Am Dienstag, 8. April 2025, 22:29:37 Mitteleuropäische Sommerzeit schrieb Michael Niedermayer:
> On Tue, Apr 08, 2025 at 11:10:21AM -0500, Romain Beauxis wrote:
> > Le mar. 8 avr. 2025 à 05:20, Michael Niedermayer
> > <michael@niedermayer.cc> a écrit :
>> [...]
> > * Any interest in storing multiple values for the same key? This seems
> > like a niche case but, as you pointed out in another thread, typically
> > vorbis metadata do allow multiple key/values for the same field.
> 
> For a single key multiple values should not be stored
> You can do
> Author1=Eve
> Author2=Adam
> or
> Author=Adam and Eve
> 
> But dont do
> Author=Eve
> Author=Adam
> because if you do that and then you get later a
> Author=Lilith
> what does that mean? that its now 1 Author or 3 Authors
> or 2 and if 2 then which 2 ?
> 
> Or said another way, you cant have multiple identical keys like that AND
> allow updates.

AFAIK, Matroska also has Metadata that are explicitly a tree and can have the same key.
A good example is the ACTOR tag: Most movies have more than one actor, the CHARACTER should be a subtag of ACTOR [1].
Currently, FFmpeg just seem to ignore keys with multiple values and display the first.

Best
Gerion

> [...]

[1] https://www.matroska.org/technical/tagging.html (search for ACTOR)