MP 0.38 Win: Very slow image display in fullscreen

[PBY]

In full screen mode, the image seems to be first displayed in low resolution, then in high resolution. In old xnview and MP 0.35, this process was very fast and practically invisible.
But in MP 0.38, not only I see big pixels, but it took practically 1 second for displaying the high resolution image.

If such big difference of resolution is need for fast change of images with limited CPU/memory resources (like my netbook), an option is needed to have the possibility to use more resources on a powerful PC for increasing the user experience.

[xnview]

Strange, no change. You can reproduce the difference between 0.35 & 0.38??

[PBY]

I tested with 0.35 and 0.38. In fact, the behavior is quite strange. It's like the next image isn't always put in cache.

1- case 1, seen on both versions
If I change of photo quite fast, the problem is often visible (which is normal if the cache is going empty), but even at a slower path (a bit more than 1 second), 10 or photos are OK, then one is slow to display, but the next are also OK.
It is not always the same photos causing trouble, and I have tested with big images.

2- case 2, only seen on 0.38
I go in another folder. All images are now slow to be displayed. I can go back on the images, the images just displayed some seconds before are still slow. If I close and reopen MP, no more problem on all images of this folder (but it restart again when going in another). I wasn't able to reproduce this problem with version 0.35


Not only theses behavior are quite strange, but the speed of display are very different in the two cases. In the first, when it is visible, it is just slow enough to see it. In case 2, it take around 1 second for seeing the image correctly.

Of course, I don't have any problems with the same photos with the old XnView.

[PBY]

I don't see any improvement with the version 0.38.10.
In fact, today I get the typical problem:
-opening MP
-directly changing from folder
-the problem is only visible as high change speed, with a moderate pace, it isn't visible
-go to another folder, the problem is always visible
-come back to the previous folder, the problem is now also always visible. I select a photo, wait 10 seconds, press right key and the next photo still needs one seconds to be displayed without big pixels.

To be sure that you understand what I speak about, I did some screenshots from the xnviewMP fulscreen window (zoom at 32%), the screenshots are themselves at real size (100%)

What I see for around 1 second (long enough to take a screenshot at the first try)

What I see for around 1 second

firstDisplay.jpg (71.44 KiB) Viewed 4102 times

What I see after

What I see after

after.jpg (74.09 KiB) Viewed 4102 times

[xnview]

How to reproduce?

You use 'cache behind' & 'Read ahead', right
Start XnViewMP, click on a file, F11, quickly press Nextfile
wait 10 sec, press Next file, and it's slow? (low resolution and high resolution loaded)

[PBY]

What is 'cache behind' ? I have activated 'Read one image ahead' and 'Keep current image' options.

For reproducing, I changed it to:

Start XnViewMP, go to another folder, click on a file, F11, quickly press Nextfile
wait 10 sec, press Next file, and it's slow? (low resolution and high resolution loaded)

I retested it, I don't the problem in the folder on which XnViewMP opens (but if I go to another one I get the problem, and I also have it after going back to the initial folder).

It seems like everything is fine without change from folder, but the change of folder seems to deactivate the cache (maybe it is still caching the initial folder?).

[xnview]

Start XnViewMP, go to another folder, click on a file, F11, quickly press Nextfile
wait 10 sec, press Next file, and it's slow? (low resolution and high resolution loaded)

I retested it, I don't the problem in the folder on which XnViewMP opens (but if I go to another one I get the problem, and I also have it after going back to the initial folder).

I've tried but can't reproduce... How many key press do you make? Which size in pixels for your pictures?

[XnTriq]

Does this occur with JPEG-encoded images only, PBY?
If so, then my guess would be that SIMD is the reason behind it.

For viewing JPEGs below a certain size, I actually prefer the loading method of XnView 1.9, because MP always displays a pixelated rendition first (even @ 100% zoom w/o HQ).

• 

Perhaps there should be some kind of threshold setting (“Don't use SIMD for pictures smaller than...”) like Use delayed high quality for pictures larger than (pixels) (browser only, also affects preview) in Tools » Options... » View » Fullscreen » Fullscreen.

[xnview]

Perhaps there should be some kind of threshold setting (“Don't use SIMD for pictures smaller than...”) like Use delayed high quality for pictures larger than (pixels) (browser only, also affects preview) in Tools » Options... » View » Fullscreen » Fullscreen.

You can adjust the minimum size in .ini with prevSize

[PBY]

I have only JPEG photos, in 4928x3264 pixels size.

I have the problem at the first key press.

Again, I don't have any problem with the old XnView with the same photos.

[XnTriq]

You can adjust the minimum size in .ini with prevSize

Wow, Pierre
That's exactly what I had in mind!
Now we have the best of both worlds

Code: Select all

[Viewer]
prevSize=@Size(160 120)

The first value specifies the width (default = 160) and the second one the height (default = 120), correct?

[xnview]

I have the problem at the first key press.

you change the folder, F11, and ONLY 1 key press??

Again, I don't have any problem with the old XnView with the same photos.

You means that it's not slow in xnview? Or you have not low resolution image displayed before high resolution?
And if you don't use 'read ahead' & 'cache current'?

[PBY]

you change the folder, F11, and ONLY 1 key press??

Yes

You means that it's not slow in xnview?

Yes

And if you don't use 'read ahead' & 'cache current'?

The problem is still here, no change.

[xnview]

And if you don't use 'read ahead' & 'cache current'?

The problem is still here, no change.

And if you desactive too these options in xnview 1.98? same or slower?

[PBY]

I had only had "read ahead" enabled on 1.98, but even with both enabled or disabled, I don't see any change.
I think that 1.98 is a bit slower than MP on my main PC, for displaying the next image, but it is directly in good quality. MP, with the problem, is fast to display the bad quality version, but the total time for seeing the next image in good quality is quite more longer than 1.98.

On the other hand, I started to use MP because 1.98 is very very slow on my netbook.