Some jpg get stuck when requesting from network path

[jga]

IrfanView 4.42

When I request a slide show from my local disc everything works fine.

But if the files come from a NAS server that I have attached as a network drive then some images get stuck for minutes while others are showed correct immediately. This error is reproducible on Win7, Vista or Win10 (others I didn't check) independent whether the connection to the local network is wireless or Ethernet. Sure, in wireless case it is more dramatic. It is also independent whether 32 bit or 64 bit version of IrfanView or operating system.

First I thought that the affected image was corrupted and I replaced it with a backup copy. Same result.

Then I copied the full image sequence to a physically different position on NAS. Exactly the same image is getting stuck.

Then I copied the full image sequence to my local disc. Everything works fine. (But that is not the intention of a NAS repository of images :-)

Windows photo viewer has no problem, neither in Win7 nor in Win10. (Btw, in Win10 the photo viewer has to be re-activated first by some registry entries.) That is my current workaround but I like IrfanView much more.

Task manager's network supervision of Win10 suggests that in the questionable time periode some smaller packages arrive in which are sent out immediately.

A Win7 screen shot can be found here:
http://jgae.bplaced.net/iv_screenshot.png

A questionable image that causes the trouble can be found here: http://jgae.bplaced.net/DSCF2781.JPG

[jazzman]

Hello Jürgen,

I am not familiar with server technology at all, but I'm just wondering whether the same image is affected when it is in a different position within the slide show. Have you tried altering the sequence?

My rationale behind this is whether, perhaps, some kind of buffer is filling up and the system tries fitting images in before emptying the buffer and the cycle starts all over again.

Good luck

[jga]

[...]
Have you tried altering the sequence?
[...]

No, the phenomenon appears already on the first access. It has nothing to do with the slide show.
You can try the sample photo that I mentioned above. But you should place it on a network drive.

[jga]

Hi guys,

I have got it.

At first, it was unclear what is the difference between good and bad files. Both look similar.

Opening a directory with the tool Exifer initially also did not show any anomalies. But opening a bad file provokes an error message:

JPEG-Fehler #60

Unfortunately the corresponding jerror.h file lives in different versions, so the error number is ambiguous. But it should be something like an invalid jpg-file structure.

Exactly it was! All these problematic files have an incomplete end. Don't ask me why. Mostly the half of last line is missing. Under normal circumstances this is hardly recognized. Only if it's known the error is visible.

Boah, that was hard ..

The question to Irfan is now: Why there are different procedures depending where the file was read from?
- From local source the error is ignored.
- From remote source there are some inquiries back to maybe even get the missing data until timeout.

Maybe the local access contains also a fixed number of inquiries in case of error but this is much faster and not perceived.

[Jacal]

ExifTool warning:

[minor] Fixed incorrect URI for xmlns:MicrosoftPhoto

Here is your file with Xmp-Microsoft tags deleted:

https://filebin.net/cgnpb3xdmaci3a52

[jga]

Hi Jacal,

Thanks. Ok, I see that ExifTool can correct the image error with dummy data. Fortunately I have all the original full resolution images. Now it's only a lot of work for me to select them and do the size reduction to HD format again. And I still do not know what was the root cause for this disaster on the network drive.