There is no ffmpeg package in Ubuntu 14.04 and the ffmpeg package in Ubuntu 15.04 doesn't have this problem. Thus this bug is invalid. Please report the problem wherever you obtained your ffmpeg package from.
There is no ffmpeg package in Ubuntu 14.04 and the ffmpeg package in Ubuntu 15.04 doesn't have this problem. Thus this bug is invalid. Please report the problem wherever you obtained your ffmpeg package from.