[mosterta]

libvdpau_sunxi.so is loaded by libvdpau. It determines that from the location of its installation and adds the path vdpau (e.g. libvdpau in "/usr/lib" then libvdpau_sunxi.so must be installed in "/usr/lib/vdapu") (all AFAIK, since I dont have the code here)

There is also a hardcoded path for libvdpau_nv_sunxi.so.1 in kodi: This lib is currently expected to be in /usr/lib/vdpau. (AFAIK)

I copy everything from /usr/local/lib/vdpau into /usr/lib/vdapu, as i wrote. I also execute "export VDPAU_DRIVER=sunxi" and "sh -c "echo "export VDPAU_DRIVER=sunxi" >> /etc/profile", nevertheless i have the line in /etc/profile. I even start everything on fresh image from scratch and still have the same error. When i just copy the original libvdpau_sunxi.so1 over your version, vdpauinfo show correct version 0x1623 and everything work. So i give up on this and try to compile XBMC with this libvdpau-sunxi. Is it possible?
Anyway, i now face new bunch of errors and missing things, as expected. The first - i have the following message during configure:

configure: WARNING: unrecognized options: --with-ffmpeg

I couldn't find info of correct parameter for ffmpeg. Is it possible and if - how to set using of external ffmpeg? I have it compiled with vdpau support. My config look like this:

------------------------
XBMC Configuration:
------------------------
Debugging: Yes
Profiling: No
Optimization: No
SWIG Available: Yes
JRE Available: Yes
Doxygen Available: Yes
Crosscomp.: No
target ARCH: arm
target CPU: no
OpenGLES: Yes
ALSA: Yes
DBUS: Yes
VDPAU: Yes
VAAPI: No
CrystalHD: No
VDADecoder: No
VTBDecoder: No
OpenMax: No
Joystick: No
XRandR: No
GOOM: No
RSXS: Yes
ProjectM: Yes
Skin Touched: No
X11: No
Bluray: Yes
TexturePacker:No
MID Support: No
ccache: Yes
ALSA Support: Yes
PulseAudio: No
HAL Support: No
DVDCSS: Yes
Google Test Framework Configured: No
Avahi: Yes
Non-free: Yes
ASAP Codec: No
MySQL: No
Webserver: Yes
libssh support: Yes
libRTMP support: Yes
libsmbclient support: Yes
libnfs client support:Yes
libafpclient support: No
AirPLay support: No
AirTunes support: No
UPnP support: Yes
Optical drive: Yes
libudev support: Yes
libusb support: No
libcec support: Yes
libmp3lame support: Yes
libvorbisenc support: Yes
libcap support: Yes
additional players: No
External FFmpeg: No
PVR add-ons: No
prefix: /usr/local
------------------------

I removed "--enable-debug" but debugging is still there. Should i use "--disable-debug" instead? With most of missing things and errors and managed to fought with, but now i have new error during make:

Makefile:301: recipe for target 'xbmc/cores/VideoRenderers/VideoRenderer.a' failed
make: *** [xbmc/cores/VideoRenderers/VideoRenderer.a] Error 2

I can't find anything related to this in config.log and i am out of ideas. I guess this not gonna hapend in my system. Anyway - thanks for the help and a good idea.
And one last thing, a little offtopic. Any idea haw can i show subtitles in players using vdpau, mpv for example? I have "export VDPAU_OSD=1" in /etc/profile, mpv show to load subtitles, but nothing on the screen.

You can't use an external ffmpeg, since I did some changes to get it working with the kodi changes.
For the other questions: Sorry, I don't understand exactly which kind of problems do you have. Do you have build problems or run time problems: can you do a "ldd -r libvdpau_sunxi.so.1" on my version of that file and check if any symbols can't be resolved? If that works, can you start kodi via "strace" and check the output for the line where libvdpau_sunxi.so.1 is loaded if the right path is used?