Bug#971322: performous: uses deprecated libavresample

[Sebastian Ramacher]

Source: performous
Version: 1.1+git20181118-4
Severity: important
Tags: sid bullseye
Usertags: libavresample-removal
Control: block 971318 by -1

Dear maintainer,

performous currently Build-Depends or Depends on libavresample-dev.
The ffmpeg developers consider libavresample as obsolete and replaced
the library with libswresample. Please switch performous to use
libswresample.

Note that this switch will require changes if performous doesn't
already have support for libsvresample.

Cheers