Tidying up Radio Downloads

[RS]

On 23/08/2017 22:49, I wrote:
>> On 23/08/2017 03:26, Vangelis forthnet wrote:
>>> >You can always (re-)tag the edited file afterwards...
>>>
>> Hi Vangelis
>>
>> I have to confess my complete ignorance of tags.  I have often 
>> wondered if I generate my own ffmpeg commands, for example to convert 
>> a file to MP3 or to extract part of a file, rather than let 
>> get_iplayer do it using the example preset in the wiki to replace 
>> aactomp3, whether I am at risk of losing tags or metadata.  The reason 
>> for my concern is that there seems to be a lot of code in get_iplayer 
>> to process metadata, although I can't pretend to understand what it 
>> all does.  Am I worrying unnecessarily?
>>

It seems this tells me how to add metadata using ffmpeg.
https://wiki.multimedia.cx/index.php/FFmpeg_Metadata
What I still haven't worked out is whether there is an equivalent of 
-codec copy
for metadata.