[libav_image_transport] apt-get install not linking catkinized_libav

[strands-project]

[libav_image_transport] apt-get install not linking catkinized_libav

[marc-hanheide]

No, I don't get this... Is libav_image_transport your code? And why would it be linking when installed via apt-get?

[nilsbore]

Yes, or I've done the linking part in there. I mean the library that I install via apt-get should link the libav libraries also installed via apt-get (when checked via ldd /hydro/lib/liblibav_image_transport.so). That it doesn't seem to be the problem on the robot. It fails because of: /opt/ros/hydro/lib/image_transport/republish: symbol lookup error: /opt/ros/hydro/lib//liblibav_image_transport.so: undefined symbol: avcodec_register_all.

[nilsbore]

That function should be part of the libavcodec library which is correctly installed in /opt/ros/hydro/lib/

[nilsbore]

The strange thing as that it is working on both my and Rares' machine but not on the robot...

[nilsbore]

Ok, hold on, that last part might not hold.

[marc-hanheide]

does it load things dynamically, probably?

[marc-hanheide]

I mean using dl_load

[nilsbore]

I discovered that you need to have a camera stream before the node actually crashes. So the common denominator between all computers is that the apt-get does not work, but catkin_make install && rm -rf build devel && source install.setup.bash and run works.

[nilsbore]

Eh, now you're speaking past me=).

[nilsbore]

The image_transport republish loads the library dynamically if that's what you mean. Using pluginlib I think.

[marc-hanheide]

nevermind... but what the .... yes, that's what I mean. I can't really see why that should be different. Hmmmm. I'll try to think a bit more in a bit

[nilsbore]

You can try it by running e.g. rosrun image_transport republish raw in:=/head_xtion/depth/image_raw libav out:=/toes, given that you have a camera feed.

[marc-hanheide]

hmmm, doesn't complain for me

[nilsbore]

Do you have a camera publishing on the in topic?

[marc-hanheide]

ah. nope...

[nilsbore]

I can supply you with a rosbag tomorrow if you want to try. It didn't work on the two machines where I had a camera.

[marc-hanheide]

got it working... and failing

[marc-hanheide]

the problem is that all libraries are stripped of the symbols... so dlopen calls like in pluginlib are probably not supported that easily...

$ nm -C /opt/ros/hydro/lib//liblibav_image_transport.so
nm: /opt/ros/hydro/lib//liblibav_image_transport.so: no symbols

I'll investigate

[nilsbore]

Ok, cool.

[nilsbore]

Are you sure that is not that the libraries are not linked correctly? The library liblibav_image_transport should link e.g. libavcodec and libavutil, which show up when I do ldd liblibav_image_transport.so on my locally compiled installed system. The apt-get library does not show them when I check with ldd however.

[marc-hanheide]

hmm.... you're probably right...

[marc-hanheide]

I'm still new to this debian stuff... I don't know for sure what's going on here. TBH

[marc-hanheide]

I have made a fix to avoid stripping that lib. Stripping can also include removing unnecessary links, so maybe it makes a difference...

[nilsbore]

Fingers crossed!

[marc-hanheide]

didn't work... It's got symbols now, but still not the link to the other file

[marc-hanheide]

no idea really, sorry. And I have to call it day now. Pretty knackered.

[nilsbore]

Hmm... I've done a little bit of research. First, to explain the setup: catkinized_libav exports a library through catkin, libav_wrap, that links all of the libraries in libav:
https://github.com/strands-project/data_compression/blob/hydro-devel/catkinized_libav/CMakeLists.txt#L43
libav_image_transport then depends on that catkin project and links libav_wrap through ${catkin_LIBRARIES}:
https://github.com/strands-project/data_compression/blob/hydro-devel/libav_image_transport/CMakeLists.txt#L9
This seems to make libav_image_transport link the libav libraries when you install it on your own system.

I also found a line it the CMake that could have something to do with this:
https://github.com/strands-project/data_compression/blob/hydro-devel/libav_image_transport/CMakeLists.txt#L147
and a thread on an issue that could be related:
ros-perception/perception_pcl#9

[nilsbore]

Maybe we should try to just remove that line?

