pdf files are not sharp -> unreadable in web app

[horstepipe 422]

hello
to bypass the lack of opening pdf files from a book library on IOS I just tried the web app. I can open them there, but they are not sharp. 
The same file is fine in browser when accessing the server directly (non web app).

 

 

[horstepipe 422]

this is Emby server v4.9.1.90

 

BR

[Luke 42077]

@Protected

[Protected 86]

Hi there. Does this happen to every file? Can you tell us more about your iOS device?

This looks like the window is very zoomed in/low resolution, which could happen in an older device and can affect page resolution calculations (because the player renders as if the pdf is in a tiny window).

[Protected 86]

Do you see the PDF player's UI (buttons) at the top?

[horstepipe 422]

HI @Protected

Yes, on every file, tested around 5. 
Yes, I see the UI (buttons) at the top.
This is indeed an older device - iPhone SE 2nd generation.

Thanks for looking into this!
BR

[horstepipe 422]

This is IOS 26.2 fyi

[Protected 86]

Thanks for the answers! Could you test something for me please? What happens if you zoom out with the pinching motion and zoom in with the zoom in button in the UI? Also the opposite - zoom out with the button, and zoom in with the pinching gesture. Since one of those is handled internally and the other one is handled externally.

[horstepipe 422]

unfortunately I can't zoom more in as soon as the page fills the screen. If I press "zoom in" via the UI button nothing happens anymore.

[horstepipe 422]

same on my Ipad Mini 5. gen.
It isn't that unsharp there - but still almost unreadable. I can't zoom in more there via buttons, either. 

[Protected 86]

Thank you. I think I fully understand the problem now. PDF reader zooming doesn't let you zoom farther than the width of the page because we don't have internal support for horizontal scrolling as of now. But since pdf is fixed layout and your screen is small, at this size the text can often be too visually small to read, as too much of it is crammed into the page. I imagine you don't have this issue with most ebooks since you can just make the text bigger and it will reflow.

You are (very reasonably) attempting to use the mobile device's zoom feature to make the pdf page bigger and therefore easier to read, but the page is only being rendered with a width matching your screen resolution (the maximum), so there are just not enough pixels in it for the text to be legible no matter how much you scale it up.

It's not the first time people report issues with iOS, and previously what happened was that ultimately I don't have access to tools or test devices that would allow me to ascertain exactly how your browser is communicating with the app. But I think in this case there are some ways we could improve your experience even without knowing that, by making some performance compromises with other device types. I'll update here when there's news.

[Neminem 1515]

Try flipping your phone to landscape.

And see if that helps.

I know stupid, right.

But I'm curious

[horstepipe 422]

17 hours ago, Neminem said:

Try flipping your phone to landscape.

And see if that helps.

I know stupid, right.

But I'm curious

still by far not enough to make it readable
In addition, I am not able to scroll vertically then.

[Neminem 1515]

Yeah. I kinda knew it would be a goose chase

But something to try, if not already tried

[horstepipe 422]

18 hours ago, Protected said:

Thank you. I think I fully understand the problem now. PDF reader zooming doesn't let you zoom farther than the width of the page because we don't have internal support for horizontal scrolling as of now. But since pdf is fixed layout and your screen is small, at this size the text can often be too visually small to read, as too much of it is crammed into the page. I imagine you don't have this issue with most ebooks since you can just make the text bigger and it will reflow.

You are (very reasonably) attempting to use the mobile device's zoom feature to make the pdf page bigger and therefore easier to read, but the page is only being rendered with a width matching your screen resolution (the maximum), so there are just not enough pixels in it for the text to be legible no matter how much you scale it up.

It's not the first time people report issues with iOS, and previously what happened was that ultimately I don't have access to tools or test devices that would allow me to ascertain exactly how your browser is communicating with the app. But I think in this case there are some ways we could improve your experience even without knowing that, by making some performance compromises with other device types. I'll update here when there's news.

thank you very much for that explanation, makes sense to me. 
If I can test something for you about it, let me know. 
I am having an iPhone SE 2nd gen and an iPad Mini 5th gen on site.
BR

[Protected 86]

OK, here's what we just added internally: When the viewport size is smaller than the PDF's built in default size ("100%"), pages will always render with a resolution of 100%, or in other words, they will render with more pixels than the actual size of the page in the viewport. This should allow you to zoom in natively in the mobile device in order to see the text with more detail. We have no other reference for size, so if the detail is still insufficient for any specific PDF, that's on the PDF's creator; you can always use third party software to edit that PDF and make it bigger. But I'm confident this will make the vast majority of PDFs legible in low res devices.

This feature will not be available in TV mode!

Please keep an eye out for when this is released and update us if it didn't solve the problem.

[brianpeterson1 0]

In Adobe Acrobat or your design app, export as High Quality Print, use 300 DPI, and avoid downsampling images.