Philippe Gorley authored Aug 01, 2018 and Adrien Béraud committed Aug 08, 2018

Using MediaFilter would make the resampling time longer and more
unpredictable than directly using libswresample.

Adds libswresample as a dependency.
Simplifies Resampler class.
Resampler detects changes in input and output formats automatically.
Changes Audiofile to use Resampler instead of MediaFilter.

Change-Id: I24919e8fa514dbb4a38408e338016976e7424136