Linux CLI help request

[Peter S Kirk]

Hi,

I'm trying to learn how to use get_iplayer CLI on Debian Linux with little 
success.

What I want to do is download the .flv with subtitles then in the convert 
to .mp4 phase:

1. Specify output filename
2. Filename less .mp4 as Title
3. Replace Artist field with blank
4. Sometimes replace downloaded thumbnail cover with a custom cover 
(jpg/png)
5. Sometimes replace Genre with custom genre

I would be grateful if some of you clever chaps provide some CLI commands 
to experiment with.

Many thanks,

Peter