Attach (recommended) or Link to PDF file here: https://d15k2d11r6t6rl.cloudfront.net/public/users/Integrators/a0a42ab5-3cb9-4912-84b7-3c6e47330d5c/smart-pr-805/Consumentenfolder_A5_zonder_paskruizen%20_2.pdf (and the similar other files under "Informatiefolder" on https://news.pressmailings.com/hvdm/partnertoolkit)

Configuration:
- Web browser and its version: Firefox 84.0 (64 bits)
- Operating system and its version: Arch Linux
- PDF.js version: 2.7.262 (built-in) and 2.7.434 (development version at time of writing)
- Is a browser extension: no

Steps to reproduce the problem:
1. Open the linked PDF file linked above.
2. Notice that the first page is rendered completely broken. There are no warnings/errors in the console unfortunately, and it's not related to layers since the document does not contain any.

What is the expected behavior? (add screenshot)
![good](https://user-images.githubusercontent.com/1993262/103363234-e158d580-4aba-11eb-9eb7-fe0db9f0a193.png)

What went wrong? (add screenshot)
![broken](https://user-images.githubusercontent.com/1993262/103363239-e4ec5c80-4aba-11eb-9f7d-3edac62ece3c.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension): -
const height = imgData.height,
    width = imgData.width;
  const partialChunkHeight = height % FULL_CHUNK_HEIGHT;
  const fullChunks = (height - partialChunkHeight) / FULL_CHUNK_HEIGHT;
  const totalChunks = partialChunkHeight === 0 ? fullChunks : fullChunks + 1;
  const chunkImgData = ctx.createImageData(width, FULL_CHUNK_HEIGHT);
  let srcPos = 0;
  const src = imgData.data;
  const dest = chunkImgData.data;
  for (let i = 0; i < totalChunks; i++) {
    const thisChunkHeight =
      i < fullChunks ? FULL_CHUNK_HEIGHT : partialChunkHeight;
    
    
    let destPos = 3; 
    for (let j = 0; j < thisChunkHeight; j++) {
      let elem,
        mask = 0;
      for (let k = 0; k < width; k++) {
        if (!mask) {
          elem = src[srcPos++];
          mask = 128;
        }
        dest[destPos] = elem & mask ? 0 : 255;
        destPos += 4;
        mask >>= 1;