"extractFrames" get parameter is added by PDFTron while fetching previews


I’ve faced with issues about how webviewer + webviewer-video are consuming HLS links.

Following documentation, I’m trying to load the video in the following way:

const videoURL = "https://amazon-cloudfront.com/VIDEO_ID/playlist.m3u8?Key-Pair-Id=key"
const viewer = await initializeVideoViewer(instance)
await viewer.loadVideo(videoURL)

That works well, I can play video, go through any video moment, however, annotations’ previews and frames are black.

I’ve revealed that when I try to open frames or there’re some annotations exist, the webviewer is trying to make the request using my videoURL with one more query parameter extractFrames=true. E.g.:


Therefore, such requests fail because the URL has been signed with the key for CloudFront so therefor adding more parameters will fail the key signature.

So the question is: is there a way to intercept each request and manually remove extractFrames query parameter?
Or is there some special purpose for this query parameter?

Thank you!

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Thank you for your bug report!

The query param is there for historical reasons but not needed anymore. We will remove it in a patch. I can get it to you in a few days. Just to make sure there are no edges cases.

Best Regards,

Kristian Hein

Developer - WebViewer

PDFTron Systems, Inc.


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Check your ticket status - https://support.pdftron.com/support/tickets/36492

Hello @Kristian_Hein ,

Sure, thank you. It would be helpful.

Hello @ihor.levchenko ,

I removed the query param in v4.26.5 of webviewer-video. Please try it out and let me know if you encounter any other issues.

  • Kristian

Thank you for the update.

I have checked already, and that looks good to me. Thank you for your work.

The only thing is… ffprobe request is failing with 504 error. So, once PDFTron loaded, frames previews loading stuck until ffprobe request finally ends (in my case fail), then all previews continue to appear.

Probably, ffprobe doesn’t work with HLS streams correctly?

I can provide more details if necessary. Let me know.

Hello @ihor.levchenko ,

I don’t believe we support HLS files. Does the video play after loading it? Would it be possible to share the file with us so we can investigate further?