In gstreamer1.0 source package, dh_gstscancodecs.1 is generated from debian/dh_gstscancodecs by using command `perldoc -o man`, but the output file does not seems conforming man format which causing malformed output while doing `man dh_gstscancodecs`. However, it displays just like a manpage in terminal when not redirecting the perldoc command output to a file.
Under Darwin iPad 20.4.0 Darwin Kernel Version 20.4.0: Sun Feb 28 21:05:09 PST 2021; root:xnu-7195.100.367~3/RELEASE_ARM64_T8101 arm64 arm Darwin, but this issue should not be relevant to operating system.