The problem is the following:
You have a machine with ubuntu already installed library h264 codec.
You want to collect it from source ffmpeg library with support for this codec, and the computer already installed the ffmpeg library, it is necessary to put in another directory (specifying --prefix)
Be installed is installed, but without the h264 as swears ./configure an earlier version of the h264 codec that is already installed in the system. It cannot be removed, as the machine military and used to the fullest. We collected (without uninstalling old version) and the latest version of h264, but ffmpeg still complains. The idea that you can specify in the command ./confugure obviously need a version of h264 codec. But I do not know whether it is possible to do so and will it help in this case. Can who faced such problem? Thank you.