The ‘binary’ version of audacity supplied by certain distros lacks functionality, due to patent issues, so the best option is to compile it yourself..

For some time, there have been compatibility issues at compile time between the latest released versions of audacity and ffmpeg, on many systems..

For audacity version 2.0.5, on my systems (Fedora 20) the compile fails with the current ffmpeg code and headers, but will work with the ‘legacy’ ffmpeg-compat ..

A simple method of forcing the audacity compile to find the legacy headers etc. is to simply edit ~/src/FFmpeg.h, as follows, around line 39:

From:
   #include <libavcodec/avcodec.h>
   #include <libavformat/avformat.h>
   #include <libavutil/fifo.h>
   #include <libavutil/mathematics.h>
To:
   #include <ffmpeg-compat/libavcodec/avcodec.h>
   #include <ffmpeg-compat/libavformat/avformat.h>
   #include <ffmpeg-compat/libavutil/fifo.h>
   #include <ffmpeg-compat/libavutil/mathematics.h>

The compile should then complete OK, but on my system the # make install still fails, so just copy the audacity executable to /usr/bin (or the equivalent on your particular system)

With ffmpeg support included, I can use audacity to edit the sound tracks on AVCHD (MTS) video clips, amongst others..

Robert Gadsdon.   February 4, 2014.