You're using FFmpeg in there somewhere so you'll need to offer your copy of FFmpeg's source if you've used the LGPL version. If you've used the GPL version then your whole app will need to be GPL.
FFmpeg binary is compiled with "--enable-gpl". So yes, either author should recompile it with GPL disabled or release the source code of his application.
Anyway, with LGPL (I assume the point of your comment is educational, and you don't really need the source code for FFmpeg SVN-r17142), author can just provide instructions for downloading the source code for this revision from FFmpeg SVN, as written here: http://www.gnu.org/licenses/gpl-faq.html#AnonFTPAndSendSourc...
Anyway, with LGPL (I assume the point of your comment is educational, and you don't really need the source code for FFmpeg SVN-r17142), author can just provide instructions for downloading the source code for this revision from FFmpeg SVN, as written here: http://www.gnu.org/licenses/gpl-faq.html#AnonFTPAndSendSourc...