Bug#909448: Bug #909448: Dependencies suggestions

[Kyle Robbertze <krobbertze@gmail.com>]

Hi Romain,

> The following dependencies changes can/should be considered:
> - curl is now used instead of wget for file download
> - awscli can optionally be used to download from s3 and/or generate speech
> synthesis
> - ffmpeg (command line) can optionally be used to convert to wav via the
> ffmpeg2wav protocol
> - ocaml-ffmpeg can be used to enable builtin operators and decoders

I am busy packaging ocaml-ffmpeg so that I can include it as a 
dependency. I just haven't had much time lately to continue with it.

> - youtube-dl can optionally be used to download videos from multiple
> providers
> - ocaml-ssl (libssl-ocaml-dev) can be used to enable https handlers

Unfortunately I cannot link against ocaml-ssl, as it depends on openssl.
The OpenSSL license is incompatible with the GPL:

https://lintian.debian.org/tags/possible-gpl-code-linked-with-openssl.html

> - libinotify-ocaml-dev can be used to enable use of inotify when monitoring
> file changes (used for playlist reload)
> 
> I would advise again enabling support for the graphics library unless
> there's a clear use case for it.

Do you mean against?

Unfortunately I won't be able to get the new 1.3.5 version packaged in
time for Buster, but I will work on it once Buster has shipped.

Cheers
Kyle