DR1000 PDF pre-fetching doesn't work on fullscreen mode

[bokjeid]

Hello,
Today I found out some strange problem regarding PDF on DR1000S.
When I use it on "fullscreen mode", there shows up a loading box every time I turn to the next page nevertheless I waited much time to let DR1000S pre-fetch the next pages.
But this problem doesn't appear on "not fullscreen mode" - in this case, DR1000S normally pre-fetchs the next pages.
So it hinders me in using DR1000S on "fullscreen mode" ;;

Why is it? How can I solve it?

Is there anybody who has similar experience?

If you want more detailed explanation, please tell me.

[Mackx]

Hi bokje,

I did some quick experiments, but did not see too much difference. Maybe rendering to the bigger 'full-screen' size is taking an un-proportional amount of extra cpu power?
The document I am reading now is rather simple, that might explain that I do not see any wait-dialogs. I also used a e-magazine, which gives both dialogs with normal and full-screen for most pages.

Unfortunately pre-caching is done by UDS of which no source code is published.

[Shaggy]

Originally Posted by Mackx

Hi bokje,

I did some quick experiments, but did not see too much difference. Maybe rendering to the bigger 'full-screen' size is taking an un-proportional amount of extra cpu power?
The document I am reading now is rather simple, that might explain that I do not see any wait-dialogs. I also used a e-magazine, which gives both dialogs with normal and full-screen for most pages.

Unfortunately pre-caching is done by UDS of which no source code is published.

I imagine a text-PDF vs an image-PDF would make a difference, as well as the resolution/etc if it's image based. The DR isn't terribly fast at scaling images.

[rvs]

I haven't seen any difference either, but you might try converting to djvu. This might shave off a few seconds on the page load time, which might be enough to get the prefetching working again.

I have a feeling that when the pages load too slow (perhaps somewhere between 10-15 seconds), the prefetching normally doesn't happen. I could be wrong though, I haven't tested this thoroughly.

[bokjeid]

Originally Posted by Mackx

Hi bokje,

I did some quick experiments, but did not see too much difference. Maybe rendering to the bigger 'full-screen' size is taking an un-proportional amount of extra cpu power?
The document I am reading now is rather simple, that might explain that I do not see any wait-dialogs. I also used a e-magazine, which gives both dialogs with normal and full-screen for most pages.

Unfortunately pre-caching is done by UDS of which no source code is published.

Hello Mackx,

You can check it with this test pdf file which I attached at my another thread in this forum some time ago.

https://www.mobileread.com/forums/att...3&d=1298962624

And, I agree with you. It seems that only 'full screen' mode takes some rendering time every page turning on some exact PDF files. In my case, most of my PDF files don't show this problem but only 2 PDF files did.
But I couldn't express it well so I just mentioned it as 'pre-fetching'..

Then, if it is a problem or bug of the 'full screen' mode itself, it means that we can't solve it as a user, not a developer?

So far, the only solution for this problem which I've found is 'to turn off full screen mode'..

Originally Posted by Shaggy

I imagine a text-PDF vs an image-PDF would make a difference, as well as the resolution/etc if it's image based. The DR isn't terribly fast at scaling images.

Hello Shaggy,
Yes, sometimes DR1000S shows phenomenal page turning speed on some text PDF files such as especially the DR1000S manual PDF inside. No loading time, nearly.
Maybe developers were satisfied with its PDF page turning speed as they test it with only that kind of PDF files.. Of course I don't know well..

Originally Posted by rvs

I haven't seen any difference either, but you might try converting to djvu. This might shave off a few seconds on the page load time, which might be enough to get the prefetching working again.

I have a feeling that when the pages load too slow (perhaps somewhere between 10-15 seconds), the prefetching normally doesn't happen. I could be wrong though, I haven't tested this thoroughly.

Hello rvs,
Yeah, I also assume that djvu converting would be one of the best options. So I've tried it many times as what I posted in one of my old threads.

But some issues of this method blocked me..
1) a clash with CBZ
2) we can't merge the scribbles with Xournal
3) it would take much time to convert all of dozens of PDF files..
4) the margin data of a PDF file was lost when converting to a djvu file - this was the most serious problem in my case

However, if you don't have to care of those in your case, it can be a good solution.

