After pressing the Start button it gets gray - but the cpu does not work at all.

Greetings
Trundicho

Hi again,

my workaround is to use ffmpeg by console

in example:
$ ffmpeg -i mymovie.MOV -s 1920x1080 -r 25 -b 120000k -threads 2 -vcodec dnxhd -acodec copy mymovie_transcoded.MOV

Greetings
trundicho

I had to make a symbolic link to ffmpeg in /usr/bin:
sudo ln -s /opt/local/bin/ffmpeg /usr/bin/ffmpeg