Qt-embedded link failure: undefined reference

[Kaijun]

Whe I use openembedded Qt-embedded SDK to link my Qt GUI application against my static library or ffmpeg shared lib, it fails. The libraries are there, I can not figure out why it still complains. Any idea?

arm-angstrom-linux-gnueabi-g++ -Wl,-rpath-link,/home/tang/usr/local/angstrom/arm/arm-angstrom-linux-gnueabi//usr/lib -o Aips main.o dataobject.o utils.o message.o qmlapplicationviewer.o moc_qmlapplicationviewer.o moc_dataobject.o moc_message.o -L/home/tang/usr/local/angstrom/arm/arm-angstrom-linux-gnueabi//usr/lib -L/home/tang/Projects/OE/build/Aips/../tmp/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib -lgplayer -lglib-2.0 -lavcodec -lavformat -lavutil -lvorbis -lvorbisenc -lspeex -lmp3lame -L/home/tang/Projects/OE/build/Aips/../tmp/sysroots/beagleboard-angstrom-linux-gnueabi/usr/lib/gstreamer-0.10 -lgstffmpeg -lgstticodecplugin -lQtDeclarativeE -lQtScriptE -lQtSvgE -lQtSqlE -lQtXmlPatternsE -lQtGuiE -lQtNetworkE -lQtCoreE -lpthread
main.o: In function `QPlayer':
/home/tang/Projects/OE/build/Aips/main.cpp:22: undefined reference to `av_register_all()'
main.o: In function `QPlayer::run()':
/home/tang/Projects/OE/build/Aips/main.cpp:28: undefined reference to `gplayer(_GList*)'
collect2: ld returned 1 exit status

[high_flyer]

The link error does not complain about not finding the libs - but not finding references in them.
This is probably due to wrong version of the libs.
You can use grep to see if the symbols really are missing in the respective libs.

[Kaijun]

The link error does not complain about not finding the libs - but not finding references in them.
This is probably due to wrong version of the libs.
You can use grep to see if the symbols really are missing in the respective libs.

Yes they are in.

nm /home/tang/Projects/OE/build/Aips/../tmp/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib/libgplayer.a | grep gplayer
00000394 T gplayer
00000000 t gplayer_callback
nm ../tmp/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib/libavformat.so |grep av_register_all
00016910 T av_register_all

[high_flyer]

Aren't you missing an -L here?:

-L/home/tang/usr/local/angstrom/arm/arm-angstrom-linux-gnueabi//usr/lib -L/home/tang/Projects/OE/build/Aips/../tmp/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib

[Kaijun]

Aren't you missing an -L here?:

../tmp/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib is relative path against my work directory. No problem. I tried the same build for x86 platform with Qt creator.
it still got same errors. That is strange!

[high_flyer]

But without -L I am not sure it is considered as lib search path.
Try
-L../tmp/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib

I tried the same build for x86 platform with Qt creator.

Just checking: you built these libs for your current target too, right?

[Kaijun]

But without -L I am not sure it is considered as lib search path.
Try
-L../tmp/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib

Just checking: you built these libs for your current target too, right?

You see -L is there -L/home/tang/Projects/OE/build/Aips/../tmp/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib.
I build for beagleboard. To figure out, I tried my build and libraries on x86 platform. But if I put gst_init() of gstreamer-0.10.so in my code. It has no problem.

[high_flyer]

To figure out, I tried my build and libraries on x86 platform. But if I put gst_init() of gstreamer-0.10.so in my code. It has no problem.

Do you only copy the libs between the platforms, or do you build them for each platform?

[Kaijun]

Do you only copy the libs between the platforms, or do you build them for each platform?

I build them for different platform in different environment.