[rvs]

Hi bokjeid,

I checked your file and I get the same results as you (prefetching works on normal view, but not on full-screen). I have another pdf on my DR though where it happens both with normal and full-screen view, so the bug (if it is a bug and not a power-saving 'feature') is not limited to full-screen per se.

[rvs]

I think I might've found a somewhat workable workaround for this problem.

Before turning a page, hold the lower middle button (menu button) for 3/4 to 15 seconds. Now prefetching should work on the next page.

You don't have to do it right before you turn the page. The time needed depends on the book and if you do it right after you turn a page (this takes longer, so you still can't skip through a book very fast).

PS. Hold it for at least 3/4 seconds, otherwise the menu will show up.

[bokjeid]

Originally Posted by rvs

I think I might've found a somewhat workable workaround for this problem.

Before turning a page, hold the lower middle button (menu button) for 3/4 to 15 seconds. Now prefetching should work on the next page.

You don't have to do it right before you turn the page. The time needed depends on the book and if you do it right after you turn a page (this takes longer, so you still can't skip through a book very fast).

PS. Hold it for at least 3/4 seconds, otherwise the menu will show up.

Wow! Miracle!
I tested it yesterday and it really worked!!
And I'll test it at 2nd time tomorrow.
Is there anybody who tried it, too?
Thank you so much, rvs.
Do you know how and why it works?
I've really never seen this method anywhere until now.

[Mackx]

Originally Posted by bokjeid

Do you know how and why it works?

The key-press is waking-up the DR so it continues with its activities, which was pre-fetching/rendering the next page(s). It seems that when not in fullscreen the page can be rendered before idle-mode starts, and in full-screen mode not. If this helps then increasing the timeout for the idl-mode should also help with this problem. The timeout currently is 5s, but it is fixed in code.
What I find strange is that the pre-fetcher does not prevent the idle-mode from starting, there is a possibility to prevent this using a system-call. There could also be a bug in UDS, which only shows up when entering full-screen mode.
It is also strange that it is reproducable with a lot of documents. If it is really a matter of longer rendering time, I would expect it to go wrong only when rendering takes about 5s. Unless redering for full-screen takes a considerable extra amount of time. (Maybe, due to a bug, the page is first rendered to the non-fullscreen resolution and after that also to the full-screen resolution?)

[rvs]

Originally Posted by Mackx

The key-press is waking-up the DR so it continues with its activities, which was pre-fetching/rendering the next page(s). It seems that when not in fullscreen the page can be rendered before idle-mode starts, and in full-screen mode not. If this helps then increasing the timeout for the idl-mode should also help with this problem. The timeout currently is 5s, but it is fixed in code.

I already tried this (setting it to 10s), but it didn't seem to do anything. I may have made a mistake somewhere though.

[Mackx]

Originally Posted by rvs

I already tried this (setting it to 10s), but it didn't seem to do anything. I may have made a mistake somewhere though.

Maybe there is a time-out in UDS, allowing a pre-render of 5s and killing it when it does not finish within that time?

[bokjeid]

Yes, it would be certainly 'one of bugs' of DR1000S that 'pre-rendering' doesn't work well on full screen mode on some PDF files. This problem makes the full screen mode unusable.
I tested it again today and thought that to keep pressing the middle button is a valid solution to this problem in most times but it is inconvenient to keep pressing the middle button every time turning page.
The best way for this would be to fix and eradicate the bug inside but it seems that there is no update or patch of the firmware any more from IRX, doesn't it? But users can fix it?

[rvs]

I think in principle it might be possible. I don't know if there'll be any adverse side-effects though (like noticeable increased power consumption) and I don't know how to implement it (yet).

Basically what you do when you press the button is create a wake up event, which is handled outside of UDS. So in that way it looks promising.

[bokjeid]

Originally Posted by rvs

I think in principle it might be possible. I don't know if there'll be any adverse side-effects though (like noticeable increased power consumption) and I don't know how to implement it (yet).

Basically what you do when you press the button is create a wake up event, which is handled outside of UDS. So in that way it looks promising.

I see.
Anyway, thank you for the very useful information.

[rvs]

Setting it to 10 seconds does seem to work. I think I made a mistake earlier when directing the output from the compiler.