/usr/share/doc/gstreamer0.10-ffmpeg-dbg/changelog.Debian.gz is in gstreamer0.10-ffmpeg-dbg 0.10.13-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gstreamer0.10-ffmpeg-dbg/../gstreamer0.10-ffmpeg/changelog.Debian.gz