Bug#971330: opencv: uses deprecated libavresample

[Sebastian Ramacher]

Source: opencv
Version: 4.2.0+dfsg-6
Severity: important
Tags: sid bullseye
Usertags: libavresample-removal
Control: block 971318 by -1

Dear maintainer,

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

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

Cheers