Yes, I finally got it to work with some hacks(I manually re-edited the Makefiles to fix the bug related to duplicate PATH that I mentionned in this discussion threads).
I am looking for help to catch and understand the root cause of that bug so that the generated Makefiles don't carry such issue. The bug seems to be related with the "environment-setup" script in /ti-sdk-am335x-evm-07.00.00.00/linux-devkit/ in conflict with the "configure" script from the gst-plugins-bad package!