[marc-hanheide]

Could try... though I really don't understand the consequences. That command seems magic...

[nilsbore]

TBH, me neither. It's in the original package though.

[marc-hanheide]

I just checked the last build log: https://lcas.lincoln.ac.uk/jenkins/job/ros-hydro-libav-image-transport_binarydeb_precise_amd64/4/console Nothing obvious in there that looks different to what you would do on your own machine.

[nilsbore]

Have you tried building and installing on yours? Shouldn't be necessary though since it worked on two other machines=P. I'll try removing the line and check what happens when I build locally.

[nilsbore]

Yeah, it's still working so maybe it's worth a try. Did you already do it or should I supply a patch?

[marc-hanheide]

I didn't do anything. give it a shot and let me know to re-release.

[nilsbore]

Ok, merged: #54. Please try again.

[nilsbore]

No luck there...=(

[nilsbore]

EDIT: Forget this, will try again
Ok @marc-hanheide , so you reported make[4]: *** No rule to make target devel/lib/libavcodec.so, needed by devel/lib/liblibav_image_transport.so. Stop. from the build farm. This does not happen on my system. Does this mean that the files required by libav_image_transport at https://github.com/strands-project/data_compression/blob/hydro-devel/libav_image_transport/CMakeLists.txt#L155 do not exist in the build server when this is compiled? They do exist after installing with apt-get in /opt/ros/hydro/lib. Or is it faulty to define it this way? It seems to work for libav_wrap: https://github.com/strands-project/data_compression/blob/hydro-devel/catkinized_libav/CMakeLists.txt#L40 which compiles on the build farm.

[nilsbore]

I think I messed things up in that attempt, will try a new one.

[marc-hanheide]

Yes, the problem is that it expects that lib in the devel space: devel/lib/libavcodec.so and it certainly does not exist in there.

[nilsbore]

Yeah, exactly=). Will change that now.

[nilsbore]

But on the build farm, /opt/ros/hydro/lib should be in LD_LIBRARY_PATH right? So there shouldn't be any need of prefixing the path?

[nilsbore]

So I'm beginning to see what the problem might be. There is one difference when building on the build farm vs locally. I'm guessing that on the build farm, the package catkinized_libav is built for itself and then installed. That installed library is then used to build libav_image_transport. Locally I build the packages together, so libav_image_transport uses the catkinized_libav in devel for building and linking. These are then installed together. Gonna try to verify that this is the problem.

[nilsbore]

Good news! This was it! Now I just gotta figure out how to solve it!

[marc-hanheide]

Yes, that is the difference! But I still don't see what the problem is...

[nilsbore]

#57 should fix it, works on my machine at least.

[marc-hanheide]

See https://lcas.lincoln.ac.uk/jenkins/job/pr-hydro-data_compression/11/console

Sorry I'm mostly offline tonight...

[nilsbore]

Wow, that's pretty devastating=(. This works fine on my machine when I first compile and install catkinized_libav and then compile libav_image_transport using the installed library. I don't understand the error message... Shouldn't it try to compile catkinized_libav (which is a dependency of libav_image_transport) before trying to read its libraries? Anyways, I'm going to bed now, see you tomorrow.

[nilsbore]

Specifically, I'm confused about the help offered:

CMake Error at /tmp/test_repositories/build_repository/devel/share/catkinized_libav/cmake/catkinized_libavConfig.cmake:141 (message):
  Project 'libav_image_transport' tried to find library 'avdevice'.  The
  library is neither a target nor built/installed properly.  Did you compile
  project 'catkinized_libav'? Did you find_package() it before the
  subdirectory containing its code is included?

In the log, I don't see catkinized_libav being built, which it should, since I did indeed find_package() it.

[nilsbore]

Is there any way to give me temporary access to trigger re-releases of data
compression?
Den 22 nov 2014 00:00 skrev "Marc Hanheide" [email protected]:

See
https://lcas.lincoln.ac.uk/jenkins/job/pr-hydro-data_compression/11/console

Sorry I'm mostly offline tonight...

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#52 (comment)
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[marc-hanheide]

see private email!

[nilsbore]

Happy to close this now...