to mainly affect inline images.
-    for (let i = 0, ii = bytes.length - 1; i < ii; i++) {
-      if (bytes[i] === 0xff && bytes[i + 1] === 0xd8) {
-        if (i > 0) {
-          bytes = bytes.subarray(i);
-        }
-        break;
-      }
-    }
+  get jpegOptions() {
     const jpegOptions = {
       decodeTransform: undefined,
       colorTransform: undefined,
@@ -93,8 +90,34 @@ class JpegStream extends DecodeStream {
         jpegOptions.colorTransform = colorTransform;
       }
     }
-    const jpegImage = new JpegImage(jpegOptions);
+    return shadow(this, "jpegOptions", jpegOptions);
+  }
+
+  #skipUselessBytes(data) {
+    // Some images may contain 'junk' before the SOI (start-of-image) marker.
+    // Note: this seems to mainly affect inline images.
+    for (let i = 0, ii = data.length - 1; i < ii; i++) {
+      if (data[i] === 0xff && data[i + 1] === 0xd8) {
+        if (i > 0) {
+          data = data.subarray(i);
+        }
+        break;
+      }
+    }
+    return data;
+  }
+
+  decodeImage(bytes) {
+    if (this.eof) {
+      return this.buffer;
+    }
+    bytes = this.#skipUselessBytes(bytes || this.bytes);
 
+    // TODO: if an image has a mask we need to combine the data.
+    // So ideally get a VideoFrame from getTransferableImage and then use
+    // copyTo.
+
+    const jpegImage = new JpegImage(this.jpegOptions);
     jpegImage.parse(bytes);
     const data = jpegImage.getData({
       width: this.drawWidth,
@@ -113,6 +136,48 @@ class JpegStream extends DecodeStream {
   get canAsyncDecodeImageFromBuffer() {
     return this.stream.isAsync;
   }
+
+  async getTransferableImage() {
+    if (!(await JpegStream.canUseImageDecoder)) {
+      return null;
+    }
+    const jpegOptions = this.jpegOptions;
+    if (jpegOptions.decodeTransform) {
+      // TODO: We could decode the image thanks to ImageDecoder and then
+      // get the pixels with copyTo and apply the decodeTransform.
+      return null;
+    }
+    let decoder;
+    try {
+      // TODO: If the stream is Flate & DCT we could try to just pipe the
+      // the DecompressionStream into the ImageDecoder: it'll avoid the
+      // intermediate ArrayBuffer.
+      const bytes =
+        (this.canAsyncDecodeImageFromBuffer &&
+          (await this.stream.asyncGetBytes())) ||
+        this.bytes;
+      if (!bytes) {
+        return null;
+      }
+      const data = this.#skipUselessBytes(bytes);
+      if (!JpegImage.canUseImageDecoder(data, jpegOptions.colorTransform)) {
+        return null;
+      }
+      // eslint-disable-next-line no-undef
+      decoder = new ImageDecoder({
+        data,
+        type: "image/jpeg",
+        preferAnimation: false,
+      });
+
+      return (await decoder.decode()).image;
+    } catch (reason) {
+      warn(`getTransferableImage - failed: "${reason}".`);
+      return null;
+    } finally {
+      decoder?.close();
+    }
+  }
 }
 
 export { JpegStream };

src/core/jpg.js

@@ -744,55 +744,109 @@ function findNextFileMarker(data, currentPos, startPos = currentPos) {
   };
 }
 
+function prepareComponents(frame) {
+  const mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
+  const mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);
+  for (const component of frame.components) {
+    const blocksPerLine = Math.ceil(
+      (Math.ceil(frame.samplesPerLine / 8) * component.h) / frame.maxH
+    );
+    const blocksPerColumn = Math.ceil(
+      (Math.ceil(frame.scanLines / 8) * component.v) / frame.maxV
+    );
+    const blocksPerLineForMcu = mcusPerLine * component.h;
+    const blocksPerColumnForMcu = mcusPerColumn * component.v;
+
+    const blocksBufferSize =
+      64 * blocksPerColumnForMcu * (blocksPerLineForMcu + 1);
+    component.blockData = new Int16Array(blocksBufferSize);
+    component.blocksPerLine = blocksPerLine;
+    component.blocksPerColumn = blocksPerColumn;
+  }
+  frame.mcusPerLine = mcusPerLine;
+  frame.mcusPerColumn = mcusPerColumn;
+}
+
+function readDataBlock(data, offset) {
+  const length = readUint16(data, offset);
+  offset += 2;
+  let endOffset = offset + length - 2;
+
+  const fileMarker = findNextFileMarker(data, endOffset, offset);
+  if (fileMarker?.invalid) {
+    warn(
+      "readDataBlock - incorrect length, current marker is: " +
+        fileMarker.invalid
+    );
+    endOffset = fileMarker.offset;
+  }
+
+  const array = data.subarray(offset, endOffset);
+  offset += array.length;
+  return { appData: array, newOffset: offset };
+}
+
+function skipData(data, offset) {
+  const length = readUint16(data, offset);
+  offset += 2;
+  const endOffset = offset + length - 2;
+
+  const fileMarker = findNextFileMarker(data, endOffset, offset);
+  if (fileMarker?.invalid) {
+    return fileMarker.offset;
+  }
+  return endOffset;
+}
+
 class JpegImage {
   constructor({ decodeTransform = null, colorTransform = -1 } = {}) {
     this._decodeTransform = decodeTransform;
     this._colorTransform = colorTransform;
   }
 
