Crash with -keepcspace

[Wae666]

Command: "nconvert.exe -c 2 -overwrite -out jpeg -o ResultFile.jpeg -dpi 100 -keepcspace CMYK_31080x17275.JPG"

File:
CMYK 8-bit
31080x17275 px
DPI 200
Size 103 MB

OS Windows 10 64-bit

Don`t understand... Why does the nconvert.exe crash with this command?

If I use the same file with a lower resolution, it works well.

File that crashed:
https://www.dropbox.com/s/pusnyi8vwxgb4 ... 5.JPG?dl=0

File that works well:
https://www.dropbox.com/s/r4kshqu1tu4gj ... 5.JPG?dl=0

[cday]

Code: Select all

"nconvert.exe -c 2 -overwrite -out jpeg -o ResultFile.jpeg -dpi 100 -keepcspace CMYK_31080x17275.JPG"

I don`t understand... Why does the nconvert.exe crash with this command?

I am not sure, but two comments on your code which may, or may not, have some relevance:

1. The quality of JPEG images is normally set using the -q option:

Code: Select all

 -q value          : JPEG/FPX/WIC/PDF/JPEG2K/WebP quality (default : 85)

I haven't seen -c used before, although it is mentioned in the help file but with a possible value of 8:

Code: Select all

-c value          : Compression number
              default : 0 (uncompressed)
              PDF    : 1 (Fax), 2 (Rle), 3 (LZW), 4(ZIP), 5 (JPEG)
              TIFF   : 1 (Rle), 2 (LZW), 3 (LZW+Prediction)
                       4 (ZLIB)
                       5 (CCITT G3), 6 (CCITT G3-2D), 7 (CCITT G4) only B/W
                       8 (JPEG) only 24/32 bits

2. The -dpi option is used to set the resolution at which a PDF (for example) file is rasterised when opened using Ghostscript, I have never tested whether it can also be used to change the DPI of an image although the help file seems to indicate that:

Code: Select all

-dpi res_dpi      : Set the resolution in DPI

Support for NConvert is usually fairly limited, so generally best to back up as far as possible and then test to see what works!

[Wae666]

Simplified the command to:

"nconvert.exe -overwrite -out jpeg -o ResultFile.jpeg -keepcspace CMYK_31080x17275.JPG"

Unfortunately, using (or not using) flags "-c" and "-dpi" has no effect on crashes.

Only "-keepcspace", CMYK color space and file resolution are affected.

There are no problems with RGB.

[cday]

Are you by any chance using NConvert 32-bits?

If so, given the large pixel dimensions of your image and your comment that a lower resolution file converts correctly, you could test using the NConvert 64-bit version, in case the issue is the 32-bit software addressable memory limit.

[Wae666]

I am using the 64-bit version.

Also tried several versions of nconvert :
v6.56
v7.136

The result is the same

It seems to me that there is some limitation in the number of pixels for CMYK. About 2^29 px. But I don't know where to find information about it.

I experimented with files of this resolution:
[-] 38796*13911 = 539 691 156
[-] 31085*17279 = 537 117 715
[-] 38699*13876 = 536 987 324
[-] 31080*17276 = 536 938 080
[-] 38697*13875 = 536 920 875
[-] 31079*17276 = 536 920 804
[-] 26032*20625 = 536 910 000
[+] 40752*13175 = 536 907 600
[-] 31080*17275 = 536 907 000
[+] 38696*13875 = 536 907 000
[+] 43829*12250 = 536 905 250
[+] 32788*16375 = 536 903 500
[+] 13216*40625 = 536 900 000
[+] 31079*17275 = 536 889 725
[+] 31078*17275 = 536 872 450
[+] 31077*17274 = 536 824 098

[+] - success
[-] - crash

[cday]

It seems to me that there is some limitation in the number of pixels for CMYK. About 2^29 px. But I don't know where to find information about it.

Pierre?

[cday]

Both downloads open in XnView MP 64-bit but the crash file takes noticeably longer, what terminal output do you get running your NConvert code?

[Wae666]

I'm getting an allert from Windows.

"The program "nconvert.exe" is not working.
A problem has caused the program to stop working. Windows will close the program."

[cday]

Do you get that alert quickly or after a reasonable delay -- could Windows possibly be assuming that as no output has been produced yet that NConvert has crashed?

I don't know how you could determine that, but opening the image in XnView MP 64-bit was very slow: do you have a faster computer, or could someone maybe test on a powerful computer?

[Wae666]

After entering a command in PowerShell, there is a delay of 1 minute. After that it crashes.

Latency is the same on my local PC as it is on the production server.

On the server there is a notification from Windows, on the local PC - no.

[cday]

And the approximate times for the smaller images that do convert, as the file size is increased do they increase to near 1 minute? If so, that would seem to suggest an arbitrary Windows time limit before conversion is assumed to have failed, wouldn't it?

[Wae666]

Most often I convert large files up to 45000x45000, it takes more than a minute and the process does not crash. But those files are RGB, so there is no problem with them.

I don't think the operating system limits nconvert's run time.

[cday]

I give up...

Pierre ?

[klv_guest]

I got "Segmentation fault" message when I'm trying to convert problem image @ Win 10.
Tried same command on Linux: it gave me "Segmentation fault (core dumped)"
Probably developers could debug it with gdb

[xnview]

ok will be fixed