Pdf-lib: Trying to parse invalid object

[antoinerousseau]

When I open my beautiful PDF with this lib, all is great.
But because the file is big, I compressed it using smallpdf.com, and now when I open the compressed version, I get these warnings:

Trying to parse invalid object: {"line":140,"column":0,"offset":33170})
Invalid object ref: 9 0 R
Trying to parse invalid object: {"line":301,"column":0,"offset":65943})
Invalid object ref: 21 0 R
Trying to parse invalid object: {"line":309,"column":0,"offset":65969})
Invalid object ref: 22 0 R
Trying to parse invalid object: {"line":317,"column":0,"offset":65995})
Invalid object ref: 23 0 R

Any idea why? Is this an issue if I just use drawText?

[Hopding]

Hello @antoinerousseau!

The warnings will not cause you any issues. pdf-lib's parser failed to parse those objects, but that's because they are a very specific type of empty object that don't do anything in your document anyways. Regardless, I fixed the parser bug in #370. So when the next release of pdf-lib goes out, you will no longer see these warnings.

[antoinerousseau]

Wow, so fast, thanks!
So I wonder, those extra whitespace-like characters, are they useless? If so, I guess smallpdf.com can further reduce the output size of the PDF in their code ;)

[Hopding]

Haha, indeed. They are useless as far as I can tell. Though, even if they aren't, smallpdf.com could eliminate the extra whitespace in them. But they only contribute a few bytes to the total size of the document, so I guess it's probably more effort than its worth for them.

[yakupteke]

Hi,
I have the same issue.

Trying to parse invalid object: {"line":342,"column":6,"offset":132428})
Invalid object ref: 389 0 R
Trying to parse invalid object: {"line":393,"column":6,"offset":137107})
Invalid object ref: 390 0 R

How can I solve this issue?
Thanks.

[antoinerousseau]

@yakupteke did you read this thread?...

So when the next release of pdf-lib goes out, you will no longer see these warnings.

[Hopding]

@antoinerousseau Version 1.4.1 is now published. It contains the fix for this issue (@yakupteke it will hopefully fix your issue as well). The full release notes are available here.

You can install this new version with npm:

npm install [email protected]

It's also available on unpkg:

• https://unpkg.com/[email protected]/dist/pdf-lib.js
• https://unpkg.com/[email protected]/dist/pdf-lib.min.js

As well as jsDelivr:

• https://cdn.jsdelivr.net/npm/[email protected]/dist/pdf-lib.js
• https://cdn.jsdelivr.net/npm/[email protected]/dist/pdf-lib.min.js

[yakupteke]

Thanks a lot.

[deammer]

Hi @Hopding, I seem to be running into the same issue when I delete a page from some PDF files, like this one. I'm using 1.4.1 and seeing the console warnings below:

Trying to parse invalid object: {"line":24,"column":6,"offset":5055}) PDFParser.js:213:12
Invalid object ref: 4 0 R PDFParser.js:215:12
Trying to parse invalid object: {"line":152,"column":6,"offset":21555}) PDFParser.js:213:12
Invalid object ref: 8 0 R PDFParser.js:215:12
Trying to parse invalid object: {"line":273,"column":6,"offset":40714}) PDFParser.js:213:12
Invalid object ref: 12 0 R PDFParser.js:215:12
Trying to parse invalid object: {"line":390,"column":6,"offset":55361}) PDFParser.js:213:12
Invalid object ref: 16 0 R PDFParser.js:215:12
Trying to parse invalid object: {"line":439,"column":6,"offset":61912}) PDFParser.js:213:12
Invalid object ref: 20 0 R PDFParser.js:215:12
Trying to parse invalid object: {"line":504,"column":6,"offset":69247}) PDFParser.js:213:12
Invalid object ref: 24 0 R PDFParser.js:215:12
Trying to parse invalid object: {"line":566,"column":6,"offset":77542}) PDFParser.js:213:12
Invalid object ref: 28 0 R PDFParser.js:215:12
Trying to parse invalid object: {"line":641,"column":6,"offset":99802}) PDFParser.js:213:12
Invalid object ref: 34 0 R PDFParser.js:215:12
Trying to parse invalid object: {"line":700,"column":6,"offset":106641}) PDFParser.js:213:12
Invalid object ref: 38 0 R PDFParser.js:215:12
Trying to parse invalid object: {"line":755,"column":6,"offset":112760})

Do you have any idea why that would be happening?

Sample relevant code, nothing too wild:

const deleteFirstPage = async (pdfUrl: string) => {
  const pdfBytes: ArrayBuffer = await axios
    .get(pdfUrl, {
      responseType: 'arraybuffer'
    })
    .then(res => res.data as ArrayBuffer)

  const document = await PDFDocument.load(pdfBytes)
  document.removePage(1)

  const updatedPdfBytes = await document.save()

  return new Blob([updatedPdfBytes], { type: 'application/pdf' })
}

[kimsean]

I just installed this package.. Im using 1.4.1 and i still get the parse invalid object error. Any idea? Thanks

[Hopding]

@deammer It looks like the problem you're encountering is due to the fact that your PDF is encrypted. pdf-lib does not currently support encrypted documents.

Just to be clear, when I run the following script:

import { PDFDocument } from 'pdf-lib';

(async () => {
  const url = 'https://www.uscis.gov/sites/default/files/files/form/i-130.pdf';
  const i130Bytes = await fetch(url).then((res) => res.arrayBuffer());
  const pdfDoc = await PDFDocument.load(i130Bytes);
})();

It produces the following output:

Trying to parse invalid object: {"line":24,"column":6,"offset":5055})
Invalid object ref: 4 0 R
...
Trying to parse invalid object: {"line":3862,"column":6,"offset":563722})
Invalid object ref: 408 0 R
Error: Input document to `PDFDocument.load` is encrypted. You can use `PDFDocument.load(..., { ignoreEncryption: true })` if you wish to load the document anyways.
    at new EncryptedPDFError (/Users/user/github/pdf-lib/scratchpad/build/src/api/errors.js:11:24)
    at new PDFDocument (/Users/user/github/pdf-lib/scratchpad/build/src/api/PDFDocument.js:52:19)
    at Function.<anonymous> (/Users/user/github/pdf-lib/scratchpad/build/src/api/PDFDocument.js:123:47)
    at step (/Users/user/github/pdf-lib/node_modules/tslib/tslib.js:139:27)
    at Object.next (/Users/user/github/pdf-lib/node_modules/tslib/tslib.js:120:57)
    at fulfilled (/Users/user/github/pdf-lib/node_modules/tslib/tslib.js:110:62)

Notice the encryption error. The ignoreEncryption flag is explained here. It doesn't actually do anything but suppress the error. I only added it to the library for backwards compatibility reasons. In hindsight it probably should not have been added.

[Hopding]

@kimsean Can you share the document that is causing the error?

[pedro-surf]

Still getting this error.
I'm on latest (1.11.2)

Link for the PDF file: https://www.icloud.com/iclouddrive/0de0B7Vuvr6gTeYYAn4c9GC_Q#large

Errors:

[tranghuyen215]

Still getting this error.
I'm on latest (1.11.2)

Link for the PDF file: https://www.icloud.com/iclouddrive/0de0B7Vuvr6gTeYYAn4c9GC_Q#large

Errors:

same to me