I want to display some jpg - pictures in a QPixmap.
On my Host machine it is working, but if I compile the program for QNX then the images are not loaded.
pixmap.load() returns “false”.
There are no error messages or warnings when starting the program, so I don´t know what the problem could be…
As plugin there is “libqjpeg.so” under “usr/lib/qt4/plugins/imageformats”
And with QML, jpg´s are working.
Does anyone have an idea what I am doing wrong?
EDIT:
By using the shell the QML demo programs are running properly, but by using momentics to start the programs (and stopped shell) then I get also an error:
What does “on my host it is working”? Is your host a Windows system or something else?
What do you mean by “using Momentics to start the program”? Are you starting the program on a QNX target system from Momentics on a host system?
Why does the error message have “file:///tabs/content/images/tab_r.jpg” as the format. “file:///…” is not part of the QNX file system. This prefix is a URL indicating that the resource should come from the local file system, but “file://” should not be there when passed to the QNX open() call. I don’t know if this is just a confusion created by Qt or if something is actually wrong.
The error message suggests that JPEG support might not be compiled into Qt. This seems unlikely. I suspect that Qt uses libjpeg for this support, and so it might indicate that Qt is not finding or the libjpeg.so is missing from your target.
I use QNX Momentics for compiling and sending the resulting binary to a beagleboard via ethernet. → So, Yes I start the program from the host machine
I don´t know why this error message is appearing, but this program was a demo from the QNX for Beagleboard demo available at foundry27
Further information:
I stop the shell at the begining, because it disrupts my communication via RS232.
The demo is running properly when started from shell. My program can also load the jpg´s but is not displaying anything.
Without the shell the mentioned error appears. So some environment variables are missing.
I tried to export in the .profile-file all variables I can see if I type “set” into the shell.
But it is still not working…
( “#” marks the point after which I added the variables)
EDIT:
I played a little bit around with the setting and now the jpg´s are working if started with momentics.
The missing part was LD_LIBRARY_PATH and PATH in the “run configurator” as additional environment variable.
BUT if I start the binary from the board then the jpg´s cannot be loaded anymore.
This is confusing me a bit, because I could get the needed setings from the shell with “set”.
Are these settings deleted if I kill the shell?
Ok, I think it is pretty clear right now. Your problem has to do with environment variables and specifically LD_LIBRARY_PATH.
The shell is merely a conduit for environment variables. When you start a program from the shell, it passes them on to the program being executed. If you start a program from somewhere other than the shell, you have to either create or pass them on yourself.
I think that what has happened is that the Qt routines are looking for libjpeg.so. If they are using the LD_LIBRARY_PATH to find then, and it’s not set up right, they won’t find it.
Do you know a good way to give a program started on the Board these environment variables?
In my case I either make a bin which consists off
cd /folder
./program_name -qws &
and start it via QNX momentics or I use a rc.local - file from the demo in which I can write some additional commands. These commands are executed after the startup script. There I start the aforementioned bin.
I already tried to execute the export commands, but this isn´t working. (In fact, it looks like a freeze of the OS )
You can set environment variables in the boot script, or if you use one in the rc.local script.
There’s also shell syntax that sets a variable for a specific program, eg.:
