Pylonsrc for arm64 ubuntu 18.04 with pylon version 6 or version 5 displays libpylonc-6.2.0.so: cannot open shared object file: No such file or director

[ILENIMARIUS]

Hello,
When compiling and running pylonsrc with arm64 ubuntu 18.04 on both pylon version 6 or pylon version 5 I got:
Error -> Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstpylon.so': libpylonc-6.2.0.so: cannot open shared object file: No such file or directory

Please see below the steps used:
_Pylon + gst-plugins-vision build/compilation steps:

1. install latest Pylon6 version:

   Download

   • pylon 6.2.0 Camera Software Suite Linux ARM 64 bit - Debian Installer Package 6.2.0 .deb, 69 MB pylon Software

   install on linux arm64:

   • sudo apt-get install ./pylon_6.2.0.21487-deb0_arm64.deb

2. download and build the new gst-plugins-vision:
   git clone https://github.com/joshdoe/gst-plugins-vision.git

3. adapt the modules .make to match the latest pylon version of folder naming:

   • cd ~/Downloads/gst-plugins-vision-1.17.1/cmake/modules

   • sudo nano FindPylon.cmake
     else ()
     set (_PYLON_DIR "/opt/pylon5") -> modify this to "/opt/pylon"
     endif ()

   &

   find_library (_PylonCLib NAMES PylonC_MD_VC120 pylonc
   PATHS
   "${PYLON_DIR}/Development/lib/x64"
   "${PYLON_DIR}/lib64") modify this to -> "/lib"

4. modify the sistem location where gst-pylon-plugin should be installed:

   • cd ~/Downloads/gst-plugins-vision-1.17.1
   • sudo nano CMakeLists.txt
   • go to line 131
     else ()
     set(_PREFIX "/usr/lib") modify to -> "/usr/lib/aarch64-linux-gnu"
     endif ()

5. build gst-plugins-vision
   cd gst-plugins-vision
   mkdir build
   cd build
   cmake ..
   make

   sudo make install

Result:

(gst-inspect-1.0:27087): GStreamer-WARNING **: 17:51:15.211: Failed to load plugin '/usr/lib/aarch64-linux-gnu/gstreamer-1.0/libgstpylon.so': libpylonc-6.2.0.so: cannot open shared object file: No such file or directory
Could not load plugin file: Opening module failed: libpylonc-6.2.0.so: cannot open shared object file: No such file or directory
pes@pes-desktop:~/Downloads/gst-plugins-vision-1.17.1/build$

This plugin displays the same error for Pylon5 also._

[thortom]

I encountered the same issue when loading the installed (make install) pylonsrc.

I am now using pylonsrc with pylon version 6 with similar modifications as you ILENIMARIUS and I am able to use the pylonsrc by loading the pylonsrc from my build directory by setting export GST_PLUGIN_PATH=/<MY_PATH>/gst-plugins-vision/build

[ILENIMARIUS]

Hello Thor,
Thank you for your answer.
There is only one mention for a gstreamer similar plugin path in /gst-plugins-vision/CMakeLists.txt at line 129 for windows version:
_get_filename_component(_PREFIX "${GSTREAMER_PLUGIN_DIR}/../" REALPATH)
else ()
set(PREFIX "/usr/lib")
endif ()

Additional I haven't found a system env variable called "GST_PLUGIN_PATH" .

Could you be more specific for instance, are you using from gst-plugins-vision -> libgstpylon (as plugin) with pylon6?
or
old pylonsrc plugin from zingmars repo with pylon6?

Could you be more specific with the steps and versions?
Thank you!

[thortom]

I am using the GStreamer GST_PLUGIN_PATH env variable to load the libgstpylon plugin from the build directory, see more information here https://developer.gnome.org/gstreamer/stable/gst-running.html
You can also try different GStreamer plugin directories by running:
gst-launch-1.0 -e --gst-plugin-path=<PathToGstPluginVisionBuildDir> pylonsrc ! bayer2rgb ! videoconvert ! xvimagesink

This is just a work around. Of course we would want the installed plugin to work which is installed with the make install command.

[mrstecklo]

@ILENIMARIUS, in order to make libpylonc visible add /opt/pylon/lib to LD_LIBRARY_PATH. Or use the solution described here #55.
Your step 3 can be turned into pull request as CMake's find_library can resolve different paths.
Step 4 is wrong, you should use cmake -DCMAKE_INSTALL_PREFIX=/usr/lib/aarch64-linux-gnu .. in step 5 instead.
GST_PLUGIN_PATH is not needed in this case. libgstpylon is visible, as it is in a standard location, but libpylonc is not. That is why you should use LD_LIBRARY_PATH

[thortom]

I can confirm that adding /opt/pylon/lib to LD_LIBRARY_PATH works, thanks @mrstecklo