-  parse(data, { dnlScanLines = null } = {}) {
-    function readDataBlock() {
-      const length = readUint16(data, offset);
-      offset += 2;
-      let endOffset = offset + length - 2;
-
-      const fileMarker = findNextFileMarker(data, endOffset, offset);
-      if (fileMarker?.invalid) {
-        warn(
-          "readDataBlock - incorrect length, current marker is: " +
-            fileMarker.invalid
-        );
-        endOffset = fileMarker.offset;
-      }
-
-      const array = data.subarray(offset, endOffset);
-      offset += array.length;
-      return array;
+  static canUseImageDecoder(data, colorTransform = -1) {
+    let offset = 0;
+    let numComponents = null;
+    let fileMarker = readUint16(data, offset);
+    offset += 2;
+    if (fileMarker !== /* SOI (Start of Image) = */ 0xffd8) {
+      throw new JpegError("SOI not found");
     }
+    fileMarker = readUint16(data, offset);
+    offset += 2;
 
-    function prepareComponents(frame) {
-      const mcusPerLine = Math.ceil(frame.samplesPerLine / 8 / frame.maxH);
-      const mcusPerColumn = Math.ceil(frame.scanLines / 8 / frame.maxV);
-      for (const component of frame.components) {
-        const blocksPerLine = Math.ceil(
-          (Math.ceil(frame.samplesPerLine / 8) * component.h) / frame.maxH
-        );
-        const blocksPerColumn = Math.ceil(
-          (Math.ceil(frame.scanLines / 8) * component.v) / frame.maxV
-        );
-        const blocksPerLineForMcu = mcusPerLine * component.h;
-        const blocksPerColumnForMcu = mcusPerColumn * component.v;
-
-        const blocksBufferSize =
-          64 * blocksPerColumnForMcu * (blocksPerLineForMcu + 1);
-        component.blockData = new Int16Array(blocksBufferSize);
-        component.blocksPerLine = blocksPerLine;
-        component.blocksPerColumn = blocksPerColumn;
+    markerLoop: while (fileMarker !== /* EOI (End of Image) = */ 0xffd9) {
+      switch (fileMarker) {
+        case 0xffc0: // SOF0 (Start of Frame, Baseline DCT)
+        case 0xffc1: // SOF1 (Start of Frame, Extended DCT)
+        case 0xffc2: // SOF2 (Start of Frame, Progressive DCT)
+          // Skip marker length.
+          // Skip precision.
+          // Skip scanLines.
+          // Skip samplesPerLine.
+          numComponents = data[offset + (2 + 1 + 2 + 2)];
+          break markerLoop;
+        case 0xffff: // Fill bytes
+          if (data[offset] !== 0xff) {
+            // Avoid skipping a valid marker.
+            offset--;
+          }
+          break;
       }
-      frame.mcusPerLine = mcusPerLine;
-      frame.mcusPerColumn = mcusPerColumn;
+      offset = skipData(data, offset);
+      fileMarker = readUint16(data, offset);
+      offset += 2;
+    }
+    if (numComponents === 4) {
+      return false;
+    }
+    if (numComponents === 3 && colorTransform === 0) {
+      return false;
     }
+    return true;
+  }
 
+  parse(data, { dnlScanLines = null } = {}) {
     let offset = 0;
     let jfif = null;
     let adobe = null;
@@ -830,7 +884,8 @@ class JpegImage {
         case 0xffee: // APP14
         case 0xffef: // APP15
         case 0xfffe: // COM (Comment)
-          const appData = readDataBlock();
+          const { appData, newOffset } = readDataBlock(data, offset);
+          offset = newOffset;
 
           if (fileMarker === 0xffe0) {
             // 'JFIF\x00'