Invalid PDF Structure

[Adetimmy]

pdf parser returning invalid PDf structure, meanwhile the returned pdf web browser view url works fine.

[dosubot[bot]]

🤖

Hey there, @Adetimmy! Good to see you around the langchainjs repo again. Hope you're having a good day so far!

The issue you're experiencing could be due to the way the PDF.js library is parsing the PDF file. The PDF.js library is used in the parse method of the PDFLoader class to load the PDF from the buffer and extract the text content from each page.

The PDF.js library might not be able to correctly parse the PDF file if it contains features or structures that are not supported by the library. This could result in an invalid PDF structure error, even though the PDF file appears to work fine when viewed in a web browser.

Here is the relevant code:

public async parse(
  raw: Buffer,
  metadata: Document["metadata"]
): Promise<Document[]> {
  const { getDocument, version } = await this.pdfjs();
  const pdf = await getDocument({
    data: new Uint8Array(raw.buffer),
    useWorkerFetch: false,
    isEvalSupported: false,
    useSystemFonts: true,
  }).promise;
  // ...
  for (let i = 1; i <= pdf.numPages; i += 1) {
    const page = await pdf.getPage(i);
    const content = await page.getTextContent();
    // ...
  }
  // ...
}

In this code, the getDocument function from the PDF.js library is used to load the PDF from the buffer, and the getTextContent method is used to retrieve the text content from each page. If the PDF file contains unsupported features or structures, these functions might not be able to correctly parse the file, resulting in an invalid PDF structure error.

Unfortunately, I wasn't able to find specific features or structures in a PDF file that might not be supported by the PDF.js library used in langchainjs, or the exact error message returned by the PDF.js library when it encounters an invalid PDF structure in the langchainjs codebase.

Could you please provide more details about the PDF file you're trying to parse? This could help in identifying the specific features or structures that are causing the issue. Also, if you could share the exact error message you're seeing, that would be very helpful.

You can find the relevant code in the langchain/src/document_loaders/fs/pdf.ts file in the langchainjs repository.

I hope this helps! If you have any other questions, feel free to ask.

-Dosu

Sources

• langchain/src/document_loaders/fs/pdf.ts

---

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[Adetimmy]

@dosubot what features or structures are not supported by the pdf-parser? Even if the pdf contains only text, yet it still throws same error "Invalid Pdf structure"

[dosubot[bot]]

🤖

The "Invalid PDF Structure" error typically occurs when the PDF parser is unable to correctly interpret the structure of the PDF file. This could be due to a variety of reasons such as the PDF being encrypted, the PDF being corrupted or not properly formatted, or the PDF containing features or structures that are not supported by the parser.

The pdf-parser in the langchainjs codebase provides a wide range of functionalities as mentioned in the langchain/src/types/pdf-parse.d.ts file. However, it's important to note that while it can handle a variety of PDF structures and features, it may not support all of them. For example, it may not support certain types of encryption, certain types of fonts, or certain types of images.

If the PDF contains only text and you're still encountering the "Invalid PDF Structure" error, it's possible that the text is encoded in a way that the parser doesn't support, or the PDF might be using a structure or feature that the parser doesn't support.

To better understand the issue, it would be helpful if you could provide more information about the PDF file you're trying to parse. For example, how is the text encoded? What kind of structures or features does the PDF use? Is the PDF encrypted? This information could help identify why the parser is returning an "Invalid PDF Structure" error.

Also, please note that I'm unable to view the image you've attached as I can't process images. If there's any important information in the image, could you please describe it in text form?

For more detailed information, you might want to check the source code of the pdf-parser or the documentation of the PDF.js library that it's based on. This could give you a better understanding of what features and structures the parser supports and how it works.

I hope this helps! If you have any more questions, feel free to ask. Dosu

Sources

• langchain/src/types/pdf-parse.d.ts

---

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Help me be more useful! Please leave a 👍 if this is helpful and 👎 if it is irrelevant.

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[Adetimmy]

@dosubot: here is the error output on the terminal "Warning: Indexing all PDF objects Error at InvalidPDFExceptionClosure (webpack-internal:///(sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js:437:49) at Object.eval (webpack-internal:///(sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js:440:14) at w_pdfjs_require (webpack-internal:///(sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js:35:40) at Object.eval (webpack-internal:///(sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js:7907:35) at w_pdfjs_require (webpack-internal:///(sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js:35:40) at eval (webpack-internal:///(sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js:72:25) at eval (webpack-internal:///(sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js:73:15) at webpackUniversalModuleDefinition (webpack-internal:///(sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js:16:32) at eval (webpack-internal:///(sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js:18:3) at (sc_server)/./node_modules/pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js (C:\Users\OGUNLE.OGUNLE\Desktop\Chatpdf_Cloudinary\task.next\server_sc_server_node_modules_pdf-parse_lib_pdf_js_v1_10_100_build_pdf_js.js:20:1) at webpack_require__ (C:\Users\OGUNLE.OGUNLE\Desktop\Chatpdf_Cloudinary\task.next\server\webpack-runtime.js:33:43) at webpack_require__.t (C:\Users\OGUNLE.OGUNLE\Desktop\Chatpdf_Cloudinary\task.next\server\webpack-runtime.js:73:38) at async PDFLoader.PDFLoaderImports [as pdfjs] (webpack-internal:///(sc_server)/./node_modules/langchain/dist/document_loaders/fs/pdf.js:133:34) at async PDFLoader.parse (webpack-internal:///(sc_server)/./node_modules/langchain/dist/document_loaders/fs/pdf.js:62:42) { message: 'Invalid PDF structure' }"

[dosubot[bot]]

🤖

The "Invalid PDF structure" error you're encountering is likely due to certain limitations of the PDF.js library that is used in the PDFLoader class of langchainjs. Here are some possible causes:

1. Encrypted or password-protected PDFs: PDF.js does not support loading PDFs that are encrypted or password-protected. If the PDF file is encrypted or password-protected, the getDocument function will fail and throw an error.

2. Unsupported PDF features or structures: PDF.js does not support all features of the PDF format. Some PDFs may use features or structures that are not supported by PDF.js, such as certain types of annotations, form fields, or embedded files. If the PDF file uses unsupported features or structures, the getDocument function may fail to parse the PDF and throw an error.

3. Ill-formed PDFs: PDF.js does not support loading PDFs that are not well-formed according to the PDF specification. If the PDF file is not well-formed, the getDocument function will fail to parse the PDF and throw an error.

In the provided code, the getDocument function is used to load the PDF from the buffer:

const pdf = await getDocument({
  data: new Uint8Array(raw.buffer),
  useWorkerFetch: false,
  isEvalSupported: false,
  useSystemFonts: true,
}).promise;

If the getDocument function fails to parse the PDF, it will reject the promise and throw an error. This could be the cause of the "Invalid PDF structure" error.

The exact version of the PDF.js library used in the PDFLoader class of langchainjs is v1.10.100, as evident from the import statement in the PDFLoaderImports function:

const { default: mod } = await import(
  "pdf-parse/lib/pdf.js/v1.10.100/build/pdf.js"
);

You can find more details in the PDFLoader class source code.

If you're sure that your PDF does not fall into any of the above categories, it might be helpful to provide a minimal reproducible example or more details about the PDF file you're trying to parse. This could help in identifying the issue more accurately.

Sources

• langchain/src/document_loaders/fs/pdf.ts

---

This response is meant to be useful and save you time. It is not meant to be a precise solution, but rather a starting point for your own research.

Help me be more useful! Please leave a 👍 if this is helpful and 👎 if it is irrelevant.

If you want to continue the conversation, start your reply with @dosu-bot.

[mundume]

@Adetimmy are you using uploadthing to upload your pdf? if yes update it to the latest version ie @uploadthing/react and uploadthing,

if youre using the url directly ie https://uploadthing-prod.s3.us-west-2.amazonaws.com/${file.key} change it to file.url I hope that will fix it

[Adetimmy]

@mundume No, i'm not. neither am i using aws, rather using cloudinary for the pdf storage and retrieval.

[mundume]

I'm sorry I'm not able to help you with that. good luck

[Adetimmy]

@mundume thank you😞

[ogagnon07]

I'm getting the exact same issue here. when I upload my pdf, i send it's base64Date to my api that converts it into a pdf with fs. then I try to upload it and i'm getting the same problem as @Adetimmy.