RaspberryPi cross-compilation Toolchain

[Castim]

I am trying to cross-compile a program for RaspberryPi on my macBook, using Qt5 with QtCreator 3.1.2.
I am following the instructions provided here:

Unfortunately,I do not manage to uncompress the toolchain which is indicated as:
http://blueocean.qmh-project.org/gcc-4.7-linaro-rpi-gnueabihf.tbz

I used the example:
tar -xf
and try other options without success. The mirror for the same archive is down.
Do you by any chance know why I am encountering this problem or if this toolchain can be found somewhere